You are cordially invited to attend the Annual Meeting of Stockholders (the “Annual Meeting”) of TEMPEST THERAPEUTICS, INC., a Delaware corporation (the “Company”). The Annual Meeting will be held on December 31, 2025 at 1:00 p.m., Pacific Time and will be a virtual stockholder meeting through which you can listen to the meeting, submit questions and vote online, for the following purposes:

These items of business are more fully described in the accompanying proxy statement.

The Annual Meeting can be accessed by visiting www.virtualshareholdermeeting.com/TPST2025 and entering the control number included in the proxy card in the enclosed proxy materials. You will not be able to attend the Annual Meeting in person.

The record date for the Annual Meeting is December 4, 2025. Only stockholders of record at the close of business on that date may vote at the meeting or any adjournment thereof.

We have sent you these proxy materials because the Board of Directors (the “Board” or “Board of Directors”) of Tempest Therapeutics, Inc. (sometimes referred to as the “Company” or “Tempest”) is soliciting your proxy to vote at the 2025 Annual Meeting of Stockholders to be held on December 31, 2025 (the “Annual Meeting”), including at any adjournments or postponements of the meeting. You are invited to attend the Annual Meeting to vote on the proposals described in this proxy statement. However, you do not need to attend the meeting to vote your shares. Instead, you may simply complete, sign and return the enclosed proxy card, or follow the instructions below to submit your proxy over the telephone or through the internet.

We intend to mail these proxy materials on or about December [  ], 2025 to all stockholders of record entitled to vote at the Annual Meeting.

The Annual Meeting will be held through a live webcast at www.virtualshareholdermeeting.com/TPST2025. You will not be able to attend the Annual Meeting in person. Stockholders attending the virtual Annual Meeting will generally be afforded the same rights and opportunities to participate as they would at an in-person meeting.

You are entitled to attend the Annual Meeting if you were a stockholder as of the close of business on December 4, 2025 (the “Record Date”), or hold a valid proxy for the meeting. To be admitted to the Annual Meeting, you will need to visit www.virtualshareholdermeeting.com/TPST2025 and enter the control number found next to the label “control number” included in the proxy card in the enclosed proxy materials. If you are a beneficial stockholder, you should contact the bank, broker or other institution where you hold your account well in advance of the meeting if you have questions about obtaining your control number or proxy to vote.

The Annual Meeting will begin promptly at 1:00 p.m. Pacific Time on December 31, 2025. We encourage you to access the Annual Meeting a few minutes before it begins. Online check-in will start approximately 15 minutes before the meeting begins.

If you do not have your control number and you are a registered stockholder, please contact us at cc@tempesttx.com and we will be able to provide your control number to you. If you do not have a control number, you will be able to log-in as a guest. To view the meeting webcast, visit www.virtualshareholdermeeting.com/TPST2025 and register as a guest. If you log-in as a guest, you will not be able to vote your shares or ask questions.

If you are a beneficial owner (that is, you hold your shares in an account at a bank, broker or other holder of record), you will need to contact that bank, broker or other holder of record to obtain your control number prior to the Annual Meeting.

We will have technicians ready to assist you with any technical difficulties you may have accessing the virtual Annual Meeting. If you encounter any difficulties accessing the virtual Annual Meeting during the check-in or meeting time, please call the technical support number that will be posted at www.virtualshareholdermeeting.com/TPST2025.

A list of our record stockholders as of the close of business on the Record Date will be made available to stockholders during the meeting at www.virtualshareholdermeeting.com/TPST2025. In addition, for the 10 days

ending on the day prior to the Annual Meeting, the list will be available for examination by any stockholder of record for a legally valid purpose during regular business hours. To access the list of record stockholders, stockholders should email cc@tempesttx.com.

Only stockholders of record at the close of business on the Record Date will be entitled to vote at the Annual Meeting. On the Record Date, there were [  ] shares of common stock outstanding and entitled to vote. Whether or not you participate in the Annual Meeting, it is important that you vote your shares.

If on the Record Date your shares were registered directly in your name with the Company’s transfer agent, Computershare Trust Company, N.A., then you are a stockholder of record. As a stockholder of record, you may vote online during the meeting or vote by proxy. Whether or not you plan to attend the Annual Meeting, to ensure your vote is counted, we urge you to vote by proxy by using the enclosed proxy card, or by voting over the telephone or through the internet.

If on the Record Date, your shares were held, not in your name, but rather in an account at a brokerage firm, bank or other similar organization, then you are the beneficial owner of shares held in “street name” and these proxy materials are being forwarded to you by that organization. The organization holding your account is considered to be the stockholder of record for purposes of voting at the Annual Meeting. As a beneficial owner, you have the right to direct your broker, bank or other agent regarding how to vote the shares in your account. You are also invited to attend the Annual Meeting. However, since you are not the stockholder of record, you may not vote your shares online during the meeting unless you request and obtain a valid proxy from your broker, bank or other agent.

There are six matters scheduled for a vote:

The Board of Directors knows of no other matters that will be presented for consideration at the Annual Meeting. If any other matters are properly brought before the meeting, it is the intention of the persons named in the accompanying proxy to vote on those matters in accordance with their best judgment.

For the matter to be voted on, you may vote “For” or “Against” or abstain from voting.

The procedures for voting are fairly simple:

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 form with these proxy materials from that organization rather than from us. Simply complete and mail the voting instruction form to ensure that your vote is counted. Alternatively, you may vote by telephone or over the internet as instructed by your broker or bank. To vote online during the Annual 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 that organization to request a proxy form. You must also register to attend the meeting at www.virtualshareholdermeeting.com/TPST2025 using the control number as provided by your broker, bank or other agent.

If you are a holder of our common stock, on each matter to be voted upon, you have one vote for each share of common stock you held as of the close of business on the Record Date.

If you are a stockholder of record and do not vote by completing your proxy card, by telephone, through the internet or online during the Annual Meeting, your shares will not be voted.

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 Election of Director Proposal, “For” the Advisory Vote on Named Executive

Officer Compensation, “For” the Auditor Ratification Proposal, “For” the Rights Plan Proposal, “For” the Nasdaq Proposal and “For” the Incentive Plan Proposal. If any other matter is properly presented at the meeting, your proxyholder (one of the individuals named on your proxy card) will vote your shares using their best judgment.

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 may still be able to vote your shares in its discretion. Under the rules of the New York Stock Exchange (the “NYSE”), brokers, banks and other securities intermediaries that are subject to NYSE rules may use their discretion to vote your “uninstructed” shares with respect to matters considered to be “routine” under NYSE rules, but not with respect to “non-routine” matters. In this regard, Proposals 1, 2, 4, 5 and 6 are considered to be “non-routine” under NYSE rules meaning that your broker may not vote your shares on those proposals in the absence of your voting instructions. However, Proposal 3 is considered to be a “routine” matter under NYSE rules, meaning that if you do not return voting instructions to your broker by its deadline, your shares may be voted by your broker in its discretion on Proposal 3.

If you are a beneficial owner of shares held in street name and you do not plan to obtain a proxy from your broker, bank or other agent and vote at the Annual Meeting, in order to ensure your shares are voted in the way you would prefer, you must provide voting instructions to your broker, bank or other agent by the deadline provided in the materials you receive from your broker, bank or other agent.

A “broker non-vote” occurs when your broker submits a proxy for the meeting with respect to at least one “routine” matter but does not vote on “non-routine” matters because you did not provide voting instructions on such matters. These unvoted shares with respect to “non-routine” matters are counted as “broker non-votes.” Only Proposal 3 (the Auditor Ratification Proposal) is considered a routine matter under applicable stock exchange rules, and without your instruction, your broker, bank or other agent may vote your shares in its discretion. Proposals 1, 2, 4, 5 and 6 are considered non-routine under applicable stock exchange rules, and without your instruction, your broker, bank or other agent cannot vote your shares on these matters. Please instruct your broker, bank or other agent so your vote can be counted.

We will pay for the entire cost of soliciting proxies. In addition to these proxy materials, our directors and employees may also solicit proxies in person, by telephone, or by other means of communication. Directors and employees will not be paid any additional compensation for soliciting proxies. We may also reimburse brokerage firms, banks and other agents for the cost of forwarding proxy materials to beneficial owners.

If you receive more than one set of proxy materials, your shares may be registered in more than one name or in different accounts. Please follow the voting instructions on the proxy cards in the proxy materials to ensure that all of your shares are voted. In addition, we have hired Sodali & Co. (“Sodali”) to solicit proxies. We expect to pay Sodali a fee of $20,000 plus reasonable expenses for these services.

You can revoke your proxy at any time before the final vote at the Annual Meeting. If you are the record holder of your shares, you may revoke your proxy in any one of the following ways:

Your most current proxy card or telephone or internet proxy is the one that is counted.

If your shares are held by your broker, bank or other agent, you should follow the instructions provided by your broker, bank or other agent.

Votes will be counted by the inspector of election appointed for the meeting, who will separately count, for the proposal to elect directors, votes “For,” “Withhold” and abstentions and, with respect to the other proposals, votes “For” and “Against” and abstentions.

The following table summarizes the minimum vote needed to approve each proposal and the effect of abstentions and broker non-votes.

A quorum of stockholders is necessary to hold a valid meeting. A quorum will be present if stockholders holding at least a majority of the outstanding shares entitled to vote are present at the meeting or represented by proxy. On the Record Date, there were [  ] shares outstanding and entitled to vote. Thus, the holders of [  ] shares must be present or represented by proxy at the meeting to have a quorum.

Your shares will be counted towards the quorum only if you submit a valid proxy (or one is submitted on your behalf by your broker, bank or other nominee) or if you vote online at the Annual Meeting. Abstentions will be counted towards the quorum requirement. If there is no quorum, either the chairperson of the meeting or the holders of a majority of shares present at the meeting or represented by proxy may adjourn the meeting to another date.

Only stockholders of record as of the Record Date may submit questions or comments at the Annual Meeting. If you would like to submit a question, you may do so by joining the virtual meeting at www.virtualshareholdermeeting.com/TPST2025 and typing your question in the box in the meeting portal.

To help ensure that we have a productive and efficient meeting, and in fairness to all stockholders in attendance, you will also find posted our rules of conduct for the Annual Meeting when you log in prior to the start of the Annual Meeting. In accordance with the rules of conduct, we ask that you limit your questions and remarks to those that are relevant to the proposals at the Annual Meeting. Our management may group questions by topic with a representative question read aloud and answered. In addition, questions may be ruled out of order if they are, among other things, irrelevant to the proposals at the Annual Meeting, related to pending or threatened litigation, disorderly, repetitious of statements already made, or in furtherance of the speaker’s own personal, political or business interests.

Preliminary voting results will be announced at the Annual Meeting. In addition, final voting results will be published in a current report on Form 8-K that we expect to file within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Form 8-K within four business days after the meeting, we intend to file a Form 8-K to publish preliminary results and, within four business days after the final results are known to us, file an additional Form 8-K to publish the final results.

The proxy statement is available at ir.tempesttx.com.

On October 10, 2023, our Board declared a dividend of one preferred share purchase right (“Right”) to purchase one-thousandth of one share of our newly designated Preferred Shares (as defined below) for each outstanding share of common stock to the stockholders of record as of the close of business on October 23, 2023 (the “Record Date”), and adopted a limited duration stockholder rights plan (the “Rights Plan”), effective immediately, as set forth in the Rights Agreement, dated as of October 10, 2023 (the “Rights Agreement”), by and between the Company and Computershare Trust Company, N.A., as Rights Agent. On October 9, 2024, we entered into Amendment No. 1 to the Rights Agreement, which extended the expiration date of the Rights Agreement until immediately following the Annual Meeting or, if the Company’s stockholders approve the Rights Plan at such meeting, to October 10, 2026 (the “Final Expiration Date”), unless the Rights are earlier redeemed or exchanged by the Company. Accordingly, the Board is seeking the approval of Proposal 4 to approve the Rights Plan, which will have the effect of extending the Rights Plan until the Final Expiration Date. The Rights may expire at an earlier date if redeemed or exchanged by the Company or upon the occurrence of certain transactions.

In connection with the transactions (collectively, the “Contemplated Transactions”) contemplated by the asset purchase agreement, entered into as of November 19, 2025 (the “Asset Purchase Agreement”), by and among the Company, Erigen LLC, a Delaware limited liability company (“Erigen”), and Factor Bioscience Inc., a Delaware corporation (“Factor” and, together with Erigen, “Sellers”), we intend to effect (subject to customary terms and conditions, including the closing of the Contemplated Transactions (the “Closing”)) the issuance, pursuant to the Asset Purchase Agreement, of an aggregate of 8,268,495 shares of common stock issued to Erigen on behalf of both Sellers (the “Closing Consideration”). Promptly following the Closing and the intended dissolution of Erigen and distribution of the Closing Consideration to the equityholders of Erigen, and assuming no further issuances of shares of common stock, including pursuant to the exercise of Prefunded Warrants and Common Warrants (each as defined below under “—Will the Company obtain new financing in connection with the Contemplated Transactions?”),

the pre-Closing equityholders of the Company will own approximately 37.3% of the Company and the equityholders of Erigen, or Matt Angel, Ph.D. and Lotus Capital BVI Limited (“Lotus”), are expected to own approximately 36.7% and 26.0% of the Company, respectively. Assuming the issuance and exercise of the Warrants that are expected to be issued in the Special Dividend (each as defined below under “—If the Nasdaq Proposal is approved, will the pre-Closing stockholders receive any special dividend or distribution from the Company in connection with the completion of the Contemplated Transactions?”), and assuming no further issuances of shares of common stock, including pursuant to the exercise of Prefunded Warrants and Common Warrants, pre-Closing equityholders of the Company would own approximately 54.4% of the Company and Dr. Angel and Lotus would own approximately 26.7% and 18.9% of the Company, respectively.

For further information, please see the section entitled “Proposal 5—The Nasdaq Proposal,” as well as the annexes to this proxy statement.

We are seeking stockholder approval of the stock issuance described above in order to comply with Nasdaq Stock Market Rules 5635(a) and (b).

Under Nasdaq Stock Market Rule 5635(a), stockholder approval is required prior to the issuance of common stock, or of securities convertible into or exercisable for common stock, in connection with the acquisition of the assets of another company if such securities are not issued in a public offering for cash and: (i) the common stock has or will have upon issuance, voting power equal to or in excess of 20% of the voting power outstanding before the issuance of such common stock (or securities convertible into or exercisable for common stock); or (ii) the number of shares of common stock to be issued is or will be equal to or in excess of 20% of the number of shares of common stock outstanding before the issuance of the common stock or securities.

Under Nasdaq Stock Market Rule 5635(b), stockholder approval is required prior to the issuance of securities when the issuance or potential issuance will result in a “change of control” of the registrant. Although Nasdaq has not adopted any rule on what constitutes a “change of control” for purposes of Rule 5635(b), Nasdaq has previously indicated that the acquisition of, or right to acquire, by a single investor or affiliated investor group, as little as 20% of the common stock (or securities convertible into or exercisable for common stock) or voting power of an issuer could constitute a change of control.

Factor is a biotechnology company focused on using its patented gene-editing platform to develop life-saving cell and gene therapies. Factor Bioscience is privately held and headquartered in Cambridge, MA. Erigen is a limited liability company and an affiliate of Factor with two members, Dr. Angel and Lotus, who own 58.5% and 41.5% of Erigen, respectively. If the Contemplated Transactions are approved and consummated, the Assets (as defined below in “Proposal 5—The Nasdaq Proposal”) owned by Erigen will become the Assets of the Company. It is expected that Erigen would dissolve following Closing if the Contemplated Transactions are consummated.

At the closing of the Contemplated Transactions, Dr. Angel, Co-Founder, Chairman and Chief Executive Officer of Factor, will be named as our Chief Executive Officer and President. Dr. Angel’s scientific background and knowledge of the Assets was instrumental in the decision to appoint him as our Chief Executive Officer following the Contemplated Transactions. Stephen Brady, our current Chief Executive Officer and President of the Company, is expected to assume the role of Chairman of our Board. Nicholas Maestas, our current Chief Financial Officer, Justin Trojanowski, our current Corporate Controller and Treasurer, and Robbie Starbody, our current Associate Director, Accounting & Finance, are expected to continue in such capacities after the closing of the Contemplated Transactions as full-time employees. Samuel Whiting, our current Executive Vice President and Chief Medical Officer, will continue to support the Company as a consultant. There are no other current or planned changes to the principal executive, financial or accounting officers of Tempest.

Our Board is currently composed of five members. Upon closing of the Contemplated Transactions, it is anticipated that the Board will consist of four incumbent directors from the current Board, including Mr. Brady, and one new member, Dr. Angel, as the newly appointed Chief Executive Officer. Geoff Nichol, a current member of our Board, is expected to tender his resignation from the Board, effective upon the Closing.

It is anticipated that the current Chair of the Audit Committee of the Board (the “Audit Committee”), the Compensation Committee of the Board (the “Compensation Committee”), and the Nominating and Governance

Committee of the Board (the “Nominating and Corporate Governance Committee”) will remain in their roles upon the closing of the Contemplated Transactions. Other than as described above, there are no current plans to change the composition of the Company’s Board of Directors following the closing of the Contemplated Transactions.

See the section entitled “Proposal 5—The Nasdaq Proposal” for additional information.

As further described in our Current Report on Form 8-K with the SEC on November 26, 2025, on November 24, 2025, we entered into a securities purchase agreement (the “Purchase Agreement”) with a single institutional investor, pursuant to which we agreed to issue and sell (i) in a registered direct offering (the “Registered Direct Offering”) an aggregate of 487,000 shares of common stock, and prefunded warrants to purchase 685,414 shares of common stock (the “Prefunded Warrants”), pursuant to an effective shelf registration statement on Form S-3 (File No. 333-280918) and a related prospectus and prospectus supplement thereunder, and (ii) in a concurrent private placement (the “Private Placement” and together with the Registered Direct Offering, the “Offering”), warrants to purchase an aggregate of 1,172,414 shares of common stock (the “Common Warrants” and, together with the Prefunded Warrants, the “Warrants”). The combined purchase price of each share of common stock and accompanying Common Warrant was $3.625. The combined purchase price of each Prefunded Warrant and accompanying Common Warrant was $3.624 (equal to the combined purchase price per Share and accompanying Common Warrant, minus $0.001).

We currently plan to use the net proceeds from the Offering primarily for working capital and general corporate purposes. The gross proceeds from the Offering were approximately $4.25 million, prior to deducting the placement agent’s fees and other offering expenses payable by us. Each Prefunded Warrant has an initial exercise price per share of $0.001, subject to certain adjustments. The Prefunded Warrants may be exercised at any time until exercised in full. The Common Warrants have an exercise price of $3.50 per share and are exercisable immediately upon issuance for an eighteen month period following the effective date of the registration statement registering the resale of the shares of common stock underlying the Common Warrant.

In addition, concurrently with the execution of the Asset Purchase Agreement, we entered into a commitment letter with Factor, pursuant to which Factor agreed to provide funding to the Company until the earlier of (i) the 18-month anniversary of the closing date of the Contemplated Transactions, (ii) we have raised aggregate gross proceeds of at least $20.0 million from the sale of equity or debt securities (inclusive of the amounts raised and received in the Offering described above), or (iii) certain other termination events set forth in the commitment letter.

Our stockholders do not have dissenters’ or appraisal rights under the Delaware General Corporation Law (the “DGCL”) in connection with the Contemplated Transactions and will not be afforded such rights.

We currently expect the Closing to occur in early 2026. However, the exact timing of the Closing cannot be predicted because it subject to the satisfaction or waiver of the closing conditions specified in the Asset Purchase Agreement, some of which are outside of our direct control.

At Closing, we will issue 8,268,495 shares of our common stock as Closing Consideration. After giving effect to the issuance of Closing Consideration, our pro forma shares outstanding as of the close of business on November 26, 2025, based on 4,927,161 shares of our common stock outstanding as of such date and assuming no further issuances of shares of common stock, including pursuant to the exercise of Prefunded Warrants and Common Warrants, would have been 13,195,656. On a fully diluted basis using the treasury stock method, pre-Closing equityholders of the Company will own approximately 37.3% of the Company and Dr. Angel and Lotus, the equityholders of Erigen, are expected to own approximately 36.7% and 26.0% of the Company, respectively. Assuming the issuance and exercise of the Warrants that are expected to be issued in the Special Dividend, and assuming no further issuances of shares of common stock, including pursuant to the exercise of Prefunded Warrants and Common Warrants, pre-Closing equityholders of the Company would own approximately 54.4% of the Company and Dr. Angel and Lotus would own approximately 26.7% and 18.9% of the Company, respectively.

In connection with the Closing, we will declare a dividend to our stockholders as of a record date prior to the Closing and issue to each such holder one warrant to purchase one share of common stock for each share of common stock held as of such record date. To facilitate the dividend distribution (the “Special Dividend”), we expect to enter into a warrant agreement with Computershare Inc. and Computershare Trust Company N.A., under which we will issue warrants to purchase shares of common stock at an exercise price of $18.48 per share (the “Warrants”). The Warrants will be exercisable at any time on or after the date of the actual distribution (the “Issue Date”) and on or prior to the fifth anniversary of the Issue Date.

Our intention to declare and pay the Special Dividend to stockholders is conditioned upon the expected Closing of the Contemplated Transactions. Accordingly, we cannot assure you that the Special Dividend, or any other dividend or distribution, will be paid to stockholders before or after the completion of the Contemplated Transactions or at all, or that the Company will ever adopt a dividend policy that includes regular cash dividends to stockholders.

Our Board is divided into three classes. Each class consists, as nearly as possible, of one-third of the total number of directors, and each class has a three-year term. Vacancies on the Board may be filled only by persons elected by a majority of the remaining directors. A director elected by the Board to fill a vacancy in a class, including vacancies created by an increase in the number of directors, shall serve for the remainder of the full term of that class and until the director’s successor is duly elected and qualified.

The Board presently has five members. There is one director in Class I, which is the class whose term of office expires at the Annual Meeting. Upon the recommendation of the Nominating and Corporate Governance Committee, our Board has nominated Geoff Nichol for election as a director at the Annual Meeting. Dr. Nichol is currently a director of the Company who was previously elected by the stockholders.

The biography below under “Information Regarding Director Nominees and Continuing Directors” includes information, as of the date of this proxy statement, regarding the specific and particular experience, qualifications, attributes or skills of each director nominee that led the Nominating and Corporate Governance Committee to believe that the nominee should continue to serve on the Board. If you elect the nominee listed above, he will hold office until the 2028 Annual Meeting of Stockholders and until his successor has been duly elected and qualified, or, if sooner, until director’s death, resignation or removal. Dr. Nichol is currently serving on our Board and has consented to be named in this proxy statement and to serve if elected. There are no family relationships among any of our executive officers or directors.

If the Contemplated Transactions are consummated (see Proposal 5), Dr. Nichol is expected to tender his resignation from the Board and the Board is expected to appoint Dr. Angel to fill such vacancy as a Class I director, each effective upon the Closing.

The following table sets forth, for the Class I nominee and our other continuing directors, their ages and position or office held with us as of the date of this proxy statement:

Set forth below is biographical information for the director nominee and each person whose term of office as a director will continue after the Annual Meeting. This includes information regarding each director’s experience, qualifications, attributes or skills that led our Board to recommend them for board service.

Geoff Nichol has served as a member of our Board since June 2021, and served as a member of the board of our legacy company December 2019 until June 2021. Dr. Nichol has nearly 30 years’ experience in drug development. Dr. Nichol most recently served as SVP, Development at AbCellera Biologics, a monoclonal antibody discovery and development company from May 2023 to October 2025. From November 2016 to October 2021, Mr. Nichol served as Chief Medical Officer at BioMarin Pharmaceutical Inc., where he managed an active portfolio of clinical development programs. In October 2021, Dr. Nichol transitioned into a Senior Advisor role until his retirement from Biomarin in April 2023. Prior to Biomarin, Dr. Nichol was Executive Vice President, Research and Development at Sangamo BioSciences from July 2011 to November 2016, where he managed the preclinical development of several IND candidates and Senior Vice President of Development at Medarex, where he was responsible for a portfolio of clinical development programs. Prior to joining Medarex, Dr. Nichol was Vice President at Novartis, where he managed a clinical development therapeutic area, United States Medical Affairs, and Global Project and Portfolio Management. Before Novartis, Dr. Nichol held various positions up to Group Medical Director, Clinical Development at SmithKline Beecham, where he was responsible for anti-infective development and medical affairs. Dr. Nichol received a B.Med.Sc., M.B., Ch.B., or the equivalent of an M.D. in the United States, from Otago University Medical School in New Zealand and an M.B.A. from Warwick University in the United Kingdom. Mr. Nichol’s financial and business expertise, including his background as an executive officer of pharmaceutical and biotechnology companies, provides him with the qualifications and skills to serve as a member of our Board.

Christine Pellizzari has served as a member of our Board since July 2021. Ms. Pellizzari has served as the Chief Legal Officer of Cleerly, Inc. since September 2025 and as the Principal of CAP Strategic Advisory Services since May 2024. Ms. Pellizzari previously served as the Chief Legal and Human Resources Officer of Science 37 Holdings, Inc. (Science 37) from July 2021 to May 2024. Ms. Pellizzari has served as a director and member of audit and compensation committees of Imunon, Inc. (formerly Celsion Corporation) since June 2021 and a director and member of the audit and compensation committees of Neurosense Therapeutics Ltd. since December 2021. Ms. Pellizzari served as Chief Legal Officer of Insmed, Inc. from 2018 to 2021 and prior to that as the General Counsel and Corporate Secretary from 2013 to 2018. Prior to joining Insmed, Ms. Pellizzari held various legal positions of increasing responsibility at Aegerion Pharmaceuticals, Inc., most recently as Executive Vice President, General Counsel and Secretary. Prior to Aegerion,

Ms. Pellizzari served as Senior Vice President, General Counsel and Secretary of Dendrite International, Inc. Ms. Pellizzari joined Dendrite from the law firm of Wilentz, Goldman & Spitzer where she specialized in health care transactions and related regulatory matters. She previously served as law clerk to the Honorable Reginald Stanton, Assignment Judge for the Superior Court of New Jersey. Ms. Pellizzari received her B.A. from the University of Massachusetts, Amherst and her J.D. from the University of Colorado, Boulder. Ms. Pellizzari’s legal, financial and business expertise in the biotechnology industry, including her experience in the capital markets and financial and legal compliance, qualifies her to serve as a member of our Board.

Stephen Brady has served as our Chief Executive Officer and as a member of our Board since June 2021 and as our President since September 2023. Mr. Brady also served as President and Chief Operating Officer of our legacy company from September 2019 until June 2021. Previously, from September 2013 until April 2019, Mr. Brady served in various leadership positions, most recently as Executive Vice President, Strategy and Finance, at Immune Design, Inc., a biopharmaceutical company that was acquired by Merck in 2019. At Immune Design, Mr. Brady led the general and administrative functions at the company, including strategy, corporate development, finance and investor and public relations. Prior to Immune Design, he held roles of increasing responsibility in multiple biopharmaceutical companies, including as Vice President of Corporate Development at Proteolix, where he had primary responsibility for the company’s business development activities and sale to Onyx Pharmaceuticals. Mr. Brady served as a member of the board of directors of Atreca, Inc. from July 2021 to May 2024, and has served as a member of the board of the Biotechnology Innovation Organization (BIO), Emerging Companies Section Governing Board, since 2022. Mr. Brady received a B.A. in English from the University of Oregon, a J.D. from the University of the Pacific and an LL.M. from New York University School of Law. Mr. Brady’s role as our Chief Executive Officer, his business expertise and his prior leadership roles in biotechnology companies provides him with the qualifications and skills to serve as a member of our Board.

Michael Raab has served as a member and as Chairman of our Board since June 2021, and served as a member and Chairman of the board of directors of our legacy company from December 2018 until June 2021. Mr. Raab has served as Ardelyx Inc.’s President and Chief Executive Officer since March 2009 and as a member of the board of directors since 2008. Before Ardelyx, Mr. Raab was a partner at New Enterprise Associates (NEA), where he focused on the biotechnology and pharmaceutical sectors. Prior to joining NEA, Mr. Raab spent 15 years in commercial and operating leadership roles in the biotech and pharmaceutical industries, including serving as Senior Vice President, Therapeutics and General Manager of the Renal Division at Genzyme Corporation, or Genzyme, a biotechnology company. Mr. Raab also spent two years with Genzyme’s diagnostic products and services division. Before Genzyme, Mr. Raab held business development and sales and marketing positions at Repligen Corporation, a life sciences company, and Bristol-Myers Corporation. Mr. Raab has been the lead independent director of Amicus Therapeutics, Inc. since 2004. Mr. Raab received his B.A. from DePauw University. Mr. Raab’s industry and investment experience qualifies him to serve as a member of our Board.

Ronit Simantov, M.D. has served as member of our Board since August 2021. Dr. Simantov has served as Chief Medical Officer of Gamida Cell Ltd. since July 2017 and as the Chief Scientific Officer since July 2021. From July 2021 to July 2023, Dr. Simantov served as a member of the board of directors of Clovis Oncology, Inc. Prior to joining Gamida Cell, Dr. Simantov served as Vice President, Oncology Global Medical Affairs at Pfizer Inc., where she was responsible for multiple oncology programs in various roles. Prior to Pfizer, Dr. Simantov served as Vice President of Clinical Research at OSI Pharmaceuticals, as Chief Medical Officer at CuraGen Corporation (acquired by Celldex) where she led development of small molecules and antibody-drug conjugates, and at Bayer HealthCare Pharmaceuticals, where she led the Phase 3 study of Nexavar^® (sorafenib) resulting in the first approval of a tyrosine kinase inhibitor in renal cell carcinoma. Prior to joining industry, Dr. Simantov spent seven years on the academic faculty at Weill Medical College of Cornell University, where she directed the fellowship program and conducted angiogenesis and vascular biology research. She has authored over 40 peer-reviewed manuscripts. Dr. Simantov holds an M.D. from New York University School of Medicine and a B.A. from Johns Hopkins University. She completed a residency in internal medicine at New York Hospital Cornell Medical Center, and a fellowship in hematology and oncology at Weill Cornell Medicine. Dr. Simantov’s extensive clinical and scientific experience provides her with the qualifications and skills to serve as a member of our Board.

As required under the Nasdaq Capital Market LLC (“Nasdaq”) listing standards, “independent” directors must comprise a majority of a listed company’s board of directors. In addition, applicable Nasdaq rules require that, subject to specified exceptions, each member of a listed company’s audit committee, compensation committee and nominating and corporate governance committee be independent within the meaning of applicable Nasdaq rules. Audit Committee members must also satisfy the independence criteria set forth in Rule 10A-3 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”).

Our Board undertook a review of the independence of each director and considered whether any director has a material relationship with us that could compromise his or her ability to exercise independent judgment in carrying out his or her responsibilities. As a result of this review, our Board determined that all of our directors, other than Mr. Brady, our Chief Executive Officer and President, qualify as “independent” directors within the meaning of the Nasdaq rules. Accordingly, a majority of our directors are independent, as required under applicable Nasdaq rules. The Board also determined that each member of our Audit, Compensation and Nominating and Corporate Governance Committees satisfies the independence standards for such committees established by the SEC and the Nasdaq listing standards, as applicable.

Our non-employee directors have been meeting, and we anticipate that they will continue to meet, in regularly scheduled executive sessions at which only non-employee directors are present.

Our Corporate Governance Guidelines specify that our Board will select our Chief Executive Officer and Chairperson of the Board in the manner that it determines to be in the best interests of the Company and our stockholders. The Board will conduct an annual assessment of its leadership structure to determine that the leadership structure is the most appropriate for the Company at the time. The Board anticipates that our Chief Executive Officer will serve on the Board. The Chairperson of the Board and Chief Executive Officer positions may be held by the same individual or separated as determined by the Board. The Board also anticipates that other members of our management, who can assist the Board in fulfilling its responsibilities based on their experience and role at the Company, may serve on the Board as appropriate.

Pursuant to its charter, the Nominating and Corporate Governance Committee periodically reviews this matter and makes recommendations to the Board. The Nominating and Corporate Governance Committee has recommended, and the Board has determined, that the roles of Chief Executive Officer and Chairperson of the Board should be separate. The role of Chairperson is currently held by Michael Raab, an independent, non-employee director.

One of the Board’s key functions is informed oversight of our risk management process. In particular, our Board is responsible for monitoring and assessing strategic risk exposure, including a determination of the nature and level of risk appropriate for the Company. The Board does not have a standing risk management committee, but rather administers this oversight function directly through the Board as a whole, as well as through various Board standing committees that address risks inherent in their respective areas of oversight. Our Board and its committees consider specific risk topics, including risks associated with our strategic plan, business operations, capital structure, information technology, data privacy and cyber security. It is the responsibility of the committee chairs to report findings regarding material risk exposures to the Board as quickly as possible.

Our Audit Committee has the responsibility to consider and discuss with management and the auditors, as appropriate, our guidelines and policies with respect to financial risk management and financial risk assessment, including the Company’s major financial risk exposures and the steps taken by management to monitor and control these exposures. In addition, the Audit Committee reviews and discusses with management and the auditors, as appropriate, the Company’s guidelines and policies with respect to financial risk management and financial risk assessment, including the Company’s major litigation and risk exposures (including with respect to financial cybersecurity, data privacy and other information technology risks) and the steps taken by management to monitor and control these exposures. Our Compensation Committee assesses and monitors whether any of our compensation policies and programs has the potential to encourage excessive risk-taking, including risks related to our practices

and policies of employee compensation as they relate to risk management and risk-taking incentives, to determine whether such compensation policies and practices are reasonably likely to have a material adverse effect on us, including whether our incentive compensation plans encourage excessive or inappropriate risk taking. Our Nominating and Corporate Governance Committee monitors the effectiveness of our corporate governance guidelines, including proxy advisory firm policies and recommendations. The Nominating and Corporate Governance Committee also oversees and reviews with management our major legal compliance risk exposures and the steps management has taken to monitor or mitigate such exposures, including our procedures and any related policies with respect to risk assessment and risk management.

In connection with our reviews of the operations and corporate functions of our company, our Board addresses the primary risks associated with those operations and corporate functions. In addition, our Board reviews the risks associated with our company’s business strategies periodically throughout the year as part of its consideration of undertaking any such business strategies. While the Board and its committees oversee risk management strategy, management is responsible for implementing and supervising day-to-day risk management processes and reporting to the Board and its committees on such matters.

The Board formally met four times during the last fiscal year. Each Board member attended 75% or more of the aggregate number of meetings of the Board on which she or he served, held during the portion of the last fiscal year for which she or he was a director. In addition, we encourage each of our directors to attend our Annual Meetings of Stockholders. Each of Mr. Brady, Dr. Nichol and Dr. Simantov attended the 2024 Annual Meeting of Stockholders.

Our Board has three standing committees: Audit, Compensation, and Nominating and Corporate Governance. Our Board has also established a Science & Technology Committee. Our Board may establish other committees to facilitate the management of our business. Our Board has adopted a written charter for each of the standing committees, which are available to stockholders on our investor relations website at ir.tempesttx.com.

The following table provides membership and meeting information for the fiscal year ended December 31, 2024 for each committee. Each Board member attended 75% or more of the aggregate number of meetings of each standing committee on which she or he served, held during the portion of the last fiscal year for which she or he was a committee member.

Each of the standing committees has authority to engage legal counsel or other experts or consultants, as it deems appropriate to carry out its responsibilities. Our Board has determined that each member of our standing committees meets the Nasdaq and SEC rules and regulations regarding “independence,” as applicable, and each member is free of any relationship that would impair his or her individual exercise of independent judgment with regard to the company. The Nominating and Corporate Governance Committee periodically reviews the performance of the Board, including Board committees, and management, and makes recommendations to the Board and management, as applicable, for areas of improvement as it deems appropriate.

Below is a description of each committee of the Board.

Geoff Nichol, Christine Pellizzari and Michael Raab, served as members of the Audit Committee during 2024 with Ms. Pellizzari serving as Chair. The Board determined that each member of the Audit Committee satisfies the independence requirements under Nasdaq listing standards and Rule 10A-3(b)(1) of the Exchange Act. Our Board has determined that Ms. Pellizzari is an “audit committee financial expert” within the meaning of SEC regulations. Each member of the Audit Committee can read and understand fundamental financial statements in accordance with applicable requirements. In arriving at these determinations, our Board has examined each Audit Committee member’s scope of experience and the nature of their employment.

The primary purpose of the Audit Committee is to discharge the responsibilities of the Board with respect to the corporate accounting and financial reporting processes, systems of internal control and financial statement audits, and to oversee the independent registered public accounting firm. Specific responsibilities of the Audit Committee include:

The material in this report is not “soliciting material,” is not deemed filed with the SEC and is not to be incorporated by reference in any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof and irrespective of any general incorporation language in any such filing.

The Audit Committee has reviewed and discussed the audited financial statements for the fiscal year ended December 31, 2024 with management of the Company. The Audit Committee has discussed with the independent registered public accounting firm the matters required to be discussed by the applicable requirements of the Public Company Accounting Oversight Board (“PCAOB”) and the SEC. The Audit Committee has also received the written disclosures and the letter from the independent registered public accounting firm required by applicable requirements of the PCAOB regarding the independent accountants’ communications with the Audit Committee concerning independence and has discussed with the independent registered public accounting firm the accounting firm’s independence. Based on the foregoing, the Audit Committee has recommended to the Board of Directors that the audited consolidated financial statements be included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2024.

Michael Raab and Christine Pellizzari served as members of the Compensation Committee during 2024, with Mr. Raab as Chair. The Board determined that each member of the Compensation Committee is independent under the Nasdaq listing standards and a “non-employee director” as defined in Rule 16b-3 promulgated under the Exchange Act.

The primary purpose of the Compensation Committee is to discharge the responsibilities of the Board in overseeing the compensation policies, plans and programs and to review and determine the compensation to be paid to executive officers, directors and other senior management, as appropriate. Specific responsibilities of the Compensation Committee include:

The Compensation Committee generally meets at least two times annually and with greater frequency if necessary. The Compensation Committee also acts periodically by unanimous written consent in lieu of a formal meeting. The agenda for each meeting is usually developed by the Chair of the Compensation Committee, in consultation with management. The Compensation Committee meets regularly in executive session. However, from time to time, various members of management and other employees as well as outside advisors or consultants may be invited by the Compensation Committee to make presentations, to provide financial or other background information or advice or to otherwise participate in Compensation Committee meetings. Our Chief Executive Officer may not participate in, or be present during, any deliberations or determinations of the Compensation Committee regarding his compensation or individual performance objectives.

The charter of the Compensation Committee grants the Compensation Committee full access to all books, records, facilities and personnel of the Company. In addition, under the charter, the Compensation Committee has the authority to obtain, at the expense of the Company, advice and assistance from compensation consultants and internal and external legal, accounting or other advisors and other external resources that the Compensation Committee considers necessary or appropriate in the performance of its duties. The Compensation Committee has direct responsibility for the oversight of the work of any consultants or advisers engaged for the purpose of advising the Committee. In particular, the Compensation Committee has the sole authority to retain, in its sole discretion, compensation consultants to assist in its evaluation of executive and director compensation, including the authority to approve the consultant’s reasonable fees and other retention terms. Under the charter, the Compensation Committee may select, or receive advice from, a compensation consultant, legal counsel or other adviser to the Compensation Committee, other than in-house legal counsel and certain other types of advisers, only after taking into consideration six factors, prescribed by the SEC and Nasdaq, that bear upon the adviser’s independence; however, there is no requirement that any adviser be independent.

During the past fiscal year, after taking into consideration the six factors prescribed by the SEC and Nasdaq described above, the Compensation Committee engaged Alpine Rewards LLC as compensation consultants (the “Compensation Consultants”).

As part of its engagement, the Compensation Consultants were asked to develop a comparative group of companies and to perform analyses of competitive performance and compensation levels for that group. The Compensation Consultants ultimately developed recommendations that were presented to the Compensation Committee for its consideration.

Historically, the Compensation Committee has made most of the significant adjustments to annual compensation, determined bonus and equity awards and established new performance objectives at one or more meetings held during the first quarter of the year. However, the Compensation Committee also considers matters related to individual compensation, such as compensation for new executive hires, as well as high-level strategic issues, such as the efficacy of the Company’s compensation strategy, potential modifications to that strategy and new trends, plans or approaches to compensation, at various meetings throughout the year. Generally, the Compensation Committee’s process comprises two related elements: the determination of compensation levels and the establishment of performance objectives for the current year. For executives other than the Chief Executive Officer, the Compensation Committee solicits and considers evaluations and recommendations submitted to the Committee by the Chief Executive Officer. In the case of the Chief Executive Officer, the evaluation of his performance is conducted by the Compensation Committee, which determines any adjustments to his compensation as well as awards to be granted. For all executives and directors as part of its deliberations, the Compensation Committee may review and consider, as appropriate, materials such as financial reports and projections, operational data, tax and accounting information, tally sheets that set forth the total compensation that may become payable to executives in various hypothetical scenarios, executive and director stock ownership information, company stock performance data, analyses of historical executive compensation levels and current Company-wide compensation levels and recommendations of the Compensation Committee’s compensation consultant, including analyses of executive and director compensation paid at other companies identified by the consultant.

Geoff Nichol and Michael Raab served as members of the Nominating and Corporate Governance Committee during 2024, with Mr. Raab severing as Chair. The Board has determined that each member of the Nominating and Corporate Governance Committee is independent under the Nasdaq listing standards.

Specific responsibilities of the Nominating and Corporate Governance committee include:

The Nominating and Corporate Governance Committee believes that candidates for director should have certain minimum qualifications, including possessing relevant expertise upon which to be able to offer advice and guidance to management, having sufficient time to devote to the affairs of the Company, demonstrated excellence in his or her field, having the ability to exercise sound business judgment, be able to read and understand basic financial statements, having the highest personal integrity and ethics and having the commitment to rigorously represent the long-term interests of our stockholders. However, the Nominating and Corporate Governance Committee retains the right to modify these qualifications from time to time. Candidates for director nominees are reviewed in the context of the current composition of the Board, the operating requirements of the Company and the long-term interests of stockholders. In conducting this assessment, the Nominating and Corporate Governance Committee typically considers diversity, age, skills and other factors as it deems appropriate, given the current needs of the Board and the Company, to maintain a balance of knowledge, experience and capability.

The Nominating and Corporate Governance Committee appreciates the value of thoughtful Board refreshment, and regularly identifies and considers qualities, skills and other director attributes that would enhance the composition of the Board. In the case of incumbent directors whose terms of office are set to expire, the Board reviews such directors’ overall service during their term, including the number of meetings attended, level of participation, quality of performance, and any other relationships and transactions that might impair such directors’ independence. In the case of new director candidates, the Nominating and Corporate Governance Committee also determines whether the nominee is independent for Nasdaq purposes, which determination is based upon applicable Nasdaq listing standards, applicable SEC rules and regulations and the advice of counsel, if necessary. The Nominating and Corporate Governance Committee then uses its network of contacts to compile a list of potential candidates, but may also engage, if it deems appropriate, a professional search firm. The Nominating and Corporate Governance Committee conducts any appropriate and necessary inquiries into the backgrounds and qualifications of possible candidates after considering the function and needs of the Board. The Nominating and Corporate Governance Committee meets to discuss and consider the candidates’ qualifications and then selects a nominee for recommendation to the Board.

The Nominating and Corporate Governance Committee will consider director candidates recommended by stockholders. The Nominating and Corporate Governance Committee does not intend to alter the manner in which it evaluates candidates, including the minimum criteria set forth above, based on whether or not the candidate was recommended by a stockholder. Stockholders who wish to recommend individuals for consideration by the Nominating and Corporate Governance Committee to become nominees for election to the Board may do so by providing timely notice in writing to our Secretary. See “Other Information for Stockholders—Stockholder Proposals for the 2026 Annual Meeting of Stockholders” for additional information.

Geoff Nichol and Ronit Simantov served as members of the Science & Technology Committee during 2024, with Dr. Simantov serving as Chair. Specific responsibilities of the Science & Technology Committee include reviewing our overall scientific, research and development strategies as well as our research and development programs.

Stockholders who wish to communicate with the Board may do so by sending written communications addressed to our Secretary at 2000 Sierra Point Parkway, Suite 400, Brisbane, California, 94005. These communications will be reviewed by the Secretary, who will determine whether the communication should be presented to the Board. The purpose of this screening is to allow the Board to avoid having to consider irrelevant or inappropriate communications (such as advertisements, solicitations and hostile communications). All communications directed to the Audit Committee in accordance with our Whistleblower Policy for Accounting and Auditing Matters that relate to questionable accounting or auditing matters involving the Company will be promptly and directly forwarded to the Audit Committee.

We have adopted a Code of Business Conduct that applies to all officers, directors and employees. The Code of Business Conduct is available on our website at https://ir.tempesttx.com. The Board is responsible for overseeing the Code of Business Conduct and must approve any waivers of the Code of Business Conduct for employees, executive officers and directors. If we make any substantive amendments to the Code of Business Conduct or grant any waiver from a provision of the Code to any executive officer or director, we will promptly disclose the nature of the amendment or waiver on our website.

We have adopted Corporate Governance Guidelines to assure that the Board will have the necessary authority and practices in place to review and evaluate our business operations as needed and to make decisions that are independent of our management. The guidelines are also intended to align the interests of directors and management with those of our stockholders. The Corporate Governance Guidelines set forth the practices the Board intends to follow with respect to board composition and selection, including diversity, board meetings and involvement of senior management, Chief Executive Officer performance evaluation and succession planning, and board committees and compensation. The Corporate Governance Guidelines may be viewed on our website at https://ir.tempesttx.com.

Pursuant to our Insider Trading Policy, our employees, directors and designated consultants are prohibited from engaging in short sales, transactions in publicly traded options, such as puts or calls, hedging transactions, margin accounts, pledges or other inherently speculative transactions with respect to our common stock at any time.

We have adopted an insider trading policy governing the purchase, sale, and/or other dispositions of the Company’s securities by directors, officers, employees and designated consultants that is designed to promote compliance with insider trading laws, rules and regulations, as well as procedures designed to further the foregoing purposes. A copy of our insider trading policy is filed as an exhibit to our Annual Report on Form 10-K for our fiscal year ended December 31, 2024, originally filed with the SEC on March 27, 2025.

At the 2022 Annual Meeting of Stockholders, the stockholders indicated their preference that we solicit a non-binding advisory vote on the compensation of the named executive officers (each a “Named

Executive Officer” and collectively, the “Named Executive Officers”), commonly referred to as a “say-on-pay vote,” every year. The Board has adopted a policy that is consistent with that preference. In accordance with that policy, this year, we are asking the stockholders to approve, on an advisory basis, the compensation of our named executive officers as disclosed in this proxy statement in accordance with SEC rules.

This vote is not intended to address any specific item of compensation, but rather the overall compensation of our Named Executive Officers and the philosophy, policies and practices described in this proxy statement. The compensation of our Named Executive Officers subject to the vote is disclosed in the compensation tables and the related narrative disclosure contained in this proxy statement. We believe that our compensation policies and decisions are strongly aligned with our stockholders’ interests and consistent with current market practices. Compensation of our Named Executive Officers is designed to attract and retain talented and experienced executives to lead the Company successfully in a competitive environment.

Accordingly, the Board is asking the stockholders to indicate their support for the compensation of the Company’s Named Executive Officers as described in this proxy statement by casting a non-binding advisory vote “For” the following resolution:

The vote is advisory and therefore not binding on the Board or the Company. Nevertheless, the views expressed by our stockholders, whether through this vote or otherwise, are important to management and the Board and, accordingly, the Board and the Compensation Committee intend to consider the results of this vote in making determinations in the future regarding executive compensation arrangements.

Unless the Board decides to modify its policy regarding the frequency of soliciting say-on-pay votes on the compensation of our named executive officers, the next scheduled say-on-pay vote will be at the 2026 Annual Meeting of Stockholders.

The Audit Committee has selected Ernst & Young LLP (“Ernst & Young”) as our independent registered public accounting firm for the fiscal year ending December 31, 2025 and has further directed that management submit the selection of its independent registered public accounting firm for ratification by the stockholders at the Annual Meeting. Ernst & Young has audited the financial statements of Tempest since 2021 and was the independent registered public accounting firm for our legacy company since 2016. Representatives of Ernst & Young are expected to be present at the Annual Meeting. They will have an opportunity to make a statement if they so desire and will be available to respond to appropriate questions.

Neither our third amended and restated bylaws (“Bylaws”) nor other governing documents or law require stockholder ratification of the selection of Ernst & Young as our independent registered public accounting firm. However, the Audit Committee is submitting the selection of Ernst & Young to the stockholders for ratification as a matter of good corporate practice. If the stockholders fail to ratify the selection, the Audit Committee will reconsider whether or not to retain that firm for future annual periods. Even if the selection is ratified, the Audit Committee in its discretion may direct the appointment of different independent auditors at any time if they determine that such a change would be in the best interests of Tempest and our stockholders.

The following table represents aggregate fees billed to the Company for the fiscal years ended December 31, 2024 and 2023 by Ernst & Young, the Company’s independent registered public accountant. All fees described below were pre-approved by the Audit Committee.

The Audit Committee has adopted a pre-approval policy under which the Audit Committee approves in advance all audit and permissible non-audit services to be performed by the independent accountants (subject to a de minimis exception). These services may include audit services, audit-related services, tax services, and other non-audit services. As part of its pre-approval policy, the Audit Committee considers whether the provision of any proposed non-audit services is consistent with the SEC’s rules on auditor independence. In accordance with its pre-approval policy, the Audit Committee has pre-approved certain specified audit and non-audit services to be provided by our independent auditor. If there are any additional services to be provided, a request for pre-approval must be submitted to the Audit Committee for its consideration under the policy. The Audit Committee generally pre-approves particular services or categories of services on a case-by-case basis. Finally, in accordance with the pre-approval policy, the Audit Committee has delegated pre-approval authority to the Chair of the Audit Committee. The Chair must report any pre-approval decisions to the Audit Committee at its next meeting. The Audit Committee has determined that the rendering of services other than audit services by Ernst & Young is compatible with maintaining the principal accountant’s independence.

The following table sets forth information regarding our executive officers as of the date of this proxy statement.

Biographical information for Mr. Brady is included above with the director biographies under the caption “Information Regarding Director Nominees and Continuing Directors.”

Dr. Whiting has served as our Executive Vice President and Chief Medical Officer since November 2020 and has also served as the Chief Medical Officer of Vividion Therapeutics, Inc. since August 2025. Prior to joining us, Dr. Whiting served as Senior Vice President of Clinical Development at Calithera Biosciences, a clinical-stage biotech company focused on developing treatments for cancer and other life-threatening diseases, from January 2019 to November 2020, and as Vice President, Clinical Development, from May 2016 to December 2018. Before Calithera, Dr. Whiting served as Vice President of Research and Clinical Development at Gradalis and worked in development of small molecule targeted and immuno-oncology agents at VentiRx Pharmaceuticals and Oncothyreon. Prior to joining industry, Dr. Whiting served as Assistant Professor of Medical Oncology at the University of Washington, Assistant Member of Clinical Research at the Fred Hutchinson Cancer Research Center, and Clinical Head of Gastrointestinal Oncology at the Seattle Cancer Care Alliance. Dr. Whiting completed fellowship training in medical oncology at the Fred Hutchinson Cancer Research Center. His training in internal medicine was through the ABIM Research Pathway at the University of Washington. Dr. Whiting received his B.S. with Honors in Chemistry from Lewis and Clark College and his M.D. and Ph.D. in the Medical Scientist Training Program at the University of Washington.

Mr. Maestas has served as our Chief Financial Officer and Head of Corporate Strategy since January 2025, having previously served as Vice President, Finance and Strategy from July 2021 through December 2024, and has served as our Corporate Secretary since September 2022. Prior to joining us, Mr. Maestas served as the head of FP&A and strategic finance at Alector, a biopharmaceutical company that develops therapies for the treatment of neurodegeneration diseases, from July 2019 to July 2021. Prior to joining Alector, from November 2014 to July 2019, Mr. Maestas served in a variety of roles at Immune Design, an oncology immunotherapy company that was acquired by Merck & Co in 2019, including as Senior Director, Corporate Development & Operations from January to July 2019 and Director, Corporate Development & Operations from January 2017 to December 2018. Mr. Maestas received a B.A. in Molecular and Cell Biology from the University of California, Berkeley and an M.B.A from The Wharton School, University of Pennsylvania.

Share numbers included in the following tables and footnotes included in this Executive and Director Compensation section have been adjusted for the 1-for-13 reverse stock split (the “Reverse Stock Split”) of our common stock, on April 8, 2025, as necessary.

The following table sets forth information for each of the last two completed fiscal years regarding compensation awarded to or earned by the Named Executive Officers.

On June 5, 2025, each of our Named Executive Officers transitioned (collectively, the “Transition”) to consulting agreements with us, pursuant to which they receive hourly compensation. See “—Consulting Agreement and Former Employment Arrangements” for additional information. Prior to the Transition, our Named Executive Officers received a base salary to compensate them for services rendered to us. The base salary payable to each Named Executive Officer was intended to provide a fixed component of compensation reflecting the executive’s skill set, experience, role and responsibilities. None of our Named Executive Officers is currently party to an employment agreement or other agreement or arrangement that provides for automatic or scheduled increases in base salary. See “—Consulting Agreement and Former Employment Arrangements” for additional information.

Historically, our equity award program was the primary vehicle for offering long-term incentives to our executives. We believe that equity awards provided our executives with a strong link to our long-term performance, created an ownership culture and helped to align the interests of our executives and our stockholders. The use of options also can provide tax and other advantages relative to other forms of equity compensation.

We historically have awarded equity grants broadly to our employees, including our non-executive employees. Historically, grants to our executives, including the Named Executive Officers, and other employees were made at the discretion of the Board and were generally made upon commencement of employment, promotion or annually during the first quarter of each year. Moving forward we believe that our equity awards are an important retention tool for our Named Executive Officers, as well as for our other employees.

In connection with our annual grant process, on January 2, 2024, our Compensation Committee approved the grant to each of Mr. Brady, Dr. Whiting and Mr. Maestas of an option to purchase 19,230, 7,691 and 3,076 shares of our common stock, respectively, at an exercise price of $60.58 per share, under our 2023 EIP (as defined below). Each option originally vested in equal monthly installments over a four-year period, subject to the executive’s continuous service to us through each vesting date. See “—Outstanding Equity Awards at Fiscal Year End” for further information.

Historically we have developed a performance-based bonus program annually. Under the 2024 annual performance-based bonus program, each Named Executive Officer was eligible for an annual performance bonus based on (1) the individual’s target bonus, as a percentage of annual base salary, and (2) the percentage attainment of our 2024 corporate goals established by our Board in its sole discretion and communicated to each officer.

Each Named Executive Officer was assigned a target performance bonus expressed as a percentage of their annual base salary, which for 2024 was 55% for Mr. Brady, 40% for Dr. Whiting and 30% for Mr. Maestas. Mr. Brady’s target cash incentive payment was calculated 100% on fulfilment of corporate objectives, and Dr. Whiting and Mr. Maestas’ target cash incentive payments were calculated 75% on fulfilment of corporate objectives and 25% on fulfillment of individual objectives. For 2024, the Board determined that 85% of the corporate objectives were achieved and 110% of individual objectives for each of Dr. Whiting and Mr. Maestas were achieved. These performance-based bonuses are reflected above in the column of the Summary Compensation Table above entitled “Non-Equity Incentive Plan Compensation.”

The following table shows for the fiscal year ended December 31, 2024, certain information regarding outstanding equity awards for the Named Executive Officers. In connection with the Transition, each of Mr. Brady, Dr. Whiting and Mr. Maestas became entitled to full acceleration of all outstanding equity awards, which became fully vested and exercisable as of June 5, 2025. See “—Consulting Agreement and Former Employment Arrangements” for additional information.

On June 5, 2025, each of Mr. Brady, Dr. Whiting and Mr. Maestas transitioned to consulting agreements (collectively, the “Consulting Agreements”) with us, pursuant to which they continued to serve the Company in their respective executive roles. Each Consulting Agreement had a term of one year, unless earlier terminated by either party thereto. Pursuant to the terms of his respective Consulting Agreement, Mr. Brady, Dr. Whiting and Mr. Maestas received hourly compensation at rates of $1,100, $600 and $600 per hour, respectively. Dr. Whiting’s Consulting Agreement remains in effect as of the date of this proxy statement.

In connection with the Transition, we entered into a Separation Agreement (collectively, the “Separation Agreements”) with each of Mr. Brady, Dr. Whiting and Mr. Maestas. Each Separation Agreement provided for

severance benefits resulting from a termination by us without “cause” under each of Mr. Brady’s, Dr. Whiting’s and Mr. Maestas’s respective Former Employment Agreements (as defined below), as described below in “—Change in Control and Severance Arrangements.” In addition, each of Mr. Brady, Dr. Whiting and Mr. Maestas became entitled to full acceleration of all outstanding equity awards, which became fully vested and exercisable as of June 5, 2025. The foregoing severance benefits were contingent upon a general release of claims set forth in the Separation Agreement.

On November 19, 2025, we rehired each of Mr. Brady and Mr. Maestas on a full-time basis (collectively, the “Rehire Transition”). In connection with the Rehire Transition, we expect to enter into a letter agreement with Mr. Brady pursuant to which Mr. Brady will serve as our President and Chief Executive Officer through Closing and will receive a salary of $600,000 per year. In addition, we expect to enter into a new employment agreement with Mr. Maestas on terms substantially consistent with his Former Employment Agreement described below.

Prior to the Transition, each of our Named Executive Officers’ employment was “at will” and could have been terminated at any time. Below is a description of our employment arrangements with each of our Named Executive Officers prior to the Transition (the “Former Employment Agreements”).

We previously entered into an employment agreement, dated January 12, 2022, with Mr. Brady that superseded, amended and restated all prior agreements. Under the terms of the agreement, we agreed to an initial annual base salary, which was increased to $600,000, effective January 1, 2024. Mr. Brady was eligible to receive an annual bonus equal to 55% of his base salary, as determined by the Board in its sole discretion, and certain change in control and severance benefits as discussed below in “—Change in Control and Severance Arrangements.”

We previously entered into an employment agreement, dated January 12, 2022, with Dr. Whiting that superseded, amended and restated all prior agreements. Under the terms of the agreement, we agreed to an initial annual base salary, which was increased to $481,749, effective January 1, 2024. Dr. Whiting was eligible to receive an annual bonus equal to 40% of his base salary, as determined by the Board in its sole discretion, and to certain change in control and severance benefits as discussed below in “—Change in Control and Severance Arrangements.”

We previously entered into an employment agreement, dated January 1, 2025, with Mr. Maestas that superseded, amended and restated all prior agreements. Under the terms of the agreement, we agreed to an initial annual base salary of $425,000. Mr. Maestas was eligible for an annual bonus equal to 40% of his base salary beginning in 2025, as determined by the Board in its sole discretion, and to certain change in control and severance benefits as discussed below in “—Change in Control and Severance Arrangements.”

Pursuant to the Former Employment Agreements, if a Named Executive Officer’s employment was terminated by us without Cause or if a Named Executive Officer resigned for Good Reason (each as defined below), they would have been entitled to receive (i) bi-weekly payments equal to the sum of 12 months of the executive’s base salary for Mr. Brady, 9 months for Dr. Whiting and 9 months for Mr. Maestas, plus a prorated portion of the executive’s target annual bonus for the calendar year in which termination occurred and (ii) if the executive elected to continue health insurance coverage under COBRA, the payment of the monthly premium under COBRA until the earlier of 12 months for Mr. Brady, 9 months for Dr. Whiting and 9 months for Mr. Maestas following termination date or the date on which the executive commenced full-time employment or employment that provided eligibility for healthcare benefits substantially comparable to those provided by us.

Moreover, if a Named Executive Officer’s employment was terminated by us without Cause or a Named Executive Officer resigned for Good Reason within three months prior to or 12 months following a Change in Control, then in lieu of the severance benefits described above the Named Executive Officer would have been entitled to receive (i) a lump-sum amount equal to the sum of 18 months for Mr. Brady, 12 months for Dr. Whiting

and 12 months for Mr. Maestas of the executive’s then base salary plus the executive’s then annual target bonus at 150% for Mr. Brady, 100% for Dr. Whiting and 100% for Mr. Maestas and (ii) payment of COBRA premiums as described above for up to 18 months for Mr. Brady, 12 months for Dr. Whiting and 12 months for Mr. Maestas.

Our Named Executive Officers’ receipt of any severance benefits under the Former Employment Agreements was subject to the execution and non-revocation of a separation agreement containing, among other things a general release of claims in favor of us and our related persons and entities, confidentiality, return of property and non-solicitation and non-disparagement covenants.

Further, if we were subject to a Change in Control prior to the termination of a Named Executive Officer’s service, then 100% of any unvested shares subject to any stock options then held by the Named Executive Officer would have vested and become exercisable in full.

For purposes of each Named Executive Officer’s Former Employment Agreements, each of the following terms has the meaning ascribed to such term in the applicable offer letter agreement but are summarized below:

Prior to the Transition, our Named Executive Officers were, and following the Rehire Transitions Mr. Maestas is, eligible to participate in our employee benefit plans, including medical, dental, vision, disability and life insurance plans, in each case on the same basis as all of our other full-time employees. Any part-time employees we hire would not be eligible to participate in our employee benefit plans. We generally do not provide perquisites or personal benefits to our Named Executive Officers, except in limited circumstances, and we did not provide any perquisites or personal benefits to our Named Executive Officers in 2024.

We participate in a multiple employer tax-qualified 401(k) savings plan which allows participants to defer eligible compensation up to the maximum amount allowed under Internal Revenue Service guidelines. Under our 401(k) plan, we currently make matching contributions of 100% on up to 4% of an employee’s eligible contributions to the plan, up to a maximum of $13,800 per year.

Our Incentive Compensation Recoupment Policy (the “Clawback Policy”), designed to comply with Rule 10D-1 of the Exchange Act and Nasdaq Stock Market Rule 5608, provides for recoupment of incentive compensation in the event of an accounting restatement resulting from material noncompliance with financial reporting requirements under the relevant securities laws. The Clawback Policy applies to our current and former executive officers. Compensation that is granted, earned or vested based wholly or in part upon attainment of a Financial Reporting Measure (as defined in the Clawback Policy) is subject to recoupment.

In accordance with Item 402(v) of Regulation S-K, we are providing the following descriptions of the relationships between the information presented in the table above.

All information provided above under the “Item 402(v) Pay Versus Performance” heading will not be deemed to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Exchange Act, whether made before or after the date hereof and irrespective of any general incorporation language in any such filing, except to the extent the Company specifically incorporates such information by reference.

The following is a description of the standard compensation arrangements under which our non-employee directors are compensated for their service as directors, including as members of the various committees of our Board.

Each non-employee director receives an annual base retainer of $40,000 with the non-executive Board Chair receiving an additional annual base retainer of $35,000. In addition, our non-employee directors receive the following cash compensation for committee services, as applicable:

These retainers are payable in arrears in four equal quarterly installments on the last day of each quarter, provided that the amount of such payment will be prorated for any partial months of service. We also reimburse each of our directors for their travel expenses incurred in connection with their attendance at Board and committee meetings.

In addition, non-employee directors first appointed to the Board are eligible to receive an initial option to purchase 1,923 shares of our common stock. The shares subject to each such stock option will vest over a three-year period, subject to the director’s continued service as a director, with one-third of the award vesting on the first anniversary of the grant date and the remainder of the award vesting in equal monthly installments thereafter. Further, on the date of each annual meeting of stockholders, each non-employee director that continues to serve as a non-employee member on our Board will receive an option to purchase 1,230 shares of our common stock. The shares subject to each such stock option will vest on the earlier to occur of the first anniversary of the grant date and the date of the first annual meeting of stockholders following the grant date, subject to the director’s continued service as a director. The exercise price of these options will equal the fair market value of our common stock on the date of grant. Vested stock options will be exercisable during any period of service to the Company and for one-year thereafter; provided, that no stock option shall be exercisable more than ten years after the date of the stock option grant.

This policy is intended to provide a total compensation package that enables us to attract and retain qualified and experienced individuals to serve as directors and to align our directors’ interests with those of our stockholders.

All directors are entitled to reimbursement of ordinary expenses incurred in connection with attendance at meetings of our Board.

The following table sets forth information for the year ended December 31, 2024 regarding the compensation awarded to or earned by our non-employee directors. Mr. Brady is not included in the table below, as he was an employee and received no additional compensation for his service as director. As a Named Executive Officer, the compensation received by Mr. Brady is shown above in “—Executive Compensation—Summary Compensation Table.”

The following table summarizes our equity compensation plan information as of December 31, 2024. Award amounts in the following table and footnotes have been adjusted for the Reverse Stock Split, as necessary.

The following table sets forth information regarding beneficial ownership of our common stock as of November 18, 2025, the most recent practicable date for computing beneficial ownership, by:

We have determined beneficial ownership in accordance with the rules of the SEC. These rules generally attribute beneficial ownership of securities to persons who possess sole or shared voting or investment power with respect to those securities. Unless otherwise indicated, the persons or entities identified in this table have sole voting and investment power with respect to all shares shown as beneficially owned by them, subject to applicable community property laws.

Applicable percentage ownership is based on 4,440,161 shares of our common stock issued and outstanding as of November 18, 2025. The number of shares of common stock used to calculate the percentage ownership of each listed person includes the shares of common stock underlying options and warrants held by such persons that are currently exercisable or convertible or will be exercisable or convertible within 60 days of November 18, 2025. However, we did not deem these shares outstanding for the purpose of computing the percentage ownership of any other person.

We have adopted a written Related Person Transactions Policy that sets forth our policies and procedures regarding the identification, review, consideration and approval or ratification of “related-persons transactions.” For purposes of our policy only, a “related-person transaction” is a transaction, arrangement or relationship (or any series of similar transactions, arrangements or relationships) in which we and any “related person” are participants involving an amount that exceeds or will exceed $120,000 or, during such time as we qualify as a “smaller reporting company,” the lesser of (1) $120,000 or (2) 1% of the average of our total assets for the last two completed fiscal years. Transactions involving compensation for services provided to us as an employee, director, consultant or similar capacity by a related person are not covered by this policy. A related person is any executive officer, director, or a holder of more than 5% of our capital stock, including any of their immediate family members, and any entity owned or controlled by such persons.

Other than compensation arrangements for our directors and executive officers, which are described in the section titled “Executive and Director Compensation,” the following is a description of our related person transactions since January 1, 2023 to which we were a party or will be a party.

We have entered into indemnification agreements with each of our current directors and officers. These agreements provide for the indemnification of such persons for all reasonable expenses and liabilities incurred in connection with any action or proceeding brought against them by reason of the fact that they are or were serving in such capacity. We believe that these indemnification agreements are necessary to attract and retain qualified persons as directors and officers. Furthermore, we have obtained director and officer liability insurance to cover liabilities our directors and officers may incur in connection with their services to us.

The Board is submitting for stockholder approval a proposal to approve the Rights Plan. Stockholder approval of the Rights Plan is not required by applicable law, or by the Company’s Restated Certificate of Incorporation, the Bylaws or other governing documents. Nonetheless, the Board has determined to request stockholder approval of the Rights Plan to determine the viewpoint of stockholders as to the advisability of the Rights Plan and as a matter of good corporate governance. Additionally, pursuant to the terms of Amendment No. 1 (as defined below), as more fully described below, stockholder approval of the Rights Plan would have the effect of extending the Final Expiration Date of the Rights Plan to October 10, 2026, unless the Rights are earlier redeemed or exchanged by the Company.

On October 10, 2023, the Board adopted the Rights Plan and declared a dividend of one Right to purchase one-thousandth of one Preferred Share for each outstanding share of common stock to the stockholders of record as of the close of business on October 23, 2023. On October 9, 2024, the Company entered into Amendment No. 1 to the Rights Agreement (“Amendment No. 1”), which extended the expiration date of the Rights Agreement until immediately following the Annual Meeting or, if the Company’s stockholders approve the Rights Plan at such meeting, to October 10, 2026, or the Final Expiration Date, unless the Rights are earlier redeemed or exchanged by the Company. On December 5, 2024, the Company entered into Amendment No. 2 to the Rights Agreement (“Amendment No. 2”), which made certain technical amendments to the rights and obligations of the Board to administer and make determinations with respect to the Rights Agreement and the rights issued thereunder. The Rights Agent currently serves as the Company’s transfer agent with respect to the common stock and also has been appointed transfer agent with respect to the Series A Junior Participating Preferred Stock, par value $0.001 per share (each, a “Preferred Share” and collectively, the “Preferred Shares”), if any, that may be issued pursuant to the exercise of rights under the Rights Agreement.

In general terms, the Rights Plan works by imposing a significant penalty upon any person or group that acquires beneficial ownership of 10% (15% in the case of a passive institutional investor) or more of the outstanding shares of common stock without the approval of the Board. The Rights Plan was adopted in response to the significant and ongoing dislocation in the trading price of the common stock and not in response to a specific takeover threat. The Board adopted the Rights Plan to enable all stockholders of the Company to realize the long-term value of their investment. The Rights Plan should reduce the likelihood that any person or group gains control of the Company through open market accumulation without paying all stockholders an appropriate control premium or without providing the Board sufficient time to make informed judgments and take actions that are in the best interests of all stockholders. The Rights Plan does not prevent the Board from engaging with parties or accepting an acquisition proposal if the Board believes that it is in the best interests of the Company and its stockholders. The Rights Plan is similar to other plans adopted by publicly held companies in comparable circumstances.

The trigger of the Rights may cause substantial dilution to any person or group that attempts to acquire the Company without the approval of the Board. As a result, the overall effect of the Rights Plan and the issuance of the Rights may be to render more difficult or discourage a merger, tender or exchange offer or other business combination involving the Company that is not approved by the Board. However, the Rights Plan is not intended to prevent a takeover or deter fair offers for shares of the Company. On the contrary, the Rights Plan is designed to protect the Company and its stockholders from efforts to capitalize on recent market volatility and macroeconomic conditions to obtain control of the Company on terms that are not in the best interests of the Company and its shareholders by encouraging any person or group seeking to acquire the Company to negotiate with the Board. Since the Board may redeem the Rights prior to the Distribution Date (as defined below), the Rights will not interfere with any merger or business combination approved by the Board.

The Rights Plan is not expected to interfere with the day-to-day operations of the Company. The continuation of the existing outstanding Rights and the issuance of additional Rights in the future will not in any way alter the financial condition of the Company, impede its business plans or alter its financial statements.

The following summary of the Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the Rights Agreement. A copy of the Rights Agreement, as amended by Amendments No. 1 and Amendment No. 2, is attached to this Proxy Statement as Appendix A and incorporated by reference herein.

The Rights will not be exercisable and will trade with shares of the common stock until the earlier to occur of (a) the tenth calendar day (or such later date as may be determined by the Board) after a person or group acquires beneficial ownership of 10% (15% in the case of a passive institutional investor) or more of our outstanding common stock (an “Acquiring Person”) or (b) the tenth business day (or such later date as may be determined by action of the Board prior to such time as any person or entity becomes an Acquiring Person) following the date of commencement of, or the first announcement of, an intention to commence, a tender offer or exchange offer, the consummation of which would result in any person or entity or group of persons or entities acting in concert becoming an Acquiring Person; provided, however, the term “Acquiring Person” is subject to certain customary exceptions whereby certain stockholders that would have otherwise been an Acquiring Person are excluded from the definition of “Acquiring Person”. Any stockholders with beneficial ownership of common stock above the applicable threshold as of the time of this announcement are grandfathered at their current ownership levels but are not permitted to increase their ownership without triggering the Rights. Prior to exercise, the Right does not give its holder any dividend, voting or liquidation rights.

The date when the Rights separate from common stock and become exercisable is referred to herein as the “Distribution Date”. Until that date, common stock certificates or, in the case of uncertificated shares, notations in the book-entry account system, will evidence the Rights, and any transfer of shares of common stock will constitute a transfer of Rights. After the Distribution Date, the Rights will be evidenced by separate book-entry credits or by Rights certificates that the Company will mail to all eligible, certificated holders of common stock. Any Rights held by an Acquiring Person are null and void and may not be exercised.

After the Distribution Date, each Right will entitle the holder to purchase one-thousandth (1/1000th) of a Preferred Share for $25.00, adjusted to $325.00 following the Reverse Stock Split, subject to further adjustment (the “Exercise Price”). Each one-thousandth (1/1000th) of a Preferred Share has economic terms similar to that of one share of common stock. The Exercise Price payable, and the number of Preferred Shares or other securities or other property issuable upon exercise of the Rights will be subject to adjustment from time to time to prevent dilution in the event of a stock dividend on, or a subdivision, combination or reclassification of, the Preferred Shares. The exercise of Rights to purchase Preferred Shares will at all times be subject to the availability of a sufficient number of authorized but unissued Preferred Shares. Notwithstanding the foregoing, with certain exceptions, no adjustment in the Exercise Price will be required until cumulative adjustments require an adjustment of at least 1% in such Exercise Price. No fractional Preferred Shares will be issued (other than fractions which are integral multiples of the number of one one-hundredth (1/100th) of a Preferred Share issuable upon the exercise of one Right, which may, at the Company’s election, be evidenced by depositary receipts), and in lieu thereof, an adjustment in cash will be made based on the market price of the Preferred Shares on the last trading day prior to the date of exercise.

Certain synthetic interests in securities created by derivative positions — whether or not such interests are considered to be ownership of underlying shares of common stock or are reportable for purposes of Regulation 13D of the Securities Exchange Act of 1934, as amended — are treated as beneficial ownership of the number of shares of common stock equivalent to the economic exposure created by the derivative position, to the extent actual shares of common stock are directly or indirectly held by counterparties to the derivatives contracts. Swaps dealers unassociated with any control intent or intent to evade the purposes of the Rights Agreement are excepted from such imputed beneficial ownership. In addition, shares held by affiliates and associates of an Acquiring Person, including shares that are subject of, or the reference securities for, or that underline, any derivative position of such persons, will be deemed to be beneficially owned by the Acquiring Person. In addition, any securities beneficially owned by a third party with whom the Acquiring Person has any agreement, arrangement or understanding (whether or not in writing) (i) for the purpose of acquiring, holding or voting securities of the Company or (ii) to cooperate in obtaining, changing or influencing control of the Company, will be deemed to be beneficially owned by the Acquiring Person.

Each Preferred Share, if issued:

The value of one-thousandth interest in a Preferred Share is intended to approximate the value of one share of common stock.

Currently, the Rights will expire at the Annual Meeting. If this Proposal 4 is approved by the Company’s stockholders, the Final Expiration Date will be extended to October 10, 2026, unless the Rights are earlier redeemed or exchanged by the Company.

The Board may redeem the Rights for $0.001 per Right at any time prior to the earlier of (A) such time as any person or group becomes an Acquiring Person or (B) the close of business on the Final Expiration Date. Following the expiration of the above periods, the Rights become nonredeemable. If the Board redeems any Rights, it must redeem all of the Rights. Once the Rights are redeemed, the only right of the holders of Rights will be to receive the redemption price of $0.001 per Right. The redemption price will be adjusted if the Company effects a stock split or stock dividend of common stock.

Rights will have the benefit of certain customary anti-dilution provisions.

The terms of the Rights Agreement may be amended by the Board without the consent of the holders of the Rights. After a person or group becomes an Acquiring Person, the Board may not amend the Rights Agreement in a way that adversely affects holders of the Rights.

The Rights Agreement does not contain any dead-hand, slow-hand, no-hand or similar feature that limits the ability of a future Board to redeem the Rights. Until a Right is exercised, the holder thereof, as such, will have no rights as a stockholder of the Company, including, without limitation, the right to vote or to receive dividends.

The purpose of Proposal No. 5 is to obtain the stockholder approval of the transactions contemplated by the Asset Purchase Agreement, by and among the Company, Erigen and Factor, including, for purposes of Nasdaq Listing Rule 5635(a) and 5635(b), the issuance of 20% or more of the Company’s outstanding shares of common stock upon consummation of the transactions contemplated thereby.

On November 19, 2025, the Company entered into the Asset Purchase Agreement with Erigen and Factor, pursuant to which, among other things and subject to the terms and conditions contained therein, Erigen and Factor (the “Sellers”) have agreed to sell and transfer to the Company all right, title and interest of the Sellers as of the Closing in and to all of the assets primarily related to (a) ERI-2003, an autologous BCMA/CD19 dual-targeting CAR T-cell therapy, (b) ERI-2206, an autologous CD70/CD70 dual-targeting CAR T-cell therapy, (c) ERI-3003, an allogeneic BCMA/CD19 dual-targeting CAR T-cell therapy with a gene edit in the TRAC locus that inactivates the T cell receptor, and (d) ERI-3206, an allogeneic CD70/CD70 dual-targeting CAR T-cell therapy with a gene edit in the TRAC locus that inactivates the T cell receptor (collectively, the “Assets”), in exchange for the issuance to Erigen, on behalf of both Sellers, aggregate consideration of 8,268,495 shares of our common stock (the “Closing Consideration”). The Company will only assume (a) liabilities under the certain acquired contracts solely to the extent incurred based on events occurring after the date of the closing (the “Closing Date”) of the transactions contemplated by the Asset Purchase Agreement, and (b) any liabilities for certain tax obligations to the extent relating to the Assets for any taxable period beginning after the Closing Date (the “Assumed Liabilities”). Additionally, Factor has made a funding commitment to provide the Company with financial support for at least 18 months following the closing of the acquisition of Assets, up to a maximum amount of $20.0 million that is inclusive of any amounts raised and received by the Company after the date of the Asset Purchase Agreement, on the terms and subject to the conditions and other provisions of a funding commitment letter contemplated by and entered into concurrently with the Asset Purchase Agreement.

Pursuant to the Asset Purchase Agreement, the Company shall (i) establish a record date for a meeting of its stockholders (the “Stockholders Meeting”) for the purpose of seeking the affirmative vote of a majority of the votes cast by holders of shares of the Company’s capital stock in favor of this Proposal No. 5 (the “Required Stockholder Vote”), and (ii) duly call, give notice of, convene and hold the Stockholders Meeting as promptly as practicable. The Company shall mail a proxy statement as promptly as reasonably practicable and schedule the Stockholders Meeting to be held within sixty (60) days of the initial mailing of the proxy statement; provided, however, that the Company may postpone or adjourn the Stockholders Meeting with the prior written consent of Factor or if it reasonably believes that (x) it is necessary to ensure that any supplement or amendment to the proxy statement required by applicable law is provided to the holders of our common stock within a reasonable amount of time in advance of the Stockholders Meeting, (y) it will not receive proxies sufficient to obtain the Required Stockholder Vote, whether or not a quorum would be present, or (z) sufficient shares of our common stock will not be represented (whether in person or by proxy) to constitute a quorum necessary to conduct the business of the Stockholders Meeting, in each case as long as the date of the Stockholders Meeting is not postponed or adjourned in the aggregate by more than 60 calendar days or held any later than March 19, 2026. The Annual Meeting has been called, in part, for the purpose of satisfying the requirements above.

The offer and sale of the securities pursuant to the Asset Purchase Agreement are made pursuant to an exemption from registration in reliance upon Rule 506(b) of Regulation D or Section 4(a)(2) of the Securities Act of 1933, as amended (the “Securities Act”). Our obligation to issue the Closing Consideration pursuant to the Asset Purchase Agreement is expressly conditioned upon approval of this Proposal No. 5.

The issuance of our common stock described in this Proposal No. 5 would result in the issuance of over 20% of our outstanding shares of common stock on a pre-transaction basis. As such, for so long as Erigen or, following the intended dissolution of Erigen, its equityholders, Dr. Angel and Lotus, beneficially own a significant amount of shares of our common stock, they could significantly influence future Company decisions. Our stockholders will

incur dilution of their percentage ownership upon the issuance of shares to Erigen. Stockholder approval of Proposal No. 5 will apply to issuances of shares of our common stock to Erigen upon consummation of the Contemplated Transactions.

Our common stock is currently listed on the Nasdaq Capital Market and, as such, we are subject to the listing rules of Nasdaq. Under Nasdaq Listing Rule 5635(a), a company listed on Nasdaq is required to obtain stockholder approval prior to the issuance of common stock, among other things, in connection with the acquisition of another company’s assets, if the number of shares of common stock to be issued is in excess of 20% of the number of shares of common stock then outstanding. Issuance of the Closing Consideration will result in the issuance of more than 20% of our issued and outstanding shares of common stock immediately prior to closing in connection with the Contemplated Transactions. In addition, under Nasdaq Listing Rule 5635(b), a listed company is required to obtain stockholder approval prior to the issuance of common stock that will result in a “change of control” of the company (which may be deemed to occur if, as a result of the issuance, an investor or affiliated investor group acquires, or has the right to acquire, at least 20% of the outstanding shares of common stock (or securities convertible into or exercisable for common stock) or voting power of an issuer and such ownership or voting power would be the largest ownership position of the issuer).

If our stockholders do not approve this Proposal No. 5, the Contemplated Transactions cannot be consummated in a manner that complies with Nasdaq Listing Rule 5635(a) and 5635(b).

This summary is intended to provide you with basic information concerning the Contemplated Transactions. For a more complete description of the conditions to the completion of the Contemplated Transactions, please see the section of this proxy statement captioned “Contemplated Transactions.”

You should carefully consider and evaluate all of the information contained in this proxy statement in evaluating the proposals to be voted on at the Annual Meeting, including with respect to the transactions contemplated by the Asset Purchase Agreement and the other agreements referenced therein. In particular, you should carefully consider and evaluate the risks and uncertainties described under the heading “Risk Factors” in this proxy statement, as well as in the Company’s Annual Report on Form 10-K for the year ended December 31, 2024, the Company’s Quarterly Reports on Form 10-Q for the quarter ended March 31, 2025, June 30, 2025 and September 30, 2025. Stockholders are further advised that the risks described below and in the Company’s SEC filings may not be the only risks we face. Additional risks that we do not yet know of, or that we currently think are immaterial, may also negatively impact our business operations or financial results. Any of the risks and uncertainties set forth in this proxy statement could materially and adversely affect our business, results of operations and financial condition, which in turn could materially and adversely affect the value of our securities.

The consummation of the Contemplated Transactions is subject to numerous conditions, including receipt of the Required Stockholder Vote, the closing of the Pre-Closing Financing (as defined) below and other customary closing conditions. For a more complete description of the conditions to the completion of the Contemplated Transactions, please see the section of this proxy statement captioned “Asset Purchase Agreement—Conditions to Closing of the Contemplated Transactions.”

If the Contemplated Transactions are not completed for any reason, the price of our common stock may decline to the extent that the market price thereof reflects or previously reflected positive market assumptions that the Contemplated Transactions would be completed, and the benefits of the Contemplated Transactions would be realized. In addition, we have expended and will continue to expend significant management time and resources and have incurred and will continue to incur significant expenses due to legal, advisory, printing and financial services fees related to the Contemplated Transactions. These expenses must be paid regardless of whether the Contemplated Transactions are consummated, and such expenses may be more than anticipated, particularly if the Contemplated Transactions are not completed on the anticipated timeline. If the Contemplated Transactions are not consummated, we may be required under certain circumstances to pay a termination fee of $300,000. There can be no assurance that the Contemplated Transactions will be consummated.

Uncertainty about the effect of the Contemplated Transactions on those that do business with us or invest in our securities may have an adverse effect on us or the trading price of our common stock. These uncertainties may impair our ability to attract, retain and motivate key personnel until the Contemplated Transactions are completed and for a period of time thereafter, and could cause those that transact with us to seek to change their existing business relationships with us. During the pendency of the Contemplated Transactions, management and other personnel will be required to dedicate time and attention to execution of the Contemplated Transactions, which may partially divert their attention from the Company’s business.

Pursuant to the terms of the Asset Purchase Agreement, the Company may terminate the Asset Purchase Agreement if, by or before December 5, 2025,the Company has not consummated an equity financing with aggregate gross proceeds of at least $5.0 million (the “Pre-Closing Financing”) and the parties will not be obligated to consummate the Contemplated Transactions. Such capital may not be timely available to us on acceptable terms, or at all. Our ability to raise capital has been adversely impacted by potential worsening global economic conditions, inflation expectations, and the recent disruptions to and volatility in the credit and financial markets in the United States and worldwide resulting from geopolitical tensions. Failure to obtain this necessary capital when needed may force us to terminate the Contemplated Transactions or to delay, limit or terminate our product development efforts or our business operations.

Lawsuits may be filed challenging the Contemplated Transactions, which could prevent the Contemplated Transactions from being completed, or could result in a material delay in, or the abandonment of, the Contemplated Transactions. Even if the lawsuits are without merit, defending against these claims can result in substantial costs and divert management time and resources. An adverse judgment could result in monetary damages, which could have a negative impact on our liquidity and financial condition. Additionally, if a plaintiff is successful in obtaining an injunction prohibiting completion of the Contemplated Transactions, then that injunction may delay or prevent the Contemplated Transactions from being completed, which may adversely affect our business, financial position and results of operations.

The Asset Purchase Agreement is subject to a number of conditions that must be satisfied, including the approval by the Company’s stockholders of Proposal No. 5, or waived, prior to the completion of the Contemplated Transactions. These conditions to the completion of the Contemplated Transactions, some of which are beyond our control, may not be satisfied or waived in a timely manner or at all, and, accordingly, the Contemplated Transactions may be delayed or may not be completed. The Asset Purchase Agreement may also be terminated under certain circumstances. If the Contemplated Transactions are not completed for any reason, our access to capital, ongoing businesses and financial results may be adversely affected.

In general, the Company can refuse to complete the Contemplated Transactions if there is a material adverse change affecting the Assets. However, some types of changes do not permit the Company to refuse to complete the Contemplated Transactions, even if such changes would have a material adverse effect on any of the parties involved in the Contemplated Transactions. For example, if there are changes generally affecting the biotechnology industry, or the economy or the financial, credit or securities markets, the Company would not be permitted to refuse to complete the Contemplated Transactions. If adverse changes occur that affect the Assets but the parties are still required to complete the Contemplated Transactions, the Company’s share price, business and financial results after the completion of the Contemplated Transactions may suffer.

Although we have conducted due diligence on the Assets, we cannot assure you that this diligence revealed all material issues that may be present in the Assets and Assumed Liabilities, that it would be possible to uncover all material issues through a customary amount of due diligence, or that factors outside of our and the Sellers’ control will not arise. As a result, we may realize losses after the closing of the Contemplated Transactions. Even if our due diligence successfully identifies certain risks, unexpected risks may arise and previously known risks may materialize in a manner not consistent with our preliminary risk analysis. Even though these charges may be non-cash items and not have an immediate impact on our liquidity, the fact that we report charges of this nature could contribute to negative market perceptions about the Company or its securities or otherwise affect the Company’s to obtain future financing on favorable terms or at all.

The unaudited pro forma financial information included in this proxy statement is presented for illustrative purposes only and is not necessarily indicative of what our actual financial position or results of operations would have been had the Contemplated Transactions been completed on the dates indicated. See the section entitled “Unaudited Pro Forma Condensed Consolidated Financial Information” for more information.

We expect to incur significant nonrecurring costs associated with the Contemplated Transactions before, at, and after closing of the Contemplated Transactions. We will also incur transaction fees and costs related to formulating and implementing post-closing integration of the Assets with our pipeline and other business initiatives and operating plans.

If the benefits of the Contemplated Transactions do not meet the expectations of investors or securities analysts following consummation of the Contemplated Transactions, the market price of our common stock prior to the completion of the Contemplated Transactions may decline. The market values of our securities may vary significantly due to the market’s reaction to the Contemplated Transactions and general market and economic conditions, including from their prices on the date the Asset Purchase Agreement was executed, the date of this proxy statement, or the date on which our stockholders vote on this Proposal No. 5.

In addition, an active trading market for our common stock following the completion of the Contemplated Transactions may not be sustained. If our common stock becomes delisted from Nasdaq for any reason and is relegated to the OTC Bulletin Board (an inter-dealer automated quotation system for equity securities that is not a national securities exchange), the liquidity and price of our common stock will be more limited than if we were quoted or listed on Nasdaq or another national securities exchange. In such circumstances, the trading price of our common stock may not recover and may experience a further decline. You may be unable to sell your shares of common stock unless a market for our common stock can be sustained.

Though 50% of the shares of our common stock that will be issued to Erigen at the closing of the Contemplated Transactions will be subject to a lock-up period of 180 days, the remaining shares to be issued to Erigen will be freely tradable without restrictions upon the registration of such shares under the Securities Act. If the Contemplated Transactions are completed and if Erigen or its permitted transferees sell substantial amounts of shares of our common stock in the public market, the market price of shares of our common stock may decline.

