Fairmount Acquires Near-20% of ORKA; Fund II Buys 333,340 Shares at $15

Rhea-AI Filing Summary

Fairmount Funds Management LLC and affiliated entities report beneficial ownership of 11,162,741 shares of Oruka Therapeutics, Inc. common stock, representing 19.99% of the outstanding shares based on 55,841,629 shares as of September 17, 2025. This total includes 3,705,262 directly held shares, pre-funded warrants for 1,253,572 shares and conversion rights for 6,203,907 shares of Series B preferred stock, each subject to stated beneficial ownership limitations. On September 17, 2025 Fund II purchased 333,340 shares in a PIPE at $15.00 per share for $5,000,100; the PIPE closed on September 19, 2025. The investors received registration rights requiring the company to file an initial resale registration statