Sec Form 3 Filing - Fairmount Funds Management LLC @ Oruka Therapeutics, Inc. - 2024-08-29

FORM 3 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Fairmount Funds Management LLC 2. Issuer Name and Ticker or Trading Symbol Oruka Therapeutics, Inc. [ ORKA] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X __ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 200 BARR HARBOR DRIVE, SUITE 400 3. Date of Earliest Transaction (MM/DD/YY) 08/29/2024 (Street) WEST CONSHOHOCKEN, PA19428 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 363,614 ( 1 ) ( 2 ) I By Fairmount Healthcare Fund II L.P. ( 3 ) Common Stock 2,573,308 ( 1 ) ( 2 ) I By Fairmount Healthcare Co-Invest III L.P. ( 3 )

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Series B Non-Voting Convertible Preferred Stock ( 4 ) ( 4 ) ( 4 ) Common Stock 11,428,166 I By Fairmount Healthcare Fund II L.P. ( 3 ) ( 5 ) Pre-funded Warrant $ 0.001 ( 6 ) ( 6 ) Common Stock 5,297,664 I By Fairmount Healthcare Fund II L.P. ( 3 )

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Fairmount Funds Management LLC 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN, PA19428 X X Fairmount Healthcare Fund II L.P. 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN, PA19428 X X Fairmount Healthcare Co-Invest III L.P. 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN, PA19428 X X Kiselak Tomas 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN, PA19428 X X Harwin Peter Evan 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN, PA19428 X X Signatures /s/ Tomas Kiselak, Managing Member of Fairmount Funds Management LLC 09/06/2024 Signature of Reporting Person Date /s/ Tomas Kiselak, Managing Member of Fairmount Healthcare Fund II L.P. 09/06/2024 Signature of Reporting Person Date /s/ Tomas Kiselak, Managing Member of Fairmount Healthcare Co-Invest III L.P. 09/06/2024 Signature of Reporting Person Date /s/ Tomas Kiselak 09/06/2024 Signature of Reporting Person Date /s/ Peter Harwin 09/06/2024 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Effective as of August 29, 2024 (the "Effective Time"), a wholly-owned subsidiary of ARCA biopharma, Inc. ("ARCA") merged with and into Oruka Therapeutics, Inc. ("Oruka") with Oruka continuing as a wholly owned subsidiary of ARCA and the surviving corporation of the merger, and Oruka merged with and into a second wholly-owned subsidiary of ARCA ("Second Merger Sub"), with Second Merger Sub being the surviving entity of the merger resulting in, among other things, Oruka becoming a wholly owned subsidiary of ARCA (collectively, the "Merger"). At the Effective Time, ARCA effected a name change to "Oruka Therapeutics, Inc." (hereinafter, the "Issuer"). ( 2 )Represents the number of shares of common stock of the Issuer received by the Reporting Person in the Merger in exchange for the shares of Oruka held by the Reporting Person prior to the Merger. Each share of Oruka common stock held at the Effective Time was exchanged for 6.8569 shares of the Issuer's common stock. On September 3, 2024, the Issuer effected a 1-for-12 reverse stock split of the Company common stock. ( 3 )Fairmount Funds Management LLC ("Fairmount") is the investment manager for Fairmount Healthcare Fund II LP and Fairmount Healthcare Co-Invest III L.P. The general partner of Fairmount is Fairmount Funds Management GP LLC ("Fairmount GP"), of which Peter Harwin and Tomas Kiselak are the managing members. Fairmount, Fairmount GP, Mr. Harwin, and Mr. Kiselak disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein. ( 4 )Shares of Series B Non-Voting Convertible Preferred Stock of the Issuer, par value $0.001 per share (the "Preferred Stock"), are convertible into shares of the Issuer's common stock at any time at the option of the holder thereof, based on the Conversion Ratio and subject to certain limitations, including the Beneficial Ownership Limitation (as such terms are defined in the Certificate of Designation for the Preferred Stock filed with the Securities and Exchange Commission as Exhibit 3.9 to the Issuer's Form 8-K filed on September 5, 2024). The Preferred Stock has no expiration date. ( 5 )Consists of 137,138 shares of Preferred Stock. ( 6 )The Pre-Funded Warrants have no expiration date and are exercisable at any time after the date of issuance. A holder of Pre-Funded Warrants may not exercise the Pre-Funded 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.

Remarks: Exhibit 24 - Power of AttorneyFairmount, Fairmount Healthcare Fund II LP and Fairmount Healthcare Co-Invest III L.P. may each be deemed a director by deputization of the Issuer by virtue of the fact that Peter Harwin serves on the board of directors of the Issuer and is a Managing Member of Fairmount.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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