EXPLANATORY NOTE

The issuances of (i) all shares of Cyclerion Common Stock in exchange for each share of Korsana Common Stock and Korsana Series A Preferred Stock (including shares of Korsana Common Stock issued in the Korsana Pre-Closing Financing), (ii) all Cyclerion Warrants in exchange for Korsana Warrants (including Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing), (iii) all shares of Cyclerion Series B Preferred Stock in exchange for shares of Korsana Series Seed Preferred Stock, (iv) all options to purchase shares of Cyclerion Common Stock in exchange for Korsana Options, (v) all Cyclerion RSUs in exchange for Korsana RSUs, (vi) all shares of Cyclerion Common Stock issuable upon exercise of Cyclerion Warrants issued in exchange for Korsana Warrants, (vii) all shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock issued in exchange for Korsana Series Seed Preferred Stock, (viii) all shares of Cyclerion Common Stock issuable upon exercise of options to purchase shares of Cyclerion Common Stock issued in exchange for Korsana Options, and (ix) all shares of Cyclerion Common Stock issuable upon settlement of Cyclerion RSUs issued in exchange for Korsana RSUs, are intended to be covered by this registration statement on Form S-4 of which this proxy statement/prospectus is a part.

There is no difference between (A) the shares of Cyclerion Common Stock that will be issued in exchange for each share of Korsana Common Stock and Korsana Series A Preferred Stock (including shares of Korsana Common Stock issued in the Korsana Pre-Closing Financing), (B) the shares of Cyclerion Common Stock that will be issuable upon the exercise of Cyclerion Warrants issued in exchange for Korsana Warrants, (C) the shares of Cyclerion Common Stock that will be issuable upon conversion of Cyclerion Series B Preferred Stock issued in exchange for each share of Korsana Series Seed Preferred Stock, (D) the shares of Cyclerion Common Stock that will be issuable upon the exercise of options to purchase shares of Cyclerion Common Stock issued in exchange for Korsana Options, and (E) the shares of Cyclerion Common Stock that will be issuable upon the settlement of Cyclerion RSUs that will be issued in exchange for Korsana RSUs.

REFERENCES TO ADDITIONAL INFORMATION

This proxy statement/prospectus incorporates important business and financial information about Cyclerion Therapeutics, Inc. that is not included in or delivered with this document. You may obtain this information without charge through the Securities and Exchange Commission (“SEC”) website (www.sec.gov) or upon your written or oral request by contacting 245 First Street, 18^th Floor, Cambridge, MA 02142, Attention: Secretary, or by calling (857) 327-8778. Cyclerion also maintains a website at www.cyclerion.com, at which you may access these materials free of charge as soon as reasonably practicable after they are electronically filed with, or furnished to, the SEC. However, the information contained in or accessible through Cyclerion’s website is not part of the accompanying proxy statement/prospectus or the registration statement of which the accompanying proxy statement/prospectus forms a part.

To ensure timely delivery of these documents, any request should be made no later than    , 2026 to receive them before the Cyclerion Shareholders Meeting.

For additional details about where you can find information about Cyclerion, please see the section titled “Where You Can Find More Information” beginning on page 419 of the accompanying proxy statement/prospectus.

subject to adjustment as set forth in the Merger Agreement and described in more detail in the section titled “The Merger Agreement — Treatment of Korsana Options” beginning on page 170 of the accompanying proxy statement/prospectus; (iv) each then-outstanding restricted stock unit (a “Korsana RSU”) for shares of Korsana Common Stock will be converted into and become a restricted stock unit (a “Cyclerion RSU”) for shares of Cyclerion Common Stock on the existing terms and conditions (including with respect to vesting and accelerated vesting), subject to adjustment as set forth in the Merger Agreement and described in more detail in the section titled “The Merger Agreement — Korsana Restricted Stock Units” beginning on page 171 of the accompanying proxy statement/prospectus; and (v) each then-outstanding warrant to purchase shares of Korsana Common Stock (each, a “Korsana Warrant”) will be converted into a warrant to purchase shares of Cyclerion Common Stock on the existing terms and conditions (each, a “Cyclerion Warrant”), subject to adjustment as set forth in the Merger Agreement and described in more detail in the section titled “The Merger Agreement — Treatment of Korsana Warrants” beginning on page 172 of the accompanying proxy statement/prospectus.

Each share of Cyclerion Common Stock and Cyclerion Series A Preferred Stock that is issued and outstanding at the First Effective Time will remain issued and outstanding and such shares, subject to the proposed reverse stock split, will be unaffected by the Merger. Prior to the First Effective Time, the Cyclerion board of directors (the “Cyclerion Board”) will accelerate the vesting of all options to purchase shares of Cyclerion Common Stock (“Cyclerion Options”) and all restricted stock awards (“Cyclerion RSAs”). Each outstanding Cyclerion Option with an exercise price per share equal to or less than the volume weighted average closing trading price of a share of Cyclerion Common Stock on The Nasdaq Stock Market LLC (“Nasdaq”) for the five consecutive trading days ending three trading days prior to the Calculation Date (as defined in the Merger Agreement), as reported by Bloomberg L.P. (the “Cyclerion Closing Price” and such Cyclerion Options, “In-the-Money Cyclerion Options”), will be cancelled at the First Effective Time and such holder thereof will receive an amount in cash, without interest, less any applicable tax withholding, equal to the product obtained by multiplying the excess of the Cyclerion Closing Price over the exercise price per share of the Cyclerion Common Stock underlying such Cyclerion Option by the number of shares of the Cyclerion Common Stock underlying such Cyclerion Option (“Cyclerion Stock Option Cash Consideration”). Each Cyclerion Option with an exercise price greater than the Cyclerion Closing Price (an “Out-of-the-Money Cyclerion Option”) will be cancelled for no consideration. The vesting of each Cyclerion RSA will be accelerated in full.

Based on Cyclerion’s capitalization as of December 31, 2025 and Korsana’s capitalization as of March 31, 2026 and assuming Cyclerion’s net cash as of closing being equal to $0, each share of Korsana Common Stock and Korsana Series A Preferred Stock is currently estimated to be entitled to receive approximately 1.1009 shares of Cyclerion Common Stock. Each share of Korsana Series Seed Preferred Stock will be converted into the right to receive a number of shares of Cyclerion Series B Preferred Stock, equal to the Exchange Ratio divided by 1,000. The estimated Exchange Ratio does not give effect to the proposed Cyclerion reverse stock split and is subject to adjustment based on Cyclerion’s estimated net cash at the closing of the First Merger as described in more detail in the section titled “The Merger Agreement — Exchange Ratio” beginning on page 167 of the accompanying proxy statement/prospectus.

In connection with the Merger, on April 1, 2026, Korsana entered into a securities purchase agreement (the “Securities Purchase Agreement”) with certain institutional and accredited investors for the purchase of shares of Korsana Common Stock and Pre-Funded Warrants to purchase shares of Korsana Common Stock (the “Korsana Pre-Funded Warrants”) for an aggregate purchase price of approximately $380.0 million, immediately prior to the closing of the Merger (referred to herein as the “Korsana Pre-Closing Financing”). The shares of Korsana Common Stock and Korsana Pre-Funded Warrants that are issued in the Korsana Pre-Closing Financing will be converted into the right to receive a number of shares of Cyclerion Common Stock and Cyclerion Pre-Funded Warrants, respectively, equal to the Exchange Ratio described in more detail in the section titled “The Merger Agreement — Exchange Ratio” beginning on page 167 of the accompanying proxy statement/prospectus. Korsana and the investors participating in the Korsana Pre-Closing Financing have also agreed to enter into a registration rights agreement (the “Registration Rights Agreement”) at the closing of the Korsana Pre-Closing Financing, pursuant to which, among other things, the Combined Company will agree to provide for the registration and resale of certain shares of Korsana Common Stock that are held by the investors participating in the Korsana Pre-Closing Financing from time to time pursuant to Rule 415 under the Securities Act (“Rule 415”). The Korsana Pre-Closing Financing is more fully described in the sections titled “Agreements Related to the Merger — Securities Purchase Agreement” and “Agreements Related to the Merger — Registration Rights Agreement” beginning on pages 186 and 188, respectively, of the accompanying proxy statement/prospectus.

Immediately after the Merger, based on the estimated Exchange Ratio as described in the accompanying proxy statement/prospectus, Cyclerion securityholders as of immediately prior to the Merger are expected to own

approximately 1.5% of the outstanding shares of capital stock of the Combined Company (on a fully-diluted basis), and former holders of Korsana securities (including those issued in the Korsana Pre-Closing Financing) are expected to own approximately 98.5% of the outstanding shares of capital stock of the Combined Company (on a fully-diluted basis), subject to certain assumptions, including, but not limited to, Cyclerion’s net cash as of closing being equal to $0. Under certain circumstances described in more detail in the section titled “The Merger Agreement — Exchange Ratio” beginning on page 167 of the accompanying proxy statement/prospectus, the ownership percentages may be adjusted up or down including, but not limited to, if Cyclerion’s net cash as of closing is less than or greater than $0.

Shares of Cyclerion Common Stock are currently listed on Nasdaq under the symbol “CYCN.” Cyclerion plans to file an initial listing application for the Combined Company with Nasdaq. After completion of the Merger, Cyclerion will be renamed “Korsana Biosciences, Inc.” and it is expected that the common stock of the Combined Company will trade on Nasdaq under the symbol “KRSA.” It is a condition to the consummation of the Merger that Cyclerion will receive confirmation from Nasdaq that the Combined Company has been approved for listing on Nasdaq, but there can be no assurance such listing condition will be met or that Cyclerion will obtain such confirmation from Nasdaq. If such listing condition is not met or if such confirmation is not obtained, the Merger will not be consummated unless the condition is waived. The Nasdaq condition set forth in the Merger Agreement is not expected to be waived by the applicable parties. However, in the event that the shares of Cyclerion Common Stock to be issued in the Merger are not approved for listing on Nasdaq, it is possible that Cyclerion and Korsana may mutually agree to waive the applicable condition and nonetheless proceed with completion of the Merger. If such condition is waived, Cyclerion will not recirculate an updated proxy statement/prospectus, nor will it solicit a new vote of shareholders prior to proceeding with the Merger. Accordingly, you are advised that Cyclerion shareholders will not have certainty regarding the listing of the Combined Company’s shares at the time you are asked to vote at the annual meeting described below. On    , 2026, the last trading day before the date of the accompanying proxy statement/prospectus, the closing sale price of Cyclerion Common Stock was $     per share.

Cyclerion shareholders are cordially invited to attend the annual meeting of Cyclerion (the “Cyclerion Shareholders Meeting”) to be held on    , 2026, at    a.m. Eastern Time, unless postponed or adjourned to a later date, in order to obtain the shareholder approvals necessary to complete the Merger and related matters. At the Cyclerion Shareholders Meeting, Cyclerion will ask its shareholders to:

As described in the accompanying proxy statement/prospectus, current directors and officers of Cyclerion who in the aggregate owned approximately 24.2% of the outstanding shares of Cyclerion capital stock on an as-converted to Cyclerion Common Stock basis as of March 31, 2026, and certain Korsana stockholders (solely in their respective capacities as Korsana stockholders) who in the aggregate owned approximately 43.9% of the outstanding shares of Korsana capital stock as of March 31, 2026, are parties to stockholder support agreements with Cyclerion and Korsana, respectively, whereby such stockholders have agreed to vote in favor of the adoption of the Merger Agreement and the approval of the Merger and related transactions contemplated by the Merger Agreement, subject to the terms of the support agreements. Following the effectiveness of the registration statement on Form S-4 of which the accompanying proxy statement/prospectus is a part and pursuant to the Merger Agreement, Korsana stockholders holding a sufficient number of shares of Korsana capital stock to adopt the Merger Agreement and approve the Merger and related transactions will be asked to execute written consents providing for such adoption and approval.

After careful consideration, each of the Cyclerion and the Korsana boards of directors has approved the Merger Agreement and has determined that it is advisable to consummate the Merger. The Cyclerion Board has approved the proposals described in the accompanying proxy statement/prospectus and recommends that its shareholders vote “FOR” the proposals described in the accompanying proxy statement/prospectus.

More information about Cyclerion, Korsana, the Merger Agreement and transactions contemplated thereby and the foregoing proposals are contained in the accompanying proxy statement/prospectus. Cyclerion urges you to read the accompanying proxy statement/prospectus carefully and in its entirety. IN PARTICULAR, YOU SHOULD CAREFULLY CONSIDER THE MATTERS DISCUSSED UNDER “RISK FACTORS” BEGINNING ON PAGE 32 OF THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS.

Cyclerion and Korsana are excited about the opportunities the Merger brings to Cyclerion’s shareholders and Korsana’s stockholders and thank you for your consideration and continued support.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of the accompanying proxy statement/prospectus. Any representation to the contrary is a criminal offense.

The accompanying proxy statement/prospectus is dated    , 2026, and is first being mailed to Cyclerion’s shareholders on or about    , 2026.

CYCLERION THERAPEUTICS, INC.

245 First Street, 18th Floor

Cambridge, MA 02142

NOTICE OF ANNUAL MEETING OF SHAREHOLDERS

To the shareholders of Cyclerion Therapeutics, Inc.:

NOTICE IS HEREBY GIVEN that a virtual annual meeting of shareholders (the “Cyclerion Shareholders Meeting”) will be held on    ,    , 2026 at     a.m. Eastern Time, unless postponed or adjourned to a later date. The Cyclerion Shareholders Meeting will be held exclusively online. You will be able to attend and participate in the Cyclerion Shareholders Meeting online by visiting www.virtualshareholdermeeting.com/    , where you will be able to listen to the meeting live, submit questions and vote.

The Cyclerion Shareholders Meeting will be held for the following purposes:

These proposals are collectively referred to as the “Proposals.”

The Cyclerion Board has fixed    , 2026 as the record date (the “Record Date”) for the determination of shareholders entitled to notice of, and to vote at, the Cyclerion Shareholders Meeting and any adjournment or postponement thereof. Only holders of record of shares of Cyclerion Common Stock at the close of business on the Record Date are entitled to notice of, and to vote at, the Cyclerion Shareholders Meeting. At the close of business on    , 2026, Cyclerion had     shares of common stock outstanding and entitled to vote.

Your vote is important. The affirmative vote of a majority of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 1 and Proposal No. 5. The affirmative vote of a majority of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting is required for approval of Proposal No. 2, and Proposal No. 3. The affirmative vote of not less than two-thirds of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4A. The affirmative vote of not less than two-thirds of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4B. The number of affirmative votes exceeding the number of votes opposing the matter, assuming a quorum is present, is required for the approval of Proposal No. 6, Proposal No. 7, Proposal No. 8, Proposal No. 9, Proposal No. 10 and Proposal No. 11. Approval of each of Proposal No. 1, Proposal No. 2, and Proposal No. 3 is a condition to the completion of the Merger. Therefore, the Merger cannot be consummated without the approval of Proposal Nos. 1, 2, and 3, unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waives such conditions. The approvals of Proposal Nos. 4A, 4B, 7, 8, and 9 are not conditions to the completion of the Merger, however, each of these proposals is conditioned on the consummation of the Merger and will not be implemented if the Merger is not consummated. Approvals of Proposal Nos. 3, 5, 6, 10, and 11 are requested whether or not the Merger is consummated.

All shareholders are cordially invited to attend the annual meeting. Even if you plan to attend the Cyclerion Shareholders Meeting, Cyclerion requests that you sign and return the enclosed proxy or vote by mail or online to ensure that your shares will be represented at the Cyclerion Shareholders Meeting if you are unable to attend. You may change or revoke your proxy at any time before it is voted at the Cyclerion Shareholders Meeting.

THE CYCLERION BOARD HAS DETERMINED AND BELIEVES THAT EACH OF THE PROPOSALS OUTLINED ABOVE IS FAIR TO, IN THE BEST INTERESTS OF, AND ADVISABLE TO CYCLERION AND ITS SHAREHOLDERS AND HAS APPROVED EACH SUCH PROPOSAL. THE CYCLERION BOARD RECOMMENDS THAT CYCLERION SHAREHOLDERS VOTE “FOR” EACH SUCH PROPOSAL.

Important Notice Regarding the Availability of Proxy Materials for the Cyclerion Shareholders Meeting to Be Held on    , 2026 at    a.m. Eastern Time.

The proxy statement/prospectus, which also serves as the annual report to shareholders in connection with the annual meeting, is available at www.cyclerion.com.

By Order of the Cyclerion Board of Directors,

Regina Graul, Ph.D.

President and Chief Executive Officer

     , 2026

TABLE OF CONTENTS

i

ii

QUESTIONS AND ANSWERS ABOUT THE MERGER

Except where specifically noted, the following information and all other information contained in this proxy statement/prospectus does not give effect to the proposed reverse stock split described in Proposal No. 3 of this proxy statement/prospectus.

All references to Korsana’s “product candidates,” “programs,” “portfolio” and “pipeline” in this proxy statement/prospectus refer to the research programs with respect to which Korsana has the option to acquire intellectual property license rights pursuant to the Antibody Discovery and Option Agreement (the “Paragon ADOA”) with Paragon Therapeutics, Inc. (“Paragon”) and Parasa Holding LLC (“Parasa”), and the Platform Option Agreement (the “Paragon POA” and, together with the Paragon ADOA, the “Paragon Option Agreements”) with Paragon and Parasa. As of the date of this proxy statement/prospectus, Korsana has exercised the option for KRSA-028 pursuant to the Paragon ADOA. Korsana has not exercised the option for any other program under the Paragon Option Agreements. Korsana expects to enter into the KRSA-028 license agreement prior to the time that this registration statement on Form S-4 is declared effective by the SEC.

The following section provides answers to frequently asked questions about the Merger. This section, however, provides only summary information. For a more complete response to these questions and for additional information, please refer to the cross-referenced sections.

Q: What is the Merger?

A: On April 1, 2026, Cyclerion, Korsana, First Merger Sub and Second Merger Sub entered into the Merger Agreement, which agreement was subsequently amended on April 17, 2026. A copy of the Merger Agreement, including the amendment thereto, is attached as Annex A to this proxy statement/prospectus. The Merger Agreement contains the terms and conditions of the proposed Merger. Pursuant to the Merger Agreement, First Merger Sub will merge with and into Korsana, with Korsana continuing as a wholly owned subsidiary of Cyclerion and the surviving corporation of the First Merger. Korsana will then merge with and into Second Merger Sub, with Second Merger Sub being the surviving entity of the Second Merger. This entire transaction is referred to in this proxy statement/prospectus as the Merger. In connection with the Merger, Cyclerion will change its corporate name to “Korsana Biosciences, Inc.”

Q: Why are the two companies proposing to merge?

A: Cyclerion and Korsana believe that combining the two companies will result in a company with a promising pipeline, a strong leadership team and substantial capital resources, focused on developing novel therapies to reduce the burden of neurodegenerative diseases. For a more complete description of the reasons for the Merger, please see the sections titled “The Merger — Cyclerion’s Reasons for the Merger” and “The Merger — Korsana’s Reasons for the Merger” beginning on pages 141 and 145, respectively, of this proxy statement/prospectus.

Q: What will happen to Cyclerion if, for any reason, the Merger does not close?

A: Cyclerion has invested significant time and incurred, and expects to continue to incur, significant expenses related to the proposed Merger. In the event the Merger does not close, Cyclerion will have a limited ability to continue its current operations without obtaining additional financing. Although the Cyclerion Board may elect, among other things, to attempt to complete another strategic transaction if the Merger does not close, the Cyclerion Board may instead divest all or a portion of Cyclerion’s business or take steps necessary to liquidate or dissolve Cyclerion’s business and assets if a viable alternative strategic transaction is not available. If Cyclerion decides to dissolve and liquidate its assets, Cyclerion would be required to pay all of its contractual obligations, and to set aside certain reserves for potential future claims, and there can be no assurance as to the amount of and the timing of such liquidation and distribution of available cash left to distribute to shareholders after paying the obligations of Cyclerion and setting aside funds for reserves.

1

Q: Why am I receiving this proxy statement/prospectus?

A: You are receiving this proxy statement/prospectus because you have been identified as a shareholder of Cyclerion as of the applicable Record Date, and you are entitled to vote to approve the matters set forth herein. This document serves as:

Q: What is the Korsana Pre-Closing Financing?

A: In connection with the Merger, Korsana entered into the Securities Purchase Agreement with certain investors named therein, including, among others, Fairmount, Venrock Healthcare Capital Partners, General Atlantic, TCGX, Forbion, Wellington Management, Commodore Capital, RA Capital Management, RTW Investments, Vivo Capital, Janus Henderson Investors, Foresite Capital, J.P. Morgan Life Sciences Private Capital, SR One, Sanofi Ventures, Kalehua Capital, Spruce Street Capital, and other leading investment management firms, pursuant to which such investors agreed to purchase shares of Korsana Common Stock and Korsana Pre-Funded Warrants for an aggregate purchase price of approximately $380.0 million. Shares of Korsana Common Stock and Korsana Pre-Funded Warrants issued pursuant to this financing transaction will be converted into shares of Cyclerion Common Stock and Cyclerion Pre-Funded Warrants, in accordance with the Exchange Ratio and the Merger Agreement.

Immediately after the First Merger, the shares of Korsana Common Stock and Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing are expected to represent approximately 57.7% of the outstanding shares of common stock of the Combined Company (on a fully-diluted basis). Korsana and the investors participating in the Korsana Pre-Closing Financing have also agreed to enter into a Registration Rights Agreement at the closing of the Korsana Pre-Closing Financing, pursuant to which, among other things, the Combined Company will agree to provide for the registration and resale of certain shares of Cyclerion Common Stock that are held by the investors participating in the Korsana Pre-Closing Financing from time to time pursuant to Rule 415. The closing of the Korsana Pre-Closing Financing is conditioned upon the satisfaction or waiver of the conditions to the closing of the Merger as well as certain other conditions.

For a more complete description of the Korsana Pre-Closing Financing, please see the sections titled “Agreements Related to the Merger — Securities Purchase Agreement” and “— Registration Rights Agreement” beginning on pages 186 and 188 of this proxy statement/prospectus, respectively.

Q: What proposals will be voted on at the Cyclerion Shareholders Meeting in connection with the Merger?

A: Pursuant to the terms of the Merger Agreement, the following proposals must be approved by the requisite shareholder vote at the Cyclerion Shareholders Meeting in order for the Merger to close:

2

Proposal No. 1 - The Nasdaq Stock Issuance Proposal to approve (i) the issuance of shares of Cyclerion Common Stock, including the shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, which will represent more than 20% of the shares of Cyclerion Common Stock outstanding immediately prior to the First Merger, to stockholders of Korsana, pursuant to the Merger Agreement, a copy of which is attached as Annex A to this proxy statement/prospectus, and (ii) the change of control of Cyclerion resulting from the Merger, pursuant to Nasdaq Listing Rules 5635(a) and 5635(b), respectively.

Proposal No. 2 - Authorized Share Increase Proposal to approve an amendment to the Cyclerion Articles to increase the number of shares of Cyclerion Common Stock that Cyclerion is authorized to issue from 400,000,000 to    , in the form attached as Annex H to this proxy statement/prospectus.

Proposal No. 3 - Reverse Stock Split Proposal to approve an amendment to the Cyclerion Articles to effect a reverse stock split of Cyclerion’s issued and outstanding common stock at a ratio in the range of one new share for every    shares and one new share for every    shares (or any number in between), with the final ratio and effectiveness of such amendment and the abandonment of such amendment to be mutually agreed by the Cyclerion Board and the Korsana Board prior to the First Effective Time or, if the Nasdaq Stock Issuance Proposal is not approved by Cyclerion shareholders, determined solely by the Cyclerion Board, in the form attached as Annex I to this proxy statement/prospectus.

Proposal No. 4 - The Redomestication Proposal to approve (A) the redomestication of Cyclerion from the Commonwealth of Massachusetts to the Cayman Islands by domestication and (B)(i) the redomestication of Cyclerion from the Commonwealth of Massachusetts to the Cayman Islands by way of continuation and (ii) the adoption of the Cayman Articles.

Approval of each of Proposal Nos. 1, 2, and 3 is a condition to the completion of the Merger. Therefore, the Merger cannot be consummated without the approval of Proposal Nos. 1, 2, and 3, unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waives such conditions. The issuance of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, and Cyclerion Series B Preferred Stock in connection with the Merger and the change of control of Cyclerion resulting from the Merger will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to increase the number of authorized shares of Cyclerion Common Stock will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to effect a reverse stock split of Cyclerion’s issued and outstanding common stock, will not take place unless Proposal Nos. 1, 2, and 3 are approved by the requisite Cyclerion shareholders. However, the Cyclerion Board may determine to effect the reverse stock split, if approved by Cyclerion shareholders, following the Shareholders Meeting, even if Proposal Nos. 1 and 2 are not approved or the Merger is not otherwise completed.

In addition to the requirement of obtaining Cyclerion shareholder approval of Proposal Nos. 1, 2, and 3, the closing of the Merger is subject to the satisfaction or waiver of each of the other closing conditions set forth in the Merger Agreement. For a more complete description of the closing conditions under the Merger Agreement, please see the section titled “The Merger Agreement — Conditions to the Completion of the Merger” beginning on page 181 of this proxy statement/prospectus.

The presence, by attending or being represented by proxy, at the Cyclerion Shareholders Meeting of the holders of a majority of the shares of Cyclerion Common Stock outstanding and entitled to vote at the Cyclerion Shareholders Meeting is necessary to constitute a quorum at the meeting for the Proposals.

Q: What proposals are to be voted on at the Cyclerion Shareholders Meeting, other than the Nasdaq Stock Issuance Proposal, the Reverse Stock Split Proposal and the Authorized Share Increase Proposal?

A: At the Cyclerion Shareholders Meeting, the holders of Cyclerion Common Stock will also be asked to consider the following proposals:

3

Proposal No. 5 - The Director Election Proposal to elect Errol B. De Souza, Ph.D., Regina M. Graul, Ph.D., Peter M. Hecht, Ph.D., Michael Higgins, Steven E. Hyman, M.D., and Dina Katabi, Ph.D., to serve until Cyclerion’s 2027 annual meeting of shareholders, or until his or her successor has been duly elected and qualified, or until his or her earlier death, resignation or removal;

Proposal No. 6 - The Auditor Ratification Proposal to ratify the selection of Ernst & Young LLP as Cyclerion’s independent registered public accounting firm for the fiscal year ending December 31, 2026;

Proposal No. 7 - The Stock Plan Proposal to approve the Korsana Biosciences, Inc. 2026 Stock Incentive Plan;

Proposal No. 8 - The ESPP Proposal to approve the Korsana Biosciences, Inc. 2026 Employee Stock Purchase Plan;

Proposal No. 9 - The Merger Compensation Proposal to approve, on an advisory basis, certain compensation arrangements for Cyclerion’s named executive officers that are based on or otherwise relate to the Merger;

Proposal No. 10 – The Say-on-Pay Proposal to approve, on an advisory basis, the compensation of Cyclerion’s named executive officers; and

Proposal No. 11 - The Adjournment Proposal to approve an adjournment of the Cyclerion Shareholders Meeting, if necessary, to solicit additional proxies if there is not a sufficient number of votes in favor of the Nasdaq Stock Issuance Proposal, the Authorized Share Increase Proposal, and/or the Reverse Stock Split Proposal.

The approvals of Proposal Nos. 4A, 4B, 5, 6, 7, 8, 9, 10, and 11 are not a condition to the Merger. However, the implementation of Proposal Nos. 7, 8, and 9 are conditioned on the consummation of the Merger. Cyclerion does not expect that any matter other than the Proposals will be brought before the Cyclerion Shareholders Meeting.

The presence, by attending or being represented by proxy, at the Cyclerion Shareholders Meeting of the holders of a majority of the shares of Cyclerion Common Stock outstanding and entitled to vote at the Cyclerion Shareholders Meeting is necessary to constitute a quorum at the meeting for the purpose of approving the Proposals.

Q: What shareholder votes are required to approve the Proposals at the Cyclerion Shareholders Meeting?

A: The affirmative vote of a majority of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 1 and Proposal No. 5. The affirmative vote of a majority of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting is required for approval of Proposal No. 2, and Proposal No. 3. The affirmative vote of not less than two-thirds of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4A. The affirmative vote of not less than two-thirds of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4B. The number of affirmative votes exceeding the number of votes opposing the matter, assuming a quorum is present, is required for the approval of Proposal No. 6, Proposal No. 7, Proposal No. 8, Proposal No. 9, Proposal No. 10 and Proposal No. 11.

Approval of each of Proposal No. 1, Proposal No. 2, and Proposal No. 3 is a condition to the completion of the Merger. Therefore, the Merger cannot be consummated without the approval of Proposal Nos. 1, 2, and 3, unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waives such conditions. The issuance of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, and Cyclerion Series B Preferred Stock in connection with the Merger and the change of control of Cyclerion resulting from the Merger will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to increase the number of authorized shares of Cyclerion Common Stock

4

will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to effect a reverse stock split of Cyclerion’s issued and outstanding common stock, will not take place unless Proposal Nos. 1, 2, and 3 are approved by the requisite Cyclerion shareholders. However, the Cyclerion Board may determine to effect the reverse stock split, if approved by Cyclerion shareholders, following the Shareholders Meeting, even if Proposal Nos. 1 and 2 are not approved or the Merger is not otherwise completed.

Additionally, Proposal Nos. 4A, 4B, 7, 8, and 9 are each conditioned on the consummation of the Merger. Therefore, if Proposal Nos. 1, 2, and 3 are not approved or the Merger is not consummated, Proposal Nos. 4A, 4B, 7, 8, and 9 will each have no effect, even if approved by Cyclerion shareholders.

Q: What are Cyclerion contingent value rights?

A: Immediately prior to the First Effective Time, Cyclerion and the designated rights agent (“Rights Agent”) are expected to enter into a Contingent Value Rights Agreement (the “Cyclerion CVR Agreement”), pursuant to which holders of Cyclerion Common Stock and Cyclerion Series A Preferred Stock as of the close of business on the last business day prior to the day on which the First Effective Time occurs will receive one contingent value right (each, a “Cyclerion CVR”) for each outstanding share of Cyclerion Common Stock or Cyclerion Series A Preferred Stock.

Each Cyclerion CVR will represent the contractual right to receive certain net proceeds, if any, derived from any consideration that is paid to Cyclerion as a result of the disposition of Cyclerion’s pre-Merger legacy assets (the “Cyclerion Legacy Assets”), net of any indemnity obligations, transaction costs and certain other expenses, during the period beginning on the date of the closing of the Merger and ending (i) with respect to the sale, transfer, license or other disposition of Cyclerion Legacy Assets other than those Cyclerion Legacy Assets described in the following clauses (ii) and (iii), upon the second (2nd) anniversary of the Closing Date, (ii) with respect to Cyclerion’s right to receive payments under that License Agreement, dated June 3, 2021, between Cyclerion and Akebia Therapeutics, Inc. (the “Akebia License Agreement”), the earlier of (A) the fifteenth (15th) anniversary of the date of entry into the Cyclerion CVR Agreement and (B) the expiration pursuant to its terms or earlier termination by Akebia of the Akebia License Agreement, and (iii) with respect to the sale, transfer or other disposition of the equity interests of Tisento Therapeutics Holdings, Inc. (“Tisento”) beneficially owned by Cyclerion, the earliest of (A) nine (9) months following the date of the consummation of Tisento’s initial public offering pursuant to a registration statement filed with, and declared effective by, the Securities and Exchange Commission pursuant to the Securities Act, (B) the sale of Tisento, and (C) the seventh (7th) anniversary of the Closing Date.

During the Legacy Assets Transaction Period (as defined in the Cyclerion CVR Agreement), the Combined Company shall expend up to $50,000 (the “CVR Expense Cap”) for costs and expenses associated with the retention of an employee or consultant of Cyclerion for the purpose of business development efforts related to Cyclerion Legacy Assets and related activities, including seeking and negotiating and, with the prior written consent of Combined Company (not to be unreasonably withheld, conditioned or delayed), executing agreements with respect to Cyclerion Legacy Assets, which amount shall be included as a deduction in the determination of Cyclerion’s net cash in accordance with the Merger Agreement. At the end of the Legacy Assets Transaction Period, the amount, if any, by which the CVR Expense Cap exceeds the aggregate amount of costs and expenses associated with the retention of an employee or consultant of Cyclerion will constitute net proceeds under the Cyclerion CVR Agreement and will be payable as CVR proceeds to the CVR holders in accordance with the terms of the Cyclerion CVR Agreement.

The contingent payments under the Cyclerion CVR Agreement, if they become payable, will become payable to the Rights Agent for subsequent distribution to the holders of the Cyclerion CVRs. In the event that no such proceeds are received, holders of the Cyclerion CVRs will not receive any payment pursuant to the Cyclerion CVR Agreement. There can be no assurance that any holders of Cyclerion CVRs will receive any payments with respect thereto.

5

The right to the contingent payments contemplated by the Cyclerion CVR Agreement is a contractual right only and will not be transferable, except in the limited circumstances specified in the Cyclerion CVR Agreement. The Cyclerion CVRs will not be evidenced by a certificate or any other instrument and will not be registered with the SEC. The Cyclerion CVRs will not have any voting or dividend rights and will not represent any equity or ownership interest in Cyclerion or any of its affiliates. No interest will accrue on any amounts payable in respect of the Cyclerion CVRs.

Q: What will Cyclerion securityholders receive in the Merger?

A: Each share of Cyclerion Common Stock and Cyclerion Series A Preferred Stock that is issued and outstanding at the First Effective Time of the Merger will remain issued and outstanding and such shares, subject to the proposed reverse stock split, will be unaffected by the Merger. Prior to the First Effective Time, the Cyclerion Board will accelerate the vesting of all Cyclerion Options and Cyclerion RSAs. Each outstanding Cyclerion Option with an exercise price less than or equal to the Cyclerion Closing Price will be cancelled at the First Effective Time and such holder thereof will receive an amount in cash, without interest, less any applicable tax withholding, equal to the product obtained by multiplying the excess of the Cyclerion Closing Price over the exercise price per share of the Cyclerion Common Stock underlying such Cyclerion Option by the number of shares of the Cyclerion Common Stock underlying such Cyclerion Option. The vesting of each Cyclerion RSA will be accelerated in full.

Immediately after the Merger, Cyclerion securityholders as of immediately prior to the Merger are expected to own approximately 1.5% of the outstanding shares of the Combined Company on a fully-diluted basis, former Korsana securityholders, excluding holders of Korsana Common Stock and Korsana Pre-Funded Warrants purchased in the Korsana Pre-Closing Financing, are expected to own approximately 40.8% of the outstanding shares of the Combined Company on a fully-diluted basis, and Korsana Common Stock and Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing are expected to represent approximately 57.7% of the outstanding shares of capital stock of the Combined Company on a fully-diluted basis, subject to certain assumptions, including, but not limited to, Cyclerion’s Net Cash as of Closing being $0.

For a more complete description of the treatment of Cyclerion securities in the Merger, please see the sections titled “The Merger Agreement — Merger Consideration,” “The Merger Agreement — Exchange Ratio,” and “Market Price and Dividend Information” beginning on pages 166, 167 and 31, respectively, of this proxy statement/prospectus.

Q: What will Korsana securityholders receive in the Merger?

A: At the First Effective Time, upon the terms and subject to the conditions set forth in the Merger Agreement, (i) each then-outstanding share of Korsana Common Stock and Korsana Series A Preferred Stock (including shares of Korsana Common Stock issued in the Korsana Pre-Closing Financing), excluding any shares to be cancelled pursuant to the Merger Agreement and any dissenting shares, will be converted into the right to receive a number of shares of Cyclerion Common Stock and/or Cyclerion Pre-Funded Warrants, as applicable, equal to the Exchange Ratio (described in more detail in the section titled “The Merger Agreement — Exchange Ratio” beginning on page 167 of this proxy statement/ prospectus), (ii) each then-outstanding share of Korsana Series Seed Preferred Stock, excluding any shares of Korsana Series Seed Preferred Stock to be cancelled pursuant to the Merger Agreement and any dissenting shares, will be converted into the right to receive a number of shares of Cyclerion Series B Preferred Stock equal to the Exchange Ratio divided by 1,000; (iii) each then-outstanding Korsana Option will be converted into and become an option to purchase shares of Cyclerion Common Stock on the existing terms and conditions (including with respect to vesting and accelerated vesting), subject to adjustment as set forth in the Merger Agreement, (iv) each then-outstanding Korsana RSU will be converted into and become a Cyclerion RSU on the existing terms and conditions (including with respect to vesting and accelerated vesting), subject to adjustment as set forth in the Merger Agreement, and (v) each then-outstanding and unexercised Korsana Warrant (including Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing) will be converted into a Cyclerion Warrant, subject to adjustment as set forth in the Merger Agreement.

6

For a more complete description of the treatment of Korsana securities in the Merger, please see the sections titled “The Merger Agreement — Merger Consideration,” and “The Merger Agreement — Exchange Ratio” beginning on pages 166 and 167 of this proxy statement/prospectus. For a description of the effect of the Korsana Pre-Closing Financing on Korsana’s current securityholders, please see the section titled “Agreements Related to the Merger — Securities Purchase Agreement” beginning on page 186 of this proxy statement/prospectus.

Q: Will the common stock of the Combined Company trade on an exchange?

A: Shares of Cyclerion Common Stock are currently listed on Nasdaq under the symbol “CYCN.”

Cyclerion intends to file an initial listing application for the common stock of the Combined Company with Nasdaq. After completion of the Merger, Cyclerion will be renamed “Korsana Biosciences, Inc.” and it is expected that the common stock of the Combined Company will trade on Nasdaq under the symbol “KRSA.” It is a condition to the consummation of the Merger that Cyclerion will receive confirmation from Nasdaq that the Combined Company has been approved for listing on Nasdaq, but there can be no assurance such listing condition will be met or that Cyclerion will obtain such confirmation from Nasdaq. If such listing condition is not met or if such confirmation is not obtained, the Merger will not be consummated unless the condition is waived. The Nasdaq condition set forth in the Merger Agreement is not expected to be waived by the applicable parties; however, if such condition is waived, Cyclerion will not recirculate an updated proxy statement/prospectus, nor will it solicit a new vote of shareholders prior to proceeding with the Merger. Accordingly, you are advised that Cyclerion shareholders will not have certainty regarding the listing of the Combined Company’s shares at the time you are asked to vote at the Cyclerion Shareholders Meeting. For more information, please see the section entitled “Risk Factors — Risks Related to the Merger - Cyclerion and Korsana may mutually agree to waive the condition to the Merger requiring approval for listing on Nasdaq, and if such condition is waived, the Combined Company’s stock may not be listed on Nasdaq following completion of the Merger.” on page 32 of this proxy statement/prospectus.

On    , 2026, the last trading day before the date of this proxy statement/prospectus, the closing sale price of Cyclerion Common Stock was $    per share.

Q: Who will be the directors of the Combined Company immediately following the Merger?

A: Immediately following the Merger, the Combined Company’s board of directors will be composed of six members, all six of whom will have been designated by Korsana.

Effective as of the First Effective Time, the Cyclerion Board will appoint the following Korsana designees: Andrew Gottesdiener, Tomas Kiselak, Michelle Pernice, Nimish Shah, and Dr. Jonathan Violin to the board of directors of the Combined Company with one seat remaining vacant, and concurrent therewith all of Cyclerion’s current directors will resign from their positions as directors of the Cyclerion Board effective as of the First Effective Time.    is expected to be appointed as Chair of the board of directors of the Combined Company.

If the Cayman Redomestication is effected, the Combined Company will have a staggered structure of three classes following the completion of the Merger. See the section titled “Management Following the Merger” for additional information.

Q: Who will be the executive officers of the Combined Company immediately following the Merger?

A: Immediately following the Merger, the executive management team of the Combined Company is expected to consist of the following members of the Korsana executive management team:

7

Q: As a Cyclerion shareholder, how does the Cyclerion Board recommend that I vote?

A: The Cyclerion Board, in consultation with financial and legal advisors and management, evaluated the terms of the Merger Agreement and the related transactions contemplated thereby and: (i) determined that the Merger and the related transactions contemplated by the Merger Agreement are fair to, advisable and in the best interests of Cyclerion and its shareholders; (ii) approved and declared advisable the Merger Agreement and the related transactions contemplated by the Merger Agreement and approved the issuance of shares of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, in connection with the Merger and the Korsana Pre-Closing Financing, respectively; and (iii) recommends that Cyclerion’s shareholders vote “FOR” each of the Proposals.

Q: What risks should I consider in deciding whether to vote in favor of the Merger?

A: You should carefully review the section titled “Risk Factors” beginning on page 32 of this proxy statement/prospectus and the documents incorporated by reference herein, which set forth certain risks and uncertainties related to the Merger, risks and uncertainties to which the Combined Company’s business will be subject, and risks and uncertainties to which each of Cyclerion and Korsana, as independent companies, are subject.

Q: When do you expect the Merger to be consummated?

A: The Merger is anticipated to close in the third quarter of 2026, but the exact timing cannot be predicted. For more information, please see the section titled “The Merger Agreement — Conditions to the Completion of the Merger” beginning on page 181 of this proxy statement/prospectus.

Q: Why is Cyclerion seeking approval for the redomestication to the Cayman Islands (the “Cayman Redomestication”)?

A: The Cyclerion and Korsana boards of directors believe that there are several reasons why the Cayman Redomestication is in the best interests of Cyclerion and Cyclerion’s shareholders. The Cyclerion Board believes the Cayman Redomestication may help the Combined Company attract and retain qualified management by reducing the risk of lawsuits being filed against the Combined Company and its directors and officers. Cyclerion and Korsana believe that for the reasons described in this proxy statement/prospectus, in general, Cayman Islands law will provide greater protection to the Combined Company and its directors and officers than Massachusetts law. Additionally, the Cyclerion Board believes that the Cayman Redomestication will give the Combined Company more flexibility and predictability in various corporation transactions. For more information, please see the section titled “Proposal No. 4 — The Redomestication Proposal” below.

Q: How will the Cayman Redomestication affect the rights of the Combined Company’s shareholders?

A: Your rights as a shareholder currently are governed by Massachusetts law and the provisions of the restated articles of organization of Cyclerion, and Cyclerion’s amended and restated bylaws. As a result of the Cayman Redomestication, you will become a shareholder of the Combined Company with rights governed by Cayman Islands law and the provisions of the Cayman Articles, in the form attached as Annex K to this proxy statement/prospectus, which differ in certain respects from your current rights. These important differences are discussed and summarized in this proxy statement/prospectus under “Proposal No. 4 — The Redomestication Proposal — Effects of the Cayman Redomestication — Comparison of Rights of Holders of the Massachusetts Corporation Capital Stock and the Cayman Company Share Capital” beginning on page 235 of this proxy statement/prospectus.

8

Q: What are the U.S. federal income tax considerations of the Cayman Redomestication to the Combined Company’s stockholders?

A: Subject to the limitations and qualifications described in the section titled “Proposal No. 4 — The Redomestication Proposal — U.S. Federal Income Tax Considerations of the Cayman Redomestication” beginning on page 258 of this proxy statement/prospectus, Cyclerion intends that the Cayman Redomestication qualify as a “reorganization” within the meaning of Section 368(a) of the Code. As a result, a U.S. Holder (as defined therein) of the Combined Company stock (as defined therein) will not recognize gain or loss upon the Cayman Redomestication. For a more detailed discussion of the U.S. federal income tax considerations of the Cayman Redomestication, see the section titled “Proposal No. 4 — The Redomestication Proposal — U.S. Federal Income Tax Considerations of the Cayman Redomestication” beginning on page 258 of this proxy statement/prospectus.

Q: What do I need to do now?

A: Cyclerion urges you to read this proxy statement/prospectus carefully, including the annexes and the documents incorporated by reference, and to consider how the Merger affects you.

Shareholder of Record: Shares Registered in Your Name

If you are a shareholder of record, you may vote at the Cyclerion Shareholders Meeting, vote by proxy over the telephone, vote by proxy through the Internet or vote by proxy using a proxy card that you may request or that we may elect to deliver at a later time, the form of which is attached as Annex R to this proxy statement/prospectus. Whether or not you plan to attend the Cyclerion Shareholders Meeting, we urge you to vote by proxy to ensure your vote is counted. You may still attend the meeting and vote even if you have already voted by proxy.

Beneficial Owner: Shares Registered in the Name of Broker or Bank

If you are a beneficial owner of shares registered in the name of your broker, bank, or other agent, you should have received a Notice containing voting instructions from that organization rather than from Cyclerion. Simply follow the voting instructions in the Notice to ensure that your vote is counted. You may vote by telephone or over the Internet as instructed by your broker or bank. To vote at the Cyclerion Shareholders Meeting, you must obtain a valid proxy from your broker, bank, or other agent. Follow the instructions from your broker or bank included with these proxy materials, or contact your broker or bank to request a proxy form.

Q: What if I return a proxy card or otherwise vote but do not make specific choices?

A: If you return a signed and dated proxy card or otherwise vote without marking voting selections, your shares will be voted, as applicable, “For” the Nasdaq Stock Issuance Proposal, “For” the Authorized Share Proposal, “For” the Reverse Stock Split Proposal, “For” the Redomestication Proposal, “For” the Director Election Proposal, “For” the Auditor Ratification Proposal, “For” the Stock Plan Proposal, “For” the ESPP Proposal,

9

“For” the Merger Compensation Proposal, “For” the Say-on-Pay Proposal and “For” the Adjournment Proposal. If any other matter is properly presented at the meeting, your proxy holder (one of the individuals named on your proxy card) will vote your shares using his or her best judgment.

Q: What happens if I do not return a proxy card or otherwise vote or provide proxy instructions, as applicable?

A: If you are a shareholder of record and fail to return your proxy card or otherwise vote, your shares will not be voted. If you are a beneficial owner of Cyclerion Common Stock and fail to provide proxy instructions, your shares will not be voted on non-routine matters.

Q: If my Cyclerion shares are held in “street name” by my broker and I do not provide my broker or bank with voting instructions, what happens?

A: If you are a beneficial owner of shares held in street name and you do not instruct your broker, bank or other agent how to vote your shares, your broker, bank or other agent will only be able to vote your shares with respect to proposals considered to be “routine.” Your broker, bank or other agent is not entitled to vote your shares with respect to “non-routine” proposals, which Cyclerion refers to as a “broker non-vote.” Whether a proposal is considered routine or non-routine is subject to stock exchange rules and final determination by the stock exchange. Even with respect to routine matters, some brokers are choosing not to exercise discretionary voting authority. As a result, Cyclerion urges you to direct your broker, bank or other agent how to vote your shares on all proposals to ensure that your vote is counted.

Q: What are broker non-votes and do they count for determining a quorum?

A: Generally, a “broker non-vote” occurs when shares held by a broker are not voted with respect to a particular proposal because the broker has not received voting instructions from its client(s) with respect to such shares on how to vote and does not have discretionary authority to vote on the matter.

Broker non-votes, if any, will be treated as shares present for the purpose of determining the presence of a quorum for the transaction of business at the Cyclerion Shareholders Meeting. Broker non-votes, if any, will have no effect on Proposal Nos. 1, 4B, 5, 6, 7, 8, 9, 10, and 11 and will have the same effect as a vote “AGAINST” Proposal Nos. 2, 3, and 4A.

Q: May I revoke and/or change my vote after I have submitted a proxy or provided proxy instructions?

A: Cyclerion shareholder of record, unless such shareholder’s vote is subject to a support agreement, may revoke and/or change their vote at any time before their proxy is voted at the Cyclerion Shareholders Meeting in one of four ways:

Q: What are the material U.S. federal income tax considerations of the Merger to a U.S. Holder of Korsana Common Stock and Korsana Preferred Stock?

A: Subject to the limitations and qualifications described in the section titled “The Merger — U.S. Federal Income Tax Considerations of the Merger” beginning on page 160 of this proxy statement/prospectus, each of Cyclerion and Korsana intend that the Merger qualify as a “reorganization” within the meaning of Section 368(a) of the Internal Revenue Code of 1986, as amended (the “Code”) for U.S. federal income tax purposes. Assuming

10

the Merger so qualifies, a U.S. Holder of Korsana stock (as defined therein) will not recognize gain or loss upon the exchange of its Korsana stock for Cyclerion stock. For a more detailed discussion of the U.S. federal income tax considerations of the Merger, see the section titled “The Merger — U.S. Federal Income Tax Considerations of the Merger” beginning on page 160.

Q: What are the material U.S. federal income tax consequences of the issuance of the Cyclerion CVRs, including any distributions of Cyclerion capital stock under the Cyclerion CVRs?

A: Although the U.S. federal income tax treatment of the Cyclerion CVRs is uncertain and the matter is not free from doubt, the Combined Company intends to treat a holder’s receipt of the Cyclerion CVRs as a distribution of property with respect to the holder’s existing shares of Cyclerion capital stock for U.S. federal income tax purposes. Please review the information in the section titled “Agreements Related to the Merger—Cyclerion CVR Agreement—Material U.S. Federal Income Tax Consequences of the Cyclerion CVRs to Holders of Cyclerion Capital Stock” for a discussion of the material U.S. federal income tax consequences of the Cyclerion CVRs to holders of Cyclerion capital stock.

Q: What are the U.S. federal income tax considerations of the reverse stock split to a U.S. Holder of Cyclerion Common Stock?

A: A U.S. Holder of Cyclerion Common Stock should not recognize gain or loss upon the reverse stock split, except to the extent such holder receives cash in lieu of a fractional share of Cyclerion Common Stock, and subject to the discussion in the section titled “Proposal No. 3 — The Reverse Stock Split Proposal — U.S. Federal Income Tax Considerations of the Reverse Stock Split” beginning on page 228 of this proxy statement/prospectus. Please review the information in the section titled “Proposal No. 3 — The Reverse Stock Split Proposal — U.S. Federal Income Tax Considerations of the Reverse Stock Split” beginning on page 228 of this proxy statement/prospectus for a more complete description of the U.S. federal income tax considerations of the reverse stock split to a U.S. Holder of Cyclerion Common Stock.

Q: Who can help answer my questions?

A: If you are a Cyclerion shareholder and would like additional copies of this proxy statement/prospectus without charge or if you have questions about the Merger or related matters, including the procedures for voting your shares, you should contact:

Banks and Brokers Call:

Stockholders Call Toll Free:

11

PROSPECTUS SUMMARY

This summary highlights selected information from this proxy statement/prospectus and may not contain all of the information that is important to you. To better understand the Merger and the proposals being considered at the Cyclerion Shareholders Meeting, you should read this entire proxy statement/prospectus carefully, including the Merger Agreement and the other annexes to which you are referred in this proxy statement/prospectus, and the documents incorporated by reference therein. For more information, please see the section titled “Where You Can Find More Information” beginning on page 419 of this proxy statement/prospectus. Except where specifically noted, the following information and all other information contained in this proxy statement/prospectus does not give effect to the proposed reverse stock split described in Proposal No. 3 of this proxy statement/prospectus.

The Companies

Cyclerion

Cyclerion is a preclinical biotechnology company focused on building a pipeline of innovative therapeutics to address serious neuropsychiatric disorders with significant unmet medical need. Cyclerion’s current strategic focus is centered on the development of a novel therapeutic approach for neuropsychiatric conditions, with the lead indication being treatment-resistant depression (“TRD”), which Cyclerion believes represents a substantial clinical and commercial opportunity. Over the past year, Cyclerion has refined its strategic direction toward programs that combine established pharmacologic agents with enabling technologies designed to improve precision, reproducibility, and patient outcomes. As part of this strategy, Cyclerion has evaluated multiple opportunities and prioritized CYC-126, an individualized therapy for TRD as its foundational development program.

Cyclerion’s executive offices are located at 245 First Street, 18th Floor, Cambridge, MA 02142. Its telephone number is (857) 327-8778.

Korsana

Korsana is a biopharmaceutical company developing therapeutics to treat neurodegenerative diseases beginning with Alzheimer’s disease (“AD”). Korsana’s lead product candidate, KRSA-028, is an anti-amyloid beta (“Aß”) antibody that combines the proprietary Therapeutic Targeting (“THETA^™”) platform with well-validated aspects from other anti-Aß products that have achieved regulatory approval or are in late-stage clinical trials. KRSA-028 was designed to build upon the success of these prior products while addressing shortcomings that limit their clinical and commercial success, such as the ability to penetrate the brain. Korsana believes that KRSA-028 has the potential to rapidly clear amyloid plaques resulting in meaningful impacts on clinical symptoms in AD patients, and to do so while avoiding adverse effects associated with the specific designs of prior products. Korsana intends to submit a Clinical Trial Notification (“CTN”) in Australia or a Clinical Trial Application (“CTA”) in New Zealand by the end of 2026 and an Investigational New Drug (“IND”) application in the United States in the first quarter of 2027. Pharmacokinetic data in healthy volunteers is anticipated by mid-year 2027 and interim proof-of-concept data showing amyloid plaque reduction in AD patients is anticipated by the end of 2027.

AD is a progressive and devastating neurodegenerative disease that slowly destroys cognition and leads to progressive impairment in patients’ ability to conduct activities of daily living. Prevalence increases with age; up to one-third of people over age 85 have symptoms. There are seven million people suffering from AD in the United States, a number that is expected to double by 2050 due to an aging population. AD is the seventh-leading cause of death in the United States with an estimated 500,000 deaths every year.

Until recently, approved treatments for AD addressed only symptoms and had no impact on the course of the disease. That situation changed after the approval of antibody-based therapeutics that targeted Aß. Clinical

12

trials of these therapeutics have provided clear evidence that antibody-mediated depletion of Aß in the brain correlates with a reduction in the rate of cognitive decline in symptomatic AD.

KRSA-028 was designed to improve upon the clinical efficacy and safety profiles of these pioneering antibody-based therapeutics by combining clinically validated features of these products with a proprietary combination of validated antibody engineering technologies. KRSA-028 targets what is believed to be the most clinically relevant form of Aß and is optimized for improved brain uptake while reducing effects on reticulocytes. It was also designed with physicochemical properties and stability intended to enable potent anti-Aß activity to the brain via subcutaneous injections. Key features of KRSA-028’s design include:

The proprietary THETA technology used to create KRSA-028 combines the benefits of TfR-mediated shuttling to the brain with Fc modifications to extend half-life and spare reticulocytes from destruction shown to be caused by third-party TfR-shuttled investigational products. The THETA technology was designed to retain phagocytic capacity, the mechanism by which the two approved disease-modifying products are thought to clear amyloid plaques from the brain. Korsana believes that the THETA platform will lead to meaningful improvements in the ability to deliver therapeutic modalities, such as antibodies, to the brain, while minimizing the frequency of adverse events associated with other TfR-based shuttle systems. Korsana intends to expand its pipeline by advancing other product candidates that incorporate THETA technology. Korsana anticipates disclosing details on its next product candidate in late 2026 or 2027.

Korsana was founded in 2024 and launched to research and develop brain-targeted antibody candidates licensed from Paragon, an antibody discovery engine founded by Fairmount Funds Management LLC (“Fairmount”) and led by industry veterans with extensive experience in drug discovery and development. Korsana entered into an Antibody Discovery and Option Agreement (the “Paragon ADOA”) with Paragon Therapeutics, Inc. (“Paragon”) and Parasa Holding LLC (“Parasa”). Under the Paragon ADOA, Paragon identifies, evaluates, and develops antibodies against one or more mutually agreed therapeutic targets and a mutually agreed brain transit target. The Paragon ADOA covers KRSA-028, an additional research program targeting Aß and TfR1, and one undisclosed program, with the ability to add additional programs by mutual agreement. Under the Paragon ADOA, Korsana has the exclusive option, on a program-by-program basis (each, an “ADOA Option”), to negotiate and enter into a license agreement (each, a “License”) granting Korsana (a) an exclusive, worldwide license to the product-specific intellectual property from the applicable program and (b) a non-exclusive, worldwide license to certain incorporated platform technology. Korsana entered into a Platform Option Agreement (the “Paragon POA” and, together with the Paragon ADOA, the “Paragon Option Agreements”) with Paragon and Parasa, in connection with the Paragon ADOA. Under the Paragon POA, Korsana funds certain Paragon research activities, including development of proprietary platform technology for delivery of therapeutic agents across the blood-brain barrier. As partial consideration, the Paragon POA grants Korsana exclusive options (each, a “POA Option”) to enter into agreements with Paragon to develop, manufacture, and commercialize antibodies utilizing that platform technology. As of the date of this proxy statement/prospectus, Korsana has exercised the option for KRSA-028 pursuant to the Paragon ADOA. Korsana has not exercised the option for any other program under the Paragon

13

Option Agreements. Korsana expects to enter into the KRSA-028 license agreement prior to the time that this registration statement on Form S-4 is declared effective by the SEC.

Korsana’s principal executive offices are located at 203 Crescent Street, Bldgs. #3/3A/4, Suite 503, Waltham, MA 02453, and its telephone number is (781) 516-2325.

First Merger Sub

First Merger Sub is a direct, wholly owned subsidiary of Cyclerion and was formed solely for the purpose of carrying out the Merger. First Merger Sub’s executive offices are located at 245 First Street, 18th Floor, Cambridge, MA 02142. Its telephone number is (857) 327-8778.

Second Merger Sub

Second Merger Sub is a direct, wholly owned subsidiary of Cyclerion and was formed solely for the purpose of carrying out the Merger. Second Merger Sub’s executive offices are located at 245 First Street, 18th Floor, Cambridge, MA 02142. Its telephone number is (857) 327-8778.

The Merger (see page 134)

Subject to the terms and conditions of the Merger Agreement, and in accordance with the Delaware General Corporation Law (“DGCL”) and the Delaware Limited Liability Company Act (“DLLCA”), (i) at the First Effective Time, First Merger Sub will merge with and into Korsana, with Korsana continuing as a wholly owned subsidiary of Cyclerion and the surviving corporation of the First Merger and (ii) immediately following the First Merger and as part of the same overall transaction as the First Merger, Korsana will merge with and into Second Merger Sub, with Second Merger Sub being the surviving entity.

Cyclerion’s Reasons for the Merger (see page 141)

In the course of its evaluation of the Merger, the Merger Agreement and the transactions contemplated by the Merger Agreement (the “Contemplated Transactions”), the Cyclerion Board held numerous meetings, consulted with Cyclerion management, its legal counsel and its financial advisor and reviewed and assessed a significant amount of information and, in reaching its decision to approve the Merger, the Merger Agreement and the Contemplated Transactions, as described later in this proxy statement/prospectus under the section titled “The Merger-Cyclerion’s Reasons for the Merger.”

Korsana’s Reasons for the Merger (see page 145)

In the course of reaching its decision to approve the Merger and the Korsana Pre-Closing Financing, the Korsana Board consulted with Korsana’s senior management, legal counsel, and financial advisors, and considered a wide variety of factors. Ultimately, the Korsana Board concluded that a merger with Cyclerion, together with the additional financing committed from the Korsana Pre-Closing Financing, was the best option to generate capital resources to support the advancement of Korsana’s pipeline and fund the combined organization.

Additional factors the Korsana Board considered included the following (which factors are not necessarily presented in any order of relative importance):

14

The Korsana Board also considered a number of uncertainties and risks in its deliberations concerning the Merger and the other transactions contemplated by the Merger Agreement, including the following:

15

Recommendation of the Cyclerion Board of Directors (see page 129)

16

Interests of Cyclerion’s Directors and Executive Officers in the Merger (see page 154)

In considering the recommendation of the Cyclerion Board with respect to approving the Merger, shareholders should be aware that Cyclerion’s directors and executive officers have interests in the Merger that are different from, or in addition to, the interests of Cyclerion shareholders generally. These interests may present them with actual or potential conflicts of interest. These interests include the following:

17

The Cyclerion Board was aware of these potential conflicts of interest and considered them, among other matters, in reaching its decision to approve the Merger Agreement and the Merger, and to recommend that the Cyclerion shareholders approve the Merger as contemplated by this proxy statement/prospectus.

Interests of Korsana’s Directors and Executive Officers in the Merger (see page 156)

In considering the recommendation of the Korsana Board with respect to approving the Merger, stockholders should be aware that Korsana’s directors and executive officers have interests in the Merger that are different from, or in addition to, the interests of Korsana stockholders generally. These interests may present them with actual or potential conflicts of interest. These interests include the following:

The Korsana Board was aware of these potential conflicts of interest and considered them, among other matters, in reaching its decision to approve the Merger Agreement and the Merger, and to recommend that the Korsana stockholders approve the Merger as contemplated by this proxy statement/prospectus.

Opinion of Gemini to the Cyclerion Board (see page B-1)

Cyclerion retained Gemini Valuation Services, LLC (“Gemini”) as its financial advisor in connection with the Merger and the other transactions contemplated by the Merger Agreement. On March 31, 2026, Gemini rendered to the Cyclerion Board its oral opinion, which was subsequently confirmed by a written opinion addressed to the Cyclerion Board, dated March 31, 2026, that, as of such date and based upon and subject to the various assumptions made, and the qualifications and limitations upon the review undertaken by Gemini in preparing its opinion, the Exchange Ratio was fair, from a financial point of view, to Cyclerion.

The full text of the written opinion of Gemini, dated March 31, 2026, which describes the assumptions made and the qualifications and limitations upon the review undertaken by Gemini in preparing its opinion, is attached

18

as Annex B to this proxy statement/prospectus and is incorporated herein by reference. Gemini’s financial advisory services and opinion were provided for the information and assistance of the Cyclerion Board (in their capacity as directors and not in any other capacity) in connection with and for purposes of the Cyclerion Board’s consideration of the Merger and the opinion of Gemini addressed only the fairness, from a financial point of view, as of the date thereof, to Cyclerion of the Exchange Ratio pursuant to the terms of the Merger Agreement. The opinion of Gemini did not address any other term or aspect of the Merger Agreement or the Merger and does not constitute a recommendation to any shareholder of Cyclerion as to whether or how such holder should vote with respect to the Merger or otherwise act with respect to the Merger or any other matter.

The full text of the written opinion of Gemini should be read carefully in its entirety for a description of the assumptions made and limitations upon the review undertaken by Gemini in preparing its opinion.

Overview of the Merger Agreement and Agreements Related to the Merger Agreement

Merger Consideration (see page 158)

At the First Effective Time, upon the terms and subject to the conditions set forth in the Merger Agreement, (i) each then-outstanding share of Korsana Common Stock and Korsana Series A Preferred Stock (including shares of Korsana Common Stock issued in the Korsana Pre-Closing Financing), excluding shares of Korsana capital stock to be cancelled pursuant to the Merger Agreement and any dissenting shares, will be converted into the right to receive a number of shares of Cyclerion Common Stock and/or Cyclerion Pre-Funded Warrants, as applicable, equal to the Exchange Ratio (described in more detail in the section titled “The Merger Agreement — Exchange Ratio” beginning on page 167 of this proxy statement/prospectus), (ii) each then-outstanding share of Korsana Series Seed Preferred Stock (excluding any shares of Korsana Series Seed Preferred Stock to be cancelled pursuant to the Merger Agreement and any dissenting shares) will be converted into the right to receive a number of shares of Cyclerion Series B Preferred Stock equal to the Exchange Ratio divided by 1,000, in accordance with the terms of the Merger Agreement, (iii) each then-outstanding Korsana Option will be converted into and become an option to purchase shares of Cyclerion Common Stock on the existing terms and conditions (including with respect to vesting and accelerated vesting), subject to adjustment as set forth in the Merger Agreement, (iv) each then-outstanding Korsana RSU will be converted into and become a Cyclerion RSU on the existing terms and conditions (including with respect to vesting and accelerated vesting), subject to adjustment as set forth in the Merger Agreement, and (v) each then-outstanding and unexercised Korsana Warrant (including Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing) will be converted into a Cyclerion Warrant, subject to adjustment as set forth in the Merger Agreement.

Immediately after the Merger, Cyclerion securityholders as of immediately prior to the Merger are expected to own approximately 1.5% of the outstanding shares of capital stock of the Combined Company on a fully-diluted basis and former holders of Korsana securities are expected to own approximately 98.5% of the outstanding shares of capital stock of the Combined Company on a fully-diluted basis. Under certain circumstances further described in the Merger Agreement, the ownership percentages may be adjusted up or down including, but not limited to, if Cyclerion’s Net Cash as of Closing is less than or greater than $0.

Treatment of Korsana Options (see page 170)

Under the terms of the Merger Agreement, Cyclerion will assume Korsana’s 2025 Equity Incentive Plan and each option to purchase shares of Korsana Common Stock that is outstanding and unexercised immediately prior to the First Effective Time, whether or not vested, will be assumed and converted into an option to purchase shares of Cyclerion Common Stock.

Accordingly, from and after the First Effective Time: (i) each outstanding Korsana Option assumed by Cyclerion may be exercised solely for shares of Cyclerion Common Stock; (ii) the number of shares of Cyclerion Common Stock subject to each outstanding Korsana Option assumed by Cyclerion will be determined by

19

multiplying (A) the number of shares of Korsana Common Stock that were subject to such Korsana Option assumed by Cyclerion, as in effect immediately prior to the First Effective Time, by (B) the Exchange Ratio, and rounding the resulting number down to the nearest whole number of shares of Cyclerion Common Stock; and (iii) the per share exercise price of each Korsana Option assumed by Cyclerion will be determined by dividing (A) the per share exercise price of such Korsana Option, as in effect immediately prior to the First Effective Time, by (B) the Exchange Ratio, and rounding the resulting exercise price up to the nearest whole cent. Each Korsana Option assumed by Cyclerion will otherwise continue in full force and effect and the term, exercisability, vesting schedule, acceleration rights and other terms and conditions of such Korsana Option will otherwise remain unchanged.

Each Korsana stock option shall, in accordance with its terms, continue to be subject to further adjustment as appropriate to reflect any stock split, division or subdivision of shares, stock dividend, reverse stock split, consolidation of shares, reclassification, recapitalization or other similar transaction with respect to shares of Cyclerion Common Stock subsequent to the First Effective Time. In addition, the Combined Company’s compensation committee will succeed to the authority and responsibility of the Korsana Board as administrator of Korsana’s 2025 Equity Incentive Plan.

Treatment of Korsana Warrants (see page 171)

Under the terms of the Merger Agreement, each Korsana Warrant that is outstanding and unexercised immediately prior to the First Effective Time, whether or not vested, will be converted into a Cyclerion Warrant.

Accordingly, from and after the First Effective Time: (i) each outstanding Korsana Warrant assumed by Cyclerion may be exercised solely for shares of Cyclerion Common Stock; (ii) the number of shares of Cyclerion Common Stock subject to each outstanding Korsana Warrant assumed by Cyclerion will be determined by multiplying (A) the number of shares of Korsana Common Stock issuable upon exercise of the Korsana Warrant that were subject to such Korsana Warrant, as in effect immediately prior to the First Effective Time, by (B) the Exchange Ratio, and rounded up to the next whole share of Cyclerion Common Stock to the extent the aggregate amount of fractional shares of Cyclerion Common Stock such holder would otherwise be entitled to is equal to or exceeds 0.50; and (iii) the per share exercise price for the Cyclerion Common Stock issuable upon exercise of each Korsana Warrant assumed by Cyclerion will be determined by dividing (A) the per share exercise price of Cyclerion Common Stock subject to such Korsana Warrant as in effect immediately prior to the First Effective Time, by (B) the Exchange Ratio, and rounding the resulting exercise price up to the nearest whole cent. Each Korsana Warrant assumed by Cyclerion will otherwise continue in full force and effect and the term, any restriction on the exercise and other provisions of such Korsana Warrant will otherwise remain unchanged.

Each Korsana Warrant shall, in accordance with its terms, continue to be subject to further adjustment as appropriate to reflect any stock split, division or subdivision of shares, stock dividend, reverse stock split, consolidation of shares, reclassification, recapitalization or other similar transaction with respect to shares of Cyclerion Common Stock subsequent to the First Effective Time.

Korsana Restricted Stock Units (see page 171)

Under the terms of the Merger Agreement, Cyclerion will assume Korsana’s 2025 Equity Incentive Plan and each Korsana RSU that is outstanding immediately prior to the First Effective Time, whether or not vested, will be assumed and converted into a Cyclerion RSU.

Accordingly, from and after the First Effective Time: (i) each outstanding Korsana RSU assumed by Cyclerion may be settled solely for shares of Cyclerion Common Stock; and (ii) the number of shares of Cyclerion Common Stock subject to each outstanding Korsana RSU assumed by Cyclerion will be determined by multiplying (A) the number of shares of Korsana Common Stock that were subject to such Korsana RSU assumed by Cyclerion, as in effect immediately prior to the First Effective Time, by (B) the Exchange Ratio, and

20

rounding the resulting number up to the next whole number of shares of Cyclerion Common Stock to the extent the aggregate amount of fractional shares of Cyclerion Common Stock such holder of the assumed restricted stock units would otherwise be entitled to is equal to or exceeds 0.50, and otherwise rounded down. Each Korsana RSU assumed by Cyclerion will otherwise continue in full force and effect and the term, settlement, vesting schedule, acceleration rights and other terms and conditions of such Korsana RSU will otherwise remain unchanged.

Each Korsana RSU shall, in accordance with its terms, continue to be subject to further adjustment as appropriate to reflect any stock split, division or subdivision of shares, stock dividend, reverse stock split, consolidation of shares, reclassification, recapitalization or other similar transaction with respect to shares of Cyclerion Common Stock subsequent to the First Effective Time. In addition, the Combined Company’s compensation committee will succeed to the authority and responsibility of the Korsana Board as administrator of the Korsana 2025 Equity Incentive Plan.

Treatment of Cyclerion Common Stock, Cyclerion Options and Cyclerion Restricted Stock Awards (see page 154)

Except as contemplated by the proposed increase in the number of authorized shares of Cyclerion Common Stock described in Proposal No. 2 of this proxy statement/prospectus and the proposed reverse stock split of issued and outstanding Cyclerion Common Stock described in Proposal No. 3 of this proxy statement/prospectus, Cyclerion Common Stock will remain unaffected by the Merger.

Under the terms of the Merger Agreement, prior to the Closing, the Cyclerion Board will accelerate the vesting of all equity awards of Cyclerion then outstanding but not then vested or exercisable. At the First Effective Time, (i) each In-the-Money Cyclerion Option will be cancelled and converted into the right to receive an amount in cash, without interest, less any applicable tax withholding, equal to the product obtained by multiplying (A) the excess of the Cyclerion Closing Price over the exercise price per share of Cyclerion Common Stock underlying such Cyclerion Option by (B) the number of shares of Cyclerion Common Stock underlying such Cyclerion Option and (ii) each Out-of-the-Money Cyclerion Option will be cancelled for no consideration. The vesting of each Cyclerion RSA will be accelerated in full.

Conditions to the Completion of the Merger (see page 181)

To complete the Merger, Cyclerion shareholders must approve Proposal No. 1, Proposal No. 2, and Proposal No. 3 (unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waive such conditions) and Korsana stockholders must adopt the Merger Agreement and approve the Merger and the related transactions contemplated by the Merger Agreement. Additionally, each of the other closing conditions set forth in the Merger Agreement must be satisfied or waived.

Non-Solicitation (see page 177)

The Merger Agreement contains non-solicitation provisions prohibiting Cyclerion and Korsana from soliciting a competing transaction. Each of Cyclerion and Korsana has agreed that, subject to certain exceptions, Cyclerion and Korsana and any of their respective subsidiaries will not, nor will either party or any of its subsidiaries authorize or permit any of the directors, officers, employees, investment bankers, financial advisors, attorneys, accountants or other advisors, agents or representatives retained by it or any of its subsidiaries to, directly or indirectly:

21

Board Recommendation Change (see page 179)

Neither the Korsana Board nor Cyclerion Board may change its recommendation in favor of the Merger, except that prior to receipt by such party of its stockholder approval, such party’s board of directors may effect a change in recommendation as a result of (i) a material development or change in circumstances, or (ii) with respect to a superior offer that did not result from a material breach of the Merger Agreement (each of (i) and (ii), an “Intervening Event”), if:

In the event of any material amendment to any superior offer, the party considering the superior offer would be required to provide the other party with notice of such material amendment and there would be a new three-business day period following such notification during which the parties would be obligated to comply again with the requirements described above.

In the case of an Intervening Event, the party suffering such event shall promptly notify the other party before effecting a change in recommendation. The written notice is required to state the material facts and circumstances related to the applicable Intervening Event and that such party’s board of directors intends to make a change in recommendation.

Termination of the Merger Agreement (see page 182)

Either Cyclerion or Korsana may terminate the Merger Agreement under certain circumstances, which would prevent the Merger from being consummated.

22

Termination Fee (see page 184)

If the Merger Agreement is terminated under certain circumstances, Cyclerion could be required to pay Korsana a termination fee of $235,000 or Korsana could be required to pay Cyclerion a termination fee of $10,736,000.

Support Agreements (see page 186)

Certain stockholders of Korsana (solely in their respective capacities as Korsana stockholders) holding approximately 43.9% of the outstanding shares of Korsana capital stock have entered into support agreements with Cyclerion and Korsana to vote all of their shares of Korsana capital stock in favor of the adoption and approval of the Merger Agreement and the transactions contemplated thereby (the “Korsana Support Agreements”).

The directors and officers of Cyclerion holding approximately 24.2% of the outstanding shares of Cyclerion capital stock as of March 31, 2026 on an as-converted to Cyclerion Common Stock basis have entered into support agreements with Cyclerion and Korsana to vote all of their shares of Cyclerion Common Stock in favor of the adoption and approval of the Merger Agreement and the transactions contemplated thereby and the Reverse Stock Split and against any alternative Acquisition Proposals (the “Cyclerion Support Agreements”).

Lock-Up Agreements (see page 186)

Certain executive officers, directors and stockholders of Korsana have entered into lock-up agreements, pursuant to which such parties have agreed not to, except in limited circumstances, offer, pledge, sell, contract to sell, sell any option or contract to purchase, purchase any option or contract to sell, grant any option, right or warrant to purchase, or otherwise transfer or dispose of, directly or indirectly, any shares of Cyclerion Common Stock or any securities convertible into or exercisable or exchangeable for Cyclerion Common Stock, currently or thereafter owned, but excluding, as applicable, shares purchased by existing Korsana stockholders in the Korsana Pre-Closing Financing (including any shares of Cyclerion Common Stock issuable upon exercise of Cyclerion Pre-Funded Warrants issued in exchange for Korsana Pre-Funded Warrants sold in the Korsana Pre-Closing Financing), until 180 days after the First Effective Time.

Cyclerion CVR Agreement (see page 188)

Immediately prior to the First Effective Time, Cyclerion and the Rights Agent are expected to enter into the Cyclerion CVR Agreement, pursuant to which holders of Cyclerion Common Stock and Cyclerion Series A Preferred Stock as of the close of business on the last business day prior to the day on which the First Effective Time occurs will receive one Cyclerion CVR for each outstanding share of Cyclerion Common Stock or Cyclerion Series A Preferred Stock.

Each Cyclerion CVR will represent the contractual right to receive certain net proceeds, if any, derived from any consideration that is paid to Cyclerion as a result of the disposition of Cyclerion Legacy Assets, net of any indemnity obligations, transaction costs and certain other expenses, during the period beginning on the date of the closing of the Merger and ending (i) with respect to the sale, transfer, license or other disposition of all Cyclerion Legacy Assets other than those Cyclerion Legacy Assets described in the following clauses (ii) and (iii), upon the second (2nd) anniversary of the Closing Date, (ii) with respect to Cyclerion’s right to receive payments under the Akebia License Agreement, the earlier of (A) the fifteenth (15th) anniversary of the date of entry into the Cyclerion CVR Agreement and (B) the expiration pursuant to its terms or earlier termination by Akebia Therapeutics, Inc. of the Akebia License Agreement, and (iii) with respect to the sale, transfer or other disposition of the equity interests of Tisento that were acquired by Cyclerion pursuant to that certain Asset Purchase Agreement, dated May 13, 2023, by and among Cyclerion, Tisento and JW Cycle, Inc., the earliest of (A) nine (9) months following the date of the consummation of Tisento’s initial public offering pursuant to a

23

registration statement filed with, and declared effective by, the Securities and Exchange Commission pursuant to the Securities Act, (B) the sale of Tisento, and (C) the seventh (7th) anniversary of the Closing Date.

During the Legacy Assets Transaction Period (as defined in the Cyclerion CVR Agreement), the Combined Company shall expend up to the CVR Expense Cap for costs and expenses associated with the retention of an employee or consultant of Combined Company for the purpose of business development efforts related to Cyclerion Legacy Assets and related activities, including seeking and negotiating and, with the prior written consent of the Combined Company (not to be unreasonably withheld, conditioned or delayed), executing agreements with respect to Cyclerion Legacy Assets, which amount shall be included as a deduction in the determination of Cyclerion’s net cash in accordance with the Merger Agreement. At the end of the Legacy Assets Transaction Period, the amount, if any, by which the CVR Expense Cap exceeds the aggregate amount of costs and expenses associated with the retention of an employee or consultant of Cyclerion will constitute net proceeds under the Cyclerion CVR Agreement and will be payable as CVR proceeds to the CVR holders in accordance with the terms of the Cyclerion CVR Agreement.

The contingent payments under the Cyclerion CVR Agreement, if they become payable, will become payable to the Rights Agent for subsequent distribution to the holders of the Cyclerion CVRs. In the event that no such proceeds are received, holders of the Cyclerion CVRs will not receive any payment pursuant to the Cyclerion CVR Agreement. There can be no assurance that any holders of Cyclerion CVRs will receive any payments with respect thereto.

The right to the contingent payments contemplated by the Cyclerion CVR Agreement is a contractual right only and will not be transferable, except in the limited circumstances specified in the Cyclerion CVR Agreement. The Cyclerion CVRs will not be evidenced by a certificate or any other instrument and will not be registered with the SEC. The Cyclerion CVRs will not have any voting or dividend rights and will not represent any equity or ownership interest in Cyclerion or any of its affiliates. No interest will accrue on any amounts payable in respect of the Cyclerion CVRs.

Securities Purchase Agreement and Registration Rights Agreement (see page 186)

Concurrently with the execution and delivery of the Merger Agreement, certain institutional and accredited investors of Korsana entered into the Securities Purchase Agreement with Korsana, pursuant to which such investors have agreed to purchase, immediately prior to the Merger, shares of Korsana Common Stock or, in lieu thereof, Korsana Pre-Funded Warrants, representing an aggregate commitment of approximately $380.0 million in the Korsana Pre-Closing Financing.

The shares of Korsana Common Stock and Korsana Pre-Funded Warrants that are issued in the Korsana Pre-Closing Financing will be or will have the right to be, respectively, converted into shares of Cyclerion Common Stock in the Merger. The Securities Purchase Agreement contains customary representations and warranties of Korsana and also contains customary representations and warranties of the purchaser parties thereto.

The Securities Purchase Agreement also contemplates Korsana and the investors participating in the Korsana Pre-Closing Financing entering into the Registration Rights Agreement at the closing of the Korsana Pre-Closing Financing, pursuant to which, among other things, the Combined Company will agree to provide for the registration and resale of certain shares of Cyclerion Common Stock that are held by the investors participating in the Korsana Pre-Closing Financing from time to time pursuant to Rule 415.

24

Management Following the Merger (see page 367)

The following table sets forth the name, age as of April 1, 2026 and position of each of the individuals who are expected to serve as executives and directors of the Combined Company following completion of the Merger:

U.S. Federal Income Tax Considerations of the Merger (see page 160)

As discussed in detail in the section titled “The Merger — U.S. Federal Income Tax Considerations of the Merger” beginning on page 160 of this proxy statement/prospectus and subject to the limitations and qualifications described therein, Korsana and Cyclerion intend the Merger to qualify as a “reorganization” within the meaning of Section 368(a) of the Code. Assuming the Merger so qualifies, a U.S. Holder of Korsana stock (as defined therein) will not recognize gain or loss upon the exchange of its Korsana stock for Cyclerion stock. For a more detailed discussion of the U.S. federal income tax considerations of the Merger, see the section titled “The Merger — U.S. Federal Income Tax Considerations of the Merger,” beginning on page 160 of this proxy statement/prospectus.

U.S. Federal Income Tax Considerations of the Cayman Redomestication (see page 258)

Subject to the limitations and qualifications described in the section titled “Proposal No. 4— The Redomestication Proposal — U.S. Federal Income Tax Considerations of the Cayman Redomestication,” Cyclerion intends that the Cayman Redomestication qualify as a “reorganization” within the meaning of Section 368(a) of the Code. Assuming the Cayman Redomestication so qualifies, a U.S. Holder of the Combined Company stock will not recognize gain or loss upon the Cayman Redomestication. For a more detailed discussion of the U.S. federal income tax considerations of the Cayman Redomestication, please see the section titled “Proposal No. 4 — The Redomestication Proposal — U.S. Federal Income Tax Considerations of the Cayman Redomestication.”

Risk Factors (see page 32)

Both Cyclerion and Korsana are subject to various risks associated with their businesses and their industries. In addition, the Merger, including the possibility that the Merger may not be completed, poses a number of risks to each company and its respective securityholders, including the following risks:

Risks Related to the Proposed Merger

25

Risks Related to the Proposed Reverse Stock Split

Risks Related to Cyclerion

26

Risks Related to Korsana

27

Risks Related to the Cayman Redomestication

Risks Related to the Combined Company

28

These risks and other risks are discussed in greater detail under the section titled “Risk Factors” beginning on page 32 of this proxy statement/prospectus. Cyclerion and Korsana both encourage you to read and consider all of these risks carefully.

Regulatory Approvals (see page 180)

In the United States, Cyclerion must comply with applicable federal and state securities laws and the rules and regulations of Nasdaq in connection with the issuance of shares of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, to Korsana’s stockholders in connection with the transactions contemplated by the Merger Agreement and the filing of this proxy statement/prospectus with the SEC.

Completion of the Merger is conditioned on the expiration or termination of any applicable waiting period (and any extension thereof) under the HSR Act and the absence of any law or order restraining, enjoining, or otherwise prohibiting the consummation of the Merger. The HSR Act provides that certain transactions may not be completed until notification and report forms are furnished to the U.S. Department of Justice (“DOJ”) and the U.S. Federal Trade Commission (“FTC”) and the HSR Act waiting period is terminated or expires. On    , 2026, Cyclerion and Korsana each filed a notification and report form under the HSR Act with the DOJ and the FTC. The applicable waiting period required under the HSR Act will expire at 11:59 p.m., Eastern Time, on    , 2026, unless early termination is granted, Cyclerion withdraws and refiles its notification and report form, or a Second Request (as defined below) is issued.

Nasdaq Stock Market Listing (see page 162)

Cyclerion intends to file an initial listing application for the common stock of the Combined Company with Nasdaq. After completion of the Merger, Cyclerion will be renamed “Korsana Biosciences, Inc.” and it is expected that the common stock of the Combined Company will trade on Nasdaq under the symbol “KRSA.” It is a condition to the consummation of the Merger that Cyclerion will receive confirmation from Nasdaq that the Combined Company has been approved for listing on Nasdaq, but there can be no assurance such listing condition will be met or that Cyclerion will obtain such confirmation from Nasdaq. If such listing condition is not met or if such confirmation is not obtained, the Merger will not be consummated unless the condition is waived. The Nasdaq condition set forth in the Merger Agreement is not expected to be waived by the applicable parties; however, if such condition is waived, Cyclerion will not recirculate an updated proxy statement/prospectus, nor will it solicit a new vote of shareholders prior to proceeding with the Merger. Accordingly, you are advised that Cyclerion shareholders will not have certainty regarding the listing of the Combined Company’s shares at the time you are asked to vote at the Cyclerion Shareholders Meeting. For more information, please see the section entitled “Risk Factors — Risks Related to the Merger — Cyclerion and Korsana may mutually agree to waive the condition to the Merger requiring approval for listing on Nasdaq, and if such condition is waived, the Combined Company’s stock may not be listed on Nasdaq following completion of the Merger.” on page 32 of this proxy statement/prospectus.

Anticipated Accounting Treatment (see page 162)

The Merger is expected to be treated by Cyclerion as a reverse merger and is expected to be accounted for as an in-substance reverse recapitalization of Cyclerion by Korsana in accordance with U.S. Generally Accepted Accounting Principles (“GAAP”) as, at close, the transaction is, in essence, the issuance of equity by Korsana for Cyclerion’s net assets, consisting of nominal assets and liabilities before the Merger. For accounting purposes, Korsana is considered to be acquiring the assets and liabilities of Cyclerion in this transaction based on the terms of the Merger Agreement and other factors, including: (i) Korsana’s equity holders will own a substantial majority of the voting rights in the Combined Company; (ii) Korsana’s largest stockholder will retain the largest interest in the Combined Company; (iii) Korsana will designate all of the initial members of the board of directors of the Combined Company; and (iv) Korsana’s executive management team will become the

29

management of the Combined Company. The Combined Company will be named Korsana Biosciences, Inc. Accordingly, the Merger is expected to be treated as the equivalent of Korsana issuing stock to acquire the net assets of Cyclerion. As a result of the Merger, the net assets of Cyclerion will be stated at fair value, with no goodwill or other intangible assets recorded, and the historical results of operations prior to the Merger will be those of Korsana. The direct and incremental costs related to the transaction will be treated as a reduction of the net proceeds received within additional paid-in-capital. See the “Unaudited Pro Forma Condensed Combined Financial Information” elsewhere in this proxy statement/prospectus for additional information.

Appraisal Rights and Dissenters’ Rights (see page 163)

Under the MBCA, Cyclerion shareholders are not entitled to appraisal rights in connection with the Merger. Korsana stockholders are entitled to appraisal rights in connection with the Merger under Section 262 of the DGCL.

Comparison of Rights of Holders of Cyclerion Capital Stock and Korsana Capital Stock (see page 397)

Cyclerion is incorporated under the laws of the Commonwealth of Massachusetts and thus is currently subject to the MBCA and Korsana is incorporated under the laws of the State of Delaware and thus subject to the DGCL and accordingly, the rights of their respective stockholders are not identical due to differences in the law of the jurisdiction in which each entity is incorporated and due to differences in governing documents. If the Merger is completed, Korsana stockholders will become shareholders of Cyclerion, and their rights will be governed by the MBCA, the Cyclerion Articles and the Cyclerion Bylaws, in each case as they may be amended, including by Proposal Nos. 2 and 3 if approved by Cyclerion shareholders. The extent to which the rights of Korsana stockholders will change as a result of the Merger is further affected by Proposal No. 4, which, if approved and the Cayman Redomestication is effected, would result in Cyclerion shareholders (including former Korsana stockholders) no longer being governed by the MBCA and Cyclerion’s existing organizational documents, but instead by the Cayman Articles and the Cayman Islands Companies Act. For a comparison of stockholder rights under these respective regimes, see the section titled “Comparison of Rights of Holders of Cyclerion Capital Stock and Korsana Capital Stock” beginning on page 397, and, assuming the Cayman Redomestication is completed, the section titled “Proposal No. 4 — The Redomestication Proposal — Effects of the Redomestication — Comparison of Rights of Holders of the Massachusetts Corporation Capital Stock and the Cayman Company Share Capital” beginning on page 235.

If Proposal No. 4 is approved by Cyclerion shareholders and the Merger is completed, the Combined Company will effect the Cayman Redomestication pursuant to the Plan of Domestication as set forth in the form attached as Annex J to this proxy statement/prospectus, and, upon completion of the Cayman Redomestication, the rights of Cyclerion shareholders and the rights of Korsana stockholders who become the Combined Company stockholders pursuant to the Merger will no longer be governed by the Cyclerion Articles, Cyclerion’s amended and restated bylaws and the MBCA, and instead will be governed by the Cayman Articles, in the form attached as Annex K to this proxy statement/prospectus, and the Cayman Islands Companies Act. For a comparison of rights of holders of the Combined Company capital stock as a Massachusetts corporation and the Combined Company share capital as a Cayman Islands exempted company limited by shares assuming the completion of the Cayman Redomestication, see the section titled “Proposal No. 4 — The Redomestication Proposal — Effects of the Cayman Redomestication — Comparison of Rights of Holders of the Massachusetts Corporation Capital Stock and the Cayman Company Share Capital” beginning on page 235 of this proxy statement/prospectus.

30

MARKET PRICE AND DIVIDEND INFORMATION

The Cyclerion Common Stock is currently listed on the Nasdaq Capital Market under the symbol “CYCN.”

The closing price of the Cyclerion Common Stock on March 31, 2026, the last day of trading prior to the announcement of the Merger, as reported on The Nasdaq Capital Market, was $1.55 per share. The closing price of the Cyclerion Common Stock on    , 2026, as reported on The Nasdaq Capital Market, was $    per share.

Because the market price of the Cyclerion Common Stock is subject to fluctuation, the market value of the shares of the Cyclerion Common Stock that the Korsana stockholders will be entitled to receive in the Merger may increase or decrease.

Korsana is a private company, and its shares of common stock and preferred stock are not publicly traded.

Assuming approval of Proposal Nos. 1, 2, and 3 and successful application for initial listing with Nasdaq, following the consummation of the Merger, shares of Cyclerion Common Stock will trade on Nasdaq under Cyclerion’s new name, “Korsana Biosciences, Inc.,” and new trading symbol “KRSA.”

As of    , 2026, there were approximately    registered holders of record of the Cyclerion Common Stock. As of    , 2026, Korsana had    holders of record of Korsana Common Stock,    holders of record of Korsana Series Seed Preferred Stock, and    holders of record of Korsana Series A Preferred Stock. For detailed information regarding the beneficial ownership of certain Cyclerion and Korsana stockholders, see the sections of this proxy statement/prospectus titled “Principal Shareholders of Cyclerion,” “Principal Stockholders of Korsana” and “Principal Shareholders of the Combined Company.”

Dividends

Cyclerion has never declared or paid any cash dividends on the Cyclerion Common Stock and does not anticipate paying cash dividends on the Cyclerion Common Stock for the foreseeable future. Notwithstanding the foregoing, any determination to pay cash dividends subsequent to the Merger will be at the discretion of the Combined Company’s then-current board of directors and will depend upon a number of factors, including the Combined Company’s results of operations, financial condition, future prospects, contractual restrictions, restrictions imposed by applicable law and other factors the then-current board of directors deems relevant.

Korsana has never paid or declared any cash dividends on Korsana capital stock. If the Merger does not occur, Korsana does not anticipate paying any cash dividends on the Korsana capital stock in the foreseeable future, and Korsana intends to retain all available funds and any future earnings to fund the development and expansion of its business. Any future determination to pay dividends will be at the discretion of the Korsana Board and will depend upon a number of factors, including its results of operations, financial condition, future prospects, contractual restrictions, and restrictions imposed by applicable laws and other factors the Korsana Board deems relevant.

31

RISK FACTORS

The Combined Company will be faced with a market environment that cannot be predicted and that involves significant risks, many of which will be beyond its control. In addition to the other information contained or incorporated by reference in this proxy statement/prospectus, you should carefully consider the material risks described below before deciding how to vote your shares of Cyclerion Common Stock. You should also read and consider the other information in this proxy statement/prospectus. Please see the section titled “Where You Can Find More Information” beginning on page 419 of this proxy statement/prospectus for further information. Moreover, some of the factors, events and contingencies discussed below may have occurred in the past, but the disclosures below are not representations as to whether or not the factors, events or contingencies have occurred in the past and instead reflect our beliefs and opinions as to the factors, events, or contingencies that could materially and adversely affect us in the future.

Risks Related to the Proposed Merger

Failure to complete, or delays in completing, the potential Merger could materially and adversely affect Cyclerion’s results of operations, business, financial results, and/or common stock price.

On April 1, 2026, Cyclerion and Korsana entered into the Merger Agreement, which agreement was subsequently amended on April 17, 2026, pursuant to which, among other matters, and subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, First Merger Sub will merge with and into Korsana, with Korsana continuing as a wholly owned subsidiary of Cyclerion and the surviving corporation of the First Merger and, immediately following the First Merger and as part of the same overall transaction as the First Merger, Korsana will merge with and into Second Merger Sub as part of the Second Merger, with Second Merger Sub continuing as a wholly owned subsidiary of Cyclerion and the surviving entity of the Second Merger. Consummation of the Merger is subject to certain closing conditions, a number of which are not within Cyclerion’s control. Any failure to satisfy these required conditions to closing may prevent, delay or otherwise materially adversely affect the completion of the transaction. Cyclerion cannot predict with certainty whether or when any of the required closing conditions will be satisfied or if another uncertainty may arise and cannot assure you that it will be able to successfully consummate the Merger as currently contemplated under the Merger Agreement or at all.

Cyclerion’s efforts to complete the Merger could cause substantial disruptions in, and create uncertainty surrounding, its business, which may materially adversely affect its results of operation and its business. Uncertainty as to whether the Merger will be completed in a timely manner or at all may affect Cyclerion’s ability to retain and motivate existing employees. Uncertainty as to whether the Merger will be completed in a timely manner or at all could adversely affect Cyclerion’s business and its relationship with collaborators, suppliers, vendors, regulators, and other business partners. The adverse effects of the pendency of the transaction could be exacerbated by any delays in completion of the transaction or termination of the Merger Agreement.

If the conditions to the Merger are not satisfied or waived, the Merger may not occur.

Even if the Merger is approved by the stockholders of Korsana and Cyclerion, specified conditions must be satisfied or, to the extent permitted by applicable law, waived to complete the Merger. These conditions are set forth in the Merger Agreement and described further in the section titled “The Merger Agreement” of this proxy statement/prospectus. Cyclerion cannot assure you that all of the conditions to the consummation of the Merger will be satisfied or waived. If the conditions are not satisfied or waived, the Merger may not occur or the closing may be delayed.

Cyclerion and Korsana may mutually agree to waive the condition to the Merger requiring approval for listing on Nasdaq, and if such condition is waived, the Combined Company’s stock may not be listed on Nasdaq following completion of the Merger.

Pursuant to the Merger Agreement, Cyclerion agreed, to the extent required by the rules and regulations of Nasdaq, to use its commercially reasonable efforts to cause the shares of Cyclerion Common Stock being issued

32

in the Merger to be approved for listing on Nasdaq at or prior to the First Effective Time. Additionally, under the Merger Agreement, each of Cyclerion’s and Korsana’s obligation to complete the Merger is subject to the satisfaction or waiver by each of the parties of various conditions, including that the shares of Cyclerion Common Stock to be issued in the Merger have been approved for listing (subject to official notice of issuance) on Nasdaq as of the closing of the Merger. In the event that the shares of Cyclerion Common Stock to be issued in the Merger are not approved for listing on Nasdaq, it is possible that Cyclerion and Korsana may mutually agree to waive the applicable condition and nonetheless proceed with completing the Merger. If such condition is waived, Cyclerion will not recirculate an updated proxy statement/prospectus, nor will it solicit a new vote of shareholders prior to proceeding with the Merger. If Cyclerion proceeds with the Merger in these circumstances, the Combined Company’s stock may not be listed on Nasdaq.

If the Combined Company’s stock is not listed on Nasdaq following completion of the Merger, trading of the shares could be conducted in the over-the-counter market or on an electronic bulletin board established for unlisted securities such as the Pink Sheets or the OTC Bulletin Board. In such event, it is likely that there would be significantly less liquidity in the trading of the common stock of the Combined Company; decreases in institutional and other investor demand for the shares, coverage by securities analysts, market making activity and information available concerning trading prices and volume; and fewer broker dealers willing to execute trades in the common stock of the Combined Company. Also, it may be difficult for the Combined Company to raise additional capital if the Combined Company’s common stock is not listed on a major exchange. The occurrence of any of these events could result in a further decline in the market price of the common stock of the Combined Company and could have a material adverse effect on the Combined Company.

The Exchange Ratio for the Merger will not change or otherwise be adjusted based on the market price of Cyclerion Common Stock.

Applying the Exchange Ratio, based on Cyclerion’s capitalization as of December 31, 2025 and Korsana’s capitalization as of March 31, 2026 and taking into account Cyclerion’s current cash position, each share of Korsana Common Stock is currently estimated to be entitled to receive approximately 1.1009 shares of Cyclerion Common Stock. Each share of Korsana Series Seed Preferred Stock will be converted into the right to receive a number of shares of Cyclerion Series B Preferred Stock, equal to the Exchange Ratio divided by 1,000. Applying the Exchange Ratio, the former Korsana securityholders immediately before the Merger are expected to own approximately 98.5% of the aggregate number of shares of the Combined Company’s capital stock following the Merger (on a fully-diluted basis), and Cyclerion shareholders immediately before the Merger are expected to own approximately 1.5% of the aggregate number of shares of the Combined Company capital stock following the Merger (on a fully-diluted basis), subject to certain assumptions, including, but not limited to, Cyclerion’s Net Cash as of closing being equal to $0. In the event Cyclerion’s Net Cash is less than or greater than $0, the Exchange Ratio will be adjusted such that the number of shares issued to Korsana’s pre-closing securityholders will be decreased or increased, as applicable, and Cyclerion shareholders will own a smaller or larger percentage, as applicable, of the Combined Company following the consummation of the Merger.

Any changes in the market price of Cyclerion’s stock before the completion of the First Merger will not affect the number of shares Korsana stockholders will be entitled to receive pursuant to the Merger Agreement. Therefore, if before the completion of the First Merger, the market price of Cyclerion Common Stock increases from the market price on the date of the Merger Agreement, then Korsana stockholders could receive merger consideration with substantially more value for their shares of Korsana capital stock than the parties had negotiated when they established the Exchange Ratio. Similarly, if before the completion of the First Merger, the market price of Cyclerion Common Stock declines from the market price on the date of the Merger Agreement, then Korsana stockholders could receive merger consideration with substantially lower value. The Merger Agreement does not include a price-based termination right.

33

The issuance of Cyclerion Common Stock, including the shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, to Korsana stockholders pursuant to the Merger Agreement and the resulting change in control from the First Merger must be approved by Cyclerion shareholders, and the Merger Agreement and transactions contemplated thereby must be approved by the Korsana stockholders. Failure to obtain these approvals would prevent the closing of the Merger.

Before the Merger can be completed, Cyclerion shareholders must approve, among other things, the issuance of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, to Korsana stockholders pursuant to the Merger Agreement and the resulting change in control from the First Merger, and Korsana stockholders must adopt the Merger Agreement and approve the Merger and the related transactions. Failure to obtain the required stockholder approvals may result in a material delay in, or the abandonment of, the Merger. Any delay in completing the Merger may materially adversely affect the timing and benefits that are expected to be achieved from the Merger.

The Merger may be completed even though a material adverse effect may result from the announcement of the Merger, industry-wide changes or other causes.

In general, neither Cyclerion nor Korsana is obligated to complete the Merger if there is a material adverse effect affecting the other party between April 1, 2026, the date of the Merger Agreement, and the closing of the Merger. However, certain types of causes are excluded from the concept of a “material adverse effect.” Such exclusions include, but are not limited to, changes in general economic or political conditions, industry-wide changes, changes resulting from the announcement of the Merger, natural disasters, pandemics, other public health events or force majeure events and changes in U.S. generally accepted accounting principles. Therefore, if any of these events were to occur and adversely affect Cyclerion or Korsana, the other party would still be obliged to consummate the closing of the Merger notwithstanding such material adverse effect. If any such adverse effects occur and Cyclerion consummates the closing of the Merger, the stock price of the Combined Company may suffer. This in turn may reduce the value of the Merger to the shareholders of Cyclerion, Korsana or both.

If the Merger is not completed, Cyclerion’s stock price may decline significantly.

The market price of Cyclerion Common Stock is subject to significant fluctuations. Market prices for securities of pharmaceutical, biotechnology and other life science companies have historically been particularly volatile. In addition, the market price of Cyclerion Common Stock will likely be volatile based on whether shareholders and other investors believe that Cyclerion can complete the Merger or otherwise raise additional capital to support Cyclerion’s operations if the Merger is not consummated and another strategic transaction cannot be identified, negotiated and consummated in a timely manner, if at all. The volatility of the market price of Cyclerion Common Stock has been and may be exacerbated by low trading volume. Additional factors that may cause the market price of Cyclerion Common Stock to fluctuate include:

34

Moreover, the stock markets in general have experienced substantial volatility that has often been unrelated to the operating performance of individual companies. These broad market fluctuations may also adversely affect the trading price of Cyclerion Common Stock. In the past, following periods of volatility in the market price of a company’s securities, stockholders have often instituted class action securities litigation against such companies.

If Cyclerion completes the Merger, the Combined Company will need to raise additional capital and satisfy certain contractual obligations by issuing equity securities or additional debt or through licensing arrangements, which may cause significant dilution to the Combined Company’s shareholders or restrict the Combined Company’s operations.

In connection with the Merger, Korsana and Cyclerion entered into the Securities Purchase Agreement with certain investors, including existing investors of Korsana, pursuant to which the investors agreed to purchase, in the aggregate, approximately $380.0 million of Korsana Common Stock and Korsana Pre-Funded Warrants in the Korsana Pre-Closing Financing immediately prior to the closing of the Merger. The closing of the Korsana Pre-Closing Financing is conditioned upon the satisfaction or waiver of the conditions to the closing of the Merger as well as certain other conditions. The Korsana Common Stock and Korsana Pre-Funded Warrants issued in the Korsana Pre-Closing Financing will result in dilution to all securityholders of the Combined Company (i.e., both Cyclerion’s pre-Merger securityholders and former Korsana securityholders).

Additional financing may not be available to the Combined Company when it is needed or may not be available on favorable terms. To the extent that the Combined Company raises additional capital by issuing equity securities, such financing will cause additional dilution to all securityholders of the Combined Company, including Cyclerion’s pre-Merger securityholders and Korsana former securityholders. It is also possible that the terms of any new equity securities may have preferences over the Combined Company’s common stock. Any debt financing the Combined Company enters into may involve covenants that restrict its operations. These restrictive covenants may include limitations on additional borrowing and specific restrictions on the use of the Combined Company’s assets, as well as prohibitions on its ability to create liens, pay dividends, redeem its stock or make investments. In addition, if the Combined Company raises additional funds through licensing arrangements, it may be necessary to grant licenses on terms that are not favorable to the Combined Company.

In addition, as a result of Cyclerion’s assumption of the Paragon ADOA in connection with the Merger, the Combined Company will be subject to the obligation to grant to Parasa on December 31, 2026, warrants to purchase a number of shares equal to 1.00% of the outstanding shares of Cyclerion Common Stock as of the date of the grant on a fully-diluted basis, with an exercise price equal to the fair market value of the underlying shares on the grant date. Such warrants granted will result in further dilution to all securityholders of the Combined Company.

Transfers of the Combined Company’s securities utilizing Rule 144 of the Securities Act may be limited.

A significant portion of the Combined Company’s securities will be restricted from immediate resale. Holders should be aware that transfers of the Combined Company’s securities pursuant to Rule 144 may be limited as Rule 144 is not available, subject to certain exceptions, for the resale of securities initially issued by shell companies (other than business combination related shell companies) or issuers that have been at any time previously a shell company. Cyclerion’s expected disposal of Cyclerion’s historical assets and operations in connection with the Merger is expected to make Cyclerion a shell company. Cyclerion anticipates that following the consummation of the Merger, the Combined Company will no longer be a shell company. As a result, Cyclerion anticipates that holders will not be able to sell their restricted Combined Company securities pursuant to Rule 144 without registration until one year after Cyclerion files the Current Report on Form 8-K following the closing that includes the required Form 10 information that reflects that the Combined Company is no longer a shell company.

35

Cyclerion is expected to be deemed a shell company. As a result, if Cyclerion completes the Merger, the Combined Company will be subject to more stringent reporting requirements, offering limitations and resale restrictions.

Cyclerion’s or the Combined Company’s expected disposal of Cyclerion’s historical assets and operations prior to or following the Merger is expected to make Cyclerion a shell company. As such, the Combined Company would be subject to the requirements applicable to shell company business combinations. The requirements applicable to shell company business combinations are as follows:

The foregoing SEC requirements would increase the Combined Company’s time and cost of raising capital, offering stock under equity plans, and complying with securities laws. Further, such requirements will add burdensome restrictions on the resale of Combined Company shares by affiliates of Korsana and any holders of “restricted” or “control” securities.

Some of Cyclerion’s and Korsana’s directors and executive officers have interests in the Merger that are different from yours and that may influence them to support or approve the Merger without regard to your interests.

Directors and executive officers of Cyclerion and Korsana have interests in the Merger that are different from, or in addition to, the interests of other Cyclerion shareholders generally. These interests with respect to Cyclerion’s directors and executive officers may include, among others, retention bonus payments, extension of exercisability periods of previously issued stock option grants, severance payments if employment is terminated in a qualifying termination in connection with the Merger and rights to continued indemnification, expense advancement and insurance coverage.

Further, certain current members of the Korsana Board will continue as directors of the Combined Company after the First Effective Time, and, following the closing of the Merger, will be eligible to be compensated as non-employee directors of the Combined Company pursuant to Cyclerion’s non-employee director compensation policy that is expected to remain in place following the First Effective Time.

36

The Cyclerion Board was aware of and considered those interests, among other matters, in reaching their decisions to approve and adopt the Merger Agreement, approve the Merger, and recommend the approval of the Merger Agreement to Cyclerion and Korsana stockholders. These interests, among other factors, may have influenced the directors and executive officers of each company to support or approve the Merger.

Cyclerion shareholders and Korsana stockholders may not realize a benefit from the Merger commensurate with the ownership dilution they will experience in connection with the Merger, including the conversion of Korsana Common Stock issued in the Korsana Pre-Closing Financing.

If the Combined Company is unable to realize the full strategic and financial benefits currently anticipated from the Merger, Cyclerion shareholders and Korsana stockholders will have experienced substantial dilution of their ownership interests without receiving any commensurate benefit, or only receiving part of the commensurate benefit to the extent the Combined Company is able to realize only part of the strategic and financial benefits currently anticipated from the Merger.

Cyclerion securityholders will generally have a reduced ownership and voting interest in, and will exercise less influence over the management of, the Combined Company following the completion of the Merger as compared to their current ownership and voting interests in the respective companies.

After the completion of the Merger, Cyclerion’s current shareholders will generally own a smaller percentage of the Combined Company than their ownership of Cyclerion prior to the Merger. Immediately after the Merger, Cyclerion securityholders as of immediately prior to the Merger are expected to own approximately 1.5% of the outstanding shares of capital stock of the Combined Company (on a fully-diluted basis), and former holders of Korsana securities are expected to own approximately 98.5% of the outstanding shares of capital stock of the Combined Company (on a fully-diluted basis), subject to certain assumptions, including, but not limited to, Cyclerion’s Net Cash as of closing being equal to $0. The Chief Executive Officer and President of Korsana will serve as the Chief Executive Officer and President of the Combined Company following the completion of the Merger.

Certain provisions of the Merger Agreement may discourage third parties from submitting competing proposals, including proposals that may be superior to the transactions contemplated by the Merger Agreement.

While the Merger Agreement is in effect, each party is generally prohibited from, among other things, soliciting, initiating or knowingly encouraging, inducing or facilitating the communication, making, submission or announcement of any acquisition proposal or acquisition inquiry. In addition, Cyclerion’s current directors and executive officers have entered into support agreements pursuant to the terms of the Merger Agreement, and as an inducement to Korsana’s willingness to enter into the Merger Agreement, by which they have agreed to vote all of their shares of Cyclerion capital stock in favor of the Merger Agreement and the transactions contemplated thereby and against any competing proposals, subject to certain limited exceptions. These provisions could discourage a potential competing acquirer from considering or proposing an acquisition or merger, even if it were prepared to pay consideration with a higher value than that implied by the merger consideration in the combination.

Because the lack of a public market for Korsana Common Stock makes it difficult to evaluate the fair market value of its capital stock, the value of Cyclerion Common Stock to be issued to Korsana stockholders may be more or less than the fair market value of Korsana Common Stock.

The outstanding capital stock of Korsana is privately held and is not traded on any public market. The lack of a public market makes it difficult to determine the fair market value of Korsana capital stock. Because the percentage of Cyclerion’s equity to be issued to Korsana stockholders was determined based on negotiations between the parties, it is possible that the value of Cyclerion Common Stock and Cyclerion Series B Preferred

37

Stock to be issued to Korsana stockholders will be more or less than the fair market value of Korsana capital stock.

Lawsuits may be filed against Cyclerion, Korsana, or any of the members of their respective boards of directors arising out of the Merger, which may delay or prevent the Merger.

Putative stockholder complaints, including stockholder class action complaints, and other complaints may be filed against Cyclerion, the Cyclerion Board, Korsana, the Korsana Board and others in connection with the transactions contemplated by the Merger Agreement. The outcome of litigation is uncertain, and Cyclerion or Korsana may not be successful in defending against any such future claims. Lawsuits that may be filed against Cyclerion, the Cyclerion Board, Korsana, or the Korsana Board could delay or prevent the Merger, divert the attention of Cyclerion’s and Korsana’s management and employees from their day-to-day business and otherwise adversely affect Cyclerion and Korsana financially.

Cyclerion has never paid and, other than in connection with the Merger, does not intend to pay any cash dividends in the foreseeable future.

Cyclerion has never paid cash dividends on any of its capital stock. Cyclerion does not currently anticipate declaring or paying cash dividends on its capital stock in the foreseeable future.

If Cyclerion does not successfully consummate the Merger or another strategic transaction, the Cyclerion Board may decide to pursue a dissolution and liquidation of Cyclerion. In such an event, the amount of cash available for distribution to Cyclerion shareholders, if any, will depend heavily on the timing of such liquidation as well as the amount of cash that will need to be reserved for commitments and contingent liabilities, as to which Cyclerion can give you no assurance.

There can be no assurance that the Merger will be completed. If the Merger is not completed, the Cyclerion Board may decide to pursue a dissolution and liquidation of Cyclerion. In such an event, the amount of cash available for distribution to Cyclerion shareholders, if any, will depend heavily on the timing of such decision and, ultimately, such liquidation, since the amount of cash available for distribution continues to decrease as Cyclerion funds its operations while pursuing the Merger. In addition, if the Cyclerion Board were to approve and recommend, and Cyclerion shareholders were to approve, a dissolution and liquidation of Cyclerion, Cyclerion would be required under Massachusetts law to pay Cyclerion’s outstanding obligations, as well as to make reasonable provision for contingent and unknown obligations, prior to making any distributions in liquidation to shareholders. Cyclerion’s commitments and contingent liabilities may include obligations under Cyclerion’s employment and related agreements with certain employees that provide for severance and other payments following a termination of employment occurring for various reasons, including a change in control of Cyclerion, litigation against Cyclerion, and other various claims and legal actions arising in the ordinary course of business, and other unexpected and/or contingent liabilities. As a result of this requirement, a portion of Cyclerion’s assets would need to be reserved pending the resolution of such obligations.

In addition, Cyclerion may be subject to litigation or other claims related to a dissolution and liquidation of Cyclerion. If a dissolution and liquidation were to be pursued, the Cyclerion Board, in consultation with Cyclerion’s advisors, would need to evaluate these matters and make a determination about a reasonable amount to reserve. Accordingly, holders of Cyclerion Common Stock could lose all or a significant portion of their investment in the event of liquidation, dissolution or winding up of Cyclerion. A liquidation would be a lengthy and uncertain process with no assurance of any value ever being returned to Cyclerion shareholders.

Cyclerion and its shareholders will not have any right to make damage claims against Korsana for the breach of any representation, warranty or covenant made by Korsana in the Merger Agreement.

The Merger Agreement provides that all of the representations, warranties and covenants of the parties contained therein shall not survive the closing of the Merger, except for those covenants contained therein that by

38

their terms apply or are to be performed in whole or in part after the Closing, and then only with respect to breaches occurring after the closing of the Merger. Accordingly, there are no remedies available to the parties with respect to any breach of the representations, warranties, covenants or agreements of the parties to the Merger Agreement after the Closing of the Merger, except for covenants to be performed in whole or in part after the Closing. As a result, Cyclerion and its shareholders will have no remedy available to them if the Merger is consummated and it is later revealed that there was a breach of any of the representations, warranties and covenants made by Korsana at the time of the Merger.

Additionally, Cyclerion cannot assure you that the due diligence conducted in relation to Korsana has identified all material issues or risks associated with Korsana, its business or the industry in which it competes. Furthermore, Cyclerion cannot assure you that factors outside of its or Korsana’s control will not later arise, or that any previously identified risks will not materialize in a manner inconsistent with the preliminary analysis. As a result of these factors, following the closing of the Merger, the Combined Company may be exposed to liabilities and incur additional costs and expenses and it may be forced to later write-down or write off assets, restructure its operations, or incur impairment or other charges. Cyclerion and its shareholders have no indemnification rights against Korsana or its stockholders under the Merger Agreement. Accordingly, any shareholders of Cyclerion that remain stockholders of the Combined Company following the Merger could suffer a reduction in the value of their securities. Such shareholders are unlikely to have a remedy for such reduction in value unless they are able to successfully claim that the reduction was due to the breach by Cyclerion’s directors or officers of a duty of care or other fiduciary duty owed to them, or if they are able to successfully bring a private claim under securities laws that the registration statement or proxy statement/prospectus relating to the Merger contained an actionable material misstatement or material omission.

Cyclerion’s shareholders potentially may not receive any payment on the Cyclerion CVRs and the Cyclerion CVRs may otherwise expire valueless.

The Merger Agreement contemplates that, at or prior to the First Effective Time, Cyclerion and the Rights Agent (as defined in the Cyclerion CVR Agreement) will execute and deliver the Cyclerion CVR Agreement, pursuant to which each person who was a shareholder of record of Cyclerion’s capital stock as of the close of business on the last business day prior to the day on which the First Effective Time occurs will be entitled to receive a Cyclerion CVR, issued by Cyclerion subject to and in accordance with the terms and conditions of the Cyclerion CVR Agreement. Pursuant to the Cyclerion CVR Agreement, each CVR holder is entitled to certain rights to receive a pro rata portion of the proceeds, if any, received by Cyclerion as a result of the disposition of the Cyclerion Legacy Assets during specified periods of time. Such proceeds are subject to certain permitted deductions. The right of Cyclerion’s shareholders to derive any value from the Cyclerion CVRs will be contingent solely upon the disposition of such Cyclerion Legacy Assets within the time periods specified in the Cyclerion CVR Agreement or any other contingencies as provided in the Cyclerion CVR Agreement.

Cyclerion may not be able to achieve successful results from the disposition of such Cyclerion Legacy Assets as described above. If this is not achieved for any reason within the time periods specified in the CVR Agreement, no payments will be made under the Cyclerion CVRs, and the Cyclerion CVRs will expire valueless. For more information see the section titled “Agreements Related to the Merger — Cyclerion CVR Agreement.”

The tax treatment of the Cyclerion CVRs is uncertain.

The Combined Company intends to treat the issuance of the Cyclerion CVRs to the persons who prior to completion of the Merger were Cyclerion shareholders as a distribution of property with respect to Cyclerion capital stock. However, the U.S. federal income tax treatment of the CVRs is uncertain. There is no legal authority directly addressing the U.S. federal income tax treatment of contingent value rights with characteristics similar to the Cyclerion CVRs. Therefore, it is possible that the issuance of the Cyclerion CVRs may be treated as a distribution of equity with respect to Cyclerion capital stock, as an “open transaction,” or as a “debt instrument” for U.S. federal income tax purposes, and such questions are inherently factual in nature. For more information regarding the U.S. federal income tax consequences of the Cyclerion CVRs, see the section titled

39

“Agreements Related to the Merger — Cyclerion CVR Agreement — Material U.S. Federal Income Tax Consequences of the Cyclerion CVRs to Holders of Cyclerion Capital Stock.”

Risks Related to the Proposed Reverse Stock Split

The reverse stock split could result in a significant devaluation of Cyclerion’s market capitalization and the trading price of Cyclerion Common Stock.

Although Cyclerion expects that the reverse stock split will result in an increase in the market price of Cyclerion Common Stock, Cyclerion cannot assure stockholders that the reverse stock split, if implemented, will increase the market price of Cyclerion Common Stock in proportion to the reduction in the number of shares of Cyclerion Common Stock outstanding or result in a permanent increase in the market price. Accordingly, the total market capitalization of Cyclerion Common Stock after the reverse stock split may be lower than the total market capitalization before such reverse stock split and, in the future, the market price of Cyclerion Common Stock following such reverse stock split may not exceed or remain higher than the market price prior to the corresponding reverse stock split.

The effect the reverse stock split may have upon the market price of Cyclerion Common Stock cannot be predicted with any certainty. The market price of Cyclerion Common Stock is dependent on many factors, including Cyclerion’s business and financial performance, general market conditions, prospects for future success and other factors detailed from time to time in the reports Cyclerion files with the SEC.

The reverse stock split may result in some stockholders owning “odd lots” that may be more difficult to sell or require greater transaction costs per share to sell.

The reverse stock split may result in some stockholders owning “odd lots” of less than 100 shares of Cyclerion Common Stock on a post-split basis. These odd lots may be more difficult to sell, or require greater transaction costs per share to sell, than shares in “round lots” of even multiples of 100 shares.

The reverse stock split may not generate additional investor interest.

While the Cyclerion Board believes that a higher stock price may help generate investor interest, there can be no assurance that the reverse stock split will result in a per share price that will attract institutional investors or investment funds or that such share price will satisfy the investing guidelines of institutional investors or investment funds. As a result, the trading liquidity of Cyclerion Common Stock may not necessarily improve.

The reverse stock split may not increase the Combined Company’s stock price over the long term.

The principal purposes of the reverse stock split are to (i) increase the per-share market price of Cyclerion Common Stock above the minimum bid price requirement under the Nasdaq rules so that the listing of Cyclerion and the shares of Cyclerion Common Stock being issued in the Merger on Nasdaq will be approved and (ii) increase the number of authorized and unissued shares available for future issuance in connection with the Merger, though such increase will not alone be sufficient to complete the Merger. It cannot be assured, however, that the reverse stock split will accomplish any increase in the per share market price of Cyclerion Common Stock for any meaningful period of time. While it is expected that the reduction in the number of outstanding shares of Cyclerion Common Stock will proportionally increase the market price of Cyclerion Common Stock, it cannot be assured that the reverse stock split will increase the market price of Cyclerion Common Stock by a multiple of the reverse stock split ratio mutually agreed by Cyclerion and Korsana, or result in any permanent or sustained increase in the market price of Cyclerion Common Stock, which is dependent upon many factors, including Cyclerion’s business and financial performance, general market conditions and prospects for future success. Thus, while the stock price of Cyclerion Common Stock might meet the listing requirements for Nasdaq initially after the reverse stock split, it cannot be assured that it will continue to do so.

40

The reverse stock split may decrease the liquidity of the Combined Company’s common stock.

Although the Cyclerion Board believes that the anticipated increase in the market price of the Combined Company’s common stock resulting from the proposed reverse stock split could encourage interest in its common stock and possibly promote greater liquidity for its shareholders, such liquidity could also be adversely affected by the reduced number of shares outstanding after the reverse stock split. The reduction in the number of outstanding shares may lead to reduced trading and a smaller number of market makers for the Combined Company’s common stock. In addition, the reverse stock split may not result in an increase in the Combined Company’s stock price necessary to satisfy Nasdaq’s initial listing requirements for the Combined Company.

The reverse stock split may lead to a decrease in the Combined Company’s overall market capitalization.

Should the market price of the Combined Company’s common stock decline after the reverse stock split, the percentage decline will be greater, due to the smaller number of shares outstanding, than it would have been prior to the reverse stock split. A reverse stock split is often viewed negatively by the market and, consequently, can lead to a decrease in the Combined Company’s overall market capitalization. If the per share market price does not increase in proportion to the reverse stock split ratio, then the value of the Combined Company, as measured by its stock capitalization, will be reduced. In some cases, the per-share stock price of companies that have effected reverse stock splits subsequently declined back to pre-reverse split levels, and accordingly, it cannot be assured that the total market value of the Combined Company’s common stock will remain the same after the reverse stock split is effected, or that the reverse stock split will not have an adverse effect on the Combined Company’s stock price due to the reduced number of shares outstanding after the reverse stock split.

Risks Related to Cyclerion

Unless otherwise indicated or the context otherwise requires, references in this “Risks Related to Cyclerion” section to “Cyclerion,” the “Company,” “we,” “us,” “our” and other similar terms refer to Cyclerion and its subsidiaries.

Risks Related to Our Financial Position and Capital Needs

As we are a biopharmaceutical company with a limited operating history and no products approved for commercial sale, valuing our business and predicting our prospects are challenging.

We are a biopharmaceutical company that was incorporated in 2018. Our business was conducted within Ironwood Pharmaceuticals, Inc. prior to that time, and we had no history as an independent company prior to the completion of the separation which occurred in 2019. Prior to the announcement of the Merger, we were seeking to develop new products for treatment resistant depression. We have also developed a pipeline of sGC stimulators, but we have no products approved for commercial sale, and we have never generated revenue from product sales nor has Tisento or Akebia ever generated product sales from products incorporating our compounds. Our operating activities to date have been limited primarily to organizing and staffing our company, business planning, raising capital, developing our technology, identifying potential product candidates, pursuing partnership opportunities and obtaining licenses we deem necessary for our treatment resistant depression candidate, and conducting early-stage clinical trials for our product candidates. In light of the proposed Merger, we have stopped the development of our product candidates.

To date, we have not obtained marketing approval for any of our product candidates; engaged on our own or through a third party, in commercial scale manufacturing or conducted sales and marketing activities necessary for the successful commercialization of our product candidates. Our short operating history offers limited insight into our prospects for success or even viability. If we continue to progress the development of our product candidates, we expect our operating performance to fluctuate. We will encounter challenges frequently experienced by early-stage biopharmaceutical companies in rapidly evolving fields and we have not yet demonstrated an ability to successfully navigate such challenges. If we do not successfully address the challenges

41

we face or we are not able to complete the proposed Merger, our business, prospects, financial condition and results of operations will be materially harmed.

Our business has incurred significant losses and we anticipate that, if we continue to progress the development of our product candidates, we will continue to incur significant losses for the foreseeable future. We have never generated revenue from product sales and may never be profitable.

Our business has incurred operating losses due to costs incurred in connection with our research and development activities and general and administrative expenses associated with our operations. Our net losses for the years ended December 31, 2025 and 2024 were $3.5 million and $3.1 million, respectively. We expect to incur significant losses for at least the next several years, and for these losses to significantly increase, if we continue our research activities and conduct development of, and seek regulatory approvals for, our product candidates.

Our ability to generate revenue from our current and any potential future product candidates and achieve profitability depends on our ability, alone or with strategic partners, to complete the development of, and obtain the necessary regulatory and essential pricing and reimbursement approvals to commercialize, our product candidates. If we continue to progress the development of our product candidates, we do not know when, if ever, we will generate revenues from sales of our product candidates.

If we continue to progress the development of our product candidates, our expenses would increase beyond expectations if we are required by the FDA, the EMA, or other regulatory agencies, domestic or foreign, to perform clinical and other studies in addition to those that we currently anticipate. Even if one or more of the product candidates that we develop is approved for commercial sale, we may never generate revenue in amounts sufficient to achieve and maintain profitability.

There is substantial doubt about our ability to continue as a going concern. If we are not able to complete the proposed Merger and we continue to progress the development of our product candidates, we will need to raise additional funding in the near term, which may not be available on acceptable terms, if at all, to continue as a going concern and advance our product candidates. Failure to obtain capital when needed may force us to delay, limit or terminate our product development efforts or operations altogether. Raising additional capital would dilute our existing shareholders, restrict our operations or cause us to relinquish valuable rights.

There is substantial doubt regarding our ability to continue as a going concern. As of December 31, 2025, we had unrestricted cash and cash equivalents of approximately $3.2 million. Our management believes that such cash and cash equivalents will not be sufficient to fund our operating expenses and capital requirements until the completion of the Merger. If we are not able to complete the proposed Merger and we continue to progress the development of our product candidates, we will require significant additional funding to advance any of our product candidates beyond the short term and to sustain our operations. In the event that we are unable to raise the capital necessary, we may need to curtail our operations or cease operations altogether. Because there is substantial doubt about our ability to continue as a going concern for a reasonable period of time, an investment in our common stock is highly speculative and holders of our common stock could suffer a total loss of their investment.

We may also seek to raise such capital through public or private financing of our securities, royalty financing or debt financing. Raising funds in the current economic environment is, and may in the future, continue to be challenging, and such financing may not be available in sufficient amounts or on acceptable terms, if at all. The terms of any financing may harm existing shareholders. The issuance of additional securities, whether equity or debt, or the possibility of such issuance, may cause the market price of our shares to decline. The sale of additional equity or convertible securities would dilute the ownership of existing shareholders.

If we sell shares or other equity securities in one or more other transactions, or issue stock, stock options or other securities pursuant to our current equity plans, investors may be materially diluted by such subsequent

42

issuances. We will need significant additional capital in the near term to continue our current plans. No assurance can be given that we will be able to obtain such funds upon favorable terms and conditions, if at all. Failure to do so could have a material adverse effect on our business. To the extent we raise additional capital by issuing equity securities, our stockholders would likely experience substantial dilution. We may sell common stock, preferred stock, convertible securities or other equity or convertible securities in one or more transactions that may include voting rights (including the right to vote as a series on particular matters), preferences as to dividends and liquidation, antidilution, and conversion and redemption rights, subject to applicable law, and at prices and in a manner we determine from time to time. Such issuances and the exercise of any convertible securities will dilute the percentage ownership of our stockholders and may affect the value of our capital stock and could adversely affect the rights of the holders of such stock, thereby reducing the value of such stock. Moreover, any exercise of convertible securities may adversely affect the terms upon which we will be able to obtain additional equity capital, since the holders of such convertible securities can be expected to exercise them at a time when we would, in all likelihood, not be able to obtain any needed capital on terms more favorable to us than those provided in such convertible securities.

Incurring debt, if available, would result in increased fixed payment obligations, and we may agree to restrictive covenants, such as limitations on our ability to incur additional debt or limitations on our ability to acquire, sell or license intellectual property rights that could impede our ability to conduct our business. In the event we are unable to raise financing, we may need to reduce or cease operations.

If we continue to progress the development of our product candidates, we also intend to seek funds through collaborations, strategic alliances, or licensing arrangements with third parties. Such agreements may adversely impact retained rights to our assets, technologies, future revenue streams and programs, especially those that receive regulatory approval.

Risks Related to Development and Clinical Testing of Our Products and Product Candidates

If we continue to progress the development of our product candidates, our approach to the discovery and development of product candidates for the treatment of serious diseases may never lead to marketable products.

The development of drug therapies presents unique challenges, including an imperfect understanding of the biology, a frequent lack of translatability of nonclinical study results in subsequent clinical trials and dose selection, and the product candidate having an effect that may be too small to be detected using the outcome measures selected in clinical trials or if the outcomes measured do not reach statistical significance. If we are unable to complete the proposed Merger and continue to progress the development of our product candidates, our future success would be highly dependent on the successful development of our technology and our current and any potential future product candidates. The scientific evidence to support the feasibility of developing our current product candidates is both preliminary and limited. If we continue to progress the development of our product candidates but do not successfully develop and commercialize product candidates, we will not become profitable and the value of our common stock may decline.

Research and development of biopharmaceutical products is inherently risky. If we continue to progress development of our product candidates, we may encounter substantial delays in our activities, including our planned clinical studies, or we may fail to demonstrate safety and efficacy to the satisfaction of applicable regulatory authorities in the development of products to treat patients with serious diseases.

If we continue to progress development of our product candidates, our business will depend heavily on the successful development, clinical testing, regulatory approvals and commercialization of our lead product candidate for treatment resistant depression, praliciguat (out-licensed to Akebia), any potential future out-licensing of olinciguat, and any future potential product candidates we may acquire or license as well as both the product candidates we have sold to Tisento (the “Transferred Assets”). Any of our current or potential product candidates will require regulatory approval.

43

Before obtaining regulatory approvals for the commercial sale of any of our product candidates, we must demonstrate through lengthy, complex and expensive nonclinical and clinical studies that our product candidates are both safe and effective for use in each target indication. Each product candidate must demonstrate an adequate benefit-risk profile for its intended use in its intended patient population. In some instances, significant variability in safety or efficacy appear in different clinical studies of the same product candidate due to numerous factors, including changes in study protocols, differences in the number and characteristics of the enrolled study participants, variations in the dosing regimen and other clinical study parameters or the dropout rate among study participants. Product candidates in later stages of clinical studies often fail to demonstrate adequate safety and efficacy despite promising nonclinical testing and early clinical studies. Companies in the biopharmaceutical industry often suffer significant setbacks in both early and later-stage clinical studies as most product candidates that begin clinical studies are never approved for commercialization by regulatory authorities. Favorable results in earlier stage trials may not be replicated in later stage trials. If we continue to progress the development of our product candidates and fail to produce positive results in our clinical trials, the development timeline, regulatory approval and commercialization prospects of our assets and, correspondingly, our business and financial prospects, would be materially adversely affected.

In the event of difficulties in enrolling participants in any clinical studies conducted on our product candidates, those clinical trials could be delayed or prevented from proceeding.

Identifying and qualifying participants to participate in any clinical studies of our product candidates would be critical to the success of those clinical trials. The timing of any clinical studies will depend in part on the speed at which participants can be recruited to participate in testing these product candidates. Estimates of the prevalence of target indications may vary considerably. Determining the incidence of these conditions, including in specific geographies or demographic groups, would be challenging. The lower the actual prevalence of these conditions, the more challenges would be encountered enrolling participants in those clinical studies, which could delay development of those product candidates. Clinical trial enrollment may also encounter difficulties for a variety of other reasons. The number of participants eligible for a clinical trial may be substantially limited by stringent eligibility criteria in a study protocol, such as the inclusion of biomarker-driven identification or other highly specific criteria related to stage of disease progression or to specific patient reported outcome measures. The number of participants required to power the statistical analysis of the study’s endpoints may be very large leading to an extended enrollment period. Issues such as the proximity of participants to a study site, the complexity of the study design, the ability to recruit investigators with appropriate skill and experience, competing clinical studies for similar therapies or targeting similar participants, perceptions of the benefit-risk profile of the product candidate relative to other available therapies or product candidates, and ability to obtain and maintain institutional review board (“IRB”), or ethics committee (“EC”) approvals and participant consents all could have a substantial impact on the timing of clinical trial enrollment. If sufficient participants cannot be enrolled in clinical studies in a timely way, obtaining study results would be delayed, which may harm our business, prospects, financial condition and results of operations.

The regulatory approval processes of the FDA and comparable foreign regulatory authorities are lengthy, time-consuming and inherently unpredictable. If we, assuming we continue to progress the development of our product candidates, or Tisento, Akebia or any other future licensees, as applicable, are ultimately unable to obtain regulatory approval for the product candidates, we will be unable to generate product revenue and our business will be substantially harmed.

A product candidate cannot be commercialized until the appropriate regulatory authorities have reviewed and approved the product candidate. The time required to obtain approval by the FDA and comparable foreign regulatory authorities is unpredictable, typically takes many years following the commencement of clinical studies and depends upon numerous factors, including the type and complexity of the product candidates involved. Regulatory authorities have substantial discretion in the approval process and may refuse to accept an application for review or may decide that data are insufficient for approval and require additional nonclinical, clinical, or other information (e.g., product quality data or manufacturing controls). No regulatory approval for

44

any of our product candidates we own, licensed to Akebia or sold to Tisento has been requested or obtained, and it is possible that none of these existing product candidates or any product candidates we, if we continue to progress the development of our product candidates, or our licensees or Tisento may seek to develop in the future will ever obtain regulatory approval.

Any ongoing clinical studies may not be completed on schedule, and any planned clinical studies may not begin on schedule, if at all. The completion or commencement of clinical studies can be delayed or prevented for a number of reasons, including, among others:

Clinical studies may also be delayed or terminated as a result of ambiguous or negative interim results. In addition, a clinical study may be suspended or terminated by us, our licensees, Tisento, the FDA or other

45

comparable authorities, the IRBs or ECs overseeing a clinical study, a data and safety monitoring board overseeing the clinical study, or other regulatory authorities due to a number of factors, including, among others:

If we continue to progress the development of our product candidates, our product candidates may cause side effects or adverse events that are presented in the product labeling approved by regulatory authorities. Some may result in label restrictions.

If we continue to progress the development of our product candidates, our current and any potential future product candidates may cause serious side effects which could cause us, our licensees, Tisento, or regulatory authorities to interrupt, delay or halt clinical studies and could result in restrictive label language or delay or denial of regulatory approval.

If we continue to progress the development of our product candidates, changes in regulatory requirements, FDA guidance or unanticipated events during nonclinical studies and clinical studies of our product candidates, which may result in changes to nonclinical or clinical study protocols or additional nonclinical or clinical study requirements, which could result in increased costs and could delay development timelines.

If we continue to progress the development of our product candidates, changes in regulatory requirements, FDA guidance or unanticipated events during nonclinical studies and clinical studies may force amendment to nonclinical studies and clinical study protocols or the FDA may impose additional nonclinical studies and clinical study requirements. Amendments or changes to clinical study protocols would require resubmission to the FDA and IRBs for review and approval, which may increase the cost or delay the timing or successful completion of clinical studies. Similarly, amendments to nonclinical studies may increase the cost or delay the timing or successful completion of those nonclinical studies. In the event of delays in completing, or the termination of, any of nonclinical or clinical studies, or if it is required that additional nonclinical or clinical studies be conducted, the commercial prospects for product candidates may be harmed and our ability to generate product revenue will be delayed for those product candidates we retain our out-license or to realize value in our equity position in Tisento.

If we continue to progress the development of our product candidates, obtaining and maintaining regulatory approval of product candidates in one jurisdiction does not mean that there will be success in obtaining regulatory approval of our product candidates in other jurisdictions.

In order to market any product outside of the United States, compliance with the numerous and varying safety, efficacy and other regulatory requirements of other countries is required. If we continue to progress the development of our product candidates, obtaining and maintaining regulatory approval of product candidates in one jurisdiction does not guarantee that obtaining or maintaining regulatory approval in any other jurisdiction will be possible, but a failure or delay in obtaining regulatory approval in one jurisdiction may have a negative effect on the regulatory approval process in others. For example, even if the FDA or other comparable foreign regulatory authority grants marketing approval of a product candidate, comparable regulatory authorities in

46

foreign jurisdictions must also approve the manufacturing, marketing and promotion of the product candidate in those countries. Approval procedures vary among jurisdictions and can involve requirements and administrative review periods different from those in the United States, including additional nonclinical or clinical studies, as studies conducted in one jurisdiction may not be accepted by regulatory authorities in other jurisdictions. The marketing approval processes in other countries may implicate all of the risks detailed above regarding FDA approval in the United States, as well as other risks. In many jurisdictions outside the United States, a product candidate must be approved for reimbursement before it can be approved for sale in that jurisdiction. In some cases, the price intended to be charged for a product candidate is also subject to approval.

Obtaining foreign regulatory approvals and compliance with foreign regulatory requirements could result in significant delays, difficulties and costs and could delay or prevent the introduction of product candidates in certain countries. Failure to obtain marketing approval in other countries or any delay or other setback in obtaining such approval would impair the ability to market product candidates in such countries. Any such impairment would reduce the size of the potential market, which could have a material adverse impact on our business, prospects, financial condition and results of operations.

If we continue to progress the development of our product candidates, data/market exclusivity may be more limited than we expect based upon the competitive landscape and other factors outside of our control that may occur during development or after approval.

If we continue to progress the development of our product candidates, there are many types of data/market exclusivity mechanisms that we or our licensees may seek to secure for our product candidates. Many of these have risk of loss of exclusivity if the competitive landscape changes or regulations are revised. If we, our licensees or Tisento seek and are awarded orphan drug designation in the US and/or the EU based upon criteria in effect at the time, this designation may be rescinded if a similar drug or another therapy that confers a significant benefit over these product candidates is subsequently approved. If these product candidates were to fail to obtain orphan drug status, or lose such status after it is obtained, or the marketing exclusivity that such status provides, our business, prospects, financial condition and results of operations could be materially harmed. There are other types of data/market exclusivity rights granted after approval that may not confer exclusivity anticipated if the competitive landscape changes and our business, prospects, financial condition and results of operations could be materially harmed.

Risks Related to Reliance on Licensees, Tisento and Other Third Parties

If we continue to progress the development of our product candidates, we may not succeed in our pursuit of capital, capabilities, and transactions for the development and commercialization of our future clinical stage assets, which would affect our financial condition. 

If we continue to progress the development of our product candidates, we will seek capital, capabilities, and transactions to advance the development of our product candidate for treatment resistant depression and other product candidates we may acquire rights to in the future. There can be no assurance that this process will result in any effective negotiations toward, reaching terms of, executing agreements relating to, or completing any transaction or that any such transaction will be successful. Failure to complete any of the foregoing efforts would materially adversely affect our business, prospects, financial condition and results of operations.

Akebia may not be successful in developing any therapies through the praliciguat out-license and we may not realize any future revenue from the out-license.

On June 3, 2021, we entered into the Akebia License Agreement relating to the exclusive worldwide license to Akebia of our rights to the development, manufacture, medical affairs and commercialization of pharmaceutical products containing the pharmaceutical compound praliciguat and other related products and forms thereof enumerated in such agreement. Under the agreement, Akebia is responsible for all research,

47

development, regulatory, and commercialization activities for certain products. On December 13, 2024, we and Akebia entered into Amendment #1 to License Agreement (the “2024 Amendment”) to the original Akebia License Agreement. Under the terms of the 2024 Amendment, Akebia paid the Company (i) $1.25 million in December 2024 and an additional $0.5 million in September 2025. In addition, Akebia has agreed to assume control of the preparation, filing, prosecution and maintenance of certain Cyclerion patents, and the expenses associated therewith, at an earlier date than as originally agreed between the parties. The parties have agreed to the reduction of certain development milestones and the increase of certain royalty rates on net sales and sublicense income. Pursuant to the terms of the Akebia License Agreement, as amended, Akebia will pay Cyclerion tiered royalties ranging from mid-single digit to twenty percent of net sales. Cyclerion’s obligations to deliver certain drug products have also ceased. The agreement may be terminated by either party in the event of a material breach by the other party or by us in the event of certain patent disputes. There can be no assurances that the agreement will result in any therapies or that it will not be terminated prior to the realization by us of any remaining eligible revenues or that Akebia will be able to successfully bring any of the licensed product candidates to market due to financial limitations or other business factors in the future or if Akebia is unable to raise additional capital on favorable terms, if at all. Akebia may at any time terminate the Akebia License Agreement upon 180 days written notice, subject to Akebia’s obligation to grant Cyclerion a non-exclusive, royalty-free license, with the right to grant multiple tiers of sublicenses, to certain licensed compounds or products as defined in the Akebia License Agreement as well as certain rights to regulatory submissions, product trademarks, contracts with third party suppliers and certain other rights.

Tisento may not be successful in developing any therapies and we may not realize any future value from the Tisento common stock we received under the Asset Purchase Agreement with Tisento.

Our investment in Tisento is subject to all of the risks associated with an earlier stage biotechnology company. The pharmaceutical and biotechnology industries are characterized by rapidly advancing technologies, intense competition and a strong emphasis on proprietary products. While we believe that Tisento’s technology, development experience and scientific knowledge provide it with competitive advantages, it may face potential competition from many different sources, including large pharmaceutical and biotechnology companies, academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection and establish collaborative arrangements for the research, development, manufacturing and commercialization of similar products. Any investigational products that Tisento may successfully develop and commercialize will compete with new immunotherapies that may become available in the future. As a result, our investment in Tisento is risky and our equity interest in Tisento could be significantly diluted in the future if Tisento seeks to raise additional capital or is unable to raise additional capital on favorable terms, if at all. If Tisento suffers adverse effects, it may not be able to continue as a going business concern, and we may lose our entire investment. Tisento is a privately-held company and there is no public market for its securities. As a result, it may be difficult to sell any of our securities position in Tisento in the near term, if at all.

We lack operational control over Tisento.

Our investment in Tisento represents a minority or passive stake and we may have little to no participation, input or control over the management, policies, and operations of Tisento. Further, we may lack sufficient ownership of voting securities to impact, without the vote of additional equity holders, any matters submitted to stockholders or members of such business for a vote. There is inherent risk in making minority equity investments in companies over which we have little to no control. Without control of the management and decision-making of these businesses, we cannot control their direction, strategy, policies and business plans, and we may be powerless to improve any declines in their performance, operating results and financial condition.

48

If we continue to progress the development of our product candidates, any collaboration or license arrangements that we enter into in the future may not be successful, which could impede our ability to develop and commercialize our product candidates.

If we continue to progress the development of our product candidates, we may seek additional collaboration or license arrangements for the commercialization, and/or potentially for the development, of certain of our product candidates depending on the merits of retaining commercialization rights for ourselves as compared to entering into collaboration or license arrangements. We face significant challenges in seeking appropriate partners. Moreover, collaboration and license arrangements are complex and time-consuming to negotiate, document, implement and maintain. We may not be successful in our efforts to establish and implement such arrangements. The terms of any collaborations, licenses or other arrangements that we may establish may not be favorable to us.

If we continue to progress the development of our product candidates, any future collaboration or license arrangements that we enter into may not be successful. The success of such arrangements will depend heavily on the efforts and activities of our partners. Collaboration and license arrangements are subject to numerous risks, including that:

If we continue to progress the development of our product candidates, we expect in the future to rely on third parties to conduct any nonclinical or clinical studies for any existing or potential future product candidates. If these third parties do not successfully carry out their contractual duties or meet expected deadlines, necessary regulatory approvals for or commercialization of any potential future product candidates may not be obtainable and our business could be substantially harmed.

We do not have the infrastructure or internal resources and capabilities to independently conduct nonclinical or clinical studies. If we continue to progress the development of our product candidates, we expect to rely on contract laboratories, medical institutions, clinical investigators, licensees and other third parties, such as CROs, to conduct nonclinical studies on any future discovery compounds and product candidates and clinical studies on product candidates. We expect to rely heavily on such parties for execution of nonclinical and clinical studies and as a result that we will only be able to control certain aspects of their activities. As a result, if we continue to

49

progress the development of our product candidates, we expect we will have limited direct control over the conduct, timing and completion of our nonclinical and clinical studies and the management of data developed through these studies. Communicating with outside parties can also be challenging, potentially leading to mistakes as well as difficulties in coordinating activities. Outside parties may have staffing difficulties, fail to comply with contractual obligations, experience regulatory compliance issues, undergo changes in priorities, become financially distressed or form relationships with other entities, some of which may be our competitors.

These factors may materially impede the willingness or ability of third parties to complete quality nonclinical and clinical studies and may subject us to unexpected cost increases that are beyond our control. Nevertheless, we may be responsible for ensuring that each of any future nonclinical and clinical studies is conducted in accordance with any applicable protocol, legal, regulatory and scientific requirements and standards, and our reliance on CROs and other third parties does not necessarily relieve us of our regulatory responsibilities. We, and any future CROs and other third parties are required to comply with regulations and guidelines, such as good laboratory practices (“GLPs”), good clinical practices (“GCPs”), and current Good Manufacturing Practices. These regulations are enforced by the FDA and comparable foreign regulatory authorities for any products in clinical development. The FDA enforces compliance to regulations through periodic inspections of clinical study sponsors, principal investigators, and third parties. If the FDA determines there was a failure to comply with the regulations, the clinical data generated in any clinical studies may be deemed unreliable and the FDA or comparable foreign regulatory authorities may require the performance of additional clinical studies before approving any marketing applications. We cannot assure you that, upon inspection, the FDA will determine that any potential future nonclinical studies, clinical studies or product manufacturing will comply with these regulations. Our failure or the failure of our CROs or other third parties to comply with these regulations may require the repeat of those clinical studies, which would delay the regulatory approval process and could also result in enforcement action up to and including civil and criminal penalties.

Although we or our current licensee or any future licensees may design or approve the designs of our product candidate clinical studies, CROs and other third parties conduct those clinical studies. As a result, if we continue to progress the development of our product candidates many important aspects of the execution of the development programs for our product candidates may be outside of our direct control. In addition, the CROs, or other third parties, may not perform all of their obligations under arrangements with us or our licensees or in compliance with regulatory requirements, but we may remain responsible and are subject to enforcement action that may include civil penalties and criminal prosecution for any violations of FDA laws and regulations during the conduct of clinical studies. If we continue to progress the development of our product candidates and the CROs, or our licensees, do not perform clinical studies in a satisfactory manner, breach their obligations to us or fail to comply with regulatory requirements, the development and commercialization of our product candidates may be delayed, or our development program materially and irreversibly harmed. We may not be able to control the amount and timing of resources these CROs or our licensees devote to our clinical products.

If any relationships with these third-party CROs terminate, arrangements with alternative CROs may not be achievable. If CROs do not successfully carry out their contractual duties or obligations or meet expected deadlines, if they need to be replaced, or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to required clinical protocols, regulatory requirements or for other reasons, any clinical studies such CROs are associated with may be extended, delayed or terminated, and required regulatory approval for or successful commercialization of our product candidates may not be obtainable. As a result, we believe that our financial results and the commercial prospects for our product candidates in the approved indication would be harmed, our costs could increase and our ability to generate revenue could be delayed or lost.

50

If we continue to progress the development of our product candidates then except as out-licensed, we must rely completely on third-party suppliers to manufacture any nonclinical and clinical drug supplies for our product candidates, and we intend to rely on third parties to produce commercial supplies of any product candidates that are approved.

We do not currently have, nor do we plan to acquire, the infrastructure or capability to internally manufacture the drug supply of our current or any potential future product candidates, for use in the conduct of our nonclinical and clinical studies. We lack the internal resources and the capability to manufacture any product candidates on any scale. If we continue to progress the development of our product candidates, we expect to depend on third-party contract manufacturing organizations, or CMOs, for all our requirements of raw materials, drug substances and drug product for any future nonclinical studies and clinical trials. We do not have long-term supply agreements in place with any CMO and we expect that any potential future product candidates will be individually contracted under a services agreement on a purchase order basis. If we continue to progress the development of our product candidates, we expect to rely on CMOs for the supply of later-stage development and commercialization, as well as for the supply of any other discovery compounds or product candidates that we may identify, and we may not be able to enter into long-term supply agreements with such CMOs on favorable terms. As a further result, we are subject to price fluctuations for any clinical drug supplies. If the prices charged by these CMOs increase, our business, prospects, financial condition and results of operations could be materially harmed. We expect in the future to apply industry risk management practices to minimize the impact to nonclinical and clinical timelines associated with delays to our clinical supplies. However, these delays could still lead to clinical trials delays that could adversely impact our business.

In addition, any facilities which may be used by contract manufacturers to manufacture the active pharmaceutical ingredient and final drug product must complete a pre-approval inspection by the FDA and other comparable foreign regulatory agencies to assess compliance with applicable requirements, including current GMP, after we submit our new drug application, or NDA, or relevant foreign regulatory submission to the applicable regulatory agency. If the FDA or an applicable foreign regulatory agency determines now or in the future that these facilities are noncompliant, we may need to find alternative manufacturing facilities, which would impede our ability to develop, obtain regulatory approval for or market our product candidates.

Our anticipated reliance on third parties if we continue to progress the development of our product candidates requires us to share our confidential information, including trade secrets and know-how, which increases the possibility that our confidential information will be misappropriated or disclosed.

Because we will seek to involve third party licensees and collaborators on potential future product candidates if we continue to progress the development of our product candidates, we expect we will rely on third parties to manufacture our product candidates, and because we expect to collaborate with various CROs and other third parties to conduct our nonclinical studies and clinical trials, we must, at times, share our trade secrets or know-how with them. We seek to protect our confidential information, including know-how and trade secrets, in part by entering into confidentiality agreements and, if applicable, material transfer agreements, collaborative research agreements, consulting agreements or other similar agreements with our collaborators, advisors and consultants prior to beginning our collaborations or disclosing confidential information to such parties. These agreements typically limit the rights of the third parties to use or disclose our confidential information, such as trade secrets and know-how. Despite these contractual provisions, the need to share our confidential information with third parties increases the risk that confidential information such as trade secrets and know-how becomes known by our competitors, is inadvertently incorporated into the technology of others, or is disclosed or used in violation of these agreements. Given that our proprietary position is based, in part, on our confidential information including know-how and trade secrets, a competitor’s discovery of our confidential information or other unauthorized use or disclosure could impair our competitive position and may have a material adverse effect on our business, prospects, financial condition and results of operations.

51

Risks Related to Our Intellectual Property Rights

If we or our licensors, licensees or Tisento are unable to adequately protect proprietary technologies, or obtain and maintain issued patents that are sufficient to protect their respective product candidates, others could compete against us, our licensees and Tisento more directly, which would have a material adverse impact on our business, prospects, financial condition and results of operations.

Our success will depend in part on our licensors, licensees and Tisento’s ability to obtain and maintain patent and other proprietary protection in the United States and other countries for commercially important technology, inventions and know-how related to our business, defend and enforce patents, should they issue, preserve the confidentiality of trade secrets and operate without infringing the valid and enforceable patents and proprietary rights of third parties. We strive to protect and enhance the proprietary technologies that we believe are important to our business, including seeking patents intended to cover our product candidates and compositions, their methods of use and any other inventions that are important to the development of our business.

We have 22 issued U.S. patents, 12 pending U.S. patents applications and numerous foreign patents and pending patent applications. Patent families are filed either as utility U.S. patents or under an international patent law treaty (PCT) that provides a unified procedure for filing a single initial patent application to seek patent protection for an invention simultaneously in each of the 158 contracting states, followed by the process of entering national phase, which requires a separate application in each of the member states in which national patent protection is sought. We also rely on patents issued to licensors providing patent licenses for our treatment resistant depression candidate.

See “Cyclerion’s Business — Intellectual Property.” We also rely on trade secrets to protect aspects of our business that are not amenable to, or that we do not consider appropriate for, patent protection.

The patent positions of biotechnology and pharmaceutical companies, including ours, involve complex legal and factual questions, which in recent years have been the subject of much litigation, and, therefore, the issuance, scope, validity, enforceability and commercial value of any patent claims that we may obtain cannot be predicted with certainty. Patent applications may not be granted as issued patents in any particular jurisdiction and, even if they do, these patents may not include claims with a sufficient scope to protect our product candidates or otherwise provide any competitive advantage.

Even if patent applications are issued, competitors and other third parties may infringe, misappropriate or otherwise violate patents and other intellectual property rights. We may not be able to prevent infringement, misappropriation or other violations of intellectual property rights, particularly in countries where the laws may not protect those rights as fully as in the United States. To counter infringement or unauthorized use, filing infringement claims may be required, which can be expensive and time-consuming and divert the attention of management and key personnel from business operations.

Moreover, patents, if issued, may be challenged, deemed unenforceable, invalidated or circumvented in the United States and abroad. U.S. patents and patent applications may also be subject to interference, derivation, ex-parte re-examination, post-grant review, or inter-partes review proceedings, supplemental examination and challenges in district or other courts. Interference proceedings provoked by third parties or brought by us or our licensees may be necessary to determine the priority of inventions with respect to patents or patent applications. An unfavorable outcome could require ceasing the use of the related technology or to attempt to license rights to it from the prevailing party. Our business could be harmed if the prevailing party does not offer a license on commercially reasonable terms. Involvement in litigation or interference proceedings may fail and, even if successful, may result in substantial costs, and distract management and other employees. Furthermore, an adverse decision in an interference or derivation proceeding can result in a third party receiving the sought-out patent right, which in turn could affect the ability to develop, market or otherwise commercialize our product candidates.

52

Patents may also be subjected to opposition, post-grant review or comparable proceedings lodged in various foreign, both national and regional, patent offices or courts. Such proceedings could result in revocation or amendment of patents in such a way that they no longer cover our product candidates or competitive products. In addition, such proceedings may be costly. Thus, any patents, should they issue, may not provide any protection against competitors.

Furthermore, though a patent, if it were to issue, is presumed valid and enforceable, its issuance is not conclusive as to its validity or its enforceability and it may not provide adequate protection to exclude competitors from making similar products. Even if a patent issues and is held to be valid and enforceable, competitors may be able to design around or circumvent our patents, such as by using pre-existing or newly developed technology or products in a non-infringing manner. If these developments were to occur, they could have a material adverse effect on our business, prospects, financial condition and results of operations.

Any litigation to enforce or defend patent rights, even if successful, would be costly and time-consuming and would divert the attention of management and key personnel from business operations. We may not prevail in any lawsuits that we initiate, and the damages or other remedies awarded if we were to prevail may not be commercially meaningful.

In addition, proceedings to enforce or defend any patents, if and when issued, put those patents at risk of being invalidated, held unenforceable or not infringed, or interpreted narrowly. Such proceedings could also provoke third parties to assert counterclaims, including that some or all of the claims in one or more patents are invalid, not infringed or unenforceable. Grounds for a validity challenge include alleged failures to meet any of several statutory requirements, including lack of novelty, obviousness or non-enablement. Grounds for unenforceability assertions of a patent include allegations that someone connected with prosecution of the patent application that matured into the patent withheld relevant information from the U.S. Patent and Trademark Office, or the USPTO, or made a misleading statement, during prosecution of the patent application. In an infringement proceeding, a court may disagree with allegations and refuse to stop the other party from using the technology at issue on the grounds that patents do not cover the technology in question or may decide that a patent is invalid or unenforceable. An adverse result in any litigation, defense or post-grant proceedings could result in one or more patents being invalidated or interpreted narrowly. Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation, there is a risk that some confidential information could be compromised by disclosure during this type of litigation. There could also be public announcements of the results of hearings, motions or other interim proceedings or developments. If securities analysts or investors perceive these results to be negative, it would have a material adverse effect on the price of our common stock.

The outcome following legal assertions of invalidity and unenforceability is unpredictable. With respect to validity, for example, there cannot be certainty that there is no invalidating prior art, of which we, our licensees and the patent examiner were unaware during prosecution. If a defendant were to prevail on a legal assertion of invalidity and/or unenforceability, at least part, and perhaps all, of the patent protection on our product candidates could be lost.

If any patents, if and when issued, covering our product candidates are invalidated or found not infringed or unenforceable, our business, prospects, financial condition and results of operations could be materially harmed.

We may infringe the intellectual property rights of others, which may prevent or delay our product development efforts and stop us from commercializing or increase the costs of commercializing our product candidates, if approved.

Our success will depend in part on our ability to operate without infringing, misappropriating or otherwise violating the intellectual property and proprietary rights of third parties. Other parties may allege that our product candidates or the use of our technologies or technologies licensed by us infringe or otherwise violate patent

53

claims or other intellectual property rights held by them or that we are employing their proprietary technology without authorization. There may be third-party patents or patent applications with claims to compositions, materials, formulations, methods of manufacture or methods for treatment related to our product candidates. Because patent applications can take many years to issue, third parties may have currently pending patent applications which may later result in issued patents that our product candidates may infringe, or which such third parties claim are infringed by our technologies.

The pharmaceutical industry is characterized by extensive litigation regarding patents and other intellectual property rights. Patent and other types of intellectual property litigation can involve complex factual and legal questions, and their outcome is uncertain and cannot be adequately quantified in advance. The coverage of patents is subject to interpretation by the courts, and the interpretation is not always uniform. If we are sued for patent infringement, we would need to demonstrate that our product candidates, products or methods either does not infringe the patent claims of the relevant patent or that the patent claims are invalid or unenforceable, and we may not be able to do this. Even if we are successful in these proceedings, we may incur substantial costs and the time and attention of our management and scientific personnel could be diverted in pursuing these proceedings, which could have a material adverse effect on our business and operating results. In addition, we may not have sufficient resources to bring these actions to a successful conclusion.

If we are unable to avoid infringing the patent rights of others, we may be required to seek a license, defend an infringement action or challenge the validity of the patents in court, or redesign our product candidates. In addition, if any such claim were successfully asserted against us and we could not obtain such a license, we may be forced to stop or delay developing, manufacturing, selling or otherwise commercializing our product candidates. Any claim relating to intellectual property infringement that is successfully asserted against us may require us to pay substantial damages, including treble damages and attorneys’ fees if we are found to be willfully infringing another party’s patents, for past use of the asserted intellectual property and royalties and other consideration going forward if we are forced to take a license.

Any of these risks coming to fruition could have a material adverse effect on our business, prospects, financial condition and results of operations.

We may be subject to claims challenging the inventorship or ownership of our patents and other intellectual property we own or license from third parties.

Our employee, consultants, non-academic outside scientific collaborators and other advisors enter into confidentiality and intellectual property assignment agreements with us or have entered into confidentiality and intellectual property assignment agreements with Ironwood or third parties licensing intellectual property to us. We seek to have inventions assigned to us by the parties rendering services whenever possible. Our in-bound licenses seek to insure that all of the intellectual property licensed to us is owned by the licensor. However, we may not be able to enter into these agreements with all parties (for example with academic collaborators) or these agreements may not be honored and may not effectively assign intellectual property rights to us.

Litigation may be necessary to defend against these and other claims challenging inventorship or ownership. If we fail in defending any such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights, such as exclusive ownership of, or right to use, valuable intellectual property, or we may have to in-license intellectual property owned by another party. Such an outcome could have a material adverse effect on our business. Even if we are successful in defending against such claims, litigation could result in substantial costs and be a distraction to management and other employees.

Obtaining and maintaining patent protection depends on compliance with various procedural, document submission, fee payment and other requirements imposed by governmental patent agencies and patent protection could be reduced or eliminated for non-compliance with these requirements.

The USPTO and various foreign governmental patent agencies require compliance with a number of procedural, documentary, fee payment and other similar provisions over the lifetime of owned patents and

54

applications For in-bound licensed intellectual property rights, failure to maintain compliance with such requirements would adversely impact our rights as regards those patents and applications. In some cases, an inadvertent lapse can be cured by payment of a late fee or by other means in accordance with the applicable rules. However, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. In such an event, competitors or other third parties might be able to enter the market earlier than would otherwise have been the case and this circumstance could have a material adverse effect on our business, prospects, financial condition and results of operations.

We and our licensees and Tisento may not seek to protect our intellectual property rights in all jurisdictions throughout the world and we may not be able to adequately enforce our intellectual property rights even in the jurisdictions where we seek protection.

The statutory deadlines for pursuing patent protection in individual foreign jurisdictions are based on the priority date of each of our patent applications and we may not timely file foreign patent applications. Thus, for each of the patent families that are believed to provide coverage for our product candidates, we, and our licensees, will need to decide whether and where to pursue protection outside the United States. Filing and prosecuting patent applications and defending patents on product candidates in all countries and jurisdictions throughout the world would be prohibitively expensive, and so it is unlikely to pursue and maintain patents in all countries worldwide. As such, competitors may use technologies in jurisdictions where patent protection is not pursued and obtained to develop their own products.

The laws of some foreign countries may not protect intellectual property rights to the same extent as the laws of the United States. Consequently, it may not be possible to prevent third parties from practicing our inventions in all countries outside the United States even if there is a patent in that jurisdiction. Further, a competitor may export otherwise infringing products to territories where patent protection exists, but enforcement is not as strong as that in the United States. These products may compete with our product candidates and patents or other intellectual property rights may not be effective or sufficient to prevent them from competing. Even pursuing and obtaining issued patents in particular jurisdictions, patent claims or other intellectual property rights may not be effective or sufficient to prevent third parties from so competing.

Many companies have encountered significant problems in protecting and defending intellectual property rights in certain foreign jurisdictions. The legal systems of some countries, particularly developing countries, do not favor the enforcement of patents and other intellectual property protection, especially those relating to biotechnology or pharmaceuticals. This could make it difficult to stop the infringement of patents, if obtained, or the misappropriation of or marketing of competing products in violation of other intellectual property rights. For example, many foreign countries have compulsory licensing laws under which a patent owner must grant licenses to third parties. In addition, many countries limit the enforceability of patents against third parties, including government agencies or government contractors. In these countries, patents may provide limited or no benefit. Patent protection must ultimately be sought on a country-by-country basis, which is an expensive and time-consuming process with uncertain outcomes. Accordingly, patent protection might not be sought in certain countries, and there will not be a benefit of patent protection in such countries.

Proceedings to enforce patent rights in foreign jurisdictions could result in substantial costs and divert efforts and attention from other aspects of our business, could put patents at risk of being invalidated or interpreted narrowly, could put patent applications at risk of not issuing, and could provoke third parties to assert claims. We, or our licensees, may not prevail in any lawsuits that we initiate, and the damages or other remedies awarded, if any, may not be commercially meaningful. Accordingly, efforts to enforce intellectual property rights around the world may be inadequate to obtain a significant commercial advantage from the intellectual property that developed or licensed.

55

If we, or our licensees, do not obtain additional protection under the Drug Price Competition and Patent Term Restoration Act of 1984, or the Hatch-Waxman Act, and similar foreign legislation by extending the patent terms and obtaining data exclusivity for our product candidates, our business, prospects, financial condition and results of operations may be materially harmed.

Depending upon the timing, duration and specifics of FDA marketing approval of our product candidates, one or more of the U.S. patents owned may be eligible for a limited patent term extension under the Hatch-Waxman Act, which permits a patent term extension as compensation for patent term lost during the FDA regulatory review process. A maximum of five years can be restored to the eligible patent. In all cases, the total patent life for the product with the patent extension cannot exceed 14 years from the product’s approval date, or in other words, 14 years of potential marketing time. However, an extension might not be granted because of, for example, failing to apply within applicable deadlines, failing to apply prior to expiration of relevant patents or otherwise failing to satisfy applicable requirements. Moreover, the applicable time period or the scope of patent protection afforded could be less than we request. If unable to obtain a patent term extension or the term of any such extension is less than we request, the duration of patent protection obtained for our product candidates may not provide any meaningful commercial or competitive advantage, competitors may obtain approval of competing products earlier than they would otherwise be able to do so, and our ability to generate revenues could be harmed.

If we continue to progress the development of our product candidates, changes in U.S. patent law could diminish the value of patents in general, thereby impairing our ability to protect our product candidates.

As is the case with other biotechnology companies, if we continue to progress the development of our product candidates, our success will be heavily dependent on intellectual property, particularly patents. Obtaining and enforcing patents in the biotechnology industry involves both technological and legal complexity, and is therefore costly, time-consuming and inherently uncertain. In addition, the United States has enacted and implemented wide-ranging patent reform legislation: the Leahy-Smith America Invents Act, or the America Invents Act. The America Invents Act includes a number of significant changes to U.S. patent law. These provisions affect the way patent applications will be prosecuted and may also affect patent litigation. It is not yet clear what, if any, impact the America Invents Act will have on the operation of certain elements of our product candidates. However, the America Invents Act and its implementation could increase the uncertainties and costs surrounding the prosecution of our patent applications and the enforcement or defense of any patents that may issue from our patent applications, all of which could have a material adverse effect on our business, prospects, financial condition and results of operations.

In addition to increasing uncertainty with regard to our ability to obtain future patents, this combination of events has created uncertainty with respect to the value of patents once obtained. Depending on these and other decisions by the U.S. Congress, the federal courts and the USPTO, the laws and regulations governing patents could change in unpredictable ways that could weaken our ability to obtain new patents or to enforce any patents that may issue in the future.

We may be subject to damages resulting from claims that we or our employees, consultants or advisors have wrongfully used or disclosed alleged trade secrets of their current or former employers.

Our current employee and any employees we may hire in the future may have been previously employed at other biotechnology or pharmaceutical companies, including our competitors or potential competitors. We also engage and, in the future, intend to engage advisors and consultants who are concurrently employed at universities or who perform services for other entities.

We may be subject to claims that we or our employees, advisors or consultants or third parties from whom we license certain technologies have inadvertently or otherwise used or disclosed intellectual property, including trade secrets or other proprietary information, of a former employer or other third party. We may be subject to

56

claims that an employee, advisor or consultant performed work for us that conflicts with that person’s obligations to a third party, such as an employer, and thus, that the third party has an ownership interest in the intellectual property arising out of work performed for us. Litigation may be necessary to defend against these claims. Even if we are successful in defending against these claims, litigation could result in substantial costs and be a distraction to management. If we fail in defending such claims, in addition to paying monetary damages, we may lose valuable intellectual property rights or personnel. A loss of key personnel or their work product could hamper or prevent our ability to commercialize our product candidates, which would materially harm our commercial development efforts.

Risks Related to the Future Commercialization of Our Current or Potential Future Product Candidates

The incidence and prevalence for target patient populations of our current and any potential future product candidates we may acquire have not been established with precision. If we continue to progress the development of our product candidates and the market opportunities for our current and potential future product candidates are smaller than we estimate, or if any approval that we obtain is based on a narrower definition of the patient population, our revenue and ability to achieve profitability may be harmed.

The incidence and prevalence for all the conditions we aim to address with our current and any potential future programs vary considerably. Projections of both the number of people who have these diseases, as well as the subset of people with these diseases who have the potential to benefit from treatment with our product candidates, are based on beliefs and estimates. These estimates have been derived from a variety of sources, including scientific literature, surveys of clinics, patient foundations or market research, and may prove to be incorrect. Further, new trials may change the estimated incidence or prevalence of these diseases. If we continue to progress the development of our product candidates, the total addressable market across all of our product candidates will ultimately depend upon, among other things, the diagnosis criteria included in the final label for each of our product candidates, if approved for sale for these indications, acceptance by the medical community and patient access, drug pricing and reimbursement. The number of patients in the United States and other major markets and elsewhere may turn out to be lower than expected, patients may not be otherwise amenable to treatment with our product candidates or new patients may become increasingly difficult to identify or gain access to, all of which would harm our results of operations and our business. Further, even if significant market share for our product candidates is obtained, because the potential target populations are very small, we may never achieve profitability despite obtaining such significant market share.

If we continue to progress the development of our product candidates and are unable to establish sales and marketing capabilities or enter into agreements with third parties to sell and market any product candidates, if approved, we may not be successful in commercializing those product candidates if and when they are approved.

We do not currently have an infrastructure for the sale, marketing, market access, patient service and distribution of pharmaceutical products. In order to market our product candidates, if approved by the FDA or any other regulatory authority outside the United States, we must build our sales, marketing, managerial and other non-technical capabilities, or arrange with third parties to perform these services. There are risks involved with both establishing our own commercial capabilities and entering into arrangements with third parties to perform these services. For example, recruiting and training a sales force or reimbursement specialists is expensive and time-consuming and could delay any product candidate launch. If we continue to progress the development of our product candidates and commercialization is delayed or does not occur, we would have prematurely or unnecessarily incurred such expenses. This may be costly, and our investment would be lost if we cannot retain or reposition our commercialization personnel.

If we enter into arrangements with third parties to perform sales, marketing, commercial support and distribution services, any product candidate revenue or the profitability of that revenue may be lower than if we were to market and sell any products we may develop ourselves. In addition, we may fail to enter into

57

arrangements with third parties to commercialize our product candidates or may be unable to do so on terms that are favorable to us. We may have little control over such third parties, and any of them may fail to devote the necessary resources and attention to sell and market our product candidates effectively. If we do not establish commercialization capabilities successfully, either on our own or in collaboration with third parties, or if we are unable to do so on commercially reasonable terms, we will not be successful in commercializing our product candidates if approved and our business, prospects, financial condition and results of operations will be materially harmed.

Even if we continue to progress the development of our product candidates and ultimately obtain regulatory approval for our product candidates, our product candidates may not achieve broad market acceptance by patients, physicians, healthcare payors or others in the medical community, which would limit the revenue that we generate from their sales.

If we continue to progress the development of our product candidates, the future commercial success of our product candidates, if approved by the FDA or other applicable regulatory authorities outside the United States, will depend upon the awareness and acceptance of our product candidates among the medical community, including patients, physicians and healthcare payors. If we continue to progress the development of our product candidates and any of our product candidates are approved but do not achieve an adequate level of acceptance by patients, physicians, healthcare payors and others in the medical community, we may not generate sufficient revenue to become, or remain, profitable. Market acceptance of our product candidates, if approved, will depend on a number of factors, including, among others:

If we continue to progress the development of our product candidates and our product candidates are ultimately approved but do not achieve an adequate level of acceptance by patients, physicians and payors, we may not generate sufficient revenue from our product candidates to become or remain profitable. Before granting reimbursement approval, healthcare payors may require us to demonstrate that our product candidates, in addition to treating these target indications, also provide incremental health benefits to patients. Efforts to educate the medical community and third-party payors about the benefits of our product candidates may require significant resources and may never be successful.

58

Reimbursement may be limited or unavailable in certain market segments for our product candidates, which could make it difficult for us to sell our product candidates profitably, if we continue to progress the development of our product candidates. Price controls may be imposed in certain markets, which may harm our future profitability.

If we continue to progress the development of our product candidates, market acceptance and sales of any approved product candidates will depend significantly on the availability of adequate coverage and reimbursement from third-party payors and government authorities and may be affected by existing and future health care reform measures and cost-cutting measures at the federal and state level currently proposed for Medicaid and other programs. Government authorities and third-party payors, such as private health insurers and health maintenance organizations, decide which drugs they will pay for and establish reimbursement levels. Reimbursement by a third-party payor may depend upon a number of factors, including the third-party payor’s determination that use of a product is: a covered benefit under its health plan; safe, effective and medically necessary; appropriate for the specific patient; cost-effective; and neither experimental nor investigational.

Obtaining coverage and reimbursement approval for a product from a government or other third-party payor is a time consuming and costly process that could require the provision of supporting scientific, clinical and cost-effectiveness data for the use of our product candidates to the payor. We or our partners may not be able to provide data sufficient to gain acceptance with respect to coverage and reimbursement. We cannot be sure that coverage or adequate reimbursement will be available for any of our product candidates. Also, we cannot be sure that reimbursement amounts will not reduce the demand for, or the price of, our product candidates. If reimbursement is not available or is available only to limited levels, we may not be able to commercialize certain of our product candidates. In addition, in the United States, third-party payors are increasingly attempting to contain health care costs by limiting both coverage and the level of reimbursement of new drugs. As a result, if we continue to progress the development of our product candidates significant uncertainty exists as to whether and how much third-party payors will reimburse patients for their use of newly approved drugs, which in turn will put pressure on the pricing of drugs.

In some countries, particularly member states of the European Union, the pricing of prescription drugs is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take considerable time after receipt of marketing approval for a product. In addition, there can be considerable pressure by governments and other stakeholders on prices and reimbursement levels, including as part of cost containment measures. Political, economic and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing used by various European Union member states and parallel distribution, or arbitrage between low-priced and high-priced member states, can further reduce prices. In some countries, we or our partners may be required to conduct a clinical trial or other studies that compare the cost-effectiveness of our product candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If reimbursement of our product candidates is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, our business could be harmed.

If we fail to comply with healthcare and other regulations, we could face substantial penalties and our business, prospects, financial condition and results of operations could be harmed.

Any product candidates that we may evaluate in clinical studies are subject to certain federal and state healthcare laws and regulations that may affect our business. These laws and regulations include:

59

In addition, we may be subject to privacy and security laws in the various jurisdictions in which we operate, obtain or store personally identifiable information. For example, if we conduct clinical studies in any of the member states of the European Union, the processing of personal data in the European Economic Area, or the EEA, is subject to the 1995 Data Protection Directive, imposing strict obligations and restrictions on the ability to collect, analyze and transfer personal data. In May 2018, the General Data Protection Regulation, or the GDPR, took effect, increasing our obligations with respect to clinical studies conducted in the EEA and increasing the scrutiny applied by clinical study sites located in the EEA to transfers of personal data from such sites to countries that are considered by the European Commission to lack an adequate level of data protection, such as the United States. The compliance obligations imposed by the GDPR may increase our cost of doing business. In addition, the GDPR imposes substantial fines for breaches of data protection requirements, and it confers a private right of action on data subjects for breaches of data protection requirements.

If our operations are found to be in violation of any of the laws described above or any other laws, rules or regulations that apply to us, we will be subject to penalties, including civil and criminal penalties, damages, fines and the curtailment or restructuring of our operations. Any penalties, damages, fines, curtailment or restructuring of our operations could impede our ability to operate our business and our financial results. We cannot be certain that compliance programs will address all areas of potential exposure and the risks in this area cannot be entirely eliminated, particularly because the requirements and government interpretations of the requirements in this space are constantly evolving. Any action against us for violation of these laws, rules or regulations, even if we successfully defend against it, could cause us to incur significant legal expenses and divert our management’s attention from the operation of our business, as well as damage our business or reputation. Moreover, achieving and sustaining compliance with applicable federal and state privacy, security, fraud and reporting laws may prove costly.

We face significant competition in an environment of rapid technological and scientific change, and our competitors may achieve regulatory approval before us or develop therapies that are safer, more advanced or more effective than ours, which may harm our ability, or a licensee’s ability, to successfully market or commercialize any product candidates we may develop and ultimately harm our financial condition.

Our future success depends on our ability, or a licensee’s ability, to demonstrate and maintain a competitive advantage with respect to the design, development and commercialization of our product candidates. In many cases, our product candidates that may be commercialized will compete with existing, market-leading products. The development and commercialization of new drug products is highly competitive. We may face competition with respect to any product candidates that are developed or commercialized in the future from major pharmaceutical companies, specialty pharmaceutical companies and biotechnology companies worldwide. Potential competitors also include academic institutions, government agencies and other public and private research organizations that conduct research, seek patent protection and establish collaborative arrangements for research, development, manufacturing, and commercialization.

60

If our product candidates do not obtain regulatory approvals in target indications prior to these or any other competing product candidates, or if our product candidates do not demonstrate superior efficacy, safety or tolerability compared to these and any other approved therapeutics for our target indications, then those product candidates may not be able to compete effectively.

Many of our current or potential competitors, either alone or with their strategic partners, have significantly greater financial resources and expertise in research and development, manufacturing, nonclinical testing, conducting clinical studies, obtaining regulatory approvals and marketing approved products than we do. Mergers and acquisitions in the pharmaceutical and biotechnology industries may result in even more resources being concentrated among a smaller number of our competitors. Our commercial opportunity could be reduced or eliminated if our competitors develop and commercialize products that are safer, more effective, have fewer or less severe side effects, are more convenient or are less expensive than any products that we may develop. Our competitors also may obtain FDA or other regulatory approval for their products more rapidly than we may obtain approval for ours and may obtain orphan product exclusivity from the FDA for indications our product candidates are targeting, which could result in our competitors establishing a strong market position before we are able to enter the market.

In addition, we or our licensees could face litigation or other proceedings with respect to the scope, ownership, validity and/or enforceability of our patents relating to our competitors’ products and our competitors may allege that our product candidates infringe, misappropriate or otherwise violate their intellectual property. The availability of our competitors’ products could limit the demand, and the price that could be charged, for any of our product candidates that may be developed and commercialized. See “-Risks Related to Our Intellectual Property Rights.”

The impact of healthcare reform and other governmental and private payor initiatives, as well as the Inflation Reduction Act of 2022, may harm our business.

Our revenue prospects could be affected by changes in healthcare spending and policy in the United States and abroad. We operate in a highly regulated industry and new laws, regulations or judicial decisions, or new interpretations of existing laws, regulations or decisions, related to health care availability, the method of delivery or payment for health care products and services could harm our business, operations and financial condition. There is significant interest in promoting health care reform, as evidenced by the enactment in the United States of the Patient Protection and Affordable Care Act and the Health Care and Education Reconciliation Act in 2010 and in reducing the costs of certain prescription drugs as evidenced by the Inflation Reduction Act of 2022. It is likely that federal and state legislatures within the United States and foreign governments will continue to consider changes to existing health care legislation. We cannot predict the reform initiatives that may be adopted in the future or whether initiatives that have been adopted will be repealed or modified. The continuing efforts of the government, insurance companies, managed care organizations and other payors of healthcare services to contain or reduce costs of healthcare may adversely affect: the demand for any drug products for which we may obtain regulatory approval; our ability to set a price that we believe is fair for our product candidates; our ability to obtain coverage and reimbursement approval for a product; our ability to generate revenues and achieve or maintain profitability; and the level of taxes that we are required to pay.

If we continue to progress the development of our product candidates, our future growth may depend, in part, on our, or a licensee’s, ability to commercialize any current and potential future product candidates outside the United States, where we would be subject to additional regulatory burdens and other risks and uncertainties.

If we continue to progress the development of our product candidates, our future profitability may depend, in part, on our or a licensee’s ability to commercialize our current and any potential future product candidates outside the United States for which we may rely on partnerships with third parties. If we commercialize our product candidates outside the United States, we would be subject to additional risks and uncertainties, including:

61

Foreign sales of our product candidates could also be harmed by the imposition of governmental controls, political and economic instability, trade restrictions and changes in tariffs.

Our ability to generate meaningful revenues in jurisdictions outside of the United States may be limited due to the strict price controls and reimbursement limitations imposed by governments outside of the United States.

In some countries, particularly in the European Union, the pricing of prescription pharmaceuticals is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take considerable time after the receipt of marketing approval for a drug. To obtain coverage and reimbursement or pricing approval in some countries, we or our licensees may be required to conduct a clinical trial that compares the cost-effectiveness of our product candidate to other available therapies, or to meet other criteria for pricing approval. If reimbursement of a product candidate, if approved, is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, our business, prospects, financial condition and results of operations could be harmed.

If we continue to progress the development of our product candidates and any of our product candidates obtain regulatory approval, additional competitors could enter the market with generic versions of such drugs, which may result in a material decline in sales of affected products.

Under the Hatch-Waxman Act, a pharmaceutical manufacturer may file an abbreviated new drug application, or (an “ANDA”), seeking approval of a generic copy of an approved, small-molecule innovator product. Under the Hatch-Waxman Act, a manufacturer may also submit a new drug application (“NDA”) that references the FDA’s prior approval of the small-molecule innovator product. The Hatch-Waxman Act also provides for certain periods of regulatory exclusivity. These include, subject to certain exceptions, the period during which an FDA-approved drug is subject to orphan drug exclusivity. In addition to the benefits of regulatory exclusivity, an innovator NDA holder may have patents claiming the active ingredient, product formulation or an approved use of the drug, which would be listed with the product in the FDA publication, “Approved Drug Products with Therapeutic Equivalence Evaluations,” known as the “Orange Book.” If there are patents listed in the Orange Book, a generic or NDA applicant that seeks to market its product before expiration of the patents must include in the ANDA a “Paragraph IV certification,” challenging the validity or enforceability of, or claiming non-infringement of, the listed patent or patents.

62

Accordingly, if we continue to progress the development of our product candidates and any of our product candidates are approved, competitors could file ANDAs for generic versions of our small-molecule drug products or NDAs that reference our small-molecule drug products, respectively. If there are patents listed for our small-molecule drug products in the Orange Book, those ANDAs and NDAs would be required to include a certification as to each listed patent indicating whether the ANDA applicant does or does not intend to challenge the patent. We cannot predict which, if any, patents in our current portfolio or patents we may obtain in the future will be eligible for listing in the Orange Book, how any generic competitor would address such patents, whether we would sue on any such patents, or the outcome of any such suit.

We may not be successful in securing or maintaining proprietary patent protection for products and technologies we or our licensees may develop or license. Moreover, if any of our patents that are listed in the Orange Book are successfully challenged by way of a Paragraph IV certification and subsequent litigation, the affected product could immediately face generic competition and its sales would likely decline rapidly and materially.

Risks Related to Our Business Operations

Our prospects for success depend on our ability to retain Regina Graul, our President and Chief Executive Officer and in the future to attract, retain and motivate qualified personnel.

We are highly dependent on Regina Graul, Ph.D. who is currently our sole employee. Despite our efforts to retain valuable employees, members of our management, scientific and development teams may terminate their employment with us on short notice. Our success also depends on our ability in the future to attract, retain and motivate highly skilled junior, mid-level and senior managers as well as junior, mid-level and senior scientific and medical personnel.

We may not be able to attract or retain qualified management and scientific personnel in the future due to the competition for a limited number of qualified personnel among biopharmaceutical, biotechnology, pharmaceutical and other businesses. Many of the other pharmaceutical companies that we compete against for qualified personnel have greater financial and other resources, different risk profiles and a longer history in the industry than we do. They also may provide more diverse opportunities and better chances for career advancement. Some of these characteristics may be more appealing to high quality candidates than what we may be able to offer. The failure to succeed in nonclinical or clinical studies may make it more challenging to recruit and retain qualified personnel. In addition, in order to induce employees to continue their employment with us, we have provided equity awards that vest over time and the value to our employees of such equity awards may be significantly affected by movements in our stock price that are beyond our control and may be at any time insufficient to counteract more lucrative offers from other companies. If we are unable to attract and retain high quality personnel, the rate and success at which we can develop and commercialize product candidates will be limited.

We face potential product liability exposure, and, if claims are brought against us, we may incur substantial liability.

The use of our current and any potential future product candidates in clinical studies and any sale thereof, if approved, exposes us to the risk of product liability claims. Product liability claims might be brought against us by patients, healthcare providers or others selling or otherwise coming into contact with our product candidates. For example, we may be sued if any such product candidate we develop allegedly causes injury or is found to be otherwise unsuitable during product testing, manufacturing, marketing or sale. Any such product liability claims may include allegations of defects in manufacturing, defects in design, a failure to warn of dangers inherent in the product, including as a result of interactions with alcohol or other drugs, negligence, strict liability and a breach of warranties. Claims could also be asserted under state consumer protection acts. If we become subject to product liability claims and cannot successfully defend ourselves against them, we could incur substantial

63

liabilities. In addition, regardless of merit or eventual outcome, product liability claims may result in, among other things: withdrawal of subjects from our clinical studies; substantial monetary awards to patients or other claimants; decreased demand for our product candidates or any future product candidates following marketing approval, if obtained; damage to our reputation and exposure to adverse publicity; increased FDA warnings on product labels; litigation costs; distraction of management’s attention from our primary business; loss of potential revenue; and the inability to successfully commercialize our product candidates or any potential future product candidates, if approved.

We maintain product liability insurance coverage for our clinical studies through both domestic and international insurance policies, subject to an annual coverage limit. Nevertheless, our insurance coverage may be insufficient to reimburse us for any expenses or losses we may suffer if a judgment or settlement exceeds available insurance proceeds. Moreover, in the future, we may not be able to maintain insurance coverage at a reasonable cost or in sufficient amounts to protect us against losses, including if insurance coverage becomes increasingly expensive. If and when we obtain marketing approval for our product candidates, we intend to expand our insurance coverage to include the sale of commercial products; however, we may not be able to obtain this product liability insurance on commercially reasonable terms. Large judgments have been awarded in class action lawsuits based on drugs that had unanticipated side effects. The cost of any product liability litigation or other proceedings, even if resolved in our favor, could be substantial, particularly in light of the size of our business and financial resources. A product liability claim or series of claims brought against us could cause our stock price to decline and, if we are unsuccessful in defending such a claim or claims and the resulting judgments exceed our insurance coverage, our business, prospects, financial condition and results of operations could be materially harmed.

During the course of treatment, patients may suffer adverse events, including death, for reasons that may or may not be related to our product candidates. Such events could subject us to costly litigation, require us to pay substantial amounts of money to injured patients, delay, negatively impact or end our opportunity to receive or maintain regulatory approval to market our product candidates, if approved, or require us to suspend or abandon our commercialization efforts of any approved product candidates. Even in a circumstance in which we do not believe that an adverse event is related to our product candidates, the investigation into the circumstance may be time-consuming or inconclusive. These investigations may interrupt our sales efforts, delay our regulatory approval process, or impact and limit the type of regulatory approvals our product candidates receive or maintain. As a result of these factors, a product liability claim, even if successfully defended, could have a material adverse effect on our business, prospects, financial condition and results of operations.

If we fail to maintain proper and effective internal controls, our ability to produce accurate and timely financial statements could be impaired, which could result in sanctions or other penalties that would harm our business.

We are subject to the reporting requirements of the Securities Exchange Act of 1934, or The Exchange Act, the Sarbanes-Oxley Act of 2002, or the Sarbanes-Oxley Act, and the rules and regulations of the Nasdaq Capital Market. We are a “smaller reporting company.” For so long as we remain a smaller reporting company, we will be exempt from Section 404(b) of the Sarbanes-Oxley Act, which requires auditor attestation to the effectiveness of internal control over financial reporting. As a smaller reporting company, we are exempt from compliance with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act and reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements. We cannot predict if investors will find our common stock less attractive because we may rely on the exemptions available to us as a smaller reporting company. If some investors find our common stock less attractive as a result, there may be a less active trading market for our common stock and our stock price may be more volatile.

We are, however, subject to Section 404(a) of the Sarbanes-Oxley Act. Beginning with our annual report on Form 10-K for the fiscal year ended December 31, 2024, we must include a management assessment of the effectiveness of our internal control over financial reporting. As of the expiration of our smaller reporting

64

company status, we will be broadly subject to enhanced reporting and other requirements under the Exchange Act and Sarbanes-Oxley Act. We have engaged in a process to document and evaluate our internal control over financial reporting, which is both costly and challenging. In this regard, we will need to continue to dedicate internal resources, engage outside consultants and adopt a detailed work plan to assess and document the adequacy of internal control over financial reporting, continue steps to improve control processes, validate through testing that controls are functioning as documented and implement a continuous reporting and improvement process for internal control over financial reporting. There can be no assurances that in future periods we will be able to timely conclude that our internal control over financial reporting is effective as required by Section 404(a).

We may discover weaknesses in our system of internal financial and accounting controls and procedures that could result in a material misstatement of our financial statements. Our internal control over financial reporting will not prevent or detect all errors and all fraud. A control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system’s objectives will be met. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that misstatements due to error or fraud will not occur or that all control issues and instances of fraud will be detected.

If we are not able to comply with the requirements of Section 404 of the Sarbanes-Oxley Act in a timely manner, or if we are unable to maintain proper and effective internal controls over financial reporting, we may not be able to produce timely and accurate financial statements. If that were to happen, our business, prospects, financial condition and results of operations could be harmed, our investors could lose confidence in our reported financial information, the market price of our stock could decline, and we could be subject to sanctions or investigations by the SEC or other regulatory authorities.

Unfavorable global economic and political conditions could harm our business, prospects, financial condition and results of operations.

Our results of operations could be harmed by general conditions in the global economy and in the global financial markets as well as adverse economic conditions caused by political unrest or loss of government funding for product candidates. A severe or prolonged economic downturn and severe political disruption could result in a variety of risks to our business, including weakened demand for our product candidates and our ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could also strain our suppliers, possibly resulting in supply disruption. Any of the foregoing could harm our business, prospects, financial condition and results of operations.

If our information technology systems or data, or those of CRO and other third parties upon which we rely, are or were compromised, we could experience adverse impacts resulting from such compromise, including, but not limited to, regulatory investigations or actions; litigation; fines and penalties; interruptions to our commercial operations, clinical trials or other operations; harm to our reputation; loss of revenue or profits; loss of sales and other adverse consequences.

In the ordinary course of our business, we and our third-party service providers may process proprietary, confidential, and sensitive data, including personal data (such as health-related data and data related to our clinical trials), intellectual property, and trade secrets (collectively, sensitive information).

Cyberattacks, malicious internet-based activity, and online and offline fraud are prevalent and continue to increase. These threats are becoming increasingly difficult to detect. These threats come from a variety of sources, including traditional computer “hackers,” threat actors, personnel (such as through theft or misuse), “hacktivists”, organized criminal threat actors, sophisticated nation-states, and nation-state-supported actors. Some actors now engage and are expected to continue to engage in cyberattacks, including without limitation nation-state actors for geopolitical reasons and in conjunction with military conflicts and defense activities.

65

During times of war and other major conflicts, we and the third parties upon which we rely may be vulnerable to a heightened risk of these attacks, including retaliatory cyberattacks that could materially disrupt our systems and operations, supply chain, and ability to produce, sell and distribute our products. We and the third parties upon which we rely may be subject to a variety of other evolving threats, including, but not limited to, social-engineering attacks (including through deep fakes, which may be increasingly more difficult to identify as fake, and phishing attacks), malicious code (such as viruses and worms), malware (including as a result of advanced persistent threat intrusions), denial-of-service attacks, credential stuffing, credential harvesting, personnel misconduct or error, ransomware attacks, supply-chain attacks, software bugs, server malfunctions, software or hardware failures, loss of data or other information technology assets, adware, telecommunications failures, attacks enhanced or facilitated by artificial intelligence, and other similar threats. In particular, ransomware attacks, including those from organized criminal threat actors, nation-states and nation-state supported actors, are becoming increasingly prevalent and severe and can lead to significant interruptions, delays, or outages in our operations, ability to provide our products, disruption of clinical trials, loss of data (including data related to clinical trials), loss of income, significant extra expenses to restore data or systems, reputational loss and the diversion of funds. To alleviate the financial, operational and reputational impact of a ransomware attack, it may be preferable to make extortion payments, but we may be unwilling or unable to do so (including, for example, if applicable laws prohibit such payments). Additionally, hybrid and remote work has become more common and has increased risks to our information technology systems and data, as more of our employees utilize network connections, computers, and devices outside our premises or network, including working at home, while in transit, and in public locations. Future or past business transactions (such as acquisitions or integrations) could also expose us to additional cybersecurity risks and vulnerabilities, as our systems could be negatively affected by vulnerabilities present in acquired or integrated entities’ systems and technologies. Furthermore, we may discover security issues that were not found during due diligence of such acquired or integrated entities, and it may be difficult to integrate companies into our information technology environment and security program.

We rely upon third parties and technologies to operate critical business systems to process sensitive information in a variety of contexts, including, without limitation, third-party providers of cloud-based infrastructure, encryption and authentication technology, employee email, and other functions. We also rely on third parties to provide certain products, including active pharmaceutical ingredients, to operate our business. Our ability to monitor these third parties’ information security practices is limited, and these third parties may not have adequate information security measures in place. While we may be entitled to damages if the third parties upon which we rely fail to satisfy their privacy or security-related obligations to us, any award may be insufficient to cover our damages, or we may be unable to recover such award. In addition, supply-chain attacks have increased in frequency and severity, and we cannot guarantee that third parties’ infrastructure in our supply chain or our third-party partners’ supply chains have not been compromised. We may share or receive sensitive information with or from third parties.

While we have implemented security measures designed to protect against security incidents, there can be no assurance that these measures will be effective. We take steps designed to detect, mitigate and remediate vulnerabilities in our information security systems (such as our hardware and/or software, including that of third parties upon which we rely), but we may not be able to detect, mitigate, and remediate all such vulnerabilities including on a timely basis. Further, we may experience delays in developing and deploying remedial measures and patches designed to address identified vulnerabilities. Vulnerabilities could be exploited and result in a security incident.

Any of the previously identified or similar threats could cause a security incident or other interruption that could result in unauthorized, unlawful, or accidental acquisition, modification, destruction, loss, alteration, encryption, disclosure of, or access to our sensitive information or our information technology systems, or those of the third parties upon whom we rely. A security incident or other interruption could disrupt our ability (and that of third parties upon whom we rely) to provide our products. We may expend significant resources or modify our business activities (including our clinical trial activities) to try to protect against security incidents. Certain data privacy and security obligations require us to implement and maintain specific security measures, industry-

66

standard or reasonable security measures to protect our information technology systems and sensitive information.

Applicable data security and public company disclosure obligations may require us to notify relevant stakeholders of certain security incidents, including affected individuals, customers, regulators and investors. Such disclosures are costly, and the disclosures or the failure to comply with such requirements could lead to adverse consequences. If we (or a third party upon whom we rely) experience a security incident or are perceived to have experienced a security incident, we may experience adverse consequences. These consequences may include: government enforcement actions (for example, investigations, fines, penalties, audits, and inspections); additional reporting requirements and/or oversight; restrictions on processing sensitive information (including personal data); litigation (including class claims); indemnification obligations; negative publicity; reputational harm; monetary fund diversions; diversion of management attention; interruptions in our operations (including availability of data); financial loss and other similar harms. For example, the loss of clinical trial data from completed or ongoing clinical trials for any of our product candidates could result in delays in our regulatory approval efforts and significantly increase our costs to recover or reproduce the data.

Whether a cybersecurity incident is reportable to our investors may not be straightforward, may take considerable time to determine, and may be subject to change as the investigation of the incident progresses, including changes that may significantly alter any initial disclosure that we provide. Moreover, experiencing a material cybersecurity incident and any mandatory disclosures could lead to negative publicity, loss of customer, investor or partner confidence in the effectiveness of our cybersecurity measures, diversion of management’s attention, governmental investigations, lawsuits, and the expenditure of significant capital and other resources.

Our contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in our contracts are sufficient to protect us from liabilities, damages, or claims related to our data privacy and security obligations. In addition, our insurance coverage may not be adequate or sufficient to protect us from or to mitigate liabilities arising out of our privacy and security practices or that such coverage will continue to be available on commercially reasonable terms or at all, or that such coverage will pay future claims.

In addition to experiencing a security incident, third parties may gather, collect, or infer sensitive information about us from public sources, data brokers, or other means that reveals competitively sensitive details about our organization and could be used to undermine our competitive advantage or market position. Sensitive information of us or our customers could also be leaked, disclosed, or revealed as a result of or in connection with our employee’s, personnel’s, or vendor’s use of generative AI technologies.

Our employee or future employees may engage in misconduct or other improper activities, including violating applicable regulatory standards and requirements or engaging in insider trading, which could significantly harm our business.

We are exposed to the risk of employee fraud or other misconduct. Misconduct by employees could include intentional failures to comply with the regulations of the FDA and applicable foreign regulators, provide accurate information to the FDA and applicable foreign regulators, comply with healthcare fraud and abuse laws and regulations in the United States and abroad, report financial information or data accurately and/or disclose unauthorized activities to us. In particular, research and development, commercialization and business arrangements in the healthcare industry are subject to considerable laws and regulations intended to prevent fraud, misconduct, kickbacks, self-dealing and other abusive practices. These laws and regulations restrict, regulate or prohibit a wide range of activities pertaining to clinical trials including the informed consent process, data integrity and conducting the study in accordance with the investigational plan, and for approved products, pricing, discounting, marketing and promotion, sales commission, customer incentive programs and other business arrangements. Employee misconduct could also involve the improper use of, including trading on, information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm

67

to our reputation. It is not always possible to identify and deter employee misconduct, and the precautions we take to detect and prevent this activity may be ineffective in controlling unknown or unmanaged risks or losses or in protecting us from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations. Additionally, we are subject to the risk that a person could allege such fraud or other misconduct, even if none occurred. If any such actions are instituted against us, and we are not successful in defending ourselves or asserting our rights, those actions could have a significant impact on our business, including the imposition of significant fines or other sanctions, possible exclusions from participation in Medicare, Medicaid and other U.S. federal healthcare programs, contractual damages and reputational harm.

If we or any contract manufacturers and suppliers we engage fail to comply with environmental, health and safety laws and regulations, we could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of our business.

We, and any contract manufacturers and suppliers we engage, are subject to numerous federal, state and local environmental, health and safety laws, regulations and permitting requirements, including those governing laboratory procedures; the generation, handling, use, storage, treatment and disposal of hazardous and regulated materials and wastes; the emission and discharge of hazardous materials into the ground, air and water; and employee health and safety. Under certain environmental laws, we could be held responsible for costs relating to any contamination at our current or past facilities and at third-party facilities. We also could incur significant costs associated with civil or criminal fines and penalties.

We could be adversely affected by violations of the U.S. Foreign Corrupt Practices Act, or the FCPA, and other worldwide anti-bribery laws.

We are subject to the FCPA, which prohibits U.S. corporations and their representatives from offering, promising, authorizing or making payments to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business abroad. The scope of the FCPA includes interactions with certain healthcare professionals in many countries. Other countries have enacted similar anti-corruption laws and/or regulations. In some countries in which we operate, the pharmaceutical and life sciences industries are exposed to a high risk of corruption associated with the conduct of clinical trials and other interactions with healthcare professionals and institutions. Any such activities could expose us to potential liability under the FCPA, which may result in us incurring significant criminal and civil penalties and to potential liability under the anti-corruption laws and regulations of other jurisdictions in which we operate. In addition, the costs we may incur in defending against an FCPA investigation could be significant.

Risks Related to Ownership of Our Common Stock

We could be delisted from Nasdaq, which would seriously harm the liquidity of our stock and ability to raise capital.

On June 1, 2022, the Company received a notice from the Nasdaq Stock Market (“Nasdaq”) notifying the Company that the closing bid price for the Company’s common stock listed on Nasdaq has been below the minimum $1.00 per share required for continued listing on the Nasdaq Global Select Market pursuant to Nasdaq Listing Rule 5450(a)(1) (the “Bid Price Requirement”).

In accordance with Nasdaq Listing Rule 5810(c)(3)(A), the Company was provided a period of 180 calendar days, or until November 28, 2022, to regain compliance with the Bid Price Requirement. The Company did not regain compliance with the Bid Price Requirement by the initial compliance date. On November 29, 2022, however, Nasdaq notified the Company of its eligibility for an additional 180 calendar day period, or until May 29, 2023 (the “Extended Compliance Date”), to regain compliance with the Bid Price Requirement. Nasdaq’s determination was based on the Company meeting the continued listing requirement for market value of publicly held shares and all other applicable requirements for initial listing on the Nasdaq Capital Market with

68

the exception of the Bid Price Requirement, and the Company’s written notice of its intention to cure the deficiency during the second compliance period by effecting a reverse stock split, if necessary. Effective November 25, 2022, the Company transferred its listing of the Company’s common stock from the Nasdaq Global Market to the Nasdaq Capital Market, a continuous trading market that operates in substantially the same manner as the Nasdaq Global Market. The Company’s common stock continues to trade under the symbol “CYCN”.

We effected a 20:1 reverse stock split in May 2023. As a result, we have regained compliance with the Bid Price Requirement. If the Company does not regain compliance with the Bid Price Requirement in the future, the Company’s stock will again be subject to delisting. As a result of amendments in October 2024 to the Nasdaq delisting procedures, NASDAQ now may automatically delist companies which conduct multiple reverse stock splits in any 12-month period.

The Company intends to monitor the closing bid price of its common stock and may, if appropriate, consider available options to regain compliance with the Bid Price Requirement, including initiating a reverse stock split. However, there can be no assurance that the Company will be able to maintain compliance with the Bid Price Requirement, would receive sufficient shareholder support for a reverse stock split, or will otherwise be in compliance with other Nasdaq Listing Rules.

In January 2026, Nasdaq refiled with the SEC an application to allow Nasdaq to delist certain companies from the Nasdaq Capital Market and Nasdaq Global Market where companies with a market value of listed securities below $5 million for 30 consecutive business days face immediate suspension and delisting, without the usual compliance period or automatic stay (the “Proposed Market Value Rule”). The SEC has requested comments on the proposed application. The comment period for public comments ended on February 19, 2026, after which time the SEC may elect to accept the Nasdaq proposal. If approved by the SEC, the rule will become effective within 45 days of publication in the Federal Register, or within up to 90 days if extended by the SEC pursuant to Section 19(b)(2) of the Exchange Act. Currently, the Company would not meet the requirements of the Proposed Market Value Rule and if the Proposed Market Value Rule is approved, the Company may not meet the requirements under the Proposed Market Value Rule to maintain its current listing on the Nasdaq Capital Market. The loss of the Company’s listing on the Nasdaq Capital Market would result in the Company’s common stock trading on the OTC Market, which could adversely affect the market price of the Company’s common stock.

The market price of our common stock may fluctuate widely and you could lose all or part of your investment in our common stock as a result.

The market price for our common stock has fluctuated widely, and may in the future fluctuate widely, depending upon many factors, some of which are beyond our control, including the following:

69

In addition, if the market for stocks in our industry or industries related to our industry, or the stock market in general, experiences a loss of investor confidence, the trading price of our common stock could decline for reasons unrelated to our business, results of operations, financial condition and prospects. If any of the foregoing occurs, it could cause our stock price to fall and may expose us to lawsuits that, even if unsuccessful, could be costly to defend and a distraction to management.

The market price for our common stock is particularly volatile.

The market for our common stock is characterized by significant price volatility when compared to seasoned issuers, and we expect that our stock price will continue to be more volatile than those of a seasoned issuer. Several factors cause the volatility in our share price. We are a speculative or “risky” investment due to our short operating history, lack of revenues and the uncertain success (including of regulatory approval) of any of our product candidates. As a consequence of this risk, more risk-averse investors may, under the fear of losing all or most of their investment in the event of negative news or lack of progress, be more inclined to sell their shares of our common stock more quickly and at greater discounts than would be the case with the stock of a seasoned issuer. Plaintiffs have, in the past, initiated securities class action litigation against a company following periods of volatility in the market price of its securities. We may in the future be the target of such litigation. Securities litigation could result in substantial costs and liabilities and could divert management’s attention and resources.

We run the risk of inadvertently being deemed an investment company required to register under the Investment Company Act of 1940.

We run the risk of inadvertently being deemed an investment company required to register under the Investment Company Act of 1940 (the “Investment Company Act”) because a significant portion of our assets

70

consists of investments in companies in which we own less than a majority interest. The risk varies depending on events beyond our control, such as significant appreciation or depreciation in the market value of certain of our publicly traded holdings, adverse developments with respect to our ownership of certain of our subsidiaries, transactions involving the sale of certain assets and our participation in any partnership or other fund established to finance future broadband and real estate projects in which we may engage. If we are deemed to be an inadvertent investment company, we may seek to rely on a safe harbor under the Investment Company Act that would provide us a one-year grace period to take steps to avoid being deemed to be an investment company. In order to ensure we avoid being deemed an investment company, we have taken, and may need to continue to take, steps to reduce the percentage of our assets that constitute investment assets under the Investment Company Act. These steps have included, among others, selling marketable securities that we might otherwise hold for the long term and deploying our cash in non-investment assets. We may be forced to sell our investment assets at unattractive prices or to sell assets that we otherwise believe benefit our business in the future to remain below the requisite threshold. We may also seek to acquire additional non-investment assets to maintain compliance with the Investment Company Act, and we may need to incur debt, issue additional equity or enter into other financing arrangements that are not otherwise attractive to our business. Any of these actions could have a material adverse effect on our results of operations and financial condition.

Moreover, we can make no assurance that we would successfully be able to take the necessary steps to avoid being deemed to be an investment company in accordance with the safe harbor. If we were unsuccessful, then we would have to register as an investment company, and we would be unable to operate our business in its current form. We would be subject to extensive, restrictive, and potentially adverse statutory provisions and regulations relating to, among other things, operating methods, management, capital structure, indebtedness, dividends, and transactions with affiliates. If we were deemed to be an investment company and did not register as an investment company when required to do so, there would be a risk, among other material adverse consequences, that we could become subject to monetary penalties or injunctive relief, or both, that we would be unable to enforce contracts with third parties, and/or that third parties could seek to obtain rescission of transactions with us undertaken during the period in which we were an unregistered investment company.

Uncertainties in the interpretation and application of existing, new and proposed tax laws and regulations could materially affect our tax obligations and effective tax rate.

The tax regimes to which we are subject or under which we operate are unsettled and may be subject to significant change. The issuance of additional guidance related to existing or future tax laws, or changes to tax laws or regulations proposed or implemented by the current or a future U.S. presidential administration, Congress, or taxing authorities in other jurisdictions, including jurisdictions outside of the United States, could materially affect our tax obligations and effective tax rate. To the extent that such changes have a negative impact on us, including as a result of related uncertainty, these changes may adversely impact our business, financial condition, results of operations, and cash flows.

The amount of taxes we pay in different jurisdictions depends on the application of the tax laws of various jurisdictions, including the United States, to our international business activities, tax rates, new or revised tax laws, or interpretations of tax laws and policies, and our ability to operate our business in a manner consistent with our corporate structure and intercompany arrangements. The taxing authorities of the jurisdictions in which we operate may challenge our methodologies for pricing intercompany transactions pursuant to our intercompany arrangements or disagree with our determinations as to the income and expenses attributable to specific jurisdictions. If such a challenge or disagreement were to occur, and our position was not sustained, we could be required to pay additional taxes, interest, and penalties, which could result in one-time tax charges, higher effective tax rates, reduced cash flows, and lower overall profitability of our operations. Our financial statements could fail to reflect adequate reserves to cover such a contingency. Similarly, a taxing authority could assert that we are subject to tax in a jurisdiction where we believe we have not established a taxable connection, often referred to as a “permanent establishment” under international tax treaties, and such an assertion, if successful, could increase our expected tax liability in one or more jurisdictions.

71

Effective January 1, 2022, the Tax Cuts and Jobs Act of 2017 eliminated the option to deduct research and development expenses for tax purposes in the year incurred and requires taxpayers to capitalize and subsequently amortize such expenses over five years for research activities conducted in the United States and over 15 years of research activities conducted outside the United States. Unless the United States Department of the Treasury issues regulations that narrow the application of this provision to a smaller subset of our research and development expenses or the provision is deferred, modified, or repealed by Congress, in future years we may experience a material decrease in our cash flows from operations and an offsetting similarly sized increase in our net deferred tax assets over these amortization periods. The actual impact of this provision will depend on multiple factors, including the amount of research and development expenses we will incur and whether we conduct our research and development activities inside or outside the United States and our overall net operating loss position.

Our ability to use net operating loss carryforwards and certain other tax attributes to offset future taxable income and taxes may be subject to limitations.

Under current law, our federal net operating losses (“NOLs”) generated in tax years beginning after December 31, 2017, may be carried forward indefinitely, but the deductibility of such federal NOLs is limited to 80% of taxable income. As of December 31, 2025, we had federal NOLs of $211 million. It is uncertain if and to what extent various states will conform to federal tax laws. In addition, under Sections 382 and 383 of the Internal Revenue Code of 1986, as amended, and corresponding provisions of state law, if a corporation undergoes an “ownership change,” which is generally defined as a greater than 50% change, by value, in its equity ownership over a three-year period, the corporation’s ability to use its pre-change NOL carryforwards and other pre-change U.S. tax attributes (such as research tax credits) to offset its post-change income or taxes may be limited. It is possible that we have experienced an ownership change in the past. In addition, we may experience ownership changes in the future as a result of subsequent shifts in our stock ownership, some of which may be outside of our control, as well as the issuance of additional securities if we are successful in raising equity capital.

As a result, our federal NOL carryforwards may be subject to a percentage limitation if used to offset income in tax years following an ownership change. In addition, it is possible that we have in the past undergone, and in the future may undergo, additional ownership changes that could limit our ability to use all of our pre-change NOL carryforwards and other pre-change tax attributes (such as research tax credits) to offset our post-change income or taxes. Similar provisions of state tax law may also apply to limit our use of accumulated state tax attributes. In addition, at the state level, there may be periods during which the use of NOL carryforwards is suspended or otherwise limited, which could accelerate or permanently increase state taxes owed. As a result, we may be unable to use all or a material portion of our NOL carryforwards and other tax attributes, which would harm our future operating results by effectively increasing our future tax obligations.

We maintain our cash at financial institutions, often in balances that exceed federally insured limits.

We maintain the majority of our cash and cash equivalents in accounts at banking institutions in the United States that we believe are of high quality. Cash held in these accounts often exceeds the FDIC insurance limits. If such banking institutions were to fail, we could lose all or a portion of amounts held in excess of such insurance limitations. In the event of failure of any of the financial institutions where we maintain our cash and cash equivalents, there can be no assurance that we would be able to access uninsured funds in a timely manner or at all. Any inability to access or delay in accessing these funds could adversely affect our business and financial position.

72

If securities or industry analysts fail to initiate or maintain coverage of our stock, publish a negative report or change their recommendations regarding our stock adversely, our stock price and trading volume could decline.

The trading market for our common stock will be influenced by the research and reports that industry or securities analysts publish about us, our business, our market or our competitors. Currently, no industry analysts cover our stock. If securities or industry analysts fail to initiate coverage of our stock, the lack of exposure to the market could cause our stock price or trading volume to decline. If any of the analysts who cover us or may cover us in the future publish a negative report or change their recommendation regarding our stock adversely, or provide more favorable relative recommendations about our competitors, our stock price would likely decline. If any analyst who covers us or may cover us in the future were to cease coverage of our company or fail to regularly publish reports on us, we could lose visibility in the financial markets, which in turn could cause our stock price or trading volume to decline.

We do not expect to pay any cash dividends for the foreseeable future.

We have never paid cash dividends and we do not anticipate that we will pay any cash dividends to holders of our common stock in the foreseeable future. Instead, we plan to retain any earnings to maintain and expand our operations. In addition, any future debt financing arrangement may contain terms prohibiting or limiting the amount of dividends that may be declared or paid on our common stock. Accordingly, investors must rely on sales of their common stock after price appreciation, which may never occur, as the only way to realize any return on their investment. As a result, investors seeking cash dividends should not purchase our common stock.

We have anti-takeover provisions in our articles of organization and bylaws and are subject to provisions of Massachusetts law that may frustrate any attempt to remove or replace our current board of directors or to effect a change of control or other business combination involving our company.

Our restated articles of organization and bylaws and certain provisions of Massachusetts law may discourage certain types of transactions involving an actual or potential change of control of our company that might be beneficial to us or our security holders. For example, our bylaws grant our directors the right to adjourn any meetings of shareholders. Our board of directors also may issue shares of any class or series of preferred stock in the future without shareholder approval and upon such terms as our board of directors may determine. The rights of the holders of our common stock will be subject to, and may be harmed by, the rights of the holders of any class or series of preferred stock that may be issued in the future. Massachusetts state law also prohibits us from engaging in specified business combinations unless the combination is approved or consummated in a prescribed manner. These provisions, alone or together, could delay hostile takeovers and changes in control of our company or changes in our management.

Our articles of organization designate the state and federal courts located within the Commonwealth of Massachusetts as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by our shareholders, which could discourage lawsuits against us and our directors and officers.

Our restated articles of organization designate the state and federal courts located within the Commonwealth of Massachusetts as the sole and exclusive forum for any derivative action or proceeding brought on our behalf, any action asserting a claim of breach of a fiduciary duty owed by any of our directors or officers to us or our shareholders, creditors or other constituents, any action asserting a claim arising pursuant to any provision of the Massachusetts Business Corporation Act, or the MBCA, or any action asserting a claim governed by the internal affairs doctrine, in all cases subject to the court’s having personal jurisdiction over the indispensable parties named as defendants. In addition, our articles of organization provide that unless our board of directors consents in writing to the selection of an alternative forum, the U.S. federal district courts shall be the exclusive forum for the resolutions of any complaint asserting a cause of action arising under the U.S. federal securities laws. This exclusive forum provision may limit the ability of our shareholders to bring a claim in a judicial forum that such

73

shareholders find favorable for disputes with us or our directors or officers, which may discourage such lawsuits against the company and our directors and officers. Alternatively, if a court outside of Massachusetts were to find this exclusive forum provision inapplicable to, or unenforceable in respect of, one or more of the specified types of actions or proceedings described above, we may incur additional costs associated with resolving such matters in other jurisdictions, which could harm our business, prospects, financial condition and results of operations.

Risks Related to Korsana

All references to Korsana’s “product candidates,” “programs,” “portfolio” and “pipeline” in this proxy statement/prospectus refer to the research programs with respect to which Korsana has the option to acquire intellectual property license rights pursuant to the Paragon Option Agreements. As of the date of this proxy statement/prospectus, Korsana has exercised the option for KRSA-028. Korsana has not exercised the option for any other program under the Paragon Option Agreements. Korsana expects to enter into the KRSA-028 license agreement prior to the time that this registration statement on Form S-4 is declared effective by the SEC.

Risks Related to Korsana’s Limited Operating History, Financial Position and Capital Requirements

Korsana is a preclinical stage biotechnology company with a limited operating history on which to assess its business; Korsana has not completed any clinical trials, and it has no products approved for commercial sale, which may make it difficult to evaluate its current business and likelihood of success and viability.

Korsana is a preclinical stage biotechnology company with a limited operating history. Since its inception, Korsana has incurred operating losses with no corresponding revenue and has utilized substantially all of its resources to identify and develop its product candidates, organize and staff its company, and provide other general and administrative support for its operations. Korsana has no significant experience as a company in initiating, conducting, or completing preclinical studies or clinical trials. In part because of this lack of experience, Korsana cannot be certain that its preclinical studies or clinical trials will begin or be completed on time, if at all. In addition, Korsana has not yet demonstrated an ability to obtain regulatory approvals, manufacture a commercial-scale product, or arrange for a third party to do so on its behalf, or conduct sales, marketing, and distribution activities necessary for successful product commercialization. Consequently, any predictions about Korsana’s future success or viability may not be as accurate as they could be if Korsana had a longer operating history.

In addition, as Korsana’s business grows, Korsana may encounter unforeseen expenses, restrictions, difficulties, complications, delays, and other known and unknown factors. Korsana will need to transition at some point from a company with an early research and development focus to a company capable of supporting larger scale clinical trials and eventually commercial activities. Korsana may not be successful in such a transition.

Even if the Merger and the Korsana Pre-Closing Financing are successful, Korsana will require substantial additional capital to finance its operations in the future. If Korsana is unable to raise such capital when needed, or on acceptable terms, Korsana may be forced to delay, reduce, and/or eliminate one or more of its development programs or future commercialization efforts.

Developing biotechnology products is a long, time-consuming, expensive, and uncertain process that takes years to complete. Korsana expects its expenses to increase in connection with its ongoing activities, particularly as Korsana conducts preclinical studies and clinical trials of, and seeks regulatory approval for, its product candidates, and advances discovery efforts with respect to its research and development programs, and advances any future programs and product candidates that Korsana may license. Even if one or more of the programs that Korsana develops is approved for commercial sale, Korsana anticipates incurring significant costs associated with sales, marketing, manufacturing, and distribution activities to launch any such product. Korsana’s expenses could increase beyond expectations if Korsana is required by the FDA or other regulatory agencies to perform preclinical studies or clinical trials in addition to or more expansive than those that Korsana currently anticipates.

74

Because the design and outcome of Korsana’s planned and anticipated clinical trials are highly uncertain, Korsana cannot reasonably estimate the actual amount of funding that will be necessary to successfully complete the development and commercialization of any program Korsana develops. Korsana’s future capital requirements depend on many factors, including but not limited to:

As a result, Korsana will require substantial additional funding to continue its operations. As of December 31, 2025, Korsana had $154.1 million in cash and cash equivalents. Korsana expects that its existing cash and cash equivalents, and investments, combined with the gross proceeds of approximately $380.0 million from the Korsana Pre-Closing Financing, will be sufficient to fund the Combined Company’s operating expenses and capital expenditure requirements into 2029. Even if the Merger and the Korsana Pre-Closing Financing are successful, Korsana will still need to raise additional capital to continue to fund its operations in the future. If Korsana is unable to raise additional capital when needed, that could raise substantial doubt about Korsana’s ability to continue as a going concern.

Korsana may be required to seek additional funds sooner than planned through public or private equity offerings, debt financings, collaborations and licensing arrangements, or other sources, and adequate additional financing may not be available to Korsana on acceptable terms, or at all. Such financing may dilute Korsana’s stockholders or the failure to obtain such financing may restrict Korsana’s operating activities. Any additional fundraising efforts may divert Korsana’s management from their day-to-day activities, which may adversely affect Korsana’s business. To the extent that Korsana raises additional capital through the sale of equity or convertible debt securities, the ownership interest of Korsana’s stockholders will be diluted, and the terms may include liquidation or other preferences and anti-dilution protections that adversely affect the rights of Korsana’s stockholders. Debt financing may result in the imposition of debt covenants, increased fixed payment obligations or other restrictions that may affect Korsana’s business. If Korsana raises additional funds through upfront payments or milestone payments pursuant to future collaborations with third parties, Korsana may have to

75

relinquish valuable rights to Korsana’s product candidates, or grant licenses on terms that are not favorable to Korsana. Korsana’s ability to raise additional capital may be adversely impacted by global macroeconomic conditions and volatility in the credit and financial markets in the United States and worldwide. Korsana’s failure to raise capital as and when needed or on acceptable terms would have a negative impact on Korsana’s financial condition and Korsana’s ability to pursue its business strategy, and Korsana may have to delay, reduce the scope of, suspend, or eliminate one or more of its product candidates, clinical trials, or future commercialization efforts or cease Korsana’s operations.

Korsana expects to continue to incur losses for the foreseeable future and may not be able to achieve or sustain profitability in the future. Korsana has no products approved for sale, has not generated any revenue from its product candidates, and may never generate revenue or become profitable.

Investment in biotechnology product development is a highly speculative undertaking and entails substantial upfront capital expenditures and significant risks that any product candidate will fail to demonstrate adequate efficacy or an acceptable safety profile, gain regulatory approval, and become commercially viable. Korsana has no products approved for commercial sale, has not generated any revenue from product sales to date, and continues to incur significant research and development and other expenses related to Korsana’s ongoing operations. Korsana does not expect to generate product revenue unless or until Korsana successfully completes preclinical and clinical development and obtains regulatory approval for, and then successfully commercializes, at least one of its product candidates.

Korsana may never succeed in these activities and, even if it does, may never generate revenues that are significant or large enough to achieve profitability. If Korsana is unable to raise sufficient additional capital to advance a product candidate to commercialization or generate sufficient revenue through the sale of any approved products, Korsana may be unable to continue operations without additional funding.

Korsana incurred significant net losses in each period since it commenced operations in November 2024. Korsana generated net losses of $35.7 million for the period from November 2024 (inception) to December 31, 2025. As of December 31, 2025, Korsana had an accumulated deficit of $35.7 million. Korsana expects to continue to incur losses for the foreseeable future. Korsana’s operating expenses and net losses may fluctuate significantly from quarter to quarter and year to year. Korsana anticipates that its expenses will increase substantially if and as Korsana:

76

In addition, Korsana’s expenses will increase if, among other things, it is required by the FDA or other regulatory authorities to perform clinical trials or studies in addition to, or different than, those that Korsana currently anticipates, there are any delays in completing Korsana’s clinical trials or the development of any of its product candidates, or there are any third-party challenges to Korsana’s intellectual property or Korsana needs to defend against any intellectual property-related claim.

Even if Korsana obtains regulatory approval for, and is successful in commercializing, one or more of Korsana’s product candidates, Korsana expects to incur substantial additional research and development and other expenditures to develop and market additional product candidates and/or to expand the approved indications of any marketed product. Korsana may encounter unforeseen expenses, difficulties, complications, delays, and other unknown factors that may adversely affect its business. The size of Korsana’s future net losses will depend, in part, on the rate of future growth of Korsana’s expenses and its ability to generate revenue.

Korsana’s failure to become profitable would decrease its value and could impair its ability to raise capital, maintain its research and development efforts, expand its business, and/or continue its operations. A decline in the value of the Combined Company’s stock could also cause stockholders to lose all or part of their investment.

Risks Related to Korsana’s Discovery, Development, and Commercialization

Korsana faces competition from entities that have developed or may develop product candidates for the diseases addressed by Korsana’s product candidates.

The development and commercialization of drugs is highly competitive. Korsana’s product candidates, if approved, will face significant competition and Korsana’s failure to effectively compete may prevent it from achieving significant market penetration. Korsana competes with a variety of multinational biopharmaceutical companies, specialized biotechnology companies, and emerging biotechnology companies, as well as academic institutions, governmental agencies, and public and private research institutions, among others. If approved for the treatment of patients with Alzheimer’s disease, KRSA-028 would compete with two anti-amyloid antibody therapies that have been approved by the FDA for treatment of early Alzheimer’s disease: lecanemab (Leqembi), marketed by Eisai and Biogen, and donanemab (Kisunla), marketed by Eli Lilly. Korsana is aware of several companies with product candidates in clinical development for the treatment of patients with Alzheimer’s disease, including Roche (including Genentech, its wholly owned subsidiary), Lilly, Eisai, Biogen, AbbVie, Merck, Sanofi, Bristol Myers Squibb, Voyager Therapeutics, Denali Therapeutics, Acumen, Alzheon, AC Immune, and others. Many of the companies with which Korsana is currently competing or will compete against in the future have significantly greater financial resources and expertise in research and development, manufacturing, preclinical testing, conducting clinical trials, obtaining regulatory approvals, and commercialization than Korsana does, and are further along in the clinical development and/or commercialization process. Mergers and acquisitions in the pharmaceutical and biotechnology industry may result in even more resources being concentrated among a smaller number of Korsana’s competitors. Smaller or early-stage companies may also prove to be significant competitors, particularly through collaborative arrangements with large and established companies. These competitors also compete with Korsana in recruiting and retaining qualified scientific and management personnel, establishing clinical trial sites, raising capital, enrolling patients in clinical trials, establishing and defending rights to intellectual property, as well as in acquiring technologies complementary to, or necessary for, Korsana’s product candidates.

Korsana’s competitors have developed or are developing, and may in the future develop, product candidates or products competitive with Korsana’s product candidates. Competitive therapeutic treatments include those that

77

have already been approved and accepted by the medical community and any potential new treatments, including those currently under clinical development. Korsana’s success will depend partially on its ability to develop and commercialize products that have a competitive safety, efficacy, dosing, and/or presentation profile. Korsana’s commercial opportunity and success will be reduced or eliminated if competing products are safer, more effective, less expensive, or have a more attractive dosing profile or presentation than the products Korsana develops, or if competitors develop products or biosimilars that enter the market more quickly than Korsana and gain market acceptance. Conversely, the lack of commercial success of other competing therapies may raise concerns about the financial viability of Korsana’s product candidates.

In addition, because of the competitive landscape for Alzheimer’s disease, Korsana may also face competition for establishing clinical trial sites and enrolling patients. Patient enrollment will depend on many factors, including if potential clinical trial patients choose to undergo treatment with approved products or enroll in competitors’ ongoing clinical trials for product candidates that are under development for the same indications as Korsana’s product candidates. An increase in the number of approved products for the indications Korsana is targeting with its product candidates will likely further exacerbate this competition. Korsana’s inability to enroll a sufficient number of patients could, among other impacts, delay Korsana’s development timeline, which may further harm Korsana’s competitive position.

Korsana’s programs are in the preclinical and clinical stages of development and may fail in development or suffer delays that materially and adversely affect Korsana’s viability. If Korsana or its future collaborators are unable to complete development of or commercialize Korsana’s product candidates, or experience significant delays in doing so, Korsana’s business will be materially harmed.

Korsana has no commercially approved products. Korsana’s programs are in the preclinical and clinical stages of development, and Korsana has not completed any clinical trials. As a result, Korsana expects it will be many years before Korsana commercializes any product candidate, if ever. Korsana’s ability to achieve and sustain profitability depends on obtaining regulatory approvals for, and successfully commercializing, Korsana’s product candidates, either alone or with third parties, and Korsana cannot guarantee that it will ever obtain regulatory approval for any of its product candidates. Korsana has not yet demonstrated its ability to complete any clinical trials, obtain regulatory approvals, manufacture a commercial-scale product or arrange for a third party to do so on Korsana’s behalf, or conduct sales and marketing activities necessary for successful product commercialization. Before obtaining regulatory approval for the commercial distribution of any product candidate, Korsana or an existing or future collaborator must conduct extensive preclinical tests and clinical trials to demonstrate the safety and efficacy in humans of the product candidate.

Korsana or its collaborators may experience delays in initiating or completing preclinical studies or clinical trials. Korsana or its collaborators also may experience numerous unforeseen events during, or as a result of, any future preclinical studies or clinical trials that Korsana could conduct that could delay or prevent Korsana’s ability to receive regulatory approval or commercialize its product candidates, including:

78

Commencing clinical trials in the United States is subject to acceptance by the FDA of an IND and finalizing the trial design based on discussions with the FDA. Commencing clinical trials in jurisdictions outside of the United States is similarly subject to acceptance by the applicable regulatory authority of clinical trial documentation following discussions with such authority. In the event that the FDA or other applicable regulatory authority requires Korsana to complete additional preclinical studies or Korsana is required to satisfy other FDA or foreign regulatory authority requests, respectively, prior to commencing clinical trials, the start of Korsana’s first clinical trial for a product candidate may be delayed. Even after Korsana receives and incorporates guidance from these regulatory authorities, the FDA or other regulatory authorities could disagree as to whether Korsana has satisfied their requirements to commence any clinical trial or change their position on the acceptability of Korsana’s trial design or the clinical endpoints selected, which may require Korsana to complete additional preclinical studies or clinical trials, delay the enrollment of Korsana’s clinical trials or impose stricter approval conditions than Korsana currently expects. There are analogous processes and risks applicable to clinical trial applications in other countries, including but not limited to Canada, New Zealand, Australia, countries in the EU, and countries in Asia.

Korsana may not have the financial resources to continue development of its product candidates if Korsana experiences any issues that delay or prevent regulatory approval of, or Korsana’s ability to commercialize, its product candidates. Korsana or its future collaborators’ inability to complete development of, or commercialize Korsana’s product candidates, or significant delays in doing so, could have a material and adverse effect on Korsana’s business, financial condition, results of operations, and prospects.

79

Korsana is substantially dependent on the success of KRSA-028, and Korsana’s anticipated clinical trials for such product candidate may not be successful.

Korsana’s future success is substantially dependent on its ability to timely obtain regulatory approval for, and then successfully commercialize, KRSA-028. Korsana is initially investing a majority of its efforts and financial resources into the research and development of this program. Korsana plans to submit a CTN in Australia or a CTA in New Zealand by the end of 2026 and an IND in the United States in the first quarter of 2027. Pharmacokinetic data in healthy volunteers is anticipated by mid-year 2027 and interim proof-of-concept data showing amyloid plaque reduction in Alzheimer’s disease patients is anticipated by the end of 2027. The success of KRSA-028 depends on demonstrating one or more clinical advantages over other approved anti-Ab antibody products or product candidates in clinical development, which may include favorable data on amyloid plaque clearance, slowing of cognitive decline or disease progression, reduced rates of amyloid-related imaging abnormalities (“ARIA”), improved hematologic safety, and/or a convenient low-volume subcutaneous route of administration. Korsana’s belief that KRSA-028 will show favorable clinical data is based in part on the assumption that the increased brain penetration observed in mice and non-human primates (“NHPs”) through the use of the proprietary Therapeutic Targeting (“THETA^™”) platform, which confers binding to the transferrin receptor (“TfR1”),will translate to humans. If Korsana’s Phase 1 clinical trial of KRSA-028 or additional clinical trials do not demonstrate adequate brain delivery or improvements versus the limitations of other TfR1-based approaches, the clinical and commercial potential of KRSA-028 will be significantly and adversely affected.

Korsana’s product candidates will require evaluation of preclinical, clinical, and manufacturing activities, preclinical and clinical development, regulatory approval in multiple jurisdictions, substantial investment, and significant marketing efforts before Korsana generates any revenues from product sales. Korsana is not permitted to market or promote its product candidates before it receives regulatory approval from the FDA and comparable foreign regulatory authorities, and Korsana may never receive such regulatory approvals.

The success of Korsana’s product candidates will depend on a variety of factors. Korsana does not have complete control over many of these factors, including certain aspects of clinical development and the regulatory submission process, potential threats to Korsana’s intellectual property rights, potential threats from the intellectual property rights of third parties and the manufacturing, marketing, distribution, and sales efforts of any future collaborator. Accordingly, Korsana cannot assure you that it will ever be able to generate revenue through the sale of these product candidates, even if approved. If Korsana is not successful in obtaining regulatory approval for and commercializing KRSA-028 or future product candidates, or is significantly delayed in doing so, Korsana’s business will be materially harmed.

Korsana’s product candidates are based on novel technology in fields that have seen limited success in drug development, which makes it difficult to predict the time and cost of product candidate development and subsequently obtaining regulatory approval.

Korsana has focused its research and development efforts on addressing neurodegenerative diseases. Collectively, efforts by biopharmaceutical companies in the field of neurodegenerative diseases have seen limited success in drug development. There are few effective therapeutic options available for patients with neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease. Korsana’s future success is highly dependent on the successful development of its THETA^™ platform and its product candidates for treating neurodegenerative diseases. Developing and, if approved, commercializing Korsana’s product candidates for treatment of neurodegenerative diseases subjects it to a number of challenges, including engineering product candidates to cross the blood brain barrier (“BBB”) to enable optimal concentration of the therapeutic in the brain and obtaining regulatory approval from the FDA and other regulatory authorities who have only a limited set of precedents to rely on.

Korsana’s approach to the treatment of neurodegenerative diseases aims to identify and select targets with a link to neurodegenerative diseases; to identify and develop molecules that engage the intended target; to, where

80

possible, identify and develop biomarkers, which are biological molecules found in blood, other bodily fluids, or tissues that are signs of a normal or abnormal process or of a condition or disease, to select patient populations and demonstrate, where possible, target engagement, pathway engagement, and impact on disease progression of its molecules; and to engineer its molecules to cross the BBB and act directly in the brain. This strategy may not prove to be successful. Korsana may not be able to discover, develop, and utilize biomarkers to demonstrate target engagement, pathway engagement, and the impact on disease progression of its product candidates. Korsana cannot be sure that its approach will yield satisfactory therapeutic products that are safe and effective, scalable, or profitable. Moreover, public perception of drug safety issues, including adoption of new therapeutics or novel approaches to treatment, may adversely influence the willingness of subjects to participate in clinical trials, or if approved, of physicians to subscribe to novel treatments.

If Korsana does not achieve its projected development objectives in the time frames Korsana announces and expects, the commercialization of its product candidates may be delayed which may harm Korsana’s reputation and prospects, increase its expenses, and cause its stock price to decline.

From time to time, Korsana estimates the timing of the anticipated accomplishment of various scientific, clinical, regulatory and other product development goals, which Korsana sometimes refers to as milestones. These milestones may include the commencement or completion of scientific studies and clinical trials, such as the expected timing for the initiation of Korsana’s Phase 1 clinical trial of KRSA-028, the timing for receipt of clinical data, and the timing for the submission of regulatory filings. From time to time, Korsana may publicly announce the expected timing of some of these milestones. All of these milestones are and will be based on numerous assumptions. The actual timing of these milestones can vary dramatically compared to Korsana’s estimates, in many cases for reasons beyond Korsana’s control. If Korsana does not meet these milestones as publicly announced, or at all, Korsana’s prospects and reputation may be adversely affected, and its stock price may decline. Additionally, delays relative to Korsana’s projected timelines are likely to cause overall expenses to increase, which may require Korsana to raise additional capital sooner than expected and prior to achieving targeted development milestones.

Korsana’s approach to the discovery and development of its product candidates is unproven, and Korsana may not be successful in its efforts to build a pipeline of product candidates with commercial value.

Korsana’s approach to the discovery and development of its product candidates leverages established mechanisms of action and incorporates advanced antibody engineering to optimize half-life and other properties designed to overcome limitations of existing therapies, including increased binding affinity, and transferrin receptor (“TfR”) shuttling for delivering large molecule drugs across the BBB, enabling higher drug concentration inside the brain. Korsana’s product candidates are purposefully designed to improve upon existing product candidates and products while maintaining the same, established mechanisms of action. However, the scientific research that forms the basis of Korsana’s efforts to develop differentiated product candidates using half-life extension technologies, effector function modification, and/or the TfR-based THETA technology to deliver large molecule drugs across the BBB, is ongoing and may not result in viable product candidates. Korsana has no clinical data on product candidates using TfR-based THETA technology in neurodegenerative diseases and demonstrating whether they are safe or effective for long-term treatment in humans. Korsana also has no clinical data to indicate whether its antibody engineering designed to optimize half-life and modify effector function enhances brain exposure or translates into improved safety, tolerability, convenience, or efficacy in humans. The long-term safety and efficacy of Korsana’s product candidates compared to currently approved products is unknown.

Korsana may ultimately discover that utilizing half-life extension technologies, effector function modulation, and the TfR-based THETA technology to target 3pE-Ab for Korsana’s specific indications and any product candidates resulting therefrom do not possess certain properties required for therapeutic effectiveness. Korsana currently has only preclinical data regarding the increased half-life properties, effector function modulation, and targeting mechanism of Korsana’s product candidates, and the same results may not be seen in

81

humans. In addition, product candidates using half-life extension technologies and effector function modulation, or that are designed to bind to 3pE-Ab and clear amyloid plaques, may demonstrate different chemical, pharmacological and biological properties in patients than they do in laboratory studies. This technology and any product candidates resulting therefrom may not demonstrate the same chemical and pharmacological properties in humans and may interact with human biological systems in unforeseen, ineffective, or harmful ways. Many product candidates that appeared highly promising in preclinical studies or in early-stage clinical trials have failed when advanced into, or further in, clinical development.

In addition, other companies are developing drug products that target Ab or utilize TfR-mediated delivery technologies for central nervous system indications, or that utilize half-life extension technology and/or effector function modulation for other targets. The failure of those companies to demonstrate the safety and/or efficacy of their product candidates may be harmful to Korsana’s business, financial condition, results of operations, and prospects. Conversely, if those companies are successful in demonstrating safety and/or efficacy of their product candidates, these competitive products may instead gain and hold the applicable market.

In addition, Korsana may in the future seek to discover and develop product candidates that are based on novel targets and technologies that are unproven. If Korsana’s discovery or business development activities fail to identify novel targets or technologies for drug development, or such targets or technologies prove to be unsuitable for treating human disease, Korsana may not be able to develop viable additional product candidates. Korsana and its future collaborators may never receive approval to market and commercialize any product candidate. Even if Korsana or a future collaborator obtains regulatory approval, the approval may be for targets, disease indications or patient populations that are not as broad as Korsana intended or desired or may require labeling that includes significant use or distribution restrictions or safety warnings. If the products resulting from Korsana’s product candidates prove to be ineffective, unsafe, or commercially unviable, Korsana’s product candidates and pipeline would have little, if any, value, which would have a material and adverse effect on Korsana’s business, financial condition, results of operations, and prospects.

Preclinical and clinical development involves a lengthy and expensive process that is subject to delays and with uncertain outcomes, and results of earlier studies and trials may not be predictive of future clinical trial results. If Korsana’s preclinical studies and clinical trials are not sufficient to support regulatory approval of any of its product candidates, Korsana may incur additional costs or experience delays in completing, or ultimately be unable to complete, the development of such product candidate.

Before obtaining regulatory approval from regulatory authorities for the sale of any product candidate, Korsana must complete preclinical studies and then conduct extensive clinical trials to demonstrate the safety and efficacy of Korsana’s product candidate in humans. Korsana’s clinical trials may not be conducted as planned or completed on schedule, if at all, and failure can occur at any time during the preclinical study or clinical trial process. Furthermore, a failure of one or more clinical trials can occur at any clinical trial phase. The outcome of preclinical studies and early-stage clinical trials may not be predictive of the success of later clinical trials. Moreover, preclinical and clinical data are often susceptible to varying interpretations and analyses, and many companies that have believed their product candidates performed satisfactorily in preclinical studies and clinical trials have nonetheless failed to obtain regulatory approval of their product candidates. In addition, Korsana expects to rely on patients to provide feedback on subjective measures, including disease severity and quality of life, which are inherently difficult to evaluate. These measures can be influenced by factors outside of Korsana’s control and can vary widely from day to day for a particular patient, and from patient to patient and from site to site within a clinical trial.

Korsana cannot be sure that the FDA or comparable foreign regulatory authorities will agree with Korsana’s clinical development plans. Korsana plans to use the data from healthy volunteers from its Phase 1 clinical trial of KRSA-028 to support additional clinical development. However, there is no guarantee the data from such Phase 1 trial will support additional development. If the FDA or comparable foreign regulatory authorities require Korsana to conduct additional trials or enroll additional healthy volunteers or patients, Korsana’s

82

development timeline may be delayed. Korsana cannot be sure that submission of an IND or similar foreign application will result in the FDA or comparable foreign regulatory authorities, as applicable, allowing clinical trials to begin in a timely manner, if at all. Moreover, even if these trials begin, issues may arise that could cause regulatory authorities to suspend or terminate such clinical trials. Events that may prevent successful or timely initiation or completion of clinical trials include: inability to generate sufficient preclinical, toxicology or other in vivo or in vitro data to support the initiation or continuation of clinical trials; delays in reaching a consensus with regulatory authorities on study design or implementation of the clinical trials; delays or failure in obtaining regulatory authorization to commence a trial; delays in reaching agreement on acceptable terms with prospective CROs and clinical trial sites, the terms of which can be subject to extensive negotiation and may vary significantly among different CROs and clinical trial sites; delays in identifying, recruiting and training suitable clinical investigators; delays in obtaining required IRB approval or positive ethics committee opinions at each clinical trial site; delays in manufacturing, testing, releasing, validating or importing/exporting sufficient stable quantities of Korsana’s product candidates for use in clinical trials or the inability to do any of the foregoing; failure by Korsana’s CROs, other third parties or Korsana to adhere to clinical trial protocols; failure to perform in accordance with the FDA’s or any other regulatory authority’s good clinical practice (“GCP”) requirements or regulatory guidelines; changes to the clinical trial protocols; clinical sites deviating from trial protocol or dropping out of a trial; changes in regulatory requirements, guidance or clinical trial plans that require amending or submitting new clinical protocols; selection of clinical endpoints that require prolonged periods of observation or analyses of resulting data; transfer of manufacturing processes to new or larger-scale facilities and delays or failure by Korsana’s CMOs or Korsana to make any necessary changes to such manufacturing process; and third parties being unwilling or unable to satisfy their contractual obligations to Korsana.

Korsana could also encounter delays if a clinical trial is suspended or terminated by Korsana, by the IRBs or ethics committees of the institutions in which such clinical trials are being conducted, by the Data Safety Monitoring Board, if any, for such clinical trial or by the FDA or comparable foreign regulatory authorities. Such authorities may suspend or terminate a clinical trial due to a number of factors, including failure to conduct the clinical trial in accordance with regulatory requirements or Korsana’s clinical trial protocols, inspection of the clinical trial operations or trial site by the FDA or comparable foreign regulatory authorities resulting in the imposition of a clinical hold, unforeseen safety issues or adverse side effects, failure to demonstrate a benefit from the product candidate, changes in governmental regulations or administrative actions or lack of adequate funding to continue the clinical trial. If Korsana is required to conduct additional clinical trials or other testing of its product candidates beyond those that Korsana currently contemplates, if Korsana is unable to successfully complete clinical trials of its product candidates, if the results of these trials are not positive or are only moderately positive or if there are safety concerns, Korsana’s business and results of operations would be adversely affected.

Korsana may encounter difficulties enrolling patients in its clinical trials, and its clinical development activities could thereby be delayed or otherwise adversely affected.

The timely completion of clinical trials in accordance with their protocols depends, among other things, on Korsana’s ability to enroll a sufficient number of patients who remain in the trial until its conclusion. Korsana may experience difficulties in patient enrollment in clinical trials for a variety of reasons, including:

83

Korsana or its partners may encounter difficulties or delays in enrollment of its clinical trials due to the availability of newly approved therapies and competing products. For example, lecanemab received FDA approval for the treatment of Alzheimer’s disease in 2023, and donanemab received FDA approval for the treatment of Alzheimer’s disease in July 2024. As a result, Korsana or its partners’ ability to enroll participants in clinical trials for Alzheimer’s disease may be hampered if potential participants choose to instead avail themselves of approved therapies.

Preliminary, “topline” or interim data from Korsana’s clinical trials that Korsana announces or publishes from time to time may change as more patient data become available and are subject to audit and verification procedures.

From time to time, Korsana may publicly disclose preliminary or topline data from its preclinical studies and clinical trials, which are based on a preliminary analysis of then-available data. The results and related findings and conclusions are subject to change following a more comprehensive review of the data. Korsana also makes assumptions, estimations, calculations, and conclusions as part of its analyses of these data without the opportunity to fully and carefully evaluate complete data. As a result, the preliminary or topline results that Korsana reports may differ from future results of the same studies, or different conclusions or considerations may qualify such results, once additional data have been received and fully evaluated or subsequently made subject to audit and verification procedures.

Any preliminary or topline data should be viewed with caution until the final data are available. From time to time, Korsana may also disclose interim data from its preclinical studies and clinical trials. Interim data are subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available or as patients from Korsana’s clinical trials continue other treatments. Further, others, including regulatory authorities, may not accept or agree with Korsana’s assumptions, estimates, calculations, conclusions, or analyses or may interpret or weigh the importance of data differently, which could impact the value of the particular product candidate, the approvability or commercialization of the particular product candidate and of Korsana as a company. In addition, the information Korsana chooses to publicly disclose regarding a particular preclinical study or clinical trial is based on what is typically extensive information, and you or others may not agree with what Korsana determines is material or otherwise appropriate information to include in Korsana’s disclosure. As a result, you or others may have reached different conclusions based on such extensive information in comparison to Korsana’s publicly disclosed conclusion regarding a particular preclinical study or clinical trial. If the preliminary, topline, or interim data that Korsana reports differ from actual results, or if others, including regulatory authorities, disagree with the conclusions reached, Korsana’s ability to obtain approval for, and commercialize, Korsana’s product candidates may be harmed, which could harm Korsana’s business, operating results, prospects, or financial condition.

84

Korsana’s future clinical trials or those of its future collaborators may reveal significant adverse events or undesirable side effects not seen in Korsana’s preclinical studies and may result in a safety profile that could halt clinical development, inhibit regulatory approval, or limit commercial potential or market acceptance of any of Korsana’s product candidates.

Results of Korsana’s clinical trials could reveal a high or unacceptable severity and prevalence of side effects, adverse events or unexpected characteristics. Korsana has not yet completed any clinical trials in humans. If significant adverse events or other side effects are observed in any of Korsana’s future clinical trials, Korsana may have difficulty recruiting patients to such trials, patients may drop out of Korsana’s trials, or Korsana may be required to abandon the trials or Korsana’s development efforts of one or more product candidates altogether. For example, treatment-emergent adverse events (“TEAEs”) have been reported in approximately 85% of expansion cohort participants in Roche’s Brainshuttle AD study, an ongoing Phase 1/2 clinical trial investigating trontinemab in patients with prodromal or mild to moderate Alzheimer’s disease, including ARIA, anemia, infusion-related reactions, and one fatal case of cerebral macrohemmorrhage.

Because KRSA-028 will have a similar mechanism of action as trontinemab, it is possible that patients in Korsana’s future clinical trials could exhibit TEAEs of similar or worse frequency or severity. Korsana, the FDA or other applicable regulatory authorities, or an IRB or ethics committee, may suspend any clinical trials of any product candidate at any time for various reasons, including a belief that subjects or patients in such trials are being exposed to unacceptable health risks or adverse side effects. Some potential products developed in the biotechnology industry that initially showed therapeutic promise in early-stage studies and trials have later been found to cause side effects that prevented their further development. Other potential products have shown side effects in preclinical studies, which side effects do not present themselves in clinical trials in humans. Even if the side effects do not preclude the product candidate from obtaining or maintaining regulatory approval, undesirable side effects may inhibit market acceptance of the approved product due to Korsana’s tolerability versus other therapies. In addition, an extended half-life could prolong the duration of undesirable side effects, which could also inhibit market acceptance. TEAEs could also affect patient recruitment or the ability of enrolled subjects to complete Korsana’s clinical trials or could result in potential product liability claims. Potential side effects associated with Korsana’s product candidates may not be appropriately recognized or managed by the treating medical staff, as toxicities resulting from Korsana’s product candidates may not be normally encountered in the general patient population and by medical personnel. Any of these occurrences could harm Korsana’s business, financial condition, results of operations, and prospects significantly.

In addition, even if Korsana successfully advances its product candidates or any future product candidate through clinical trials, such trials will only include a limited number of patients and limited duration of exposure to Korsana’s product candidates. As a result, Korsana cannot be assured that adverse effects of Korsana’s product candidates will not be uncovered when a significantly larger number of patients are exposed to the product candidate after approval. Further, any clinical trials may not be sufficient to determine the effect and safety consequences of using Korsana’s product candidates over a multi-year period.

Korsana may expend its limited resources to pursue a particular program and fail to capitalize on programs that may be more profitable or for which there is a greater likelihood of success.

Because Korsana has limited financial and managerial resources, Korsana focuses its research and development efforts on certain selected programs. For example, Korsana is initially focused primarily on its initial product candidate, KRSA-028. As a result, Korsana may forgo or delay pursuit of opportunities with other programs that later prove to have greater commercial potential. Korsana’s resource allocation decisions may cause Korsana to fail to capitalize on viable commercial products or profitable market opportunities. Korsana’s spending on current and future research and development product candidates for specific indications may not yield any commercially viable product candidates. If Korsana does not accurately evaluate the commercial potential or target market for a particular product candidate, Korsana may relinquish valuable rights to that product candidate through collaboration, licensing, or other royalty arrangements in cases in which it would have

85

been more advantageous for Korsana to retain sole development and commercialization rights to such product candidate. In addition, Korsana may select product candidates amongst a variety of potential product candidates, and the product candidates Korsana selects may fail to be viable commercial products or the product candidates Korsana does not select may have a greater likelihood of success.

Any approved products resulting from Korsana’s current programs or any future program may not achieve adequate market acceptance among clinicians, patients, healthcare third-party payors, and others in the medical community necessary for commercial success and Korsana may not generate any future revenue from the sale or licensing of such products.

Even if regulatory approval is obtained for a product candidate resulting from one of Korsana’s current or future programs, Korsana may not gain market acceptance among physicians, healthcare professionals, patients, healthcare payors, or the medical community. Korsana may not generate or sustain revenue from sales of the product due to factors such as whether the product can be sold at a competitive cost and whether it will otherwise be accepted in the market. Market acceptance will depend on many factors, including factors that are not within Korsana’s control.

There are two approved disease-modifying therapeutic products and additional product candidates in later stages of clinical development for the treatment of Alzheimer’s disease, including Leqembi (marketed by Eisai and Biogen) and Kisunla (marketed by Lilly). However, KRSA-028 is designed to have improved brain penetration and contains modifications that are known to increase the half-life of antibodies in circulation; to date, no such disease-modifying therapy with these design modifications has been approved by the FDA for the treatment of Alzheimer’s disease, though several such agents are in clinical development. Market participants with significant influence over acceptance of new treatments, such as clinicians and third-party payors, may not adopt a biologic that incorporates effector function modification and half-life extension for Korsana’s targeted indication, and Korsana may not be able to convince the medical community and third-party payors to accept and use, or to provide favorable reimbursement for, any programs developed by Korsana or its existing or future collaborators.

Market acceptance of Korsana’s product candidates may be negatively impacted by potential poor performance of Korsana’s competitors, including the occurrence of serious adverse events in such competitors’ clinical trials or failure by such competitors to obtain and maintain regulatory approval for their product candidates. Additionally, although Korsana believes that the improved dosing and convenience it expects its product candidates to provide will improve market acceptance of such product candidates and that Korsana’s product candidates will have a competitive efficacy profile, Korsana’s predictions may not be accurate and other competitive products may instead gain and hold the applicable market. Sales of medical products also depend on the willingness of clinicians to prescribe the treatment. Korsana cannot predict whether clinicians, clinicians’ organizations, hospitals, other healthcare providers, government agencies, or private insurers will determine that Korsana’s product is safe, therapeutically effective, cost effective or less burdensome as compared with competing treatments. If any current or future product candidate is approved but does not achieve an adequate level of acceptance by such parties, Korsana may not generate or derive sufficient revenue from that product candidate and may not become or remain profitable.

Certain of Korsana’s programs may compete with Korsana’s other programs, which could negatively impact Korsana’s business and reduce Korsana’s future revenue.

Korsana is developing KRSA-028 for the treatment of Alzheimer’s disease and may in the future develop programs for additional neurodegenerative disease indications. However, developing multiple product candidates for neurodegenerative disease indications may negatively impact Korsana’s business if the product candidates compete with each other. For example, if multiple product candidates are conducting clinical trials at the same time, they could compete for the enrollment of patients. In addition, if multiple product candidates are approved for the same indication, they may compete for market share, which could limit Korsana’s future revenue.

86

Korsana’s research and development efforts are concentrated in the field of neurodegenerative diseases, which has historically experienced a high rate of clinical failure. If the scientific basis for Korsana’s approach proves insufficient or the field experiences setbacks, Korsana’s entire pipeline could be adversely affected.

Korsana has concentrated its research and development efforts on therapeutics for neurodegenerative diseases, with its lead product candidate, KRSA-028, targeting Alzheimer’s disease. The neurodegenerative disease field has historically experienced a high rate of clinical trial failure compared to other therapeutic areas, and a number of companies have invested significant resources in the development of neurodegenerative disease product candidates without obtaining regulatory approval. If the scientific basis for Korsana’s approach to treating neurodegenerative diseases, including the use of TfR-based THETA technology to deliver therapeutics across the blood brain barrier, proves to be flawed or insufficient, Korsana’s entire pipeline could be rendered nonviable. Because Korsana’s pipeline is concentrated in a single therapeutic area, Korsana does not have the benefit of diversification across multiple therapeutic areas that could offset failures in any one program. A setback in one program could have a disproportionate impact on Korsana’s business, financial condition, results of operations, and prospects relative to a company with a more diversified pipeline. Adverse developments in the neurodegenerative disease field generally, including safety signals or clinical failures by other companies developing therapies for similar indications, could negatively affect investor sentiment, regulatory scrutiny, and patient enrollment for Korsana’s clinical trials, regardless of the merits of Korsana’s own product candidates.

Korsana plans to conduct clinical trials for product candidates at sites outside the United States, and the FDA may not accept data from trials conducted in such locations.

Korsana plans to conduct its Phase 1 clinical trial of KRSA-028 in Australia or New Zealand, and Korsana may choose to conduct one or more of its future clinical trials outside the United States in whole or in part, including potentially in the UK, EU, or Canada. Although the FDA may accept data from clinical trials conducted outside the United States, acceptance of this data is subject to conditions imposed by the FDA. For example, the clinical trial must be well designed and conducted and performed by qualified investigators in accordance with ethical principles. The trial population must also adequately represent the U.S. population, and the data must be applicable to the U.S. population and U.S. medical practice in ways that the FDA deems clinically meaningful. In addition, while these clinical trials are subject to the applicable local laws, FDA acceptance of the data will depend on Korsana’s determination that the trials also complied with all applicable U.S. laws and regulations. Many foreign regulatory authorities have similar requirements for clinical data gathered outside of their respective jurisdictions. In addition, such foreign trials would be subject to the applicable local laws of the foreign jurisdictions where the trials are conducted. There can be no assurance that the FDA or any comparable foreign regulatory authority will accept data from trials conducted outside of the United States or the relevant jurisdiction, as applicable. If the FDA or any comparable foreign regulatory authority does not accept such data, it would likely result in the need for additional trials, which would be costly and time-consuming and would delay or permanently halt Korsana’s development of the applicable product candidates or delay or prevent regulatory approval for commercialization in the applicable jurisdiction. Even if the FDA or any comparable foreign regulatory authority accepted such data, it could require Korsana to modify its planned clinical trials to receive clearance to initiate such trials in the United States or the relevant jurisdiction, as applicable, or to continue such trials once initiated.

Further, conducting international clinical trials presents additional risks that may delay completion of Korsana’s clinical trials. These risks include the failure of enrolled patients in foreign countries to adhere to clinical protocol as a result of differences in healthcare services or cultural customs that could restrict or limit Korsana’s ability to conduct its clinical trials, the administrative burdens of conducting clinical trials under multiple sets of foreign regulations, foreign exchange fluctuations, diminished protection of intellectual property in some countries, as well as political and economic risks relevant to foreign countries.

87

Risks Related to Korsana’s Reliance on Third Parties

Korsana relies on collaborations and licensing arrangements with third parties, including Paragon. If Korsana is unable to maintain these collaborations or licensing arrangements, or if these collaborations or licensing arrangements are not successful, Korsana’s business could be negatively impacted.

Korsana relies on its collaboration with a third party, Paragon, for a substantial portion of its discovery capabilities and for the rights necessary to develop and commercialize its product candidates. In the future, Korsana could also rely on additional licensing arrangements with third parties. For example, Korsana has entered into the Paragon ADOA. However, Paragon could terminate the Paragon ADOA under certain circumstances, including Korsana’s failure to make any payments owed to Paragon under the agreement or any uncured material breach of the agreement by Korsana, in which event Korsana may lose intellectual property rights and may not be able to develop or commercialize the product candidates covered by that agreement, including KRSA-028.

Collaborations or licensing arrangements that Korsana enters into may not be successful, and any success will depend heavily on the efforts and activities of such collaborators or licensors. If any of Korsana’s collaborators or licensors experiences delays in performance of, or fails to perform, their obligations under their agreement with Korsana, disagrees with Korsana’s interpretation of the terms of such agreement, or terminates their agreement with Korsana, Korsana’s pipeline and product candidates and development timeline could be adversely affected. If Korsana fails to comply with any of the obligations under its collaborations or license agreements, including payment terms and diligence terms, Korsana’s collaborators or licensors may have the right to terminate such agreements, in which event Korsana may lose intellectual property rights and may not be able to develop, manufacture, market or sell the products covered by Korsana’s agreements or may face other penalties under Korsana’s agreements. Korsana’s collaborators and licensors may also fail to properly maintain or defend the intellectual property Korsana has licensed from them, if required by Korsana’s agreement with them, leading to the potential invalidation of Korsana’s intellectual property, or they may even infringe upon Korsana’s intellectual property rights, any of which could subject Korsana to litigation or arbitration, which would be time-consuming and expensive and could harm Korsana’s ability to commercialize its product candidates. In addition, collaborators could independently develop, or develop with third parties, products that compete directly or indirectly with Korsana’s product candidates and products if the collaborators believe that the competitive products are more likely to be successfully developed or can be commercialized under terms that are more economically attractive than Korsana’s.

As part of Korsana’s strategy, Korsana plans to evaluate additional opportunities to enhance its capabilities and expand its development pipeline or add development or commercialization capabilities. Korsana may not realize the benefits of such collaborations, alliances or licensing arrangements. Any of these relationships may require Korsana to incur non-recurring and other charges, increase Korsana’s near and long-term expenditures, issue securities that dilute Korsana’s existing stockholders or disrupt Korsana’s management and business.

Korsana may face significant competition in attracting appropriate collaborators, and more established companies may also be pursuing strategies to license or acquire third-party intellectual property rights that Korsana considers attractive. These companies may have a competitive advantage over Korsana due to their size, financial resources and greater clinical development and commercialization capabilities. In addition, companies may be unwilling to assign or license rights to Korsana, whether they perceive Korsana to be a competitor or for other reasons. Whether Korsana reaches a definitive agreement for a collaboration will depend, among other things, upon Korsana’s assessment of the collaborator’s resources and expertise, the terms and conditions of the proposed collaboration and the proposed collaborator’s evaluation of a number of factors. Collaborations are complex and time-consuming to negotiate, document and execute. In addition, consolidation among large pharmaceutical and biotechnology companies has reduced the number of potential future collaborators. Korsana may not be able to negotiate additional collaborations on a timely basis, on acceptable terms or at all. If Korsana fails to enter into collaborations and does not have sufficient funds or expertise to undertake the necessary

88

development and commercialization activities, Korsana may not be able to further develop its product candidates or bring them to market.

Risks associated with the in-licensing or acquisition of product candidates could cause substantial delays in the preclinical and clinical development of Korsana’s product candidates.

Korsana has relied and continues to rely on Paragon, and expects to rely on Korsana’s future licensing partners, to (i) conduct research and development in accordance with the applicable protocol, legal, regulatory, and scientific standards, (ii) accurately report the results of all preclinical studies conducted prior to Korsana’s licensing or acquisition of the relevant product candidates, and (iii) correctly collect and interpret the data from these studies. If the research and development processes or the results of the development programs prior to Korsana’s licensing or acquisition of Korsana’s product candidates prove to be unreliable, this could result in increased costs and delays in the development of Korsana’s product candidates, which could adversely affect any future revenue from such product candidates, if approved.

Korsana may also acquire or in-license additional product candidates for preclinical or clinical development in the future as Korsana continues to build its pipeline. The risks associated with acquiring or in-licensing product candidates could result in delays in the commencement or completion of Korsana’s preclinical studies and clinical trials, if they are ever commenced or completed, and Korsana’s ability to generate revenues from its product candidates may be delayed. Please see the section titled “Risk Factors—Risks Related to Korsana’s Intellectual Property—If Korsana is unable to obtain or maintain necessary rights to its programs through acquisitions and in-licenses, Korsana’s business may be materially harmed” below for additional information regarding such risks.

Korsana currently relies, and plans to rely in the future, on third parties to conduct and support its preclinical studies and clinical trials. If these third parties do not properly and successfully carry out their contractual duties or meet expected deadlines, Korsana may not be able to obtain regulatory approval of or commercialize Korsana’s product candidates.

Korsana has utilized and plans to continue to utilize and depend upon independent investigators and collaborators, such as medical institutions, CROs, contract testing labs and strategic partners, to conduct and support Korsana’s preclinical studies and clinical trials under agreements with Korsana. Korsana will rely heavily on these third parties over the course of its preclinical studies and clinical trials, and Korsana controls only certain aspects of their activities. As a result, Korsana will have less direct control over the conduct, timing and completion of these preclinical studies and clinical trials and the management of data developed through preclinical studies and clinical trials than would be the case if Korsana was relying entirely upon its own staff. Nevertheless, Korsana is responsible for ensuring that each of its studies and trials is conducted in accordance with the applicable protocol, legal, regulatory, and scientific standards, and Korsana’s reliance on these third parties does not relieve Korsana of its regulatory responsibilities. Korsana and its third-party contractors and CROs are required to comply with GCP, which are regulations and guidelines enforced by the FDA and comparable foreign regulatory authorities for all of Korsana’s product candidates in clinical development. If Korsana or any of these third parties fail to comply with applicable GCP regulations, the clinical data generated in Korsana’s clinical trials may be deemed unreliable and the FDA or comparable foreign regulatory authorities may require Korsana to perform additional clinical trials before approving Korsana’s marketing applications. Korsana cannot assure you that upon inspection by a given regulatory authority, such regulatory authority will determine that any of Korsana’s clinical trials comply with GCP. In addition, Korsana’s clinical trials must be conducted with products manufactured in accordance with cGMP. Korsana’s failure to comply with these requirements may require Korsana to repeat clinical trials, which would delay the regulatory approval process. Moreover, Korsana’s business may be implicated if any of these third parties violates federal or state fraud and abuse or false claims laws and regulations or healthcare privacy and security laws, and foreign equivalents.

Any third parties conducting Korsana’s clinical trials will not be its employees and, except for remedies available to Korsana under its agreements with such third parties, Korsana cannot control whether they devote

89

sufficient time and resources to Korsana’s programs. These third parties may encounter challenges hiring and retaining sufficient qualified personnel or they may be involved in mergers, acquisitions or similar transactions and may have relationships with other commercial entities, including Korsana’s competitors, for whom they may also be conducting clinical trials or other product development activities, which could negatively affect their performance on Korsana’s behalf and the timing thereof and could lead to products that compete directly or indirectly with Korsana’s current or future product candidates. If these third parties do not successfully carry out their contractual duties or obligations or meet expected deadlines, if they need to be replaced or if the quality or accuracy of the clinical data they obtain is compromised due to the failure to adhere to Korsana’s clinical protocols or regulatory requirements or for other reasons, Korsana’s clinical trials may be extended, delayed or terminated and Korsana may not be able to complete development of, obtain regulatory approval of or successfully commercialize its product candidates.

In addition, Korsana plans to rely on foreign CROs and CMOs, including WuXi Biologics (Hong Kong) Limited (“WuXi Biologics (Hong Kong)”), for formulation and manufacturing of Korsana’s Phase 1 clinical trial materials, and will likely continue to rely on foreign CROs and CMOs in the future. Foreign CMOs may be the target of U.S. legislation, trade restrictions and other foreign regulatory requirements which could increase the cost or reduce the supply of material available to Korsana, delay the procurement or supply of such material, restrict or even prohibit Korsana’s ability to work with such CMOs, or have an adverse effect on Korsana’s ability to secure significant commitments from governments to purchase potential therapies.

The biopharmaceutical industry in China is strictly regulated by the Chinese government. Changes to Chinese regulations or government policies affecting biopharmaceutical companies are unpredictable and may have a material adverse effect on Korsana’s collaborators in China which could have an adverse effect on Korsana’s business, financial condition, results of operations, and prospects. In addition, the United States government has imposed significant tariffs on imports from China and other countries and may impose more restrictions on goods, including biologically derived substances, manufactured in or imported from China or other countries or impose other restrictions on companies’ ability to work with Chinese or other foreign counterparties. Evolving changes in China’s public health, economic, political, and social conditions and the uncertainty around China’s relationship with other governments, such as the United States and the UK, could also negatively impact Korsana’s ability to manufacture its product candidates for its planned clinical trials or have an adverse effect on its ability to secure government funding, which could adversely affect Korsana’s financial condition and cause Korsana to delay its clinical development programs. Furthermore, if one or more of Korsana’s collaborators or vendors in China is deemed to be a biotechnology company of concern under the BIOSECURE Act, Korsana’s operations and financial condition may be negatively impacted as a result of any delays or increased costs arising from the trade restrictions and other foreign regulatory requirements affecting such collaborators. In addition, while Korsana has established relationships with CROs and CMOs outside of China, moving to those suppliers in the event of a geopolitical instability affecting Korsana’s collaborators in China could introduce delays into the development program.

Korsana relies on the use of third-party CMOs to manufacture Korsana’s product candidates, and Korsana expects to continue to rely on third-party CMOs to produce Korsana’s products, if approved. Korsana’s business could be adversely affected if Korsana is unable to use third-party manufacturing sites or if the third-party manufacturers encounter difficulties in production.

Korsana does not currently own any facility that may be used as Korsana’s clinical-scale manufacturing and processing facility and must rely on CMOs to manufacture Korsana’s product candidates. Korsana has not yet caused its product candidates to be manufactured on a commercial scale and may not be able to do so for any of Korsana’s product candidates, if approved. Korsana currently has a single source for its supply of Korsana’s product candidates. If there should be any disruption in such supply arrangement, including any adverse events affecting Korsana’s sole supplier, or if Korsana experiences delays or difficulties in transferring, or is unable to successfully transfer, Korsana’s manufacturing processes, it could have a negative effect on the clinical development of Korsana’s product candidates and other operations while Korsana works to identify and qualify

90

an alternate supply source. Korsana has limited control over the manufacturing process of, and may be dependent on, Korsana’s contract manufacturing partners for compliance with cGMP requirements and any other regulatory requirements of the FDA or comparable foreign regulatory authorities for the manufacture of Korsana’s product candidates. Beyond periodic audits, Korsana has limited control over the ability of its CMOs to maintain adequate quality control, quality assurance, and qualified personnel. If the FDA or another applicable regulatory authority does not approve these facilities for the manufacture of Korsana’s product candidates or withdraws any approval in the future, Korsana may need to find alternative manufacturing facilities, which would require the incurrence of significant additional costs and delays and materially adversely affect Korsana’s ability to develop, obtain regulatory approval for or market its product candidates, if approved. Korsana, or its future contract manufacturers, any future collaborators and their contract manufacturers could be subject to periodic unannounced inspections by the FDA, competent authorities of member states of the European Union (“EU Member States”) or other comparable foreign regulatory authorities, to monitor and ensure compliance with cGMP. Despite Korsana’s efforts to audit and verify regulatory compliance, one or more of Korsana’s third-party manufacturing vendors may be found on regulatory inspection by the FDA, competent authorities of EU Member States or other comparable foreign regulatory authorities to be noncompliant with cGMP regulations. Korsana’s failure, or the failure of Korsana’s CMOs, to comply with applicable regulations could result in sanctions being imposed on Korsana, including fines, injunctions, civil penalties, delays, suspension, variation or withdrawal of approvals, license revocation, seizures or recalls of product candidates or drugs, operating restrictions and criminal prosecutions, any of which could significantly and adversely affect supplies of Korsana’s product candidates or products, if approved, and harm Korsana’s business and results of operations.

Moreover, Korsana’s CMOs may experience manufacturing difficulties due to resource constraints, supply chain issues, intellectual property disputes or as a result of labor disputes or unstable political environments. If any CMOs on which Korsana will rely fail to manufacture quantities of Korsana’s product candidates at quality levels necessary to meet regulatory requirements and at a scale sufficient to meet anticipated demand at a commercially reasonable cost, Korsana’s business, financial condition, and prospects could be materially and adversely affected. In addition, Korsana’s CMOs are responsible for transporting temperature-controlled materials that can be inadvertently degraded during transport due to several factors, rendering certain batches unsuitable for trial use for failure to meet, among others, Korsana’s integrity and purity specifications. Korsana and any of its CMOs may also face product seizure or detention or refusal to permit the import or export of products. Korsana’s business could be materially adversely affected by business disruptions to Korsana’s third-party providers that could materially adversely affect Korsana’s anticipated timelines, potential future revenue and financial condition and increase Korsana’s costs and expenses. Each of these risks could delay or prevent the completion of Korsana’s preclinical studies and clinical trials or the approval of any of Korsana’s product candidates by the FDA or comparable foreign regulatory authorities, result in higher costs or adversely impact commercialization of Korsana’s product candidates.

Risks Related to Korsana’s Business and Operations

In order to successfully implement its plans and strategies, Korsana will need to grow the size of its organization and Korsana may experience difficulties in managing this growth.

Korsana expects to experience significant growth in the number of its employees and the scope of Korsana’s operations, particularly in the areas of preclinical and clinical drug development, technical operations, clinical operations, and regulatory affairs. To manage its anticipated future growth, Korsana must continue to implement and improve its managerial, operational, financial, and personnel systems, expand Korsana’s facilities, and continue to recruit and train additional qualified personnel. Due to its limited financial resources and the limited experience of its management team working together in managing a company with such anticipated growth, Korsana may not be able to effectively manage the expansion of its operations or recruit and train additional qualified personnel.

91

Korsana is highly dependent on its key personnel and anticipates hiring new key personnel. If Korsana is not successful in attracting and retaining highly qualified personnel, Korsana may not be able to successfully implement its business strategy.

Korsana’s ability to compete in the highly competitive biotechnology and pharmaceutical industries depends upon its ability to attract and retain highly qualified managerial, scientific, and medical personnel. Korsana is highly dependent on Korsana’s managerial, scientific, and medical personnel. Although Korsana has entered into employment agreements with Korsana’s executive officers, each of them may terminate their employment with Korsana at any time. Korsana does not maintain “key person” insurance for any of Korsana’s executives or other employees. The loss of the services of Korsana’s executive officers or other key employees could impede the achievement of Korsana’s research, development and commercialization objectives and seriously harm its ability to successfully implement its business strategy. Furthermore, replacing executive officers and key personnel may be difficult and may take an extended period of time. If Korsana does not succeed in attracting and retaining qualified personnel, it could materially adversely affect Korsana’s business, financial condition, and results of operations. Korsana could in the future have difficulty attracting and retaining experienced personnel and may be required to expend significant financial resources in Korsana’s employee recruitment and retention efforts.

Korsana’s future growth may depend, in part, on its ability to operate in foreign markets, where Korsana would be subject to additional regulatory burdens and other risks and uncertainties.

Korsana’s future growth may depend, in part, on its ability to develop and commercialize its product candidates, if approved, in foreign markets for which Korsana may rely on collaboration with third parties. Recent and ongoing changes in the United States trade policy with foreign countries, including the continued uncertainty surrounding U.S. tariffs and potential retaliatory measures by foreign governments, may disrupt the global supply chain for biopharmaceutical products. For example, in September 2025, President Trump announced plans to impose 100% tariffs on imported branded or patented pharmaceuticals, unless the importing company is building U.S. manufacturing capacity. It is not yet clear whether these tariffs would apply to the importation of active pharmaceutical ingredients and possibly bulk drug products that are intended for use in clinical trials and not for commercial sale, which could increase the costs of materials for Korsana’s clinical trials. Any direct tariffs, if imposed on pharmaceutical products, may result in increased costs for raw materials and contract manufacturing services, reduced ability to source critical CMOs, and a delay in Korsana’s development timelines.

Korsana is not permitted to market or promote any of its product candidates before Korsana receives regulatory approval from the applicable foreign regulatory authority, and Korsana may never receive such regulatory approval for any of its product candidates. To obtain separate regulatory approval in many other countries, Korsana must comply with numerous and varying regulatory requirements of such countries regarding safety and efficacy and governing, among other things, clinical trials and commercial sales, pricing, and distribution of Korsana’s product candidates, if approved, and Korsana cannot predict success in these jurisdictions. If Korsana fails to comply with the regulatory requirements in international markets and receive applicable regulatory approvals, Korsana’s target market will be reduced and Korsana’s ability to realize the full market potential of its product candidates will be harmed and its business will be adversely affected. Moreover, even if Korsana obtains approval of its product candidates and ultimately commercialize its product candidates in foreign markets, Korsana would be subject to the risks and uncertainties, including the burden of complying with complex and changing foreign regulatory, tax, accounting and legal requirements and reduced protection of intellectual property rights in some foreign countries.

Korsana’s estimates of market opportunity and forecasts of market growth may prove to be inaccurate, and even if the markets in which Korsana competes achieve the forecasted growth, Korsana’s business may not grow at similar rates, or at all.

Korsana’s market opportunity estimates and growth forecasts are subject to significant uncertainty and are based on assumptions and estimates which may not prove to be accurate. Korsana’s estimates and forecasts

92

relating to size and expected growth of its target market may prove to be inaccurate. Even if the markets in which Korsana competes meet its size estimates and growth forecasts, Korsana’s business may not grow at similar rates, or at all. Korsana’s growth is subject to many factors, including its success in implementing its business strategy, which is subject to many risks and uncertainties.

Korsana’s revenue will be dependent, in part, upon the size of the markets in the territories for which Korsana gains regulatory approval, the accepted price for the product, the ability to obtain coverage and reimbursement and whether Korsana owns the commercial rights for that territory. If the number of its addressable patients is not as significant as Korsana estimates, the indication approved by regulatory authorities is narrower than Korsana expects or the treatment population is narrowed by competition, physician choice, or treatment guidelines, Korsana may not generate significant revenue from sales of such products, even if approved.

Korsana’s employees, independent contractors, consultants, commercial collaborators, principal investigators, CROs, CMOs, suppliers and vendors may engage in misconduct or other improper activities, including noncompliance with regulatory standards and requirements.

Korsana is exposed to the risk that its employees, independent contractors, consultants, commercial collaborators, principal investigators, CROs, CMOs, suppliers and vendors acting for or on its behalf may engage in misconduct or other improper activities. Misconduct by these parties could include intentional, reckless, or negligent conduct or disclosure of unauthorized activities to Korsana that violates FDA regulations, including those laws requiring the reporting of true, complete, and accurate information to the FDA, manufacturing standards, federal and state healthcare laws and regulations, and laws that require the true, complete, and accurate reporting of financial information or data. In particular, sales, marketing and business arrangements in the healthcare industry are subject to extensive laws and regulations intended to prevent fraud, kickbacks, self-dealing and other abusive practices. These laws and regulations may restrict or prohibit a wide range of pricing, discounting, marketing and promotion, sales commission, customer incentive programs, and other business arrangements. Misconduct by these parties could also involve the improper use of individually identifiable information, including, without limitation, information obtained in the course of clinical trials, which could result in regulatory sanctions and serious harm to Korsana’s reputation. Korsana has adopted a code of conduct, but it is not always possible to identify and deter misconduct by these parties and the precautions Korsana takes to detect and prevent this activity may not be effective in controlling unknown or unmanaged risks or losses or in protecting Korsana from governmental investigations or other actions or lawsuits stemming from a failure to comply with these laws or regulations.

Korsana’s internal information technology systems, or those of any of its CROs, manufacturers, other contractors or consultants, third party service providers, or existing or future collaborators, may fail or suffer security or data privacy breaches or other unauthorized or improper access to, use of, or destruction of Korsana’s proprietary or confidential data, employee data or personal data, which could result in additional costs, loss of revenue, significant liabilities, harm to Korsana’s brand and material disruption of Korsana’s operations.

In the ordinary course of its business, Korsana and the third parties upon which Korsana relies collect, receive, store, process, generate, use, transfer, disclose, make accessible, protect, secure, dispose of, transmit, and share (collectively, “Process”) proprietary, confidential, and sensitive data, including personal data, intellectual property, trade secrets, and other sensitive data (collectively, “Sensitive Information”).

Despite the implementation of security measures in an effort to protect systems that store Korsana’s information, given their size and complexity and the increasing amounts of information maintained on Korsana’s internal information technology systems and those of Korsana’s third-party CROs, other contractors (including sites performing Korsana’s clinical trials), third party service providers and supply chain companies, and consultants, these systems are potentially vulnerable to breakdown or other damage or interruption from service

93

interruptions, system malfunction, natural disasters, terrorism, war and telecommunication and electrical failures, as well as security breaches from inadvertent or intentional actions by Korsana’s employees, contractors, consultants, business partners and/or other third parties, or from cyber-attacks by malicious third parties, which may compromise Korsana’s system infrastructure or lead to the loss, destruction, alteration or dissemination of, or damage to, Korsana’s data.

Some actors now engage and are expected to continue to engage in cyber-attacks, including without limitation nation-state actors for geopolitical reasons and in conjunction with military conflicts and defense activities. During times of war and other major conflicts, Korsana, and the third parties upon which Korsana relies, may be vulnerable to a heightened risk of these attacks, including retaliatory cyber-attacks, that could materially disrupt Korsana’s systems and operations. In particular, severe ransomware attacks are becoming increasingly prevalent and can lead to significant interruptions in Korsana’s operations, loss of sensitive data and income, reputational harm, and diversion of funds. Extortion payments may alleviate the negative impact of a ransomware attack, but Korsana may be unwilling or unable to make such payments due to, for example, applicable laws or regulations prohibiting such payments.

To the extent that any disruption or security breach were to result in loss, destruction, unavailability, alteration, or dissemination of, or damage to, Korsana’s data or applications, or for it to be believed or reported that any of these occurred, Korsana could incur liability and reputational damage and the development and commercialization of its product candidates could be delayed. Further, Korsana’s insurance policies may not be adequate to compensate Korsana for the potential losses arising from any such disruption in, or failure or security breach of, Korsana’s systems or third-party systems where information important to Korsana’s business operations or commercial development is stored.

Korsana’s remote workforce may create additional risks for its information technology systems and data because Korsana’s employees work remotely and utilize network connections, computers, and devices working at home, while in transit and in public locations. Additionally, business transactions (such as acquisitions or integrations) could expose Korsana to additional cybersecurity risks and vulnerabilities, as Korsana’s systems could be negatively affected by vulnerabilities present in acquired or integrated entities’ systems and technologies.

While Korsana has implemented security measures designed to protect against security incidents, there can be no assurance that these measures will be effective. Korsana may be unable in the future to detect vulnerabilities in its information technology systems because such threats and techniques change frequently, are often sophisticated in nature, and may not be detected until after a security incident has occurred. Further, Korsana may experience delays in developing and deploying remedial measures designed to address any such identified vulnerabilities. Applicable data privacy and security obligations may require Korsana to notify relevant stakeholders of security incidents. Such disclosures are costly, and the disclosure or the failure to comply with such requirements could lead to adverse consequences.

Korsana relies on third-party service providers and technologies to operate critical business systems to Process Sensitive Information in a variety of contexts. Korsana’s ability to monitor these third parties’ information security practices is limited, and these third parties may not have adequate information security measures in place. If its third-party service providers experience a security incident or other interruption, Korsana could experience adverse consequences. While Korsana may be entitled to damages if its third-party service providers fail to satisfy their privacy or security-related obligations to Korsana, any award may be insufficient to cover its damages, or Korsana may be unable to recover such award. In addition, supply-chain attacks have increased in frequency and severity, and Korsana cannot guarantee that third parties’ infrastructure in Korsana’s supply chain or Korsana’s third-party partners’ supply chains have not been compromised.

If Korsana (or a third party upon whom Korsana relies) experiences a security incident or is perceived to have experienced a security incident, Korsana may experience adverse consequences, such as government

94

enforcement actions (for example, investigations, fines, penalties, audits, and inspections); additional reporting requirements and/or oversight; restrictions on Processing Sensitive Information (including personal data); litigation (including class claims); indemnification obligations; negative publicity; reputational harm; monetary fund diversions; interruptions in Korsana’s operations (including availability of data); financial loss; and other similar harms. Security incidents and attendant consequences may cause stakeholders (including investors and potential customers) to stop supporting Korsana’s platform, deter new customers from products, and negatively impact Korsana’s ability to grow and operate Korsana’s business.

Korsana’s contracts may not contain limitations of liability, and even where they do, there can be no assurance that limitations of liability in Korsana’s contracts are sufficient to protect Korsana from liabilities, damages, or claims related to its data privacy and security obligations. Korsana cannot be sure that its insurance coverage will be adequate or sufficient to protect Korsana from or to mitigate liabilities arising out of Korsana’s privacy and security practices, that such coverage will continue to be available on commercially reasonable terms or at all, or that such coverage will pay future claims.

Korsana is subject to stringent and changing laws, regulations and standards, and contractual obligations relating to privacy, data protection, and data security. The actual or perceived failure to comply with such obligations could lead to government enforcement actions (which could include civil or criminal penalties), fines and sanctions, private litigation and/or adverse publicity and could negatively affect Korsana’s operating results and business.

Korsana, and third parties Korsana works with, are or may become subject to numerous domestic and foreign laws, regulations, and standards relating to privacy, data protection, and data security, the scope of which is changing, subject to differing applications and interpretations, and may be inconsistent among countries, or conflict with other rules. In addition, Korsana is and may become subject to the terms of contractual obligations related to privacy, data protection, and data security. Korsana’s obligations may also change or expand as its business grows. The actual or perceived failure by Korsana or third parties related to Korsana to comply with such laws, regulations and obligations could increase Korsana’s compliance and operational costs, expose Korsana to regulatory scrutiny, actions, fines and penalties, result in reputational harm, lead to a loss of customers, result in litigation and liability, and otherwise cause a material adverse effect on Korsana’s business, financial condition, and results of operations.

If Korsana fails to comply with environmental, health and safety laws and regulations, Korsana could become subject to fines or penalties or incur costs that could have a material adverse effect on the success of Korsana’s business.

Korsana is subject to numerous environmental, health and safety laws and regulations, including those governing laboratory procedures and the handling, use, storage, treatment and disposal of hazardous materials and wastes. Korsana’s operations may involve the use of hazardous and flammable materials, including chemicals and biological and radioactive materials. In addition, Korsana may incur substantial costs in order to comply with current or future environmental, health and safety laws and regulations. These current or future laws and regulations may impair Korsana’s research, development, or commercialization efforts. Failure to comply with these laws and regulations also may result in substantial fines, penalties, or other sanctions.

Korsana may be subject to adverse legislative or regulatory tax changes that could negatively impact its financial condition.

The rules governing U.S. federal, state and local income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service (“IRS”) and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect the Combined Company’s stockholders or Korsana. Korsana assesses the impact of various tax reform proposals and modifications to existing tax treaties in all jurisdictions where Korsana has operations to determine the potential

95

effect on its business and any assumptions Korsana has made about its future taxable income. Korsana cannot predict whether any specific proposals will be enacted, the terms of any such proposals or what effect, if any, such proposals would have on Korsana’s business if they were to be enacted.

For example, the United States enacted the Inflation Reduction Act of 2022, which implements, among other changes, a 1% excise tax on certain stock buybacks. In addition, beginning in 2022, the Tax Cuts and Jobs Act (the “TCJA”) eliminated the previously available option to deduct research and development expenditures and requires taxpayers to amortize them generally over five years for research activities conducted in the United States and over fifteen years for research activities conducted outside the United States. On July 4, 2025, the U.S. Congress enacted the One Big Beautiful Bill Act, which includes a provision restoring the immediate deductibility of domestic research and development expenditures. The impact of this newly enacted law on Korsana’s tax position will depend on how the provision is implemented and interpreted by the IRS and other regulatory authorities. In addition, Korsana has no assurance as to whether, when and how this provision may be subject to further amendment or repeal. Such changes, among others, may adversely affect Korsana’s effective tax rate, results of operations, and financial condition.

Korsana may acquire businesses, product candidates, or products, or form strategic alliances, in the future, and may not realize the benefits of such acquisitions.

Korsana may acquire additional businesses or products, form strategic alliances, or create joint ventures with third parties that Korsana believes will complement or augment its existing business. If Korsana acquires businesses with promising markets or technologies, Korsana may not be able to realize the benefit of acquiring such businesses if Korsana is unable to successfully integrate them with its existing operations and company culture. Korsana may encounter numerous difficulties in developing, manufacturing, and marketing any new product candidates or products resulting from a strategic alliance or acquisition that delay or prevent Korsana from realizing their expected benefits or enhancing Korsana’s business. There is no assurance that, following any such acquisition, Korsana will achieve the synergies expected in order to justify the transaction, which could result in a material adverse effect on Korsana’s business and prospects.

Korsana maintains its cash at financial institutions, often in balances that exceed federally-insured limits. The failure of financial institutions could adversely affect Korsana’s ability to pay its operational expenses or make other payments.

Korsana’s cash held in non-interest-bearing and interest-bearing accounts exceeds the FDIC insurance limits. If such banking institutions were to fail, Korsana could lose all or a portion of those amounts held in excess of such insurance limitations. For example, the FDIC took control of Silicon Valley Bank in March 2023. The Federal Reserve subsequently announced that account holders would be made whole. However, the FDIC may not make all account holders whole in the event of future bank failures. In addition, even if account holders are ultimately made whole with respect to a future bank failure, account holders’ access to their accounts and assets held in their accounts may be substantially delayed. Any material loss that Korsana may experience in the future or inability for a material time period to access Korsana’s cash and cash equivalents could have an adverse effect on Korsana’s ability to pay its operational expenses or make other payments, which could adversely affect Korsana’s business.

Risks Related to Korsana’s Intellectual Property

Korsana’s intellectual property portfolio is at an early stage. Therefore, its ability to obtain and protect its patent rights, and protect other proprietary rights, is uncertain, exposing it to the possible loss of competitive advantage.

Korsana will rely upon a combination of patents, trademarks, trade secret protection, copyrights and confidentiality agreements, licenses, and the Paragon Option Agreements to protect the intellectual property

96

related to Korsana’s programs and technologies and to prevent third parties from competing unfairly with Korsana. Korsana’s success depends in large part on its ability to obtain and maintain patent protection for Korsana’s product candidates and their uses, as well as Korsana’s ability to operate without infringing on or violating the proprietary rights of others. If Korsana is unable to obtain patent protection with respect to KRSA-028, or any future product candidates, Korsana’s business, financial condition, results or operations and prospects could be materially harmed.

Korsana’s intellectual property portfolio is at an early stage. Korsana does not currently own or in-license any issued patents or pending patent applications. With respect to KRSA-028, Paragon has filed provisional patent applications directed to (i) antibodies targeting Aß and (ii) antibodies targeting both Aß and TfR1, including applications covering composition of matter, pharmaceutical formulations, and methods of using such antibodies, which Korsana has the option to license pursuant to the Paragon ADOA. With respect to the THETA technology, Paragon has filed provisional patent applications directed to antibodies targeting TfR1, including applications covering composition of matter, pharmaceutical formulations, and methods for using such antibodies or compounds, such as bispecific antibodies, comprising such antibodies. Paragon, or Korsana if and when it controls prosecution, defense, maintenance and enforcement of patents, intends to file one or more non-provisional patent applications claiming priority to this provisional patent application. However, Korsana cannot provide assurances that such non-provisional patent application(s) will be filed, nor whether such non-provisional patent application(s), if filed, will issue, the breadth of any resulting issued patent(s), or whether any issued patent(s) will be found to be invalid, unenforceable, or will be challenged by third parties.

Any issued patents may not afford sufficient protection of Korsana’s product candidates or their intended uses against competitors, nor can there be any assurance that the patents issued will not be infringed, designed around, or invalidated by third parties, or effectively prevent others from commercializing competitive technologies, products, or product candidates. Even if these patents are granted, they may be difficult to enforce. Further, any issued patents that Korsana may license or own covering Korsana’s product candidates could be narrowed or found invalid or unenforceable if challenged in court or before administrative bodies in the United States or abroad, including the USPTO. If Korsana does not obtain patent coverage for the work Korsana is conducting, or if Korsana obtains such rights but they are invalidated or rendered unenforceable, Korsana may be unable to exclude competitors from pursuing and marketing the same or similar product candidates. Other risks Korsana faces if it is not able to obtain and maintain patent coverage for Korsana’s product candidates are the reduction in valuation of its product candidates, and ultimately of Korsana as a company, by potential investors, and Korsana’s inability to assert claims for infringement against third parties or counterclaim against such third parties or negotiate more advantageous settlement parameters. Further, if Korsana encounters delays in its clinical trials or delays in obtaining regulatory approval, the period of time during which Korsana could market its product candidates under patent protection would be reduced. Thus, the patents that Korsana may own or license may not afford Korsana any meaningful exclusivity period or competitive advantage.

Additionally, Korsana may not be able to obtain or protect Korsana’s intellectual property rights throughout the world and the legal systems in certain countries may not favor enforcement or protection of at least certain patents, trade secrets, or other intellectual property. Filing, prosecuting, maintaining, and defending patents on product candidates and other related inventions worldwide would be expensive and Korsana’s intellectual property rights in some foreign jurisdictions can be less extensive than those in the United States; the reverse may also occur. As such, Korsana may not have patents in all countries or all major markets and may not be able to obtain patents in all jurisdictions even if Korsana or its licensor files patent applications to obtain such rights. Korsana’s competitors may operate in countries where Korsana does not have patent protection and may be able to freely use its technologies and discoveries in such countries, at least to the extent not forbidden by law.

In addition to seeking patents for some of its technology and product candidates, Korsana may also rely on trade secrets, including unpatented know-how, technology, and other proprietary information, to maintain Korsana’s competitive position. Any disclosure, either intentional or unintentional, by Korsana’s employees, the employees of third parties with whom Korsana shares its facilities or third-party consultants and vendors that

97

Korsana engages to perform research, clinical trials or manufacturing activities, or misappropriation by third parties (such as through a cybersecurity breach) of Korsana’s trade secrets or proprietary information could enable competitors to duplicate or surpass Korsana’s technological achievements, thus eroding Korsana’s competitive position in its market. In order to protect its proprietary technology and processes, Korsana relies in part on confidentiality agreements with its collaborators, employees, consultants, outside scientific collaborators and sponsored researchers and other advisors. These agreements may not effectively prevent disclosure of confidential information and may not provide an adequate remedy in the event of unauthorized disclosure of confidential information. Korsana may need to share its proprietary information, including trade secrets, with future business partners, collaborators, contractors, and others located in countries at heightened risk of theft of trade secrets, including through direct intrusion by private parties or state actors and those affiliated with or controlled by state actors. In addition, while Korsana undertakes reasonable efforts to protect its trade secrets and other confidential information from disclosure, others may independently discover trade secrets and proprietary information, and in such cases, Korsana may not be able to assert any trade secret rights against such party. Costly and time-consuming litigation could be necessary to enforce and determine the scope of Korsana’s proprietary rights and failure to obtain or maintain trade secret protection could adversely affect Korsana’s competitive business position.

Lastly, if Korsana’s trademarks and trade names are not registered or adequately protected, then Korsana may not be able to build name recognition in its markets of interest and Korsana’s business may be adversely affected.

If Korsana is unable to obtain or maintain necessary rights to its programs through acquisitions and in-licenses, Korsana’s business may be materially harmed.

Because Korsana’s development programs currently do and may in the future require the use of proprietary rights held by third parties, the growth of Korsana’s business will depend in part on its ability to acquire, in-license, or use these third-party proprietary rights. Korsana may be unable to acquire or in-license any compositions, methods of use, processes, or other third-party intellectual property rights from third parties that Korsana identifies as necessary for its programs. The licensing and acquisition of third-party intellectual property rights is a competitive area, and a number of more established companies may pursue strategies to license or acquire third-party intellectual property rights that Korsana may consider attractive or necessary. These established companies may have a competitive advantage over Korsana due to their size, capital resources and greater clinical development and commercialization capabilities. In addition, companies that perceive Korsana to be a competitor may be unwilling to assign or license rights to Korsana. Korsana also may be unable to license or acquire third-party intellectual property rights on terms that would allow Korsana to make an appropriate return on Korsana’s investment or at all. If Korsana is unable to successfully obtain rights to required third-party intellectual property rights or maintain intellectual property rights Korsana obtains in the future, Korsana may have to abandon development of the relevant program, which could have a material adverse effect on Korsana’s business, financial condition, results of operations, and prospects.

Korsana expects to have the right to control prosecution, defense, maintenance, and enforcement of patents exclusively in-licensed under the Paragon Option Agreements once the trigger for transfer of prosecution control is met. However, there may be times when rights for patents and patent applications relating to Korsana’s product candidates are controlled by Korsana’s future licensors or collaboration partners, including with respect to patents non-exclusively in-licensed under the Paragon Option Agreements. If Korsana, Paragon or any of Korsana’s future licensors or collaboration partners fail to prosecute, defend, maintain and enforce such patents and patent applications in a manner consistent with Korsana’s best interests, including by payment of all applicable fees for patents covering its product candidates, Korsana could lose its rights to the intellectual property or its exclusivity with respect to those rights, Korsana’s ability to develop and commercialize those product candidates may be adversely affected and Korsana may not be able to prevent competitors from making, using and selling competing products. In addition, even if Korsana has the right to control prosecution of patents and patent applications Korsana has licensed to and from third parties, including under future license agreements

98

with Paragon following the point at which such control is assumed, Korsana may still be adversely affected or prejudiced by actions or inactions of Paragon, additional licensees, or licensors and their counsel prior to the date upon which Korsana assumes control over patent prosecution. For example, Paragon is currently responsible for the prosecution, defense, maintenance, and enforcement of patents related to KRSA-028. Upon entering into a license agreement for KRSA-028 pursuant to the Paragon ADOA, Korsana will control patent prosecution over patents specific to KRSA-028, but Paragon will retain control over patent prosecution for certain non-exclusively licensed integrated platform technology. With respect to the THETA technology, Paragon has filed provisional patent applications directed to antibodies targeting TfR1, including applications covering composition of matter, pharmaceutical formulations, and methods for using such antibodies or compounds, such as bispecific antibodies, comprising such antibodies.

Korsana’s future licensors may not be the sole and exclusive owners of all rights in the patents Korsana may in-license. If other third parties have rights to Korsana’s future in-licensed patents, they may be able to license such patents to Korsana’s competitors, and Korsana’s competitors could market competing products and technology. This could have a material adverse effect on Korsana’s competitive position, business, financial condition, results of operations, and prospects.

It is possible that Korsana may be unable to obtain licenses at a reasonable cost or on reasonable terms, if at all. Even if Korsana is able to obtain a license, it may be non-exclusive, thereby giving Korsana’s competitors access to the same technologies licensed to Korsana. In that event, Korsana may be required to expend significant time and resources to redesign Korsana’s product candidates, or the methods for manufacturing them or to develop or license replacement technology, all of which may not be feasible on a technical or commercial basis. If Korsana is unable to do so, Korsana may be unable to develop or commercialize the affected product candidates, which could harm Korsana’s business, financial condition, results of operations, and prospects significantly. Korsana cannot provide any assurances that third-party patents do not exist which might be enforced against Korsana’s product candidates, manufacturing methods or future products or methods resulting in either an injunction prohibiting Korsana’s manufacture or future sales, or, with respect to its future sales, an obligation on Korsana’s part to pay royalties and/or other forms of compensation to third parties, which could be significant.

Disputes may arise between Korsana and Korsana’s future licensors regarding intellectual property subject to a license agreement, including (but not limited to): the scope of rights granted under the license agreement and other interpretation-related issues; whether and the extent to which Korsana’s technology and processes infringe on intellectual property of the licensor that is not subject to the licensing agreement; Korsana’s right to sublicense patents and other rights to third parties; Korsana’s right to transfer or assign the license; the inventorship and ownership of inventions and know-how resulting from the joint creation or use of intellectual property by Korsana’s future licensors and Korsana and Korsana’s partners; and the priority of invention of patented technology. If Korsana or its future licensors breach the terms of Korsana’s license agreements, such breach may have a material adverse effect on Korsana’s business and the commercialization efforts for its programs.

Korsana may be subject to intellectual property lawsuits or may need to file lawsuits to protect Korsana’s intellectual property, which could result in substantial costs and liability and prevent Korsana from commercializing Korsana’s potential products.

Because the intellectual property landscape in the biotechnology industry is rapidly evolving and interdisciplinary, it is difficult to conclusively assess Korsana’s freedom to operate and guarantee that Korsana can operate without infringing on or violating third party rights. If certain of Korsana’s product candidates are ultimately granted regulatory approval, patent rights held by third parties could be alleged to render one or more of Korsana’s product candidates infringing. If a third party successfully brings a claim against Korsana, and Korsana’s rights are not held invalid or unenforceable, Korsana may be required to pay substantial damages, be forced to abandon any affected product candidate and/or seek a license from the patent holder. In addition, any

99

intellectual property claims (e.g., patent infringement or trade secret misappropriation) brought against Korsana, whether or not successful, may cause Korsana to incur significant legal expenses and divert the attention of Korsana’s management and key personnel from other business concerns. Korsana cannot be certain that future patents, if filed and issued, owned, or licensed by Korsana will not be challenged by others, whether in the course of litigation or in agencies like the USPTO. Some of Korsana’s competitors may be able to sustain the costs of complex intellectual property litigation more effectively than Korsana can because they have substantially greater resources. In addition, any uncertainties resulting from the initiation and continuation of any litigation could have a material adverse effect on Korsana’s ability to raise funds.

Competitors may infringe or otherwise violate Korsana’s future patents, trademarks, copyrights, or other intellectual property. To counter infringement or other violations, Korsana may be required to file claims, which can be expensive and time-consuming. Any such claims could provoke these parties to assert counterclaims against Korsana, including claims alleging that Korsana infringe their patents or other intellectual property rights. In addition, in a patent infringement proceeding, a court or administrative body may decide that one or more of the patents Korsana asserts is invalid or unenforceable, in whole or in part, construe the patent’s claims narrowly or refuse to prevent the other party from using the technology at issue on the grounds that Korsana’s patents do not cover the technology. Similarly, if Korsana asserts trademark infringement claims, a court or administrative body may determine that the marks Korsana has asserted are invalid or unenforceable or that the party against whom Korsana has asserted trademark infringement has superior rights to the marks in question. In such a case, Korsana could ultimately be forced to cease use of such marks. In any intellectual property litigation, even if Korsana is successful, any award of monetary damages or other remedy Korsana receives may not be commercially valuable.

Further, Korsana may be required to protect its future patents, if filed and issued, through procedures created to attack the validity of a patent at the USPTO. An adverse determination in any such submission or proceeding could reduce the scope or enforceability of, or invalidate, Korsana’s patent rights, which could adversely affect Korsana’s competitive position. Because of a lower evidentiary standard in USPTO proceedings compared to the evidentiary standard in United States federal courts necessary to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though the same evidence would be insufficient to invalidate the claim if first presented in a district court action.

In addition, if Korsana’s product candidates are found to infringe the intellectual property rights of third parties, these third parties may assert infringement claims against Korsana’s future licensees or customers and other parties with whom Korsana has business relationships and Korsana may be required to indemnify those parties for any damages they suffer as a result of these claims, which may require Korsana to initiate or defend protracted and costly litigation on behalf of licensees or other parties regardless of the merits of such claims. If any of these claims succeed, Korsana may be forced to pay damages on behalf of those parties or may be required to obtain licenses for the products Korsana uses.

Furthermore, because of the substantial amount of discovery required in connection with intellectual property litigation or other legal proceedings relating to Korsana’s intellectual property rights, there is a risk that some of Korsana’s confidential information could be compromised by disclosure during this type of litigation or other proceedings.

Korsana’s success will depend in part on Korsana’s and Korsana’s future licensors’ ability to obtain, maintain and enforce patent protection for Korsana’s licensed intellectual property.

Korsana’s success will depend in part on it and its future licensors’ (including Paragon’s) ability to obtain, maintain and enforce patent protection for its licensed intellectual property. Currently, Paragon controls the prosecution, maintenance, enforcement, and defense of KRSA-028. After entry into license agreements with Paragon for KRSA-028, and once the trigger for transfer of prosecution control is met, Korsana expects to hold

100

such rights. Korsana, Paragon and Korsana’s future licensors may not successfully prosecute the patent applications that cover its product candidates. Even if patents are issued in respect of these patent applications, Korsana and its future licensors (including Paragon) may fail to maintain these patents, may determine not to pursue litigation against other companies that are infringing these patents, or may pursue such litigation less aggressively than Korsana would. Without protection for any in-licensed intellectual property, other companies might be able to offer substantially identical products for sale, which could adversely affect Korsana’s competitive business position and harm its business prospects.

Korsana may be subject to claims that Korsana has wrongfully hired an employee from a competitor or that Korsana’s employees, consultants or independent contractors have wrongfully used or disclosed confidential information of third parties.

As is common in the biotechnology industry, in addition to Korsana’s employees, Korsana engages the services of consultants to assist Korsana in the development of Korsana’s product candidates. Many of these consultants, and many of Korsana’s employees, were previously employed at, or may have previously provided or may be currently providing consulting services to, other biotechnology or pharmaceutical companies including Korsana’s competitors or potential competitors. Korsana could in the future be subject to claims that Korsana or Korsana’s employees have inadvertently or otherwise used or disclosed alleged trade secrets or other confidential information of former employers or competitors. Although Korsana tries to ensure that its employees and consultants do not use the intellectual property, proprietary information, know-how or trade secrets of others in their work for Korsana, Korsana may become subject to claims that it caused an employee to breach the terms of his or her non-competition or non-solicitation agreement, or that Korsana or these individuals have, inadvertently or otherwise, used or disclosed the alleged trade secrets or other proprietary information of a former employer or competitor.

While Korsana may litigate to defend against these claims, even if Korsana is successful, litigation could result in substantial costs and could be a distraction to management and other employees. If Korsana’s defenses to these claims fail, in addition to requiring Korsana to pay monetary damages, a court could prohibit Korsana from using technologies or features that are essential to Korsana’s product candidates, if such technologies or features are found to incorporate or be derived from the trade secrets or other proprietary information of the former employers. Moreover, any such litigation or the threat thereof may adversely affect Korsana’s reputation, its ability to form strategic alliances or sublicense Korsana’s rights to collaborators, engage with scientific advisors or hire employees or consultants, each of which would have an adverse effect on Korsana’s business, results of operations and financial condition. Even if Korsana is successful in defending against such claims, litigation could result in substantial costs and be a distraction to management.

Changes to patent laws in the United States and other jurisdictions could diminish the value of patents in general, thereby impairing Korsana’s ability to protect its products.

Changes in either the patent laws or interpretation of patent laws in the United States, including patent reform legislation such as the Leahy-Smith America Invents Act (the “Leahy-Smith Act”) could increase the uncertainties and costs surrounding the prosecution of Korsana’s owned and in-licensed patent applications and the maintenance, enforcement, or defense of Korsana’s owned and in-licensed issued patents. The Leahy-Smith Act includes a number of significant changes to United States patent law. These changes include provisions that affect the way patent applications are prosecuted, redefine prior art, provide more efficient and cost-effective avenues for competitors to challenge the validity of patents, and enable third-party submission of prior art to the USPTO during patent prosecution and additional procedures to attack the validity of a patent at USPTO-administered post-grant proceedings, including post-grant review, inter partes review, and derivation proceedings. Assuming that other requirements for patentability are met, prior to March 2013, in the United States, the first to invent the claimed invention was entitled to the patent, while outside the United States, the first to file a patent application was entitled to the patent. After March 2013, under the Leahy-Smith Act, the United States transitioned to a first-to-file system in which, assuming that the other statutory requirements for

101

patentability are met, the first inventor to file a patent application will be entitled to the patent on an invention regardless of whether a third party was the first to invent the claimed invention. As such, the Leahy-Smith Act and its implementation increased the uncertainties and costs surrounding the prosecution of Korsana’s patent applications and the enforcement or defense of Korsana’s issued patents, all of which could have a material adverse effect on Korsana’s business, financial condition, results of operations, and prospects. Additionally, there have been proposals for additional changes to the patent laws of the United States and other countries that, if adopted, could impact Korsana’s ability to enforce its proprietary technology.

In addition, the patent positions of companies in the development and commercialization of biologics and pharmaceuticals are particularly uncertain. U.S. Supreme Court and U.S. Court of Appeals for the Federal Circuit rulings have narrowed the scope of patent protection available in certain circumstances and weakened the rights of patent owners in certain situations, including in the antibody arts. For example, the United States Supreme Court in Amgen, Inc. v. Sanofi (“Amgen”) recently held that Amgen’s patent claims to a class of antibodies functionally defined by their ability to bind a particular antigen were invalid for lack of enablement where the patent specification provided 26 exemplary antibodies, but the claimed class of antibodies covered a “vast number” of additional antibodies not disclosed in the specification. The Court stated that if patent claims are directed to an entire class of compositions of matter, then the patent specification must enable a person skilled in the art to make and use the entire class of compositions. This decision makes it unlikely that Korsana will be granted U.S. patents with composition of matter claims as broad as Amgen’s directed to antibodies functionally defined by their ability to bind a particular antigen. Even if Korsana is granted claims directed to functionally defined antibodies, it is possible that a third party may challenge Korsana’s patents, when issued, relying on the reasoning in Amgen or other precedential court decisions. This combination of events has created uncertainty with respect to the validity and enforceability of patents once obtained. Depending on future actions by the U.S. Congress, the federal courts and the USPTO, the laws and regulations governing patents could change in unpredictable ways that could have a material adverse effect on Korsana’s patent rights and its ability to protect, defend and enforce its patent rights in the future.

In addition, the U.S. Supreme Court’s July 2024 decision to overturn established case law giving deference to regulatory agencies’ interpretations of ambiguous statutory language has introduced uncertainty regarding the extent to which the FDA’s regulations, policies and decisions may become subject to increasing legal challenges, delays, and/or changes. Korsana cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. Geopolitical instability in the United States and in foreign countries could increase the uncertainties and costs surrounding the prosecution or maintenance of patent applications and the maintenance, enforcement, or defense of issued patents. In addition, the Unified Patent Court (“UPC”) entered into force on June 1, 2023. The UPC is a common patent court that hears patent infringement and revocation proceedings effective for EU Member States. This could enable third parties to seek revocation of a European patent in a single proceeding at the UPC rather than through multiple proceedings in each of the jurisdictions in which the European patent is validated.

Although Korsana does not currently own or license any European patents or applications, if Korsana obtains or licenses such patents and applications in the future, any such revocation and loss of patent protection could have a material adverse impact on Korsana’s business and its ability to commercialize or license its technology and products. Moreover, the controlling laws and regulations of the UPC will develop over time and may adversely affect Korsana’s ability to enforce or defend the validity of any European patents Korsana may obtain. Korsana may decide to opt out from the UPC any future European patent applications that Korsana may file and any patents Korsana may obtain. If certain formalities and requirements are not met, however, such European patents and patent applications could be challenged for non-compliance and brought under the jurisdiction of the UPC. Korsana cannot be certain that future European patents and patent applications will avoid falling under the jurisdiction of the UPC, if Korsana decides to opt out of the UPC.

102

Obtaining and maintaining patent protection depends on compliance with various procedural, document submissions, fee payment, and other requirements imposed by governmental patent agencies, and Korsana’s patent protection could be reduced or eliminated for non-compliance with these requirements.

Periodic maintenance fees, renewal fees, annuities fees and various other governmental fees on patents and/or patent applications are due to be paid to the USPTO and foreign patent agencies in several stages over the lifetime of the patent and/or patent application. The USPTO and various foreign governmental patent agencies also require compliance with a number of procedural, documentary, fee payment, and other similar provisions during the patent application process. While an inadvertent lapse can in many cases be cured by payment of a late fee or by other means in accordance with the applicable rules, there are situations in which noncompliance can result in abandonment or lapse of the patent or patent application, resulting in partial or complete loss of patent rights in the relevant jurisdiction. Non-compliance events that could result in abandonment or lapse of a patent or patent application include, but are not limited to, failure to respond to official actions within prescribed time limits, non-payment of fees and failure to properly legalize and submit formal documents. If Korsana fails to maintain any future patents and patent applications, if filed and issued, covering Korsana’s product candidates, its competitive position would be adversely affected.

Korsana may not identify relevant third-party patents or may incorrectly interpret the relevance, scope, or expiration of a third-party patent, which might adversely affect Korsana’s ability to develop and market its products.

Korsana cannot guarantee that any of Korsana’s patent searches or analyses, including the identification of relevant patents, the scope of patent claims or the expiration of relevant patents, are complete or thorough, nor can Korsana be certain that it has identified each and every third-party patent and pending application in the United States and abroad that is relevant to or necessary for the commercialization of Korsana’s product candidates in any jurisdiction. The scope of a patent claim is determined by an interpretation of the law, the written disclosure in a patent, the patent’s prosecution history and in some cases certain extrinsic evidence of the meaning of terms in a claim. Korsana’s interpretation of the relevance or the scope of a patent or a pending application may be incorrect. For example, Korsana may incorrectly determine that its products are not covered by a third-party patent or may incorrectly predict whether a third-party’s pending application will issue with claims of relevant scope. Korsana’s determination of the expiration date of any patent in the United States or abroad that Korsana considers relevant may be incorrect. Korsana’s failure to identify and correctly interpret relevant patents may negatively impact its ability to develop and market its products.

In addition, because some patent applications in the United States may be maintained in secrecy until the patents are issued, patent applications in the United States and many foreign jurisdictions are typically not published until 18 months after filing, and publications in the scientific literature often lag behind actual discoveries, Korsana cannot be certain that others have not filed patent applications for technology covered by Korsana’s future issued patents or its pending applications, if filed, or that Korsana is the first to invent the technology. Korsana’s competitors may have filed, and may in the future file, patent applications covering Korsana’s products or technology similar to Korsana’s. Any such patent application may have priority over Korsana’s future patent applications or patents, if filed and issued, which could require Korsana to obtain rights to issued patents covering such technologies.

Korsana may become subject to claims challenging the inventorship or ownership of Korsana’s patents, if issued, and other intellectual property.

Korsana may be subject to claims that former employees, collaborators or other third parties have an interest in Korsana’s future patents, if filed and issued, or other intellectual property as an inventor or co-inventor. The failure to name the proper inventors on a patent application can result in the patents issuing thereon being invalid or unenforceable. Inventorship disputes may arise from conflicting views regarding the contributions of different individuals named as inventors, the effects of foreign laws where foreign nationals are involved in the

103

development of the subject matter of the patent, conflicting obligations of third parties involved in developing Korsana’s programs or as a result of questions regarding co-ownership of potential joint inventions. Litigation may be necessary to resolve these and other claims challenging inventorship and/or ownership. Alternatively, or additionally, Korsana may enter into agreements to clarify the scope of Korsana’s rights in such intellectual property. If Korsana fails in defending any such claims, in addition to paying monetary damages, Korsana may lose valuable intellectual property rights, such as exclusive ownership of, or right to use, valuable intellectual property. Such an outcome could have a material adverse effect on Korsana’s business. Even if Korsana is successful in defending against such claims, litigation could result in substantial costs and be a distraction to management and other employees.

Korsana’s current or future licensors may have relied on third-party consultants or collaborators or on funds from third parties, such as the U.S. government, such that Korsana’s licensors are not the sole and exclusive owners of the patents Korsana in-licensed. If other third parties have ownership rights or other rights to Korsana’s in-licensed patents, they may be able to license such patents to Korsana’s competitors, and its competitors could market competing products and technology. This could have a material adverse effect on Korsana’s competitive position, business, financial condition, results of operations, and prospects.

Patent terms may be inadequate to protect Korsana’s competitive position of its product candidates for an adequate amount of time.

Patents have a limited lifespan. In the United States, if all maintenance fees are timely paid, the natural expiration of a patent is generally 20 years from Korsana’s earliest U.S. non-provisional filing date. Various extensions may be available, but the life of a patent, and the protection it affords, is limited. Even if patents covering Korsana’s product candidates are obtained, once the patent life has expired, Korsana may be open to competition from competitive products, including generics or biosimilars. Given the amount of time required for the development, testing and regulatory review of new product candidates, patents protecting such product candidates might expire before or shortly after such product candidates are commercialized. As a result, Korsana’s owned and licensed patent portfolio may not provide Korsana with sufficient rights to exclude others from commercializing products similar or identical to Korsana’s.

Korsana’s technology licensed from various third parties may be subject to retained rights.

Korsana’s future licensors may retain certain rights under the relevant agreements with Korsana, including the right to use or license the licensed technology outside of the scope of Korsana’s license, use the underlying technology for noncommercial academic and research use, to publish general scientific findings from research related to the technology, and to make customary scientific and scholarly disclosures of information relating to the technology. It is difficult to monitor whether Korsana’s licensors limit their use of the technology to these uses, and Korsana could incur substantial expenses to enforce its rights to its licensed technology in the event of misuse. In addition, while there are certain restrictions on Paragon’s ability to develop products that could be competitive with Korsana’s as more fully described in “Korsana’s Business — Paragon Option Agreements” beginning on page 309 of this proxy statement/prospectus, these restrictions may not prevent the possible future license or development by Paragon of certain technology that could lead to product candidates competitive with Korsana’s. This could have a material adverse effect on Korsana’s competitive position, business, financial condition, results of operations, and prospects.

104

Risks Related to Government Regulation

The regulatory approval processes of the FDA and other comparable foreign regulatory authorities are lengthy, time-consuming, and inherently unpredictable. If Korsana is not able to obtain, or if there are delays in obtaining, required regulatory approvals for Korsana’s product candidates, Korsana will not be able to commercialize, or will be delayed in commercializing, its product candidates, and its ability to generate revenue will be materially impaired.

The process of obtaining regulatory approvals, both in the United States and abroad, is unpredictable, expensive, and typically takes many years following commencement of clinical trials, if approval is obtained at all, and can vary substantially based upon a variety of factors, including the type, complexity and novelty of the product candidates involved. Korsana cannot commercialize product candidates in the United States without first obtaining regulatory approval from the FDA. Similarly, Korsana cannot commercialize product candidates outside of the United States without obtaining regulatory approval from comparable foreign regulatory authorities. Before obtaining regulatory approvals for the commercial sale of Korsana’s product candidates, including KRSA-028, Korsana must demonstrate through lengthy, complex, and expensive preclinical studies and clinical trials that its product candidates are both safe and effective for each targeted indication. Securing regulatory approval also requires the submission of information about the drug manufacturing process to, and inspection of manufacturing facilities by, the relevant regulatory authority. Further, Korsana’s product candidates may not be effective, may be only moderately effective, may prove to have undesirable or unintended side effects, toxicities, or other characteristics, or may fail to improve on the applicable standard of care, any of which may preclude Korsana from obtaining regulatory approval. The FDA and comparable foreign regulatory authorities have discretion in the approval process and may refuse to accept any application or may decide that Korsana’s data is insufficient for approval and require additional preclinical, clinical, or other data. Korsana’s product candidates could be delayed in receiving, or fail to receive, regulatory approval for many reasons, including: the FDA or comparable foreign regulatory authorities may disagree with the design or implementation of Korsana’s clinical trials; Korsana may be unable to demonstrate to the satisfaction of the FDA or comparable foreign regulatory authorities that a product candidate is safe and effective for Korsana’s proposed indication; the results of clinical trials may not meet the level of statistical significance required by the FDA or comparable foreign regulatory authorities for approval; serious and unexpected drug-related side effects may be experienced by participants in Korsana’s clinical trials or by individuals using drugs similar to its product candidates; Korsana may be unable to demonstrate that a product candidate’s clinical and other benefits outweigh Korsana’s safety risks; the FDA or comparable foreign regulatory authorities may disagree with Korsana’s interpretation of data from preclinical studies or clinical trials; the data collected from clinical trials of Korsana’s product candidates may not be acceptable or sufficient to support the submission of a BLA or other submission or to obtain regulatory approval in the United States or elsewhere, and Korsana may be required to conduct additional clinical trials; the FDA or the applicable foreign regulatory authority may disagree regarding the formulation, labeling and/or the specifications of Korsana’s product candidates; the FDA or comparable foreign regulatory authorities may fail to approve the manufacturing processes or facilities of third-party manufacturers with which Korsana contracts for clinical and commercial supplies; and the approval policies or regulations of the FDA or comparable foreign regulatory authorities may significantly change in a manner rendering Korsana’s clinical data insufficient for approval.

Of the large number of drugs in development, only a small percentage successfully complete the FDA or applicable foreign regulatory approval processes and are commercialized. The lengthy approval process as well as the unpredictability of future clinical trial results may result in Korsana failing to obtain regulatory approval to market Korsana’s product candidates, which would significantly harm Korsana’s business, results of operations and prospects.

If Korsana was to obtain approval, regulatory authorities may approve any of Korsana’s product candidates for fewer or more limited indications than Korsana requests, including failing to approve the most commercially promising indications, may grant approval contingent on the performance of costly post-marketing clinical trials, or may approve a product candidate with a label that does not include the labeling claims necessary or desirable

105

for the successful commercialization of that product candidate. If Korsana is not able to obtain, or if there are delays in obtaining, required regulatory approvals for Korsana’s product candidates, Korsana will not be able to commercialize, or will be delayed in commercializing, this could have a material adverse effect on Korsana’s competitive position, business, financial condition, results of operations, and prospects. In addition, the FDA and foreign regulatory authorities may undergo leadership changes, change their policies, issue additional regulations, or revise existing regulations, or take other actions, such as those implemented by the Department of Government Efficiency, which may impact Korsana’s clinical development plans or prevent or delay approval of Korsana’s product candidates under development on a timely basis. Such policy or regulatory changes could impose additional requirements upon Korsana that could delay Korsana’s ability to obtain approvals and increase the costs of compliance. Since the start of President Trump’s administration in 2025, U.S. policy changes have been implemented at a rapid pace and additional changes are likely. It is difficult to predict how executive actions that may be taken under the current administration may affect the FDA’s ability to exercise its regulatory authority. If any actions impose constraints on the FDA’s ability to engage in routine oversight and product review activities in the normal course, Korsana’s business may be negatively impacted. Additionally, federal government could adopt legislation, regulations or policies that adversely affect Korsana’s business or create a more challenging and costly environment to pursue the development, approval, and commercialization of Korsana’s product candidates.

Korsana may not be able to meet requirements for the chemistry, manufacturing, and control of Korsana’s product candidates.

In order to receive approval of Korsana’s products by the FDA and comparable foreign regulatory authorities, Korsana must show that it and Korsana’s contract manufacturing partners are able to characterize, control and manufacture Korsana’s drug products safely and in accordance with regulatory requirements. This includes manufacturing the active ingredient, developing an acceptable formulation, manufacturing the drug product, performing tests to adequately characterize the formulated product, documenting a repeatable manufacturing process, and demonstrating that Korsana’s drug products meet stability requirements. Meeting these chemistry, manufacturing and control requirements is a complex task that requires specialized expertise. If Korsana is not able to meet the chemistry, manufacturing, and control requirements, Korsana may not be successful in getting Korsana’s products approved.

Korsana’s product candidates for which Korsana intends to seek approval as biologics may face competition from biosimilars sooner than anticipated.

The ACA includes a subtitle called the Biologics Price Competition and Innovation Act of 2009 (“BPCIA”), which created an abbreviated approval pathway for biological products that are biosimilar to or interchangeable with an FDA-licensed reference biological product. Under the BPCIA, an application for a highly similar or “biosimilar” product may not be submitted to the FDA until four years following the date that the reference product was first approved by the FDA. In addition, the approval of a biosimilar product may not be made effective by the FDA until 12 years from the date on which the reference product was first approved. During this 12-year period of exclusivity, another company may still market a competing version of the reference product if the FDA approves a full BLA for the competing product containing the sponsor’s own preclinical data and data from adequate and well-controlled clinical trials to demonstrate the safety, purity, and potency of their product.

Korsana believes that any of Korsana’s product candidates approved as biologics under a BLA should qualify for the 12-year period of exclusivity. However, there is a risk that this exclusivity could be shortened due to congressional action or otherwise, or that the FDA will not consider Korsana’s product candidates to be reference products for competing products, potentially creating the opportunity for competition sooner than anticipated. Other aspects of the BPCIA, some of which may impact the BPCIA exclusivity provisions, have also been the subject of recent litigation. Moreover, the extent to which a biosimilar, once approved, will be substituted for any reference products in a way that is similar to traditional generic substitution for non-biological products is not yet clear, and will depend on a number of marketplace and regulatory factors that are still developing.

106

Even if Korsana receives regulatory approval of Korsana’s product candidates, Korsana will be subject to extensive ongoing regulatory obligations and continued regulatory review, which may result in significant additional expense, and Korsana may be subject to penalties if it fails to comply with regulatory requirements or experience unanticipated problems with its product candidates.

Any regulatory approvals that Korsana may receive for Korsana’s product candidates will require the submission of reports to regulatory authorities and surveillance to monitor the safety and efficacy of the product candidate, may contain significant limitations related to use restrictions for specified age groups, warnings, precautions, or contraindications, and may include burdensome post-approval study or risk management requirements. For example, the FDA may require a risk evaluation and mitigation strategy (“REMS”) in order to approve Korsana’s product candidates, which could entail requirements for a medication guide, physician training and communication plans or additional elements to ensure safe use, such as restricted distribution methods, patient registries, and other risk minimization tools. Comparable foreign regulatory authorities may impose similar requirements. In addition, if the FDA or comparable foreign regulatory authorities approve Korsana’s product candidates, Korsana’s product candidates and the activities associated with their development and commercialization, including their design, testing, manufacture, safety, efficacy, recordkeeping, labeling, storage, approval, advertising, promotion, sale, distribution, import and export will be subject to comprehensive regulation by the FDA and other regulatory agencies in the United States and by comparable foreign regulatory authorities. These requirements include submissions of safety and other post-marketing information and reports, registration, as well as on-going compliance with cGMPs and GCPs for any clinical trials that Korsana conducts following approval. In addition, manufacturers of drug products and their facilities are subject to continual review and periodic, unannounced inspections by the FDA and other regulatory authorities for compliance with cGMPs. If Korsana or a regulatory authority discovers previously unknown problems with a product, such as adverse events of unanticipated severity or frequency, or problems with the facilities where the product is manufactured, a regulatory authority may impose restrictions on that product, the manufacturing facility or Korsana, including requiring recall or withdrawal of the product from the market or suspension of manufacturing, delays or restrictions on Korsana’s ability to conduct clinical trials or delays or refusal to grant a marketing authorization, including full or partial clinical holds on ongoing or planned trials, restrictions on the manufacturing process, warning or untitled letters, civil and criminal penalties, injunctions, product seizures, detentions or import bans, suspension, withdrawal or variation of any marketing authorization that has been granted, voluntary or mandatory publicity requirements and imposition of restrictions on operations, including costly new manufacturing requirements. Similar penalties may apply in case of failure by Korsana or by any of Korsana’s third-party partners, including suppliers, manufacturers and distributors, to comply with FDA and EU laws and the related national laws of individual EU Member States and other applicable regulatory authorities governing the conduct of clinical trials, manufacturing approval, marketing authorization of medicinal products and marketing of such products, both before and after grant of a marketing authorization, statutory health insurance, bribery and anti-corruption or other applicable regulatory requirements, including administrative, civil or criminal penalties. The occurrence of any event or penalty described above may inhibit Korsana’s ability to commercialize its product candidates and generate revenue and could require Korsana to expend significant time and resources in response and could generate negative publicity.

Disruptions at the FDA, the SEC and other government agencies and regulatory authorities caused by funding shortages or global health concerns could hinder their ability to hire and retain key leadership and other personnel, prevent new products and services from being developed or commercialized in a timely manner or otherwise prevent those agencies from performing normal business functions on which the operation of Korsana’s business may rely, which could negatively impact its business.

The ability of the FDA to review regulatory filings and Korsana’s ability to commence human clinical trials can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory and policy changes. Average review times at the agency have fluctuated in recent years as a result. In addition, government funding of the SEC, and other government agencies on which Korsana’s operations may rely, including those that fund research and development activities is subject to the political process, which is inherently fluid and unpredictable.

107

Disruptions at the FDA and other agencies or comparable foreign regulatory authorities may also slow the time necessary for the review and approval of applications for clinical trial or marketing authorization, which would adversely affect Korsana’s business. For example, in recent years, including in 2018, 2019 and 2025, the U.S. government shut down several times and certain regulatory agencies, such as the FDA and the SEC, had to furlough critical employees and stop critical activities. Additionally, action by the Trump administration to limit federal agency budgets or personnel may result in reductions to the FDA’s budget, employees, and operations, which may lead to slower response times and longer review periods, potentially affecting Korsana’s ability to progress development of its product candidates or obtain regulatory approval for its product candidates. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process Korsana’s regulatory submissions, which could have a material adverse effect on its business. Further, future government shutdowns could impact Korsana’s ability to access the public markets and obtain necessary capital in order to properly capitalize and continue Korsana’s operations.

If a prolonged government shutdown occurs, or if global health concerns prevent the FDA or other regulatory authorities from conducting their regular inspections, reviews, or other regulatory activities, it could significantly impact the ability of the FDA or other regulatory authorities to timely review and process Korsana’s regulatory submissions, which could have a material adverse effect on Korsana’s business.

Korsana may face difficulties from healthcare and regulatory legislative reform measures.

Existing regulatory policies may change, and additional government regulations may be enacted that could prevent, limit, or delay regulatory approval of Korsana’s product candidates. Korsana cannot predict the likelihood, nature or extent of government regulation that may arise from future legislation or administrative action, either in the United States or abroad. For example, the Trump administration has discussed several changes to the reach and oversight of the FDA, which could affect its relationship with the pharmaceutical industry, transparency in decision making and ultimately the cost and availability of prescription drugs. If Korsana is slow or unable to adapt to changes in existing requirements or the adoption of new requirements or policies, or if Korsana is not able to maintain regulatory compliance, Korsana may lose any regulatory approval that it may have obtained and it may not achieve or sustain profitability.

Korsana’s business operations and current and future arrangements with investigators, healthcare professionals, consultants, third-party payors, patient organizations, and customers will be subject to applicable healthcare regulatory laws, which could expose Korsana to penalties.

Korsana’s business operations and current and future arrangements with investigators, healthcare professionals, consultants, third-party payors, patient organizations, and customers may expose Korsana to broadly applicable fraud and abuse and other healthcare laws and regulations. These laws may constrain the business or financial arrangements and relationships through which Korsana conducts its operations, including how it researches, markets, sells and distributes its product candidates, if approved.

Ensuring that Korsana’s internal operations and future business arrangements with third parties comply with applicable healthcare laws and regulations will involve substantial costs. If Korsana’s operations are found to be in violation of any of these laws or any other governmental laws and regulations that may apply to Korsana, it may be subject to significant penalties, including civil, criminal and administrative penalties, damages, fines, exclusion from government-funded healthcare programs, integrity oversight and reporting obligations to resolve allegations of non-compliance, disgorgement, individual imprisonment, contractual damages, reputational harm, diminished profits and the curtailment or restructuring of Korsana’s operations. Further, defending against any such actions can be costly and time-consuming and may require significant personnel resources. Therefore, even if Korsana is successful in defending against any such actions that may be brought against it, Korsana’s business may be impaired.

108

Even if Korsana is able to commercialize any product candidates, due to unfavorable pricing regulations and/or third-party coverage and reimbursement policies, Korsana may not be able to offer such product candidates at competitive prices, which would seriously harm Korsana’s business.

Korsana intends to seek approval to market Korsana’s product candidates in both the United States and in selected foreign jurisdictions. If Korsana obtains approval in one or more foreign jurisdictions for Korsana’s product candidates, Korsana will be subject to rules and regulations in those jurisdictions. Korsana’s ability to successfully commercialize any product candidates that Korsana may develop will depend in part on the extent to which reimbursement for these product candidates and related treatments will be available from government health administration authorities, private health insurers, and other organizations. Government authorities and other third-party payors, such as private health insurers and health maintenance organizations, decide which medications they will pay for and establish reimbursement levels. Government authorities and other third-party payors have attempted to control costs by limiting coverage and the amount of reimbursement for particular medications. These entities may create preferential access policies for a competitor’s product, including a branded or generic/biosimilar product, over Korsana’s products in an attempt to reduce their costs, which may reduce Korsana’s commercial opportunity.

Korsana is subject to U.S. and certain foreign export and import controls, sanctions, embargoes, anti-corruption laws, and anti-money laundering laws and regulations. Korsana can face criminal liability and other serious consequences for violations, which can harm Korsana’s business.

Korsana is subject to export control and import laws and regulations, including the U.S. Export Administration Regulations, U.S. Customs regulations, various economic and trade sanctions regulations administered by the U.S. Treasury Department’s Office of Foreign Assets Controls, the U.S. Foreign Corrupt Practices Act of 1977, as amended, the U.S. domestic bribery statute contained in 18 U.S.C. § 201, the U.S. Travel Act, the USA PATRIOT Act, and other state and national anti-bribery and anti-money laundering laws in the countries in which Korsana conducts activities. Governmental regulation of the import or export of Korsana’s drug candidates, or Korsana’s failure to obtain any required import or export authorization for its candidates, when applicable, could harm international operations. Furthermore, export control laws and economic sanctions prohibit the provision of certain items, technology, and services to countries, governments, and persons targeted by sanctions programs. Anti-corruption laws are interpreted broadly and prohibit companies and their employees, agents, contractors, and other collaborators from authorizing, promising, offering, or providing, directly or indirectly, improper payments or anything else of value to or from recipients in the public or private sector. Korsana may engage third parties to sell Korsana’s products outside the United States, to conduct clinical trials, and/or to obtain necessary permits, licenses, patent registrations, and other regulatory approvals. Korsana has direct or indirect interactions with officials and employees of government agencies or government-affiliated hospitals, universities, and other organizations. Korsana can be held liable for the corrupt or other illegal activities of Korsana’s employees, agents, contractors, and other collaborators, even if Korsana does not explicitly authorize or have actual knowledge of such activities. Any violations of the laws and regulations described above may result in substantial civil and criminal fines and penalties, imprisonment, the loss of export or import privileges, debarment, tax reassessments, breach of contract and fraud litigation, reputational harm, and other consequences.

Governments outside the United States tend to impose strict price controls, which may adversely affect Korsana’s revenue, if any.

In some countries, particularly EU Member States, the pricing of prescription drugs is subject to governmental control. In these countries, pricing negotiations with governmental authorities can take considerable time after receipt of regulatory approval for a therapeutic. In addition, there can be considerable pressure by governments and other stakeholders on prices and reimbursement levels, including as part of cost containment measures. Political, economic, and regulatory developments may further complicate pricing negotiations, and pricing negotiations may continue after reimbursement has been obtained. Reference pricing

109

used by various EU Member States and parallel distribution, or arbitrage between low-priced and high-priced EU Member States, can further reduce prices. To obtain coverage and reimbursement or pricing approvals in some countries, Korsana or future collaborators may be required to conduct a clinical trial or other studies that compare the cost-effectiveness of Korsana’s product candidates to other available therapies in order to obtain or maintain reimbursement or pricing approval. Publication of discounts by third-party payors or authorities may lead to further pressure on the prices or reimbursement levels within the country of publication and other countries. If reimbursement of any product candidate approved for marketing is unavailable or limited in scope or amount, or if pricing is set at unsatisfactory levels, Korsana’s business, financial condition, results of operations, or prospects could be materially and adversely affected.

If Korsana seeks and is unable to obtain accelerated approval, the amount, size, and duration of Korsana’s clinical trials could be greater than planned, which could increase the expense, reduce the likelihood, and/or delay the timing of obtaining necessary regulatory approvals. Even if Korsana receives accelerated approval, if confirmatory trials do not verify clinical benefit, or if Korsana does not comply with rigorous post-approval requirements, such authorities may withdraw accelerated approval.

Korsana may seek accelerated approval, or other expedited development, review, or approval status, for Korsana’s product candidates. Even if granted, there is no guarantee that receiving an expedited development, review or approval status from the FDA will lead to a faster development or regulatory review or approval process, and such status does not increase the likelihood that Korsana’s product candidates will ultimately receive marketing approval. The FDA may grant accelerated approval to a product designed to treat a serious or life-threatening condition that provides meaningful therapeutic advantage over available therapies and demonstrates an effect on a surrogate endpoint or intermediate clinical endpoint that is reasonably likely to predict clinical benefit. If Korsana chooses to pursue accelerated approval, there can be no assurance that the FDA will agree that Korsana’s proposed primary endpoint is an appropriate surrogate endpoint. Similarly, there can be no assurance that after subsequent FDA feedback that Korsana will continue to pursue accelerated approval or any other form of expedited development, review, or approval, even if Korsana initially decides to do so. Furthermore, if Korsana submits an application for accelerated approval, there can be no assurance that such application will be accepted or that approval will be granted on a timely basis, or at all. The FDA also could require Korsana to conduct further studies or trials prior to considering Korsana’s application or granting approval of any type. Korsana might not be able to fulfill the FDA’s requirements in a timely manner, which would cause delays, or approval might not be granted because Korsana’s submission is deemed incomplete by the FDA. Accelerated approval may be contingent on the sponsor’s agreement to conduct, in a diligent manner, additional post-approval confirmatory studies to verify and describe the drug’s predicted effect on irreversible morbidity or mortality or other clinical benefit. Under the Food and Drug Omnibus Reform Act of 2022, the FDA may require, as appropriate, that such studies be underway prior to approval or within a specific time period after the date of approval for a product granted accelerated approval. The FDA may require that any such confirmatory study be initiated or substantially underway prior to the submission of an application for accelerated approval. Even if Korsana receives accelerated approval from the FDA, Korsana will be subject to rigorous post-approval requirements, including submission to the FDA of all promotional materials prior to their dissemination. The FDA could withdraw accelerated approval for multiple reasons, including Korsana’s failure to conduct any required post-approval study with due diligence, or the inability of such study to confirm the drug’s predicted clinical benefit relative to its risks. A failure to obtain accelerated approval or any other form of expedited review or approval for a product candidate could result in a longer time period prior to commercializing such product candidate, increase the cost of development of such product candidate, and harm Korsana’s competitive position in the marketplace. Comparable considerations apply outside of the United States.

110

General Risk Factors

Korsana may become exposed to costly and damaging liability claims, when testing a product candidate in the clinical stage or at the commercial stage, and Korsana’s product liability insurance may not cover all damages from such claims.

Korsana is exposed to potential product liability and professional indemnity risks that are inherent in the research, development, manufacturing, marketing, and use of pharmaceutical products. While Korsana currently has no products that have been approved for commercial sale, the future use of a product candidate in clinical trials, and the sale of any approved products in the future, may expose Korsana to liability claims. These claims may be made by patients that use the product or product candidate, healthcare providers, pharmaceutical companies, or others selling such product. Any claims against Korsana, regardless of their merit, could be difficult and costly to defend and could materially and adversely affect the market for Korsana’s products or any prospects for commercialization of Korsana’s products. Although Korsana intends to obtain product liability insurance for Korsana’s future clinical trials, it is possible that its liabilities could exceed Korsana’s insurance coverage or that in the future Korsana may not be able to maintain insurance coverage at a reasonable cost or obtain insurance coverage that will be adequate to satisfy any liability that may arise. If a successful product liability claim or series of claims is brought against Korsana for uninsured liabilities or in excess of insured liabilities, Korsana’s assets may not be sufficient to cover such claims and Korsana’s business operations could be impaired.

Litigation costs and the outcome of litigation could have a material adverse effect on Korsana’s business.

From time to time, Korsana may be subject to litigation claims through the ordinary course of Korsana’s business operations regarding, but not limited to, securities litigation, employment matters, security of patient and employee personal information, contractual relations with collaborators and licensors and intellectual property rights. Litigation to defend Korsana against claims by third parties, or to enforce any rights that Korsana may have against third parties, could result in substantial costs and diversion of Korsana’s resources, causing a material adverse effect on Korsana’s business, financial condition, results of operations, or cash flows.

Korsana’s business could be adversely affected by economic downturns, inflation, fluctuating interest rates, natural disasters, public health crises, political crises, geopolitical events, or other macroeconomic conditions, which could have a material and adverse effect on Korsana’s results of operations and financial condition.

The global economy, including credit and financial markets, has experienced extreme volatility and disruptions, including, among other things, diminished liquidity and credit availability, declines in consumer confidence, declines in economic growth, supply chain shortages, increases in inflation rates, fluctuating interest rates, and uncertainty about economic stability. Adverse macroeconomic conditions, including inflation, slower growth or recession, new or increased tariffs imposed by the U.S. government and potential retaliatory measures by foreign governments and other barriers to trade, especially in light of recent comments and executive orders made by the Trump administration, changes to fiscal and monetary policy or government budget dynamics (particularly in the pharmaceutical and biotech areas), government shutdowns, tighter credit, higher interest rates, volatility in financial markets, high unemployment, labor availability constraints, currency fluctuations and other challenges in the global economy have in the past adversely affected, and may in the future adversely affect, Korsana and its business partners and suppliers. For example, the COVID-19 pandemic resulted in widespread unemployment, economic slowdown, and extreme volatility in the capital markets. In addition, the U.S. has imposed and taken action to pause, resume or adjust tariffs on imports from a number of countries. Since February 2025, the United States government has imposed various tariffs on imports from most countries, including tariffs on imports from China and South Korea. In September 2025, President Trump announced plans to impose 100% tariffs on imported branded or patented pharmaceuticals, unless the importing company is building U.S. manufacturing capacity. It is not yet clear whether these tariffs would apply to the importation of active pharmaceutical ingredients and possibly bulk drug products that are intended for use in clinical trials and not for commercial sale, which could increase the costs of materials for Korsana’s clinical trials. There still

111

remains substantial uncertainty about the duration of existing tariffs and whether additional tariffs may be imposed, modified, or suspended. Historically, tariffs have led to increased trade and political tensions. In response to tariffs, other countries have implemented retaliatory tariffs on U.S. goods. Uncertainty and political tensions as a result of trade policies could reduce trade volume, investment, technological exchange, and other economic activities between major international economies, resulting in a material adverse effect on global economic conditions and the stability of global financial markets. The Federal Reserve has raised interest rates multiple times in recent years in response to concerns about inflation and it may raise them again. High interest rates, coupled with reduced government spending and volatility in financial markets, may increase economic uncertainty and affect consumer spending. Similarly, the ongoing military conflict between Russia and Ukraine and in the Middle East and rising tensions with China have created extreme volatility in the global capital markets and may have further global economic consequences, including disruptions of the global supply chain. Any such volatility and disruptions may adversely affect Korsana’s business or the third parties on whom Korsana relies. If the equity and credit markets deteriorate, including as a result of political unrest or war, it may make any necessary debt or equity financing more costly, more dilutive, or more difficult to obtain in a timely manner or on favorable terms, if at all. Increased inflation rates can adversely affect Korsana by increasing its costs, including labor and employee benefit costs.

Korsana may in the future experience disruptions as a result of such macroeconomic conditions, including delays or difficulties in initiating or expanding clinical trials and manufacturing sufficient quantities of materials. Any one or a combination of these events could have a material and adverse effect on Korsana’s results of operations and financial condition.

Risks Related to the Cayman Redomestication

Currently, Cyclerion is governed by Massachusetts law, Cyclerion Articles and Cyclerion Bylaws, but upon effectiveness of the Cayman Redomestication the Combined Company will be governed by Cayman Islands law and the Cayman Articles, provisions of which have anti-takeover implications.

Upon effectiveness of the Cayman Redomestication, the Combined Company’s organizational documents will change and the Combined Company and its organizational documents will be governed by Cayman Islands law rather than Massachusetts law. Provisions that will be included in the Cayman Articles may discourage, delay, or prevent a merger, acquisition, or other change in control of the Combined Company that shareholders may consider favorable, including transactions in which its ordinary shareholders might otherwise receive a premium price for their ordinary shares. These provisions could also limit the price that investors might be willing to pay in the future for the Combined Company’s ordinary shares, thereby depressing the market price of its ordinary shares. In addition, because the Combined Company board of directors will be responsible for appointing the members of the Combined Company management team, these provisions may frustrate or prevent any attempts by the Combined Company shareholders to replace or remove its current management by making it more difficult for shareholders to replace members of the Combined Company board of directors. Among other things, these provisions will:

112

In addition, upon effectiveness of the Cayman Redomestication, the Cayman Series B Certificate of Designation (as defined below) relating to the Cayman Series B Preferred Shares (as defined below) may delay or prevent a change in control of the Combined Company. At any time while at least 30% of the originally issued Cayman Series B Preferred Shares remain issued and outstanding, the Combined Company may not, without the affirmative vote of the holders of a majority of the then outstanding shares of the Series B Preferred Shares, (i) consummate (x) any Fundamental Transaction (as defined in the Cayman Series B Certificate of Designation) or (y) any merger or consolidation of the Combined Company with or into another entity or any stock sale to, or other business combination in which the Combined Company shareholders immediately before such transaction do not hold at least a majority of the Combined Company’s capital stock immediately after such transaction, (ii) increase the size of the Combined Company board of directors, (iii) adopt, amend or repeal any written delegation of authority policy, corporate authority matrix or similar document, framework or schedule unless such adoption, amendment or repeal has been approved by the unanimous vote of the Combined Company board of directors, or (iv) retain or replace the Combined Company’s registered independent public accounting firm, independent compensation consultant or corporate counsel. This provision of the Cayman Series B Certificate of Designation may make it more difficult for the Combined Company to enter into any of the aforementioned transactions, even potential change of control transactions that could offer a premium over the market value of the Combined Company to the ordinary shareholders, as it would require the separate consent of the majority of the issued and outstanding Cayman Series B Preferred Shares.

Because the Cayman Articles designate the courts of the Cayman Islands as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by the Combined Company’s shareholders, this could limit your ability to obtain a favorable judicial forum for disputes with the Combined Company or its directors, officers, or other employees.

The Cayman Articles will provide that unless the Combined Company consents in writing to the selection of an alternative forum, the courts of the Cayman Islands shall have exclusive jurisdiction over any claim or dispute arising out of or in connection with the Cayman Articles or otherwise related in any way to each shareholder’s shareholding in the Combined Company, including but not limited to (i) any derivative action or proceeding brought on behalf of the Combined Company, (ii) any action asserting a claim of breach of any fiduciary or other duty owed by any of the Combined Company’s current or former director, officer or other employee to the Combined Company or its shareholders, (iii) any action asserting a claim arising pursuant to any provision of the Companies Act or the Cayman Articles, or (iv) any action asserting a claim against the Combined Company governed by the internal affairs doctrine (as such concept is recognized under the laws of the United States of America) and that each shareholder irrevocably submits to the exclusive jurisdiction of the courts of the Cayman Islands over all such claims or disputes. The forum selection provision in Cayman Articles will not apply to actions or suits brought to enforce any liability or duty created by the Securities Act, Exchange Act, or any claim for which the federal district courts of the United States of America are, as a matter of the laws of the United States of America, the sole and exclusive forum for determination of such a claim.

The Cayman Articles will also provide that, without prejudice to any other rights or remedies that the Combined Company may have, each of the Combined Company’s shareholders acknowledges that damages alone would not be an adequate remedy for any breach of the selection of the courts of the Cayman Islands as exclusive forum and that accordingly the Combined Company shall be entitled, without proof of special

113

damages, to the remedies of injunction, specific performance or other equitable relief for any threatened or actual breach of the selection of the courts of the Cayman Islands as exclusive forum.

This choice of forum provision may increase a shareholder’s cost and limit the shareholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with the Combined Company or its directors, officers, or other employees, which may discourage lawsuits against the Combined Company and its directors, officers, and other employees. Any person or entity purchasing or otherwise acquiring any of the Combined Company’s shares or other securities, whether by transfer, sale, operation of law or otherwise, shall be deemed to have notice of and have irrevocably agreed and consented to these provisions. There is uncertainty as to whether a court would enforce such provisions, and the enforceability of similar choice of forum provisions in other companies’ memorandum and articles of association or other charter documents has been challenged in legal proceedings. It is possible that a court could find this type of provisions to be inapplicable or unenforceable, and if a court were to find this provision in the Cayman Articles to be inapplicable or unenforceable in an action, the Combined Company may incur additional costs associated with resolving the dispute in other jurisdictions, which could have adverse effect on the Combined Company’s business and financial performance.

Risks Related to the Combined Company

If any of the events described in “Risks Related to Cyclerion” or “Risks Related to Korsana” occur, those events could cause potential benefits of the Merger not to be realized.

Following completion of the Merger, the Combined Company will be susceptible to many of the risks described in the sections herein entitled “Risks Related to Cyclerion” and “Risks Related to Korsana.” To the extent any of the events in the risks described in those sections occur, the potential benefits of the Merger may not be realized and the results of operations and financial condition of the Combined Company could be adversely affected in a material way. This could cause the market price of the Combined Company common stock to decline.

The market price of the Combined Company common stock is expected to be volatile, and the market price of the common stock may drop following the Merger.

The market price of the Combined Company common stock following the Merger could be subject to significant fluctuations. Some of the factors that may cause the market price of the Combined Company common stock to fluctuate include:

114

Moreover, the stock markets in general have experienced substantial volatility that has often been unrelated to the operating performance of individual companies. These broad market fluctuations may also adversely affect the trading price of the Combined Company common stock. In addition, a recession, depression, or other sustained adverse market event could materially and adversely affect the Combined Company’s business and the value of its common stock. In the past, following periods of volatility in the market price of a company’s securities, stockholders have often instituted class action securities litigation against such companies. Furthermore, market volatility may lead to increased shareholder activism if the Combined Company experiences a market valuation that activists believe is not reflective of its intrinsic value. Activist campaigns that contest or conflict with the Combined Company’s strategic direction or seek changes in the composition of its board of directors could have an adverse effect on its operating results, financial condition, and cash flows.

The Combined Company may incur losses for the foreseeable future and may never achieve profitability.

The Combined Company may never become profitable, even if it is able to complete clinical development for one or more product candidates and eventually commercialize such product candidates. The Combined Company will need to successfully complete significant research, development, testing, and regulatory compliance activities that, together with projected general and administrative expenses, is expected to result in substantial increased operating losses for at least the next several years. Even if the Combined Company does achieve profitability, it may not be able to sustain or increase profitability on a quarterly or annual basis.

If the Combined Company fails to attract and retain management and other key personnel, it may be unable to continue to successfully develop or commercialize its product candidates or otherwise implement its business plan.

The Combined Company’s ability to compete in the highly competitive pharmaceuticals industry depends on its ability to attract and retain highly qualified managerial, scientific, medical, legal, sales and marketing and other personnel. The Combined Company will be highly dependent on its management and scientific personnel. The loss of the services of any of these individuals could impede, delay, or prevent the successful development of

115

the Combined Company’s product pipeline, completion of its planned clinical trials, commercialization of its product candidates or in-licensing or acquisition of new assets and could impact negatively its ability to implement successfully its business plan. If the Combined Company loses the services of any of these individuals, it might not be able to find suitable replacements on a timely basis or at all, and its business could be harmed as a result. The Combined Company might not be able to attract or retain qualified management and other key personnel in the future due to the intense competition for qualified personnel among biotechnology, pharmaceutical and other businesses.

The Combined Company will need to raise additional financing in the future to fund its operations, which may not be available to it on favorable terms or at all.

The Combined Company will require substantial additional funds to conduct the costly and time-consuming clinical efficacy trials necessary to pursue regulatory approval of each potential product candidate and to continue the development of KRSA-028 and Korsana’s future programs and future product candidates. The Combined Company’s future capital requirements will depend upon a number of factors, including: the number and timing of future product candidates in the pipeline; progress with and results from preclinical testing and clinical trials; the ability to manufacture sufficient drug supplies to complete preclinical and clinical trials; the costs involved in preparing, filing, acquiring, prosecuting, maintaining and enforcing patent and other intellectual property claims; and the time and costs involved in obtaining regulatory approvals and favorable reimbursement or formulary acceptance.

Raising additional capital may be costly or difficult to obtain and could, for example, through the sale of common stock or securities convertible or exchangeable into common stock, significantly dilute the Combined Company shareholders’ ownership interests or inhibit the Combined Company’s ability to achieve its business objectives. If the Combined Company raises additional funds through public or private equity offerings, the terms of these securities may include liquidation or other preferences that adversely affect the rights of its common shareholders. In addition, any debt financing may subject the Combined Company to fixed payment obligations and covenants limiting or restricting its ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If the Combined Company raises additional capital through marketing and distribution arrangements or other collaborations, strategic alliances, or licensing arrangements with third parties, the Combined Company may have to relinquish certain valuable intellectual property or other rights to its product candidates, technologies, future revenue streams, or research programs or grant licenses on terms that may not be favorable to it. Even if the Combined Company were to obtain sufficient funding, there can be no assurance that it will be available on terms acceptable to the Combined Company or its shareholders.

The Combined Company will incur additional costs and increased demands upon management as a result of complying with the laws and regulations affecting public companies.

The Combined Company will incur significant legal, accounting, and other expenses as a public company that Korsana did not incur as a private company, including costs associated with public company reporting obligations under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). The Combined Company’s management team will consist of the executive officers of Korsana prior to the Merger.

These executive officers and other personnel will need to devote substantial time to gaining expertise related to public company reporting requirements and compliance with applicable laws and regulations to ensure that the Combined Company complies with all of these requirements. Any changes the Combined Company makes to comply with these obligations may not be sufficient to allow it to satisfy its obligations as a public company on a timely basis, or at all. These reporting requirements, rules and regulations, coupled with the increase in potential litigation exposure associated with being a public company, could also make it more difficult for the Combined Company to attract and retain qualified persons to serve on the board of directors or on board committees or to serve as executive officers, or to obtain certain types of insurance, including directors’ and officers’ insurance, on acceptable terms.

116

Upon completion of the Merger, failure by the Combined Company to comply with the initial listing standards of Nasdaq will prevent its stock from being listed on Nasdaq.

Upon completion of the Merger, Cyclerion, under the new name “Korsana Biosciences, Inc.,” will be required to meet the initial listing requirements to maintain the listing and continued trading of its shares on Nasdaq. These initial listing requirements are more difficult to achieve than the continued listing requirements. Pursuant to the Merger Agreement, Cyclerion agreed to use its commercially reasonable efforts to cause the shares of Cyclerion Common Stock being issued in the Merger (including any common stock issuable upon conversion of the Cyclerion Series B Preferred Stock) to be approved for listing on Nasdaq at or prior to the First Effective Time. Based on information currently available to Cyclerion, Cyclerion anticipates that its stock will be unable to meet the $4.00 minimum bid price initial listing requirement at the closing of the Merger unless it effects a reverse stock split. The Cyclerion Board intends to effect a reverse stock split of the shares of Cyclerion Common Stock at a ratio of between     to     . In addition, often times a reverse stock split will not result in a trading price for the affected common stock that is proportional to the ratio of the split. Following the Merger, if the Combined Company is unable to satisfy Nasdaq listing requirements, Nasdaq may notify the Combined Company that its shares of common stock will not be listed on Nasdaq.

Upon a potential delisting from Nasdaq, if the Combined Company common stock is not then eligible for quotation on another market or exchange, trading of the shares could be conducted in the over-the- counter market or on an electronic bulletin board established for unlisted securities such as the Pink Sheets or the OTC Bulletin Board. In such event, it is likely that there would be significantly less liquidity in the trading of the Combined Company common stock; decreases in institutional and other investor demand for the shares, coverage by securities analysts, market making activity and information available concerning trading prices and volume; and fewer broker dealers willing to execute trades in the Combined Company common stock. Also, it may be difficult for the Combined Company to raise additional capital if the Combined Company common stock is not listed on a major exchange. The occurrence of any of these events could result in a further decline in the market price of the Combined Company common stock and could have a material adverse effect on the Combined Company.

Once the Combined Company is no longer a smaller reporting company or otherwise no longer qualifies for applicable exemptions, the Combined Company will be subject to additional laws and regulations affecting public companies that will increase the Combined Company’s costs and the demands on management and could harm the Combined Company’s operating results and cash flows.

The Combined Company will be subject to the reporting requirements of the Exchange Act, which requires, among other things, that the Combined Company file with the SEC, annual, quarterly, and current reports with respect to the Combined Company’s business and financial condition as well as other disclosure and corporate governance requirements. However, as a “smaller reporting company,” as such term is defined in Rule 12b-2 under the Exchange Act, in at least the near term, the Combined Company may take advantage of exemptions from disclosure requirements, including not being required to comply with the auditor attestation requirements of Section 404 of the Sarbanes-Oxley Act and reduced disclosure obligations regarding executive compensation in this proxy statement/prospectus and in the Combined Company’s periodic reports and proxy statements. Once the Combined Company is no longer a smaller reporting company or otherwise no longer qualifies for these exemptions, the Combined Company will be required to comply with these additional legal and regulatory requirements applicable to public companies and will incur significant legal, accounting, and other expenses to do so. If the Combined Company is not able to comply with the requirements in a timely manner or at all, the Combined Company’s financial condition or the market price of the Combined Company common stock may be harmed. For example, if the Combined Company or its independent auditor identifies deficiencies in the Combined Company’s internal control over financial reporting that are deemed to be material weaknesses the Combined Company could face additional costs to remedy those deficiencies, the market price of the Combined Company stock could decline or the Combined Company could be subject to sanctions or investigations by the SEC or other regulatory authorities, which would require additional financial and management resources.

117

If the Combined Company fails to maintain proper and effective internal controls, its ability to produce accurate financial statements on a timely basis could be impaired.

Provided the Combined Company continues to be listed on Nasdaq, the Combined Company will be subject to the reporting requirements of the Exchange Act, the Sarbanes-Oxley Act and the rules and regulations of Nasdaq. The Sarbanes-Oxley Act requires, among other things, that the Combined Company maintain effective disclosure controls and procedures and internal control over financial reporting. The Combined Company must perform system and process evaluation and testing of its internal control over financial reporting to allow management to report on the effectiveness of its internal controls over financial reporting in its Annual Report on Form 10-K filing for that year, as required by Section 404 of the Sarbanes- Oxley Act. As a private company, Korsana has not been required to document and test its internal controls over financial reporting nor has its management been required to certify the effectiveness of its internal controls and its auditors have not been required to opine on the effectiveness of its internal control over financial reporting. Following the Merger, the Combined Company will be required to incur substantial professional fees and internal costs to expand its accounting and finance functions and expend significant management efforts. The Combined Company may experience difficulty in meeting these reporting requirements in a timely manner.

The Combined Company may discover weaknesses in its system of internal control over financial reporting that could result in a material misstatement of its financial statements. The Combined Company’s internal control over financial reporting will not prevent or detect all errors and all fraud. A control system, no matter how well designed and operated, can provide only reasonable, not absolute, assurance that the control system’s objectives will be met. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that misstatements due to error or fraud will not occur or that all control issues and instances of fraud will be detected.

If the Combined Company is not able to comply with the requirements of Section 404 of the Sarbanes-Oxley Act, or if it is unable to maintain proper and effective internal controls, the Combined Company may not be able to produce timely and accurate financial statements. If that were to happen, the market price of its common stock could decline and it could be subject to sanctions or investigations by Nasdaq, the SEC or other regulatory authorities.

The unaudited pro forma condensed combined financial information for Cyclerion and Korsana included in this proxy statement/prospectus are preliminary, and the Combined Company’s actual financial position and operations after the Merger may differ materially from the unaudited pro forma financial information included in this proxy statement/prospectus.

The unaudited pro forma financial information for Cyclerion and Korsana included in this proxy statement/prospectus are presented for illustrative purposes only and is not necessarily indicative of the Combined Company’s actual financial condition or results of operations of future periods, or the financial condition or results of operations that would have been realized had the entities been combined during the period presented. The Combined Company’s actual results and financial position after the Merger may differ materially and adversely from the unaudited pro forma financial information included in this proxy statement/prospectus. The Exchange Ratio reflected in this proxy statement/prospectus is preliminary. The final Exchange Ratio could differ materially from the preliminary Exchange Ratio used to prepare the pro forma adjustments. For more information see the section titled “Unaudited Pro Forma Condensed Combined Financial Information” beginning on page 378.

Provisions that will be in the Combined Company’s articles of organization and bylaws and provisions under Massachusetts law could make an acquisition of the Combined Company more difficult and may prevent attempts by its shareholders to replace or remove its management.

Provisions that will be included in the Combined Company’s articles of organization and bylaws may discourage, delay, or prevent a merger, acquisition, or other change in control of the Combined Company that

118

shareholders may consider favorable, including transactions in which its common shareholders might otherwise receive a premium price for their shares. These provisions could also limit the price that investors might be willing to pay in the future for shares of the Combined Company common stock, thereby depressing the market price of its common stock. In addition, because the Combined Company board of directors will be responsible for appointing the members of the Combined Company management team, these provisions may frustrate or prevent any attempts by the Combined Company shareholders to replace or remove its current management by making it more difficult for shareholders to replace members of the Combined Company board of directors. Among other things, these provisions will:

In addition, the provisions of the Cyclerion Articles, as amended, relating to the Combined Company’s Series B Preferred Stock may delay or prevent a change in control of the Combined Company. At any time while at least 30% of the originally issued Series B Preferred Stock remains issued and outstanding, the Combined Company may not, without the affirmative vote of the holders of a majority of the then outstanding shares of the Series B Preferred Stock, (i) consummate (x) any Fundamental Transaction (as defined in the Cyclerion Articles, as amended) or (y) any merger or consolidation of the Combined Company with or into another entity or any stock sale to, or other business combination in which the Combined Company shareholders immediately before such transaction do not hold at least a majority of the Combined Company’s capital stock immediately after such transaction, (ii) increase the size of the Combined Company board of directors, (iii) adopt, amend or repeal any written delegation of authority policy, corporate authority matrix or similar document, framework or schedule unless such adoption, amendment or repeal has been approved by the unanimous vote of the Combined Company board of directors, or (iv) retain or replace the Combined Company’s registered independent public accounting firm, independent compensation consultant or corporate counsel. This provision of the Series B Certificate of Designation may make it more difficult for the Combined Company to enter into any of the aforementioned transactions, even potential change of control transactions that could offer a premium over the market value of the Combined Company to the common shareholders, as it would require the separate consent of the majority of the holders of the Series B Preferred Stock.

If Proposal No. 4 is approved by Cyclerion shareholders and the Merger is completed, the Combined Company will effect the Cayman Redomestication pursuant to the Plan of Domestication as set forth in the form attached as Annex J to this proxy statement/prospectus, and, upon completion of the Cayman Redomestication, the rights of Cyclerion shareholders and the rights of Korsana stockholders who become the Combined Company shareholders pursuant to the Merger will no longer be governed by the Cyclerion Articles, Cyclerion Bylaws and

119

the MBCA, and instead will be governed by the Cayman Articles, in the form attached as Annex K to this proxy statement/prospectus, and the Cayman Islands Companies Act. See “Risks Related to the Cayman Redomestication — Currently, Cyclerion is governed by Massachusetts, Cyclerion Articles and Cyclerion Bylaws, but upon effectiveness of the Cayman Redomestication the Combined Company will be governed by Cayman Islands law and the Cayman Articles, provisions of which have anti-takeover implications.”

The articles of organization, as amended, of the Combined Company will provide that, unless the Combined Company consents in writing to the selection of an alternative forum, certain designated courts will be the sole and exclusive forum for certain legal actions between Combined Company and its shareholders, which could limit its shareholders’ ability to obtain a favorable judicial forum for disputes with the Combined Company or its directors, officers, employees, or shareholders.

The articles of organization, as amended, of the Combined Company will provide that, unless the Combined Company consents in writing to the selection of an alternative forum, a state or federal court located within the Commonwealth of Massachusetts shall be the sole and exclusive forum for (a) any derivative action or proceeding brought on behalf of the Combined Company, (b) any action asserting a claim of breach of a fiduciary duty owed by any director, officer or other employee of the Combined Company to the Combined Company or the Combined Company’s shareholders, (c) any action asserting a claim arising pursuant to any provision of the MBCA or any successor statute, or (d) any action asserting a claim governed by the internal affairs doctrine, in all cases subject to the court having personal jurisdiction over the indispensable parties named as defendants, which for purposes of this risk factor refers to herein as the “Massachusetts Forum Provision.” The Massachusetts Forum Provision will not apply to any causes of action arising under the Securities Act and the Exchange Act. In addition, the articles of organization, as amended, of the Combined Company will provide that any person or entity purchasing or otherwise acquiring any interest in shares of its capital stock is deemed to have notice of and consented to the foregoing Massachusetts Forum Provision.

The Massachusetts Forum Provision may impose additional costs on shareholders of the Combined Company in pursuing any such claims, particularly if the shareholders do not reside in or near the Commonwealth of Massachusetts or were permitted to select another jurisdiction. Additionally, the forum selection clauses in the articles of organization, as amended, of the Combined Company may limit its shareholders’ ability to bring a claim in a judicial forum that they find favorable for disputes with the Combined Company or its directors, officers, employees, or shareholders, which may discourage such lawsuits against the Combined Company and its directors, officers, employees, and shareholders even though an action, if successful, might benefit its shareholders. Alternatively, if a court were to find the Massachusetts Forum Provision contained in the Combined Company’s articles of organization, as amended, to be inapplicable or unenforceable in an action, the Combined Company may incur additional costs associated with resolving such action in other jurisdictions, which could materially and adversely affect its business, financial condition, and results of operations.

If Proposal No. 4 is approved by Cyclerion shareholders and the Merger is completed, the Combined Company will effect the Cayman Redomestication pursuant to the Plan of Domestication as set forth in the form attached as Annex J to this proxy statement/prospectus, and, upon completion of the Cayman Redomestication, the rights of Cyclerion shareholders and the rights of Korsana stockholders who become the Combined Company shareholders pursuant to the Merger will no longer be governed by the Cyclerion Articles, Cyclerion Bylaws and the MBCA, and instead will be governed by the Cayman Articles, in the form attached as Annex K to this proxy statement/prospectus, and the Cayman Islands Companies Act. See “Risks Related to the Cayman Redomestication — Because the Cayman Articles designate the courts of the Cayman Islands as the sole and exclusive forum for certain types of actions and proceedings that may be initiated by the Combined Company’s shareholders, this could limit your ability to obtain a favorable judicial forum for disputes with the Combined Company or its directors, officers or other employees.”

120

Cyclerion and Korsana do not anticipate that the Combined Company will pay any cash dividends in the foreseeable future.

The current expectation is that the Combined Company will retain its future earnings, if any, to fund the growth of the Combined Company’s business as opposed to paying dividends. As a result, capital appreciation, if any, of the Combined Company common stock will be your sole source of gain, if any, for the foreseeable future.

An active trading market for the Combined Company common stock may not develop and its shareholders may not be able to resell their shares of common stock for a profit, if at all.

Prior to the Merger, there had been no public market for shares of Korsana capital stock. An active trading market for the Combined Company shares of common stock may never develop or be sustained. If an active market for the Combined Company common stock does not develop or is not sustained, it may be difficult for the Combined Company shareholders to sell their shares at an attractive price or at all.

Future sales of shares by existing shareholders could cause the Combined Company stock price to decline.

If existing securityholders of Cyclerion and Korsana sell, or indicate an intention to sell, substantial amounts of the Combined Company common stock in the public market after legal restrictions on resale discussed in this proxy statement/prospectus lapse, the trading price of the common stock of the Combined Company could decline. Based on shares outstanding as of December 31, 2025 for Cyclerion and March 31, 2026 for Korsana, after giving effect to the estimated Exchange Ratio and the shares of Korsana Common Stock to be issued in the Korsana Pre-Closing Financing and shares expected to be issued upon completion of the Merger and prior to giving effect to the anticipated Cyclerion Reverse Stock Split, the Combined Company is expected to have outstanding a total of approximately 206.8 million shares of common stock immediately following the completion of the Merger (or approximately 293.7 million shares of common stock after giving effect to the conversion of the Cyclerion Series B Preferred Stock and the exercise of Cyclerion Pre-Funded Warrants). Approximately 165.5 million shares (or approximately 181.0 million, if certain Korsana Pre-Funded Warrants are exercised) will be freely tradeable upon completion of the Merger, and an additional approximately 41.3 million shares (or approximately 112.7 million, if the Cyclerion Series B Preferred Stock is converted and the remaining Korsana Pre-Funded Warrants are exercised) will become available for sale in the public market beginning 180 days after the closing of the Merger as a result of the expiration of lock-up agreements between Cyclerion on the one hand and certain securityholders of Korsana on the other hand (and without giving effect to any restrictions on resale under securities laws). In addition, shares of common stock that are subject to outstanding warrants, options or restricted stock units will become eligible for sale in the public market to the extent permitted by the provisions of various vesting agreements and Rules 144 and 701 under the Securities Act. If these shares are sold, the trading price of the Combined Company common stock could decline.

After completion of the Merger, holders of Combined Company Series B Preferred Stock will have the ability to significantly influence all matters submitted to the Combined Company shareholders for approval.

Upon the completion of the Merger, and giving effect to the issuance of the shares of Korsana Common Stock and the Korsana Pre-Funded Warrants prior to the closing of the Merger pursuant to the Korsana Pre-Closing Financing, it is anticipated that holders of Combined Company Series B Preferred Stock will, in the aggregate, beneficially own approximately 36.6% of the Combined Company’s outstanding shares of common stock (on a fully-diluted basis), subject to certain assumptions, including, but not limited to, Cyclerion’s net cash as of closing being $0. As a result, if these shareholders were to choose to act together, they would be able to significantly influence all matters submitted to the Combined Company shareholders for approval, as well as the Combined Company management and affairs. For example, these shareholders, if they choose to act together, would significantly influence the election of directors and approval of any merger, consolidation, or sale of all or substantially all of the Combined Company’s assets. This concentration of voting power could delay or prevent an acquisition of the Combined Company on terms that other shareholders may desire.

121

After completion of the Merger, Preferred Directors elected by the holders of Cyclerion Series B Preferred Stock will have the ability to control or significantly influence all matters submitted to the Combined Company board of directors for approval.

Following the completion of the Merger, pursuant to the Cyclerion Articles, as amended, at all times when at least 30% of the originally issued Cyclerion Series B Preferred Stock remains issued and outstanding: (i) the holders of Cyclerion Series B Preferred Stock, exclusively and voting together as a separate class on an as-converted to common stock basis, shall be entitled to elect four directors (the “Preferred Directors”); and (ii) the holders of Cyclerion Common Stock and of any other class or series of voting stock (including the Cyclerion Series B Preferred Stock), exclusively and voting together as a single class on an as-converted to common stock basis, shall be entitled to elect the balance of the total number of directors of Cyclerion (the “At-Large Directors”). Each Preferred Director is entitled to three votes on each matter presented to the Combined Company board of directors.

Following the completion of the Merger, it is expected Mr. Gottesdiener, Mr. Kiselak, Ms. Pernice, and Mr. Shah will be elected as the four Preferred Directors by the holders of Cyclerion Series B Preferred Stock. These four Preferred Directors will represent approximately 86% of the total votes of the Combined Company board of directors (assuming no vacancies). As a result, these four Preferred Directors would be able to control or significantly influence all matters submitted to the Combined Company board of directors for approval, including business plans and policies and the appointment and removal of the Combined Company’s officers. The holders of Cyclerion Series B Preferred Stock will thereby have influence with respect to the composition of the Combined Company board of directors and, to the extent they influence the actions of the Preferred Directors, if at all, actions of the Combined Company board of directors. Affiliates of Fairmount and Venrock Healthcare Capital Partners are expected to be the sole holders of 92% of Cyclerion Series B Preferred Stock following the completion of the Merger. Mr. Kiselak is a Managing Member at Fairmount, Ms. Pernice is an Operating Partner at Fairmount, and Dr. Violin is a Venture Partner at Fairmount. Mr. Gottesdiener and Mr. Shah are partners at Venrock Healthcare Capital Partners.

Korsana expects that the decision to enter into or amend any Paragon Option Agreement (or similar agreements) or license agreement with Paragon will be subject to the approval of the Combined Company board of directors. As noted above, the Combined Company board of directors will include four Preferred Directors that are affiliated with and elected by Fairmount and Venrock Healthcare Capital Partners, two of whom are affiliated with Fairmount, in addition to Dr. Violin. As a result, Fairmount may exert influence on the decisions of the Combined Company board of directors and the Combined Company management, including as it relates to the Paragon Option Agreements and decisions to exercise options or enter into license agreements thereunder, which interests may differ from the interests of the Combined Company shareholders given Fairmount’s interest in the Combined Company and Paragon, and indirect interest in Parasa. All directors of the Combined Company will owe fiduciary duties pursuant to Massachusetts law, and directors of the Combined Company will be expected to comply with their respective fiduciary duties under Massachusetts law relevant to related party transactions. If the Cayman Redomestication is effected, all directors of the Combined Company will owe fiduciary duties pursuant to Cayman Islands law, and directors of the Combined Company will be expected to comply with their respective fiduciary duties under Cayman Islands law relevant to related party transactions. See the section titled “Proposal No. 4 — The Redomestication Proposal — Effects of the Cayman Redomestication — Comparison of Shareholder Rights under Massachusetts and Shareholder Rights under Cayman Islands Law — Fiduciary Duties and Business Judgment” beginning on page 250 of this proxy statement/prospectus. Following the completion of the Merger, Korsana anticipates that the Combined Company will adopt a related party transaction approval policy and the Combined Company’s audit committee will be responsible for the review, consideration and approval or ratification of related party transactions.

122

If equity research analysts do not publish research or reports, or publish unfavorable research or reports, about the Combined Company, its business or its market, its stock price and trading volume could decline.

The trading market for the Combined Company common stock will be influenced by the research and reports that equity research analysts publish about it and its business. Equity research analysts may elect to not provide research coverage of the Combined Company common stock after the completion of the Merger, and such lack of research coverage may adversely affect the market price of its common stock. In the event it does have equity research analyst coverage, the Combined Company will not have any control over the analysts or the content and opinions included in their reports. The price of the Combined Company common stock could decline if one or more equity research analysts downgrade its stock or issue other unfavorable commentary or research. If one or more equity research analysts ceases coverage of the Combined Company or fails to publish reports on it regularly, demand for its common stock could decrease, which in turn could cause its stock price or trading volume to decline.

The Combined Company will have broad discretion in the use of the cash and cash equivalents of the Combined Company and the proceeds from the Korsana Pre-Closing Financing and may invest or spend the proceeds in ways with which you do not agree and in ways that may not increase the value of your investment.

The Combined Company will have broad discretion over the use of the cash and cash equivalents of the Combined Company and the proceeds from the Korsana Pre-Closing Financing. You may not agree with the Combined Company’s decisions, and its use of the proceeds may not yield any return on your investment. The Combined Company’s failure to apply these resources effectively could compromise its ability to pursue its growth strategy and the Combined Company might not be able to yield a significant return, if any, on its investment of these net proceeds. You will not have the opportunity to influence its decisions on how to use the Combined Company’s cash resources.

The Combined Company’s ability to use NOL carryforwards and other tax attributes may be limited, including as a result of the Merger.

Each of Cyclerion and Korsana has incurred losses during its history, and the Combined Company does not expect to become profitable in the near future and may never achieve profitability. As of December 31, 2025, Cyclerion had federal NOL carryforwards of approximately $211 million. As of December 31, 2025, Korsana had federal NOL carryforwards of approximately $31.5 million. Under current law, U.S. federal NOLs incurred in tax years beginning after December 31, 2017 may be carried forward indefinitely, but the deductibility of such NOL carryforwards is limited to 80% of taxable income. It is uncertain if and to what extent various states will conform to federal law. In addition, under Sections 382 and 383 of the Code, U.S. federal NOL carryforwards and other tax attributes may become subject to an annual limitation in the event of certain cumulative changes in ownership. An “ownership change” pursuant to Section 382 of the Code generally occurs if one or more shareholders or groups of shareholders who own at least 5% of a company’s stock increase their ownership by more than 50 percentage points over their lowest ownership percentage within a rolling three-year period. The Combined Company’s ability to utilize its NOL carryforwards and other tax attributes to offset future taxable income or tax liabilities may be limited as a result of ownership changes, including, as discussed above, in connection with the Merger or other transactions. Similar rules may apply under state tax laws. If the Combined Company earns taxable income, such limitations could result in increased future income tax liability to the Combined Company, and the Combined Company’s future cash flows could be adversely affected.

Changes in tax law could adversely affect the Combined Company’s business and financial condition.

The Combined Company is subject to federal, state, and local income and other taxes in the United States and in foreign jurisdictions because of the scope of its operations. New tax laws, statutes, rules, regulations, or ordinances could be enacted at any time. Further, existing tax laws, statutes, rules, regulations, or ordinances could be interpreted differently, changed, repealed, or modified at any time. Any such enactment, interpretation,

123

change, repeal, or modification could adversely affect us, possibly with retroactive effect. For example, the U.S. government recently enacted legislation commonly referred to as the One Big Beautiful Bill Act that (along with prior U.S. federal tax reform legislation) has resulted in significant changes to the taxation of business entities, including, among other changes, the imposition of minimum taxes and excise taxes, changes to the taxation of income derived from international operations, changes in the deduction and amortization of research and development expenditures, and limitations on the deductibility of business interest. Future guidance from the IRS and other taxing authorities with respect to this and other legislation may affect the Combined Company, and certain aspects of such legislation could be repealed or modified in future legislation or sunset in future years. In addition, it is uncertain if and to what extent various states will conform to federal law. To the extent that any such changes in tax laws and regulations have a negative impact on the Combined Company, including as a result of related uncertainty, its business, financial condition, results of operations and cash flows may be materially and adversely impacted.

Unfavorable global economic conditions could adversely affect the Combined Company’s business, financial condition, results of operations or cash flows.

The Combined Company’s results of operations could be adversely affected by general conditions in the global economy and in the global financial markets. A severe or prolonged economic downturn could result in a variety of risks to the Combined Company’s business, including weakened demand for the Combined Company’s product candidates and the Combined Company’s ability to raise additional capital when needed on acceptable terms, if at all. A weak or declining economy could also strain the Combined Company’s suppliers, possibly resulting in supply disruption, or cause the Combined Company’s customers to delay making payments for its services. Any of the foregoing could harm the Combined Company’s business and the Combined Company cannot anticipate all of the ways in which the current economic climate and financial market conditions could adversely impact its business.

124

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus contains statements that constitute forward-looking statements within the meaning of the federal securities laws in relation to Cyclerion, Korsana, the Merger and the other proposed transactions contemplated thereby. Any express or implied statements that do not relate to historical or current facts or matters are forward-looking statements. In addition, any statements that refer to projections, forecasts or other characterizations of future events or circumstances, including any underlying assumptions, are forward-looking statements. These forward-looking statements include, but are not limited to, express or implied statements regarding Cyclerion’s or Korsana’s expectations, hopes, beliefs, intentions, or strategies regarding the future. In some cases, you can identify forward-looking statements by terminology such as “may,” “might,” “will,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “seeks,” “target,” “endeavor,” “possible,” “potential,” “continue,” “contemplate” or the negative of these terms or other comparable terminology, but the absence of these words does not mean that a statement is not forward-looking. These forward-looking statements are based on current expectations and beliefs concerning future developments and their potential effects. There can be no assurance that future developments affecting Cyclerion, Korsana or the proposed transaction will be those that have been anticipated. These forward-looking statements involve a number of risks, uncertainties (some of which are beyond Cyclerion’s or Korsana’s control) or other assumptions that may cause actual results or performance to be materially different from those expressed or implied by these forward-looking statements. In addition to other factors and matters contained in this document, Cyclerion and Korsana believe the following factors could cause actual results to differ materially from those discussed in the forward-looking statements:

125

126

Should one or more of these risks or uncertainties materialize, or should any of Cyclerion’s or Korsana’s assumptions prove incorrect, actual results may vary in material respects from those projected in these forward-looking statements. There may be additional risks that Cyclerion or Korsana considers immaterial or which are unknown. You are urged to carefully review the disclosures Cyclerion and Korsana make concerning these risks and other factors that may affect Cyclerion’s and Korsana’s business and operating results under the section titled “Risk Factors” beginning on page 32 of this proxy statement/prospectus. Additional factors that could cause actual results to differ materially from those expressed in the forward-looking statements are discussed in reports filed with the SEC by Cyclerion and incorporated by reference herein. Please see the section titled “Where You Can Find More Information” beginning on page 419 of this proxy statement/prospectus. There can be no assurance that the Merger will be completed, or if it is completed, that it will be completed within the anticipated time period or that the expected benefits of the Merger will be realized.

If any of these risks or uncertainties materialize or any of these assumptions prove incorrect, the results of Cyclerion, Korsana or the Combined Company could differ materially from the forward-looking statements. Any public statements or disclosures by Cyclerion and Korsana following this proxy statement/prospectus that modify or impact any of the forward-looking statements contained in this proxy statement/prospectus will be deemed to modify or supersede such statements in this proxy statement/prospectus. You are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date of this document and are qualified in their entirety by reference to the cautionary statements herein. Cyclerion and Korsana do not intend, and undertake no obligation, to update any forward-looking information to reflect events or circumstances after the date of this document or to reflect the occurrence of unanticipated events, unless required by law to do so.

127

THE ANNUAL MEETING OF CYCLERION SHAREHOLDERS

Date, Time and Place

The Cyclerion Shareholders Meeting will be held on    , 2026, commencing at    a.m. Eastern Time, unless postponed or adjourned to a later date. The Cyclerion Shareholders Meeting will be held exclusively online. You will be able to attend and participate in the Cyclerion Shareholders Meeting online by visiting www.virtualshareholdermeeting.com/    , where you will be able to listen to the meeting live, submit questions and vote. Cyclerion is sending this proxy statement/prospectus to its shareholders in connection with the solicitation of proxies by the Cyclerion Board for use at the Cyclerion Shareholders Meeting and any adjournments or postponements of the Cyclerion Shareholders Meeting. This proxy statement/prospectus is first being furnished to Cyclerion shareholders on or about    , 2026.

Purpose of the Cyclerion Shareholders Meeting

The purposes of the Cyclerion Shareholders Meeting are:

128

Approval of each of Proposal No. 1, Proposal No. 2, and Proposal No. 3 is a condition to the completion of the Merger. Therefore, the Merger cannot be consummated without the approval of Proposal Nos. 1, 2, and 3, unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waives such conditions. The issuance of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, and Cyclerion Series B Preferred Stock in connection with the Merger and the change of control of Cyclerion resulting from the Merger will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to increase the number of authorized shares of Cyclerion Common Stock will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to effect a reverse stock split of Cyclerion’s issued and outstanding common stock, will not take place unless Proposal Nos. 1, 2, and 3 are approved by the requisite Cyclerion shareholders. However, the Cyclerion Board may determine to effect the reverse stock split, if approved by Cyclerion shareholders, following the Shareholders Meeting, even if Proposal Nos. 1 and 2 are not approved or the Merger is not otherwise completed.

Recommendation of the Cyclerion Board of Directors

The Cyclerion Board recommends that you vote:

129

Record Date and Voting Power

Only holders of record of Cyclerion Common Stock at the close of business on the Record Date of    , 2026, are entitled to notice of, and to vote at, the Cyclerion Shareholders Meeting. At the close of business on    , 2026, there were    registered holders of record of Cyclerion Common Stock and

130

there were    shares of Cyclerion Common Stock issued and outstanding. Each share of Cyclerion Common Stock entitles the holder thereof to one vote on each matter submitted for shareholder approval.

Voting and Revocation of Proxies

The proxy accompanying this proxy statement/prospectus is solicited on behalf of the Cyclerion Board for use at the Cyclerion Shareholders Meeting.

If, as of the Record Date referred to above, your shares were registered directly in your name with the transfer agent for Cyclerion Common Stock, Computershare Trust Company, N.A., then you are a shareholder of record. As a shareholder of record, you may vote at the Cyclerion Shareholders Meeting or vote by proxy. Whether or not you plan to attend the Cyclerion Shareholders Meeting, we urge you to vote by proxy over the telephone or on the Internet as instructed below or return the proxy card we may mail to you to ensure your vote is counted, the form of which is attached hereto as Annex R to this proxy statement/prospectus.

The procedures for voting are as follows:

If you are a shareholder of record, you may vote at the Cyclerion Shareholders Meeting. Alternatively, you may vote by proxy by using the accompanying proxy card, over the Internet or by telephone. Whether or not you plan to attend the Cyclerion Shareholders Meeting, Cyclerion encourages you to vote by proxy to ensure your vote is counted. Even if you have submitted a proxy before the Cyclerion Shareholders Meeting, you may still attend the Cyclerion Shareholders Meeting and vote. In such case, your previously submitted proxy will be disregarded.

If you are a beneficial owner of shares registered in the name of your broker, bank or other agent, you should have received a voting instruction card and voting instructions with these proxy materials from that organization rather than from Cyclerion. Simply complete and mail the voting instruction card to ensure that your vote is counted. To vote at the Cyclerion Shareholders Meeting, you must obtain a valid proxy from your broker, bank or other agent. Follow the instructions from your broker, bank or other agent included with these proxy materials, or contact your broker, bank or other agent to request a proxy form.

Cyclerion provides Internet proxy voting to allow you to vote your shares online, with procedures designed to ensure the authenticity and correctness of your proxy vote instructions. However, please be aware that you must bear any costs associated with your Internet access, such as usage charges from Internet access providers and telephone companies.

If you are a beneficial owner of shares held in street name and you do not instruct your broker, bank or other agent how to vote your shares, your broker, bank or other agent will only be able to vote your shares with respect to proposals considered to be “routine.” Your broker, bank or other agent is not entitled to vote your shares with respect to “non-routine” proposals. As a result, Cyclerion urges you to direct your broker, bank or other agent how to vote your shares on all proposals to ensure that your vote is counted.

Abstentions and broker non-votes, if any, will be treated as shares present for the purpose of determining the presence of a quorum for the transaction of business at the Cyclerion Shareholders Meeting. Abstentions will be counted towards the vote totals for each proposal, will have the same effect as a vote “AGAINST” Proposal Nos.

131

2, 3, and 4A and will have no effect on Proposal Nos. 1, 4B, 5, 6, 7, 8, 9, 10, and 11. Broker non-votes, if any, will have no effect on Proposal Nos. 1, 4B, 5, 6, 7, 8, 9, 10, and 11 and will have the same effect as a vote “AGAINST” Proposal Nos. 2, 3, and 4A.

All properly executed proxies that are not revoked will be voted at the Cyclerion Shareholders Meeting and at any adjournments or postponements of the Cyclerion Shareholders Meeting in accordance with the instructions contained in the proxy. If a holder of Cyclerion Common Stock executes and returns a proxy and does not specify otherwise, the shares represented by that proxy will be voted “FOR” all of the proposals in accordance with the recommendation of the Cyclerion Board.

Required Vote

The presence at the Cyclerion Shareholders Meeting of the holders of a majority of the shares of Cyclerion Common Stock outstanding and entitled to vote at the Cyclerion Shareholders Meeting is necessary to constitute a quorum at the meeting. Abstentions and broker non-votes, if any, will be counted towards the presence of a quorum. The affirmative vote of a majority of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 1 and Proposal No. 5. The affirmative vote of a majority of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting is required for approval of Proposal No. 2, and Proposal No. 3. The affirmative vote of not less than two-thirds of the shares entitled to vote on the subject matter at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4A. The affirmative vote of not less than two-thirds of the votes properly cast by the holders of Cyclerion Common Stock in person or represented by proxy at the Cyclerion Shareholders Meeting, assuming a quorum is present, is required for approval of Proposal No. 4B. The number of affirmative votes exceeding the number of votes opposing the matter, assuming a quorum is present, is required for the approval of Proposal No. 6, Proposal No. 7, Proposal No. 8, Proposal No. 9, Proposal No. 10, and Proposal No. 11.

Approval of each of Proposal No. 1, Proposal No. 2, and Proposal No. 3 is a condition to the completion of the Merger. Therefore, the Merger cannot be consummated without the approval of Proposal Nos. 1, 2 and 3, unless, to the extent permitted by applicable law, each of Cyclerion, the Merger Subs, and Korsana waives such conditions. The issuance of Cyclerion Common Stock, including shares of Cyclerion Common Stock issuable upon conversion of Cyclerion Series B Preferred Stock, and Cyclerion Series B Preferred Stock in connection with the Merger and the change of control of Cyclerion resulting from the Merger will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to increase the number of authorized shares of Cyclerion Common Stock will not take place unless Proposal Nos. 1, 2, and 3 are approved by Cyclerion shareholders and the Merger is consummated. The amendment to the Cyclerion Articles to effect a reverse stock split of Cyclerion’s issued and outstanding common stock, will not take place unless Proposal Nos. 1, 2, and 3 are approved by the requisite Cyclerion shareholders. However, the Cyclerion Board may determine to effect the reverse stock split, if approved by Cyclerion shareholders, following the Shareholders Meeting, even if Proposal Nos. 1 and 2 are not approved or the Merger is not otherwise completed.

Additionally, Proposal Nos. 4A, 4B, 7, 8, and 9 are each conditioned on the consummation of the Merger. Therefore, if Proposal Nos. 1, 2, and 3 are not approved or the Merger is not consummated, Proposal Nos. 4A, 4B, 7, 8, and 9 will each have no effect, even if approved by Cyclerion shareholders.

Votes will be counted by the inspector of election appointed for the meeting, who will separately count “FOR” and “AGAINST” votes, abstentions and broker non-votes, if any, as applicable to each proposal. Abstentions and broker non-votes, if any, will be treated as shares present for the purpose of determining the presence of a quorum for the transaction of business at the Cyclerion Shareholders Meeting. Abstentions will be counted towards the vote totals for each proposal, will have the same effect as a vote “AGAINST”

132