Immediately following the Contemplated Transactions, our stockholders as of immediately prior to the Contemplated Transactions are expected to hold 37.3% of our common stock and Erigen is expected to hold approximately 62.7% of our common stock, in each case, calculated on a fully diluted basis and not accounting for any other issuances of common stock after the date of the Asset Purchase Agreement. If and when the Contemplated Transactions are consummated, each stockholder will remain a stockholder of the Company with a percentage ownership of the Company that will be smaller than the stockholder’s percentage of the Company prior to the Contemplated Transactions. Our stockholders will have less voting power in the Company than they currently have. Our pre-Contemplated Transactions stockholders, as a group, will be able to exercise less influence over the management and policies of the Company following the consummation of the Contemplated Transactions than they are able to exercise over the Company, immediately prior to the consummation of the Contemplated Transactions.

We received a written opinion, dated November 18, 2025 (the “MTS Opinion”) from MTS Securities, LLC (“MTS Securities”), our financial advisor, to the effect that, as of the date of such opinion and based upon and subject to the various qualifications, assumptions, limitations and other matters set forth in the MTS Opinion, the Closing Consideration pursuant to the Asset Purchase Agreement was fair, from a financial point of view, to the Company. The MTS Opinion did not constitute a recommendation to our Board (or any member thereof) as to how it should vote with respect to the Contemplated Transactions or any other matter. Changes in the operations or prospects of the Company, general market and economic conditions and other factors that may be beyond the control of the Company, and on which the MTS Opinion was based, may alter the value of the prices of shares of our common stock by the time the Contemplated Transactions are completed. Because we did not obtain, and do not expect to request MTS Securities to update its opinion, the MTS Opinion will not address the fairness of the Closing Consideration, from a financial point of view, to the Company at the time the Contemplated Transactions are consummated. The MTS Opinion does not speak to any date other than November 18, 2025, being the date of the opinion. See the section of this proxy statement titled “Opinion of the Company’s Financial Advisor.” A copy of the MTS Opinion is attached hereto as Appendix C and is incorporated by reference herein in its entirety.

In connection with the Contemplated Transactions, our management prepared and considered certain adjusted standalone financial projections with respect to the Assets. These financial projections are based on several assumptions, including regarding the successful commercialization of the Assets, future product revenue and expenditures. These financial projections were not prepared with a view to public disclosure, are subject to significant economic, competitive, industry and other uncertainties and may not be achieved in full, within projected timeframes or at all. The failure of the Company to achieve projected results with respect to the Assets could have a material adverse effect on the price of our common stock and our financial position.

Factor is advancing a pipeline of allogeneic cell therapies designed to treat devastating diseases with high unmet medical need. Its pipeline represents over a decade of work focused on harnessing the potential of the most advanced cell engineering technologies to create a new generation of medicines for patients.

Factor is a wholly-owned subsidiary of Factor Bioscience LLC. Factor also has two wholly-owned subsidiaries below it, Factor Bioscience Limited and Factor Bioscience Pty Ltd.

Dr. Angel and Bangxia Yang have been pursuing biotechnology business ventures and corporate partnerships to further develop certain Factor assets as well as identify other assets outside of Factor. Bangxia Yang has no affiliation with Factor. Bangxia Yang formed Lotus for purposes of these pursuits and is the sole owner and managing member of Lotus. Dr. Angel formed a limited liability company, Erigen, for the purposes of these pursuits. Dr. Angel is the sole manager of Erigen and holds 58.5% of the common units of Erigen (consisting of 100% of the voting common units) and Lotus holds the remaining 41.5% common units (consisting of non-voting common units).

Novatim Immune Therapeutics Co., Ltd. (“Novatim”) is a company organized under the laws of the People’s Republic of China focused on utilizing tumor immunotherapy to address unmet clinical needs. As discussed below, Erigen entered into a license and collaboration agreement with Novatim to develop and commercialize KQ-2003 and KQ-2206 (referred to hereinafter using their Erigen program names, ERI-2003 and ERI-2206) chimeric antigen receptor T-cell (“CAR-T”) therapies.

In July 2025, Erigen entered into an Exclusive License and Collaboration Agreement (the “Novatim License Agreement”) with Novatim. Pursuant to the Novatim License Agreement, Erigen obtained an exclusive license to specified patents and know-how in all fields worldwide, but excluding Greater China, India, Turkey, and Russia, to exploit the ERI-2003 and ERI-2206 programs and allogeneic CAR-T therapies based on the ERI-2003 and ERI-2206 programs. Erigen also received a right of first negotiation to negotiate a license to exploit allogeneic CAR-T therapies and in vivo CAR-T therapies in Greater China. Erigen is obligated to meet certain diligence milestones by specified dates and to use commercially reasonable efforts to develop and make commercially available at least one licensed product in the licensed territory. No upfront payment was paid pursuant to the Novatim License Agreement. Erigen is obligated to pay Novatim up to $80 million in total upon achievement of certain development milestones for the programs and up to $1.24 billion in total upon achievement of certain commercial milestones for the programs. In addition, Erigen is required to pay Novatim mid-to-high single digit royalties on net sales of licensed products, subject to certain customary reductions, up to a lifetime maximum of $800 million, following which Erigen’s license shall become fully paid and royalty-free. Either party may terminate the Novatim License Agreement for the other party’s uncured material breach or the other party’s specified insolvency events.

In November 2025, Erigen entered into an Amended and Restated License and Collaboration Agreement (the “Restated Factor License Agreement”) with Factor Bioscience Limited. Pursuant to the Restated Factor License Agreement, Erigen obtained an exclusive license to specified patents in all fields worldwide, but excluding Greater China, India, Turkey, and Russia, to exploit the ERI-3003 and ERI-3206 programs. The Restated Factor License Agreement also establishes a Joint Steering Committee for the purposes of discussing and coordinating collaboration opportunities and serving as a forum for information sharing. Erigen is obligated to meet certain diligence

milestones by specified dates and to use commercially reasonable efforts to develop and make commercially available at least one licensed product in the licensed territory. No upfront payment was paid pursuant to the Restated Factor License Agreement. Erigen is obligated to pay Factor Bioscience Limited up to $40 million in total upon achievement of certain development milestones for the programs and up to $620 million in total upon achievement of certain commercial milestones for the programs. In addition, Erigen is required to pay Factor Bioscience Limited mid-single digit to high-teens royalties on net sales of licensed products on a country-by-country and licensed product-by-licensed product basis until expiration of the last to expire valid claim of certain licensed patents covering such licensed product in such country, subject to certain customary reductions, and low-to-mid double digit sublicense fees. The Restated Factor License Agreement will continue until expiration of the last-to-expire royalty term. Either party may terminate the Restated Factor License Agreement for the other party’s uncured material breach or the other party’s specified insolvency events. In addition, Erigen may terminate the Restated Factor License Agreement at any time without cause after a specified notice period.

In November 2025, Erigen entered into an Amended and Restated Master Services Agreement (the “Restated Factor Services Agreement”) with Factor. Pursuant to the Restated Factor Services Agreement, Factor will perform services requested by Erigen on a fee-for-services basis and provide Erigen access to Factor’s facilities as mutually agreed upon in one or more written work orders. All deliverables developed as a result of Factor’s performance of the services or as set forth in a work order, other than specified improvements, will be the property and confidential information of Erigen. Furthermore, Factor grants to Erigen a freedom-to-operate license to its background intellectual property solely to the extent necessary or reasonably useful to use, practice or otherwise exploit the deliverables. Either party may terminate the Restated Factor Services Agreement at any time without cause after a specified notice period, provided that termination of the Restated Factor Services Agreement will not terminate any ongoing work orders. Either party may terminate individual work orders in accordance with the terms of the applicable work order.

As discussed above under “—Asset Purchase Agreement”, subject to the terms and conditions of the Asset Purchase Agreement, the Sellers will sell and transfer to us all rights, title and interest in all of the therapeutic assets primarily related to the Assets, including: (a) ERI-2003, an autologous BCMA/CD19 dual-targeting CAR-T therapy (to be known under Tempest control as TPST-2003), (b) ERI-2206, an autologous CD70/CD70 dual-targeting CAR-T therapy (to be known under Tempest control as TPST-2206), (c) ERI-3003, an allogeneic BCMA/CD19 dual-targeting CAR-T therapy with a gene edit in the T-cell receptor alpha constant (“TRAC”) locus that inactivates the T cell receptor (to be known under Tempest control as TPST-3003), and (d) ERI-3206, an allogeneic CD70/CD70 dual-targeting CAR-T therapy with a gene edit in the TRAC locus that inactivates the T cell receptor known as ERI-3206 (to be known under Tempest control as TPST-3206), solely in exchange for a fixed number of shares of Common Stock.

ERI-2003 is an autologous BCMA/CD19 dual-targeting CAR-T therapy designed to target and destroy BCMA and/or CD19-expressing cells, which are implicated in multiple cancers. Novatim is developing ERI-2003 for the treatment of relapsed/refractory multiple myeloma (“rrMM”) and the rare disease, POEMS syndrome, and is conducting a Phase 1 clinical trial of ERI-2003 in China for rrMM and a Phase 1 clinical trial of ERI-2003 in China for POEMS syndrome. Novatim is planning to conduct a pivotal study for ERI-2003 in rrMM, in preparation for a potential BLA application in China by the end of 2027. Under the Novatim License Agreement, Novatim is solely responsible, at its expense, for the development and commercialization of ERI-2003 in Greater China, and Erigen has the right to use clinical data generated by Novatim for Erigen’s regulatory submissions and other purposes. If Novatim does not submit a BLA for ERI-2003 in Greater China by January 18, 2028, it shall be deemed a material breach of the Novatim License Agreement, and Erigen may, in lieu of termination, elect to extend the time provided to achieve certain milestones, including, for example, initiating a first clinical trial of ERI-2003 in the United States by an amount of time equal to the duration of Novatim’s delay in submitting the BLA.

Our development strategy for ERI-2003, which, assuming the completion of Contemplated Transactions, we intend to refer to as TPST-2003, is expected to include conducting a formal transfer of manufacturing information from Novatim, and preparing an investigational new drug (“IND”) application to the FDA in preparation for a

clinical trial of ERI-2003 in the United States. We anticipate that clinical data from Novatim’s planned pivotal study of ERI-2003 in China will be available to us prior to our committing to initiate our own clinical development of ERI-2003, and we believe that these data, if positive, may support a potentially registrational clinical trial of ERI-2003 in the U.S.

ERI-2206 is an autologous CD70/CD70 dual-targeting CAR-T therapy designed to target and destroy CD70-expressing cells, which are implicated in multiple cancers. Novatim is developing ERI-2206 for the treatment of renal cell carcinoma. Our development strategy includes evaluating the preclinical data generated by Novatim, which, if positive, may support our decision to conduct a formal transfer of manufacturing information from Novatim in preparation for our future development of ERI-2206.

We intend to refer to ERI-2206 as TPST-2206 following completion of Contemplated Transactions.

ERI-3003 is an allogeneic BCMA/CD19 dual-targeting CAR-T therapy with a gene edit in the TRAC locus that inactivates the T cell receptor designed to target and destroy BCMA and/or CD19-expressing cells, which are implicated in multiple cancers. ERI-3003 is designed to use the same CAR structure as ERI-2003, while the gene edit in the TRAC locus is designed to enable the use of T cells from healthy donors as a starting material, which may result in lower manufacturing costs and shorter time to treatment, compared to an autologous product. Because ERI-3003 is designed to use the same CAR structure as ERI-2003, we anticipate that the clinical data generated during the development of ERI-2003 will be highly relevant to the development of ERI-3003, and may reduce the overall development timeline of ERI-3003.

Our development strategy for ERI-3003, which, assuming the completion of Contemplated Transactions, we intend to refer to as TPST-3003, is expected to include conducting process development related to the gene edit in the TRAC locus and generating preclinical data to support the preparation of an IND submission to the FDA. We anticipate that clinical data from Novatim’s planned pivotal study of ERI-2003 in China will be available to us prior to our committing to initiate our own clinical development of ERI-3003.

ERI-3206 is an allogeneic CD70/CD70 dual-targeting CAR-T therapy with a gene edit in the TRAC locus that inactivates the T cell receptor designed to target and destroy CD70-expressing cells, which are implicated in multiple cancers. ERI-3206 is designed to use the same CAR structure as ERI-2206, while the gene edit in the TRAC locus is designed to enable the use of T cells from healthy donors as a starting material, which may result in lower manufacturing costs and shorter time to treatment, compared to an autologous product.

Our development strategy for ERI-3206, which, assuming the completion of Contemplated Transactions, we intend to refer to as TPST-3206, is expected to include evaluating the preclinical data generated by Novatim for ERI-2206, which, if positive, may support our decision to further develop ERI-3206.

On November 19, 2025, we entered into the Asset Purchase Agreement, with Factor and Erigen, pursuant to which, among other things and subject to the terms and conditions contained therein, we agreed to purchase, assume and accept all right, title and interest of the Sellers to the Assets and the Assumed Liabilities. In exchange for the acquisition of the Assets and the assumption of the Assumed Liabilities, we will issue aggregate consideration of 8,268,495 shares of our common stock to Erigen, on behalf of the Sellers.

Furthermore, concurrently with the Asset Purchase Agreement, the Company and Factor entered into a funding commitment letter, pursuant to which Factor made a funding commitment to provide the Company with financial support for at least 18 months following the closing of the acquisition of Assets, up to a maximum amount of $20.0 million that is inclusive of any amounts raised and received by the Company after the date of the Asset Purchase Agreement, on the terms and subject to the conditions and other provisions therein. See below for more detailed discussion of the terms of the Asset Purchase Agreement and the related agreements.

In evaluating the Contemplated Transactions and recommending that our stockholders vote in favor of approval of Proposal No. 5, our Board, in consultation with the Company’s management, outside legal counsel and financial advisors, considered the following material factors that it believes support its decision to enter into the Asset Purchase Agreement and to consummate the Contemplated Transactions (which factors are not necessarily presented in order of relative importance):

The foregoing discussion of factors considered by the Board is not intended to be exhaustive but is a summary only of the material factors considered by the Board. In light of the variety of factors considered in connection with its evaluation of the Contemplated Transactions, the Board did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific factors considered in reaching its determinations and recommendations. Moreover, each member of the Board applied his or her own personal business judgment to the process and may have given different weight to different factors. The Board did not undertake to make any specific determination as to whether any factor, or any particular aspect of any factor, supported or did not support its ultimate determination. The Board based its recommendation on the totality of the information presented.

The following chronology summarizes key meetings and events that led to the signing and announcement of the Asset Purchase Agreement. This chronology does not purport to catalogue every conversation of, by, with or among members of the Board, the Company’s management, the Company’s financial advisors, legal advisors or other representatives of the Company or Factor, Erigen or any other person.

Throughout 2024 and into the first quarter of 2025, the Company undertook a series of initiatives to evaluate financing options to support its ongoing clinical programs, including the Company’s pivotal Phase 3 trial for amezalpat. Throughout this period, management observed a lack of support in the capital markets for clinical-stage immuno-oncology companies, which adversely affected the Company’s ability to raise additional capital on acceptable terms. In light of these market pressures, management and the Board undertook a comprehensive assessment of the Company’s business, financial condition, results of operations and prospects, including the viability of pursuing alternative strategic paths.

As part of this assessment, the Company continued discussions with potential investors regarding standalone capital-raising opportunities while simultaneously identifying potential counterparties for strategic transactions that could provide additional operating runway, expand the Company’s business prospects, or otherwise unlock value for stockholders and, in April 2025, the Company publicly announced that it was exploring a broad range of strategic alternatives.

The Company previously retained MTS Health Partners, L.P. (“MTS”) in October 2023 to assist the Company in its strategic review process. Prior to such engagement, the Board reviewed information provided by MTS regarding certain material relationships and, following such review, approved proceeding with the engagement of MTS to act as financial advisors to the Company.

Between April and May 2025, MTS, as authorized by the Board, contacted approximately 100 potential strategic counterparties and executed non-disclosure agreements with approximately 14 of them. Additionally, as part of this process, MTS instructed interested counterparties to submit written indications of interest. Management and representatives of MTS and Cooley LLP (“Cooley”), the Company’s outside legal counsel, met frequently with the Board to review the status of these outreach efforts, assess indications of interest, and receive direction from the Board regarding the strategic review process.

On May 9, 2025, the Company and Factor executed a mutual non-disclosure agreement, which did not contain a standstill provision.

On May 27, 2025, the Company received a written indication of interest from Factor proposing a sale of certain Factor assets to the Company in exchange for newly issued shares of common stock representing 90% of the Company’s outstanding common stock on a fully diluted basis, together with a commitment to provide financing to the Company, which Factor initially proposed would take the form of a PIPE financing.

On May 29, 2025, the Board met with management and representatives of MTS and Cooley to review Factor’s initial indication of interest and ongoing discussions with and updates with respect to other potential counterparties, including two other indications of interest received by the Company. Representatives of MTS reviewed the status of the strategic review, including indications of interest received to date. The Board discussed the preliminary terms of Factor’s indication of interest, potential improvements that might be sought, and the relative merits and risks of pursuing Factor’s proposal or other alternatives raised during the process.

On May 30, 2025, representatives of the Company, MTS and Factor held an introductory teleconference to discuss the potential transaction, anticipated timeline and Factor’s willingness and ability to backstop an equity financing. Following the meeting, the parties exchanged diligence questions and engaged in active discussions regarding transaction structure and financing considerations.

On June 4, 2025, representatives of MTS met telephonically with a second potential counterparty that had submitted a preliminary indication of interest. During the meeting, the parties discussed the counterparty’s proposed transaction structure and related terms. Following the meeting and further evaluation of the feasibility and economics of the counterparty’s proposal, the Company, in consultation with the Board, determined that such proposal was not actionable on the terms presented and did not represent a superior alternative to continuing negotiations with Factor.

On June 5, 2025, the Board met with management and its advisors to review the status of indications of interest received to date. Representatives of MTS and management provided an update regarding discussions with several potential counterparties, including Factor, and the Board discussed next steps for the ongoing process.

On June 11, 2025, the Company received approximately $4.1 million in gross proceeds from a separate equity financing, which modestly extended the Company’s cash runway. The following day, on June 12, 2025, the Board met to review the Company’s updated financial position and to evaluate the viability of continuing negotiations with Factor as well as prospects for other indications of interest. After discussion, the Board continued to view Factor’s proposal as the most actionable path due to the value of Factor’s asset portfolio, the proposed financing backstop by Factor, and the perceived certainty of closing relative to other alternatives, none of which had matured into actionable proposals.

On June 17, 2025, representatives of MTS and Factor held a call to discuss key terms of the potential transaction, including a possible concurrent PIPE financing, the anticipated composition of the Company’s post-closing Board and management team, and the form of closing consideration.

Later on June 17, 2025, at the direction of the Board, representatives of MTS delivered a counterproposal containing a draft summary of preliminary terms for an asset acquisition to representatives of Factor and a due diligence request list. These terms reflected a material improvement from Factor’s initial indication of interest, reducing the proposed equity consideration from shares representing 90% of the Company’s outstanding common stock to shares representing 65% of the Company’s outstanding common stock (in each case on a fully diluted basis) and including the issuance of pre-closing warrants to the Company’s existing stockholders to provide opportunity for them to retain additional value following the proposed transaction, among other matters. The proposal also contemplated that, concurrent with signing the definitive transaction agreement, Factor would deliver a binding commitment for financing, or agree to backstop a financing, in an amount of no less than $20.0 million.

Between June 17, 2025 and July 6, 2025, representatives of MTS, Cooley and counsel to Factor, Morse, Barnes-Brown & Pendleton, P.C. (“Morse”), exchanged multiple drafts of the summary of terms on behalf of, and as authorized by, their respective clients. Regular diligence and negotiation meetings took place during this period. The negotiations addressed, among other matters, the pre-closing warrants to be issued to the Company’s existing stockholders, the amount and terms of the equity consideration to be issued to Factor (including whether such equity would carry super-voting rights and the duration of any such rights), the structure and terms of the contemplated financing and/or backstop commitment for financing, as well as standard contractual terms such as representations, warranties and indemnification terms, fiduciary carve-outs and break-up fees, and the exclusivity provisions requested by Factor.

On June 26, 2025, representatives of MTS and Cooley met telephonically with a third potential counterparty that had submitted a preliminary indication of interest. During the meeting, the parties discussed the counterparty’s

proposed transaction structure and related terms. Following the meeting and further evaluation of the feasibility and economics of the counterparty’s proposal, the Company, in consultation with the Board, determined that such proposal was not actionable on the terms presented and did not represent a superior alternative to continuing negotiations with Factor.

On June 27, 2025, the Board met to receive an update on negotiations with Factor and discussions with other potential counterparties. Cooley reviewed the Board’s fiduciary duties and considerations relevant to evaluating and negotiating strategic transactions. After discussion, the Board authorized continued negotiations with Factor aimed at improving the terms of the proposal while maintaining optionality with respect to other potential strategic alternatives.

On July 6, 2025, the Board met again with management and representatives of Cooley and MTS to review the status of negotiations with Factor. The Board authorized management to prepare a term sheet reflecting negotiated terms, including the composition of the proposed consideration, the issuance of pre-closing warrants to the Company’s existing stockholders, the terms of a concurrent financing, post-closing management roles, and exclusivity provisions.

Between July 16, 2025 and July 26, 2025, the Company, Factor and their respective advisors negotiated a draft term sheet outlining the terms on which the parties would enter into a transaction. On July 26, 2025, the Company and Factor executed the term sheet, which included a mutual 45-day exclusivity period, subject to a customary fiduciary-out permitting the Company to respond to an unsolicited superior written proposal. The key terms provided in the term sheet included, among other things, (i) Factor’s receipt of consideration consisting of a newly created class of common stock with super-voting rights; (ii) Factor’s obligation to deliver a binding commitment to provide equity financing, or to backstop such financing, through the earlier of 18 months following closing or the Company’s receipt of at least $20.0 million in financing proceeds; (iii) the issuance to the Company’s existing stockholders of five-year warrants to purchase common stock with an exercise price equal to 200% of the implied per-share price of the Company’s common stock at signing as a mechanism for additional value retention; and (iv) the appointment of Dr. Angel as the Company’s President and Chief Executive Officer following the closing.

On July 29, 2025, representatives of the Company, MTS, Cooley and the Company’s intellectual property counsel were granted access to Factor’s virtual data room, allowing business diligence to continue and legal diligence to commence.

On August 15, 2025, Cooley delivered the initial draft of the Asset Purchase Agreement to Morse reflecting the terms provided in the term sheet. Between August 15, 2025 and October 16, 2025, the parties exchanged multiple drafts and negotiated the Asset Purchase Agreement and ancillary agreements. Negotiations during this period covered the scope of the Assets to be acquired, the terms of the concurrent financing and Factor’s backstop commitment, the form and amount of the equity consideration to be issued to Factor, the representations and warranties and other contractual protections, the Company’s post-closing governance structure, and the warrants to be issued to the Company’s existing stockholders. In parallel, the Company and Factor also negotiated revisions to certain licensing and services agreements between Erigen and Factor’s affiliates, which agreements would be assigned to the Company in connection with its acquisition of the Assets. These negotiations resulted in terms that were, in management’s and the Board’s view, more favorable to the Company and its stockholders.

On September 9, 2025, the exclusivity period expired, and, at the direction of the Board, the Company continued its discussions with Factor on a non-exclusive basis. Following the expiration of exclusivity, and consistent with its ongoing review of strategic alternatives, the Company also re-engaged with a limited number of parties that had previously expressed interest to reconfirm whether they had any actionable interest in pursuing a potential strategic transaction with the Company. Throughout September and October 2025, the Board met regularly to review updates from management and its advisors regarding negotiations with Factor, the Company’s financial condition and runway, and interactions with other potential strategic counterparties, none of which had developed into actionable alternatives. During these meetings, the Board also reviewed the Company’s financial position and considered whether an orderly dissolution might yield greater value than continuing negotiations and other explorations of strategic alternatives. After evaluating the Company’s estimated liquidation values against the economic and strategic benefits expected from a transaction with Factor, the Board consistently concluded that continuing to negotiate with Factor offered a superior potential outcome for stockholders compared to a dissolution scenario.

On September 11, 2025, representatives of MTS and management updated the Board regarding the material open terms under negotiation. Over the following days, the Company and Factor exchanged communications on key issues.

On September 15, 2025, the Company and Factor held a call with their advisors to discuss proposed revisions to the structure of the transaction, the assets to be acquired and terms of ancillary agreements, including funding commitments and amendments to arrangements involving Erigen and the assets to be acquired.

On September 17, 2025, representatives of MTS and management updated the Board regarding remaining open issues and the status of other potential counterparties, each of which, in the view of management and the Board, had not provided actionable alternatives. The Board directed management to continue negotiating improvements to the terms of the proposed transaction with Factor.

On October 13, 2025, management of the Company and Factor met in Boston to discuss the remaining open issues and anticipated timing of the proposed transaction.

On October 16, 2025, Cooley delivered a revised draft of the Asset Purchase Agreement to Morse reflecting revisions arising from the parties’ negotiations, including the parties’ agreement on a pre-closing financing commitment of $5.0 million—reflecting continued challenges of existing market conditions—and Factor’s agreement, following review of Nasdaq guidance, to forego any request for super-voting rights or other control-enhancing provisions.

Between October 18, 2025 and November 14, 2025, the Company and Cooley also held discussions with Nasdaq staff regarding the Company’s listing status and the application of Nasdaq Listing Rules to the proposed transaction.

On November 18, 2025, the Board met with management and representatives of Cooley and MTS. At the request of the Board, representatives of MTS then reviewed its financial analyses of the financial terms of the Contemplated Transactions. Following this review, at the request of the Board, representatives of MTS rendered its oral opinion to the Board, which was subsequently confirmed by delivery of its written opinion, that, as of November 18, 2025, and based upon and subject to the factors and assumptions in its written opinion, the Closing Consideration to be paid pursuant to the terms and conditions set forth in the Asset Purchase Agreement was fair, from a financial point of view, to the Company, as more fully described below in “—Opinion of the Company’s Financial Advisor.” At the meeting, Cooley reviewed the material terms of the transaction documents, the Board’s fiduciary duties, and the process for seeking stockholder approval. Following extensive discussion, the Board unanimously determined that the Contemplated Transactions were fair to and in the best interests of the Company, approved the Asset Purchase Agreement and related agreements, and resolved to recommend that the Company’s stockholders approve the Asset Purchase Agreement and the Contemplated Transactions.

Later that evening, Cooley and Morse finalized the transaction agreements.

On the morning of November 19, 2025, the Company, Factor and their respective affiliates executed the Asset Purchase Agreement and related agreements, and the Company issued a press release announcing the Contemplated Transactions prior to the opening of Nasdaq trading.

On November 26, 2025, the Company received gross proceeds of approximately $4.25 million in an equity financing.

The Company retained MTS as a financial advisor in connection with the Contemplated Transactions. On November 18, 2025, MTS Securities, an affiliate of MTS, rendered its oral opinion (the “MTS Opinion”) to the Company’s Board (which was subsequently confirmed in writing on November 18, 2025), that, as of that date and subject to the various assumptions made, procedures followed, matters considered and qualifications and limitations set forth in the MTS Opinion and described below, the Closing Consideration to be paid by the Company to Sellers in the Contemplated Transactions pursuant to the Asset Purchase Agreement is fair, from a financial point of view, to the Company.

The full text of the MTS Opinion sets forth the assumptions made, procedures followed, matters considered and qualifications and limitations on the review undertaken by MTS Securities in connection with the MTS Opinion. The MTS Opinion is attached as Appendix C to this proxy statement and is incorporated

herein by reference. The summary of the MTS Opinion set forth in this proxy statement is qualified in its entirety by reference to the full text of the MTS Opinion. We urge you to read carefully the MTS Opinion, together with the summary thereof in this proxy statement, in its entirety.

MTS Securities provided its opinion for the information and assistance of the Company’s Board in connection with its consideration of the Contemplated Transactions. The MTS Opinion addressed solely the fairness, from a financial point of view, of the Closing Consideration to be paid by the Company to Sellers in the Contemplated Transactions and does not address any other aspect or implication of the Contemplated Transactions. The MTS Opinion was not a recommendation to the Company’s Board or any stockholder of the Company as to how to vote or to take any other action in connection with the Contemplated Transactions.

In the course of performing its review and analyses for rendering the opinion described above, MTS Securities:

In arriving at its opinion, MTS Securities assumed and relied upon, without assuming liability or responsibility for independent verification, the accuracy and completeness of all of the financial, legal, regulatory, tax, accounting and other information that was publicly available or was provided to, discussed with or reviewed by MTS Securities and upon the assurances of the Company management that they were not aware of any material relevant developments or matters related to the Company or Sellers or that may affect the Contemplated Transactions that were omitted or that remained undisclosed to MTS Securities. The MTS Opinion does not address any legal, regulatory, tax, accounting or financial reporting matters, as to which MTS Securities understood that the Company had obtained such advice as it deemed necessary from experts, and MTS Securities relied with the consent of the Company’s Board on any assessments made by other advisors to the Company with respect to such matters. Without limiting the foregoing, MTS Securities did not consider any tax effects of the Contemplated Transactions or the form or transaction structure on any person or entity. MTS Securities did not conduct any independent verification of the Financial Projections and expressed no view as to the Financial Projections or the assumptions upon which they were based. Without limiting the generality of the foregoing, with respect to the Financial Projections, MTS Securities assumed, with the consent of the Board and based upon discussions with the Company management and management of Sellers, that each of the Financial Projections were reasonably prepared in good faith and that the

Financial Projections, including any estimates of certain potential benefits of the Contemplated Transactions prepared by the Company management or the management of Sellers and the timing to achieve such benefits, reflected the best currently available estimates and judgments of the Company management and management of Sellers regarding the future results of operations and financial performance of the Company and Sellers.

In arriving at its opinion, MTS Securities did not make any analysis of, and did not express any opinion as to, the adequacy of the reserves of the Company or Sellers and relied upon information provided to MTS Securities by the Company and Sellers as to such adequacy. In addition, MTS Securities did not make any independent evaluations or appraisals of the assets or liabilities (including any contingent derivatives or off balance sheet assets or liabilities) of the Company, Sellers or any of their respective subsidiaries, and MTS Securities was not furnished with any such evaluations or appraisals, nor did MTS Securities evaluate the solvency of the Company, Sellers or any other entity under any state or federal law relating to bankruptcy, insolvency or similar matters. The analyses performed by MTS Securities in connection with its opinion were going concern analyses. MTS Securities expressed no opinion regarding the liquidation value of the Company, Sellers or any other entity. MTS Securities assumed that there was no material change in the assets, financial condition, business or prospects of the Company or Sellers since the date of the most recent relevant financial statements made available to MTS Securities. Without limiting the generality of the foregoing, MTS Securities undertook no independent analysis of any pending or threatened litigation, regulatory action, possible unasserted claims or other contingent liabilities to which the Company, Sellers or any of their respective affiliates is a party or may be subject, and at the direction of the Company and with its consent, MTS Securities made no assumption concerning, and therefore did not consider, the possible assertion of claims, outcomes or damages arising out of any such matters in rendering its opinion. MTS Securities also assumed that neither the Company nor Sellers nor any of their respective subsidiaries is party to any material pending transaction that was not disclosed to MTS Securities, including, without limitation, any financing, recapitalization, acquisition or merger, divestiture or spin-off, other than the Contemplated Transactions. MTS Securities did not consider any potential legislative or regulatory changes currently being considered or that may be adopted by any governmental or regulatory bodies or any potential changes in accounting methods or generally accepted accounting principles that may be adopted.

MTS Securities assumed that the representations and warranties of each party contained in the Asset Purchase Agreement and in all other related documents and instruments that are referred to therein are and will be true and correct as of the date or the dates made or deemed made, that each party thereto will fully and timely perform all of the covenants and agreements required to be performed by it under the Asset Purchase Agreement and any other agreement contemplated thereby, that all conditions to the consummation of the Contemplated Transactions will be satisfied without waiver thereof and that the transactions contemplated by the Asset Purchase Agreement will be consummated in accordance with the terms of the Asset Purchase Agreement without waiver, modification or amendment of any term, condition or agreement thereof, including that the Company intends to seek to raise gross proceeds of at least $5.0 million through the Pre-Closing Financing. The Pre-Closing Financing will have no impact on the Closing Consideration, and accordingly, MTS expressed no opinion on the terms and condition of the Pre-Closing Financing. MTS Securities assumed that the final form of the Asset Purchase Agreement will be in all respects relevant to its analysis identical to the Draft Purchase Agreement. MTS Securities also assumed that any governmental, regulatory and other consents and approvals contemplated in connection with the Contemplated Transactions will be obtained and that, in the course of obtaining any of those consents and approvals, no restrictions will be imposed or waivers made that would have an adverse effect on the Company, Sellers or the benefits contemplated to be realized as a result of the Contemplated Transactions.

The MTS Opinion was necessarily based on economic, market, financial and other conditions existing, and on the information made available to MTS Securities, as of the date of its opinion. Although subsequent developments may affect the conclusion reached in its opinion, MTS Securities did not assume any obligation to update, revise or reaffirm the MTS Opinion.

The MTS Opinion addresses solely the fairness, from a financial point of view, to the Company of the Closing Consideration to be paid by the Company in connection with the Contemplated Transactions and does not address any other terms in the Asset Purchase Agreement or any other agreement relating to the Contemplated Transactions or any other aspect or implication of the Contemplated Transactions, including the terms and conditions of the Concurrent Financings. The MTS Opinion does not address the Company’s underlying business decision to proceed with the Contemplated Transactions or the relative merits of the Contemplated Transactions compared to other alternatives available to the Company. The MTS Opinion does not express any opinion as to the prices or ranges of

prices at which shares or other securities of any person, including shares of the common stock, will trade at any time, including following the announcement or consummation of the Contemplated Transactions. For purposes of the MTS Opinion, MTS Securities did not consider any impact of any additional rights or obligations of the Company pursuant to any other agreement entered into, or that may be entered into, by the Company in connection with the Contemplated Transactions. The MTS Opinion does not in any manner address the amount or nature of compensation to any of the officers, directors or employees of any party to the Contemplated Transactions, or any class of such persons, relative to the compensation to be paid by the Company in connection with the Contemplated Transactions or with respect to the fairness of any such compensation. MTS Securities was not requested to, and did not, solicit indications of interest or proposals from third parties regarding a possible acquisition of all or any part of the Company or any alternative transaction.

In accordance with customary investment banking practice, MTS Securities employed generally accepted valuation methods in reaching its opinion. The MTS Opinion was reviewed and approved by a fairness committee of MTS Securities.

MTS Securities performed a variety of financial analyses for purposes of rendering its opinion. The preparation of a financial opinion is a complex process and is not susceptible to partial analysis or summary description. In arriving at its opinion, MTS Securities considered the results of all of its analyses as a whole and did not attribute any particular weight to any analysis or factor considered. Each analytical technique has inherent strengths and weaknesses, and the nature of the available information may further affect the value of particular techniques. The overall conclusions MTS Securities reached were based on all the analyses and factors presented, taken as a whole, and also on application of MTS Securities’ own experience and judgment. Such conclusions may involve significant elements of subjective judgment and qualitative analysis. MTS Securities therefore gave no opinion as to the value or merit standing alone of any one or more parts of the analyses. Furthermore, MTS Securities believes that the summary provided and the analyses described below must be considered as a whole and that selecting any portion of the analyses, without considering all of them, would create an incomplete view of the process underlying MTS Securities’ analysis and opinion. As a result, the ranges of valuations resulting from any particular analysis or combination of analyses described below should not be taken to be the view of MTS Securities with respect to the actual value of the Company, Sellers or the Assets.

Some of the summaries of the financial analyses include information presented in tabular format. The tables must be read together with the full text of the corresponding summaries and are alone not a complete description of the financial analyses performed by MTS Securities. Considering the data in the tables below without considering the corresponding full narrative descriptions of the financial analyses, including the methodologies and assumptions underlying such analyses, could create a misleading or incomplete view of the financial analyses performed by MTS Securities.

In performing its analyses, MTS Securities made numerous assumptions with respect to industry performance, general business, regulatory and economic conditions and other matters, all of which are beyond MTS Securities’ control and many of which are beyond the control of the Company and/or Sellers. Any estimates used by MTS Securities in its analysis are not necessarily indicative of future results or actual values, which may be significantly more or less favorable than those suggested by such estimates.

MTS Securities performed standalone valuation analyses of both the Company and the Assets using a variety of valuation methodologies, as described below. MTS Securities then performed a relative valuation analysis in order to compare the Closing Consideration to be paid by the Company in connection with the Contemplated Transactions, to the range of exchange multipliers implied based on the respective standalone valuation ranges. MTS Securities also analyzed the performance of the pro forma combination. Except as otherwise noted, the following quantitative information, to the extent that it is based on market data, is based on market data as it existed on or before November 17, 2025 and is not necessarily indicative of current market conditions.

MTS Securities reviewed the total equity value of the Company based on the share price trading history of the common stock for the period beginning on November 17, 2024 and ending on November 17, 2025. During this period, shares of the common stock traded as low as $5.35 per share and as high as $13.65 per share, compared to the closing price of the common stock on November 17, 2025 of $9.38 per share.

In addition, MTS Securities reviewed the volume-weighted average trading price (“VWAP”) over the 10-trading day, 30-trading day, 60-trading day, 6-month, 12-month and 2-year periods ending on November 17, 2025. These VWAPs are set forth in the table below.

Given a lack of funding for the on-going operations of the Company and a standalone operating plan, this analysis does not employ standard valuation methods to value the Company equity value used to value the Closing Consideration. At the direction of the Company management, MTS Securities analyzed the implied value of the 8,268,495 shares of the common stock to be issued as the Closing Consideration for the Assets using the current the Company stock price in addition to Tempest’s 10-day and 30-day VWAP to evaluate fairness of the Closing Consideration. These implied values are set forth in the table below.

MTS Securities analyzed the valuation of the Assets using three different methodologies: a discounted cash flow analysis, a public trading comparable companies analysis and an analysis of precedent transactions MTS Securities deemed relevant. The results of each of these analyses are summarized below.

MTS Securities calculated the present value of the cash flows to be generated by the Assets based on the commercialization of four cell therapy assets during the period beginning December 31, 2025 and ending December 31, 2040.

At the direction of the Company, MTS Securities conducted certain sensitivity analyses in connection with this discounted cash flow analysis using ranges of: (i) regulatory probabilities of success, for a Phase 2b POS range of 30-50% for ERI-2003 in rrMM and 15-45% for ERI-2206 in RCC as provided by the Company’s management; (ii) revenue achievement factor range of 70%-100% per the Company’s management; and (iii) weighted average cost of capital of 17% to 21%, reflecting estimates of Factor’s weighted average cost of capital, based upon MTS Securities’ analysis of the cost of capital for the Assets derived from publicly traded comparable companies.

MTS Securities utilized the unlevered free cash flows (defined as earnings before interest and taxes, less income tax expense, less changes in net working capital (capital expenditures and associated depreciation and amortization were deemed to be de minimis for the Assets and were therefore not included)), based on the Adjusted Factor Projections, that the Company management reasonably projected the Assets will generate during the period beginning on December 31, 2025 and ending on December 31, 2040, taking into account the sensitivity metrics described above, and assuming no terminal value. The unlevered free cash flows were then discounted to present values using a range of discount rates based on Factor’s calculated weighted average cost of capital for the Assets determined by publicly traded comparable companies.

The following table reflects the ranges of enterprise value of the Assets implied by this discounted cash flow analysis for each sensitivity metric described:

MTS Securities reviewed and compared the projected operating performance of the Assets with publicly available information concerning publicly traded comparable companies with similar asset portfolios and reviewed the current market price of certain publicly traded securities of such other companies. MTS Securities selected the following early-stage (post Phase 1 Data) cell-therapy biotech companies:

Although none of the selected companies is directly comparable to the Assets, MTS Securities included these companies in its analysis because they are publicly traded companies with certain characteristics that, for purposes of analysis, may be considered similar to certain characteristics of the Assets. MTS Securities calculated the enterprise value for the selected companies, as of November 17, 2025, by multiplying the closing price per share of common stock of such company on such date by the number of such company’s fully diluted outstanding shares, using the treasury stock method, and deducting from that result such company’s total cash and cash equivalents. The table below shows the enterprise values calculated for each comparable company as of November 17, 2025:

MTS Securities derived a low-quartile and top-quartile enterprise value range for the comparable companies. MTS Securities calculated this implied asset value range for the Assets by using all the companies in the above-referenced data set. The table below notes the implied asset value range of the Assets:

Multiples for publicly trading comparables apply only to Factor’s lead asset included in the Assets, ERI-2003, which has estimated unadjusted peak sales of $2.0 billion in 2035.

MTS Securities reviewed and analyzed the proposed financial terms of the Contemplated Transactions as compared to the financial terms of certain selected business combinations that MTS Securities deemed relevant and the consideration paid in such transactions. MTS Securities examined selected business combinations or asset transactions since 2020 where the target company had clinical stage assets (post Phase 1 Data) at the time of the transaction. MTS Securities reviewed and analyzed certain publicly available information for the following five business combinations:

Although none of the selected transactions are directly comparable to the Contemplated Transactions, the target companies in the selected transactions are companies with certain characteristics that, for the purposes of analysis, may be considered similar to the Assets, and as such, for purposes of analysis, the selected transactions may be considered similar to the Contemplated Transactions.

Financial data for the precedent transactions was based on publicly available information at the time of the announcement of the relevant transactions that MTS Securities obtained from SEC filings, relevant press releases, S&P Capital IQ, Cortellis, and company websites as of November 17, 2025. Using this information, MTS Securities calculated for each selected transaction the total transaction enterprise value as a multiple of the target company’s unadjusted peak sales.

Multiples for publicly trading comparables apply only to Factor’s lead asset included in the Assets, ERI-2003, which has estimated unadjusted peak sales of $2.0 billion in 2035.

The preparation of a financial opinion is a complex analytical process involving various determinations as to the most appropriate and relevant methods of financial analysis and the application of those methods to the particular circumstances and, therefore, a financial opinion is not readily susceptible to summary description. In arriving at its opinion, MTS Securities did not draw, in isolation, conclusions from or with regard to any factor or analysis that it considered. Rather, MTS Securities made its determination as to fairness on the basis of its experience and professional judgment after considering the results of all of the analyses.

The MTS Opinion was one of the many factors taken into consideration by the Company’s Board in making its determination to approve the Asset Purchase Agreement. Consequently, the analyses as described above should not be viewed as determinative of the opinion of the Company’s Board with respect to the consideration to be received paid by the Company in connection with the Contemplated Transactions or of whether the Company’s Board would have been willing to agree to different consideration. The consideration to be paid by the Company in connection with the Contemplated Transactions was determined through arm’s-length negotiations between the Company and Sellers and was approved by the Company’s Board. MTS Health Partners and its affiliates provided advice to the Company during these negotiations. However, neither MTS Health Partners nor any of its affiliates recommended any specific amount of consideration to the Company or the Company’s Board or that any specific amount of consideration constituted the only appropriate consideration for the Contemplated Transactions.

MTS Securities has consented to the use of the MTS Opinion in this proxy statement; however, MTS Securities has not assumed any responsibility for the form or content of this proxy statement, other than the MTS Opinion itself.

MTS Health Partners and its affiliates, as part of their investment banking services, are regularly engaged in the valuation of businesses (including those in the healthcare industry) and securities in connection with mergers and acquisitions, and for other purposes. As noted above, MTS Health Partners acted as a financial advisor to the Company in connection with the Contemplated Transactions and participated in certain of the negotiations leading to the Asset Purchase Agreement. the Company selected MTS Health Partners as its financial advisor because of, among other things, its knowledge of the life sciences industry, the familiarity of several members of the Company senior management and the Company’s Board with MTS Health Partners and its experience with merger and sale transactions. Pursuant to an engagement letter agreement, dated as of October 6, 2023, between the Company and MTS Health Partners, the Company engaged MTS Health Partners to act as a financial advisor in connection with the Company’s consideration, evaluation and/or exploration of certain potential mergers and acquisitions transactions or similar transactions. As permitted by the terms of the engagement letter and pursuant to MTS Health Partners’ internal policies, MTS Securities rather than MTS Health Partners delivered the fairness opinion. As compensation for MTS Health Partners and its affiliates’ financial advisory services to the Company’s Board, the Company paid a nonrefundable retainer of $100,000 upon execution of the engagement letter (the “Retainer Fee”) and paid a fee of $500,000 for rendering the MTS Opinion in connection with the Company’s Board’s consideration of the proposed transaction with Sellers, which fee was not contingent upon the successful completion of the Contemplated Transactions, or the conclusion reached within the MTS Opinion (the “Opinion Fee”). Upon

consummation of the Contemplated Transactions, the Company will be obligated to pay a fee equal to approximately $2.5 million in connection with the Contemplated Transactions, of which the Retainer Fee and the Opinion Fee will be credited. In addition, the Company also agreed to reimburse MTS Health Partners and its affiliates for their direct, reasonable and documented out-of-pocket expenses incurred in connection with any of the matters contemplated in the engagement letter. The Company also agreed to indemnify MTS Health Partners and each of its related parties against various liabilities in connection with MTS Health Partner’s engagement. MTS Health Partners and its affiliates may also seek to provide investment banking and/or financial advisory services to the Company and Sellers in the future and would expect to receive customary fees for the rendering of any such services.

During the two years preceding the date of the MTS Opinion, neither MTS Health Partners nor MTS Securities has been engaged by, performed services for, or received any compensation from, the Company (other than the engagements and any amounts that were paid under the engagement letter described in this proxy statement).

The Company does not, as a matter of course, regularly prepare long-range projections or publicly disclose forecasts or internal projections as to future performance, revenues, earnings or other results of operations due to, among other reasons, the inherent unpredictability of the underlying assumptions and projections. However, in connection with the Board’s review of potential strategic alternatives, including its review of the Contemplated Transactions, Factor’s management prepared and provided the Factor Projections to the Company’s management, which projections comprised non-public prospective financial information with respect to the Assets on a stand-alone basis. At the direction of the Board and utilizing the Factor Projections, the Company’s management prepared adjusted projections with respect to the Assets for fiscal years 2026 through 2040, based on the best currently available estimates and good faith judgments of management at that time. The Financial Projections were provided to assist the Board with its strategic review and to inform MTS’s financial analyses prepared in connection with rendering the MTS Opinion to the Board. Consistent with the view of the Board and the Company management that the Financial Projections then reflected the best available estimates and good faith judgments as to the future financial performance of the Assets on a stand-alone basis at that time, at the direction of the Board the Financial Projections were provided to MTS for use in connection with the rendering of its fairness opinion to the Board and its related financial analyses.

The Financial Projections reflect certain estimates and assumptions made by the Company’s management, including product launch years between 2030 and 2034 for each product candidate, a seven-year trajectory to peak market shares of between 15% and 30%, loss of exclusivity for each product candidate in 2036, a nominal launch price for each product candidate of between $300,000 and $400,000 with annual price increases between 0% and 3.5%, 0% to 20% gross-to-net discounts to forecasted revenue and a probability of success through a Phase 2b study for each product candidate as further described in the table below, as well as incidence and epidemiology-based assumptions with respect to patient populations and assumptions with respect to cost of goods sold, operating expenses and other general market and financial conditions. All of these assumptions are difficult to predict and many are outside of the Company’s control. Although presented with numerical specificity, the Financial Projections necessarily rely on numerous variables and assumptions that are inherently uncertain. The Financial Projections consist entirely of forward-looking statements and, because they extend over multiple years, they become increasingly speculative with each successive year and cannot anticipate all circumstances that could affect the Assets or the Company’s general business or results of operations.

The Financial Projections were developed solely using the information available to Factor’s and the Company’s management teams at the time they were created and reflect assumptions regarding certain business decisions that remain subject to change. Important factors that may affect actual results, or cause the Financial Projections not to be achieved, include the ability to obtain regulatory approval for any or all of the Assets and the impact of related regulatory actions (including effects on product launch timing), the effectiveness of the Company’s commercial execution with respect to the Assets and the ability of the Company to generate revenue from the Assets, the decisions of Novatim (as defined below) and other potential third-party partners, the Company’s ability to partner any of the Assets and the terms of any such partnering transactions, the success of preclinical and clinical testing and development, manufacturing and supply availability, patent life and other rights or exclusivity, and variability in any epidemiological estimates and underlying incidence-driven patient population dynamics. Additional risks include the effect of global economic conditions, increases in regulatory oversight and the risk factors described in the Company’s annual report on Form 10-K for the fiscal year ended December 31, 2024, subsequent quarterly reports on Form 10-Q and current reports on Form 8-K. Modeling and forecasting future performance in the biopharmaceutical industry, in particular, is a highly speculative endeavor. As a

result, there can be no assurance that the results set forth in the Financial Projections will be realized, and actual results may be materially better or worse than those contained in the Financial Projections.

The likelihood that actual results will differ materially from the assumptions reflected in the Financial Projections is further increased by the length of time in the future over which these assumptions apply. Any assumptions and projections in early periods, and any deviations therefrom as a result of the contingencies outlined above or other variables that may become applicable, could have a compounding effect on the projections shown for later periods or the difference between such projections and actual results for those periods. The Financial Projections further reflect subjective judgment in many respects and, therefore, are susceptible to multiple interpretations and periodic revisions based on actual experience and business developments. The inclusion of the Financial Projections in this proxy statement should not be regarded as an indication that the Company, Sellers, MTS or anyone who received the Financial Projections considered, or now considers, the Financial Projections to be material information of the Company or Sellers, or that the Financial Projections are necessarily predictive of actual future results, nor should it be construed as financial guidance or relied upon as such.

None of the Company, Sellers or any of their respective affiliates, advisors or other representatives makes any representation to any stockholder regarding the validity, reasonableness, accuracy or completeness of the Financial Projections. The Financial Projections were not prepared with a view toward public disclosure or toward complying with U.S. generally accepted accounting principles (“GAAP”), the published guidelines of the SEC regarding projections or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of prospective financial information. Neither the Company’s independent registered public accounting firm, nor any other independent accountants, has audited, reviewed, compiled or performed any procedures with respect to the Financial Projections or expressed any opinion or any form of assurance related thereto. The inclusion of the Financial Projections in this proxy statement does not constitute an admission or representation of the Company that the Financial Projections or the information contained therein is material. Except as required by applicable law, neither the Company nor any of its affiliates intends to, and each of them disclaims any obligation to, update, correct or otherwise revise the Financial Projections if any or all of them have changed or change or are or become inappropriate (even in the short term). These considerations should be taken into account in evaluating the Financial Projections, which were prepared as of an earlier date.

The Financial Projections should be evaluated, if at all, in conjunction with the historical financial statements and other information regarding the Company in its public filings with the SEC and other information regarding the Company and Sellers or the Assets contained in or incorporated by reference into this proxy statement. The Financial Projections were developed by the Company management on a standalone basis without giving effect to the Contemplated Transactions or the other transactions contemplated by the Asset Purchase Agreement (or the failure of the Contemplated Transactions to be completed), and therefore the Financial Projections do not give effect to the proposed transactions or any changes to the Company’s operations or strategy that may be implemented after the consummation of the Contemplated Transactions, including costs incurred in connection with the Contemplated Transactions or the integration of the Assets.

The Total Product Revenue (Adjusted) contained in the Financial Projections set forth below are “non-GAAP financial measures,” which are financial performance measures that are not calculated in accordance with GAAP. Non-GAAP financial measures should not be viewed as a substitute for GAAP financial measures and may be different from non-GAAP financial measures used by other companies. Furthermore, there are limitations inherent in non-GAAP financial measures because they exclude charges and credits that are required to be included in a GAAP presentation. Accordingly, non-GAAP financial measures should be considered together with, and not as an alternative to, financial measures prepared in accordance with GAAP. The most directly comparable GAAP financial measure for Total Product Revenue (Adjusted) is revenue. Certain SEC rules that otherwise would require a reconciliation of a non-GAAP financial measure to a GAAP financial measure in other contexts do not apply to non-GAAP financial measures provided to a board of directors or financial advisors in connection with a proposed transaction such as the Contemplated Transactions if the disclosure is included in a document such as this proxy statement. In addition, reconciliations of non-GAAP financial measures to a GAAP financial measure were not provided to or relied upon by the Board or MTS in connection with the Contemplated Transactions. Accordingly, the Company has not provided a reconciliation of the financial measures included in the Financial Projections to the relevant GAAP financial measures. The Financial Projections may differ from published analyst estimates and forecasts and do not take into account any events or circumstances after the date they were prepared, including the announcement of the Contemplated Transactions.

In light of the foregoing factors and uncertainties inherent in the Financial Projections, holders of shares of the Company’s common stock are cautioned not to place undue, if any, reliance on the summary of the Financial Projections set forth below. The information and tables set forth below are included solely to give the Company stockholders access to a summary of the Financial Projections that were made available to the Board and MTS and are not included in this proxy statement in order to influence any stockholder’s decision to vote with respect to the Contemplated Transactions, the Nasdaq Proposal or for any other purpose: