X0202 SCHEDULE 13D/A 0001213900-24-076599 0001802528 XXXXXXXX LIVE 6 Common Stock, $0.001 par value per share 07/01/2026 false 0000907654 687604108 ORUKA THERAPEUTICS, INC.

855 Oak Grove Avenue Suite 100 Menlo Park CA 94025

Ms. Erin O'Connor (267) 262-5300 Fairmount Funds Management LLC 200 Barr Harbor Drive, Suite 400 West Conshohocken PA 19428 0001802528 N Fairmount Funds Management LLC a AF N DE 0.00 14553895.00 0.00 14553895.00 14553895.00 N 19.47 IA The securities (a) include (i) 1,131,954 shares of common stock, $0.001 par value per share (the "Common Stock"), 2,973,894 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants and 7,874,739 shares of Common Stock issuable upon conversion of 94,497 shares of Series B non-voting convertible preferred stock, par value $0.001 per share (the "Series B Preferred Stock"), directly held by Fairmount Healthcare Fund II L.P., a Delaware limited partnership ("Fund II"), and (ii) 2,573,308 shares of Common Stock directly held by Fairmount Healthcare Co-Invest III L.P., a Delaware limited partnership ("Co-Invest"), and (b) exclude 2,323,770 shares of Common Stock issuable upon exercise of Pre-Funded Warrants directly held by Fund II. The exercise of the Pre-Funded Warrants is subject to a beneficial ownership limitation of 9.99% of the outstanding Common Stock and the conversion of the Series B Preferred Stock is subject to a beneficial ownership limitation of 19.99%. The securities exclude shares of Common Stock issuable upon exercise of Pre-Funded Warrants in excess of such beneficial ownership limitation. At such time as Fairmount Funds Management LLC, a Delaware limited liability company and Securities and Exchange Commission registered investment adviser under the Investment Advisers Act of 1940 ("Fairmount"), and its affiliates beneficially own 9.0% or less of the Common Stock, the beneficial ownership limitation with respect to the Series B Preferred Stock will automatically reduce to 9.99%. Row 13 is based on 74,733,166 shares of Common Stock outstanding as of July 1, 2026, consisting of (i) 60,312,101 shares of Common Stock outstanding as of April 30, 2026, as reported in the Company's Form 10-Q filed on May 13, 2026, (ii) 3,553,410 shares of Common Stock issued upon conversion of Series B Preferred Stock by the Reporting Persons on July 1, 2026, (iii) 19,022 shares underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by the Reporting Persons, (iv) 2,973,894 shares of Common Stock underlying the 2,973,894 Pre-Funded Warrants, subject to the beneficial ownership limitation, and (iv) 7,874,739 shares of Common Stock underlying the 94,497 shares of Series B Preferred Stock owned by the Reporting Persons. 0001769651 N Fairmount Healthcare Fund II L.P. a AF N DE 0.00 11980587.00 0.00 11980587.00 11980587.00 N 16.03 PN The securities (a) include 1,131,954 shares of Common Stock, 2,973,894 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants and 7,874,739 shares of Common Stock issuable upon conversion of 94,497 shares of Series B Preferred Stock and (b) exclude 2,323,770 shares of Common Stock issuable upon exercise of Pre-Funded Warrants. The exercise of the Pre-Funded Warrants is subject to a beneficial ownership limitation of 9.99% of the outstanding Common Stock and the conversion of the Series B Preferred Stock is subject to a beneficial ownership limitation of 19.99%. The securities exclude shares of Common Stock issuable upon exercise of Pre-Funded Warrants in excess of such beneficial ownership limitation. At such time as Fairmount and its affiliates beneficially own 9.0% or less of the Common Stock, the beneficial ownership limitation with respect to the Series B Preferred Stock will automatically reduce to 9.99%. Row 13 is based on 74,733,166 shares of Common Stock outstanding as of July 1, 2026, consisting of (i) 60,312,101 shares of Common Stock outstanding as of April 30, 2026, as reported in the Company's Form 10-Q filed on May 13, 2026, (ii) 3,553,410 shares of Common Stock issued upon conversion of Series B Preferred Stock by the Reporting Persons on July 1, 2026, (iii) 19,022 shares underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by the Reporting Persons, (iv) 2,973,894 shares of Common Stock underlying the 2,973,894 Pre-Funded Warrants, subject to the beneficial ownership limitation and (v) 7,874,739 shares of Common Stock underlying the 94,497 shares of Series B Preferred Stock owned by the Reporting Persons. 0002009690 N Fairmount Healthcare Co-Invest III L.P. a AF N DE 0.00 2573308.00 0.00 2573308.00 2573308.00 N 4.03 PN The securities listed represent 2,573,308 shares of Common Stock held directly by Co-Invest. Row 13 is based on 60,312,101 shares of Common Stock outstanding as of April 30, 2026, as reported in the Company's Form 10-Q filed on May 13, 2026. 0001663607 N Harwin Peter Evan a AF N X1 19022.00 14553895.00 19022.00 14553895.00 14572917.00 N 19.50 IN The securities include (a) 19,022 shares of Common Stock issuable upon the exercise of options that are currently exercisable or will be exercisable within 60 days of the date of this filing held directly by Mr. Harwin*, (b) Fund II's direct holdings of (i) 1,131,954 shares of Common Stock, (ii) 2,973,894 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants, and (iii) 7,874,739 shares of Common Stock issuable upon conversion of 94,497 shares of Series B Preferred Stock held directly by Fund II, and (c) Co-Invest's direct holdings of 2,573,308 shares of Common Stock. The securities exclude 2,323,770 shares of Common Stock issuable upon exercise of Pre-Funded Warrants directly held by Fund II. The exercise of the Pre-Funded Warrants is subject to a beneficial ownership limitation of 9.99% of the outstanding Common Stock and the conversion of the Series B Preferred Stock is subject to a beneficial ownership limitation of 19.99%. At such time as Fairmount and its affiliates beneficially own 9.0% or less of the Common Stock, the beneficial ownership limitation with respect to the Series B Preferred Stock will automatically reduce to 9.99%. Row 13 is based on 74,733,166 shares of Common Stock outstanding as of July 1, 2026, consisting of (i) 60,312,101 shares of Common Stock outstanding as of April 30, 2026, as reported in the Company's Form 10-Q filed on May 13, 2026, (ii) 3,553,410 shares of Common Stock issued upon conversion of Series B Preferred Stock by the Reporting Persons on July 1, 2026, (iii) 19,022 shares underlying options that are currently exercisable or will be exercisable within 60 days of the date of this filing by the Reporting Persons, (iv) 2,973,894 shares of Common Stock underlying the 2,973,894 Pre-Funded Warrants, subject to the beneficial ownership limitation and (v) 7,874,739 shares of Common Stock underlying the 94,497 shares of Series B Preferred Stock owned by the Reporting Persons. * Under Mr. Harwin's arrangement with Fairmount, Mr. Harwin holds the options for one or more investment vehicles managed by Fairmount (each, a "Fairmount Fund"). Mr. Harwin is obligated to turn over to Fairmount any net cash or stock received from the option for the benefit of such Fairmount Fund. Mr. Harwin therefore disclaims beneficial ownership of the option and underlying common stock. 0001830177 N Kiselak Tomas a AF N 2B 0.00 14533895.00 0.00 14533895.00 14533895.00 N 19.47 IN The information in the "Comments" to the cover page for Fairmount Funds Management LLC above is hereby incorporated by reference. Common Stock, $0.001 par value per share ORUKA THERAPEUTICS, INC. 855 Oak Grove Avenue Suite 100 Menlo Park CA 94025 This Amendment No. 6 amends and supplements the statement on Schedule 13D originally filed with the Securities and Exchange Commission (the "SEC") on September 6, 2024, Amendment No. 1 on September 13, 2024, Amendment No. 2 on November 21, 2024, Amendment No. 3 on March 10, 2025, Amendment No. 4 on September 19, 2025, and Amendment No. 5 on May 4, 2026 (as amended, the "Statement" or the "Schedule 13D") by the Reporting Persons with respect to the Common Stock of the Company. Unless otherwise defined herein, capitalized terms used in this Amendment No. 6 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged. Item 3 of the Schedule 13D is hereby amended and supplemented as follows: On July 1, 2026, Fund II delivered to the Company a notice of conversion pursuant to Section 6.1 of the Certificate of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock (the "Certificate of Designation") to convert 42,641 shares of Series B Preferred Stock into 3,553,410 shares of Common Stock, in accordance with the terms of the Certificate of Designation. The conversion was effected for no cash consideration pursuant to the Certificate of Designation. The information in rows 11 and 13 of each of the cover pages (including the explanatory note in the "Comments") of this Amendment No. 6 is incorporated by reference herein. In the aggregate, the Reporting Persons' securities include (i) 3,705,262 shares of Common Stock, (ii) 19,022 shares of Common Stock issuable upon the exercise of options held by the Reporting Persons that are currently exercisable or will be exercisable within 60 days of the date of this filing, (iii) 2,973,894 shares of Common Stock underlying the 2,973,894 Pre-Funded Warrants, subject to the beneficial ownership limitation, and (iv) the 7,874,739 shares of Common Stock underlying the 94,497 shares of Series B Preferred Stock. The securities exclude 2,323,770 shares of Common Stock issuable upon conversion of 2,323,770 shares of Pre-Funded Warrants held directly by Fund II, the exercise of which is subject to a beneficial ownership limitation of 9.99% of the outstanding Common Stock. The information in rows 7 through 10 of each of the cover pages of this Amendment No. 6 is incorporated by reference herein. Item 5(c) of the Schedule 13D is hereby supplemented as follows: On July 1, 2026, Fund II sold in a block trade a total of 3,553,410 shares of Common Stock at a price of $84.43 per share. 99.1 Joint Filing Agreement (incorporated by reference to Exhibit 99.1 of the Reporting Persons' Schedule 13D filed with the SEC on September 6, 2024). Fairmount Funds Management LLC /s/ Peter Harwin 07/01/2026 /s/ Tomas Kiselak 07/01/2026 Fairmount Healthcare Fund II L.P. /s/ Peter Harwin 07/01/2026 /s/ Tomas Kiselak 07/01/2026 Fairmount Healthcare Co-Invest III L.P. /s/ Peter Harwin 07/01/2026 /s/ Tomas Kiselak 07/01/2026 Harwin Peter Evan /s/ Peter Harwin 07/01/2026 Kiselak Tomas /s/ Tomas Kiselak 07/01/2026