UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 17, 2025

Oruka Therapeutics, Inc.

(Exact name of Registrant as Specified in its Charter)

Registrant’s telephone number, including area code: (650) 606-7910

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 1.01 Entry into a Material Definitive Agreement.

On September 17, 2025, Oruka Therapeutics, Inc., a Delaware corporation (the “Company”), entered into a Securities Purchase Agreement (the “Purchase Agreement”) for a private placement (the “Private Placement”) with certain institutional and accredited investors (each, a “Purchaser” and collectively, the “Purchasers”). The closing of the Private Placement occurred on September 19, 2025.

Pursuant to the Purchase Agreement, the Purchasers purchased (i) an aggregate of 10,933,405 shares (the “Common Shares”) of the Company’s common stock, par value $0.001 per share (the “Common Stock”), at a price per share of $15.00, and (ii) pre-funded warrants (the “Pre-Funded Warrants”) to purchase an aggregate of 1,066,666 shares of Common Stock (the “Pre-Funded Warrant Shares”) at a purchase price of $14.999 per Pre-Funded Warrant, which represents the per share purchase price of the Common Shares less the $0.001 per share exercise price for each Pre-Funded Warrant, for an aggregate purchase price of approximately $180 million.

The Pre-Funded Warrants will be exercisable at any time after the date of issuance. A holder of Pre-Funded Warrants may not exercise the warrant if the holder, together with its affiliates, would beneficially own more than 9.99% of the number of shares of Common Stock outstanding immediately after giving effect to such exercise. A holder of Pre-Funded Warrants may increase or decrease this percentage to a percentage not in excess of 19.99% by providing at least 61 days’ prior notice to the Company.

The Purchase Agreement contains customary representations and warranties of the Company, on the one hand, and the Purchasers, on the other hand, and customary conditions to closing.

Also on September 17, 2025, the Company entered into a Registration Rights Agreement (the “Registration Rights Agreement”) with the Purchasers, which provides that the Company will register the resale of the Common Shares and the Pre-Funded Warrant Shares. The Company is required to prepare and file a registration statement with the Securities and Exchange Commission no later than October 15, 2025, and to use its commercially reasonable efforts to have the registration statement declared effective within 90 days thereafter, subject to certain exceptions.

The Company has also agreed to, among other things, indemnify the Purchasers, their officers, directors, agents, partners, members, managers, stockholders, affiliates, investment advisers and employees under the registration statement from certain liabilities and pay all fees and expenses (excluding any legal fees of the selling holder(s), and any underwriting discounts and selling commissions) incident to the Company’s obligations under the Registration Rights Agreement.

The securities issued and sold to the Purchasers under the Purchase Agreement will not be registered under the Securities Act of 1933, as amended (the “Securities Act”) in reliance on the exemption from registration provided by Section 4(a)(2) of the Securities Act, or under any state securities laws. The Company relied on this exemption from registration based in part on representations made by the Purchasers. The securities may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. Neither this Current Report on Form 8-K, nor the exhibits attached hereto, is an offer to sell or the solicitation of an offer to buy the securities described herein.

The Company has engaged Jefferies LLC, TD Securities (USA) LLC, Guggenheim Securities, LLC and LifeSci Capital LLC as placement agents for the Private Placement. The Company has agreed to pay customary placement fees and reimburse certain expenses of the placement agents.

The foregoing summary of the Purchase Agreement, the Registration Rights Agreement and the Pre-Funded Warrants does not purport to be complete and is qualified in its entirety by reference to the Purchase Agreement, the form of Registration Rights Agreement and the form of Pre-Funded Warrant, copies of which are filed as Exhibits 10.1, 10.2 and 4.1 to this Current Report on Form 8-K, respectively, and are incorporated by reference herein.

Following the closing of the Private Placement, the Company has 48,384,150 shares of Common Stock issued and outstanding and approximately 67.1 million shares of Common Stock issued and outstanding on a pro forma basis, which gives effect to the full conversion of the Company’s Series B Non-Voting Convertible Preferred Stock, par value $0.001 per share (“Series B Preferred Stock”), as of September 19, 2025, without regard to beneficial ownership limitations that may limit the ability of certain holders of Series B Preferred Stock to convert such shares to Common Stock at such time, and assumes the exercise of all outstanding pre-funded warrants.

Item 3.02 Unregistered Sales of Equity Securities.

To the extent required by Form 8-K, the disclosures in Item 1.01 above are incorporated herein by reference.

Item 7.01 Regulation FD Disclosure.

On September 17, 2025, the Company made available a press release announcing the Private Placement. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

Also on September 17, 2025, the Company made available a press release announcing certain clinical data from its Phase 1 clinical trial of ORKA-001, as well as upcoming scientific presentations at the European Academy of Dermatology and Venereology Congress. A copy of the press release is furnished as Exhibit 99.2 to this Current Report on Form 8-K.

The information in Item 7.01 of this Current Report on Form 8-K, including the information in the press releases attached as Exhibit 99.1 and Exhibit 99.2 to this Current Report on Form 8-K, is furnished pursuant to Item 7.01 of Form 8-K and shall not be deemed “filed” for the purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section. Furthermore, the information in Item 7.01 of this Current Report on Form 8-K, including the information in the press releases attached as Exhibit 99.1 and Exhibit 99.2 to this Current Report on Form 8-K, shall not be deemed to be incorporated by reference in the filings of the Company under the Securities Act.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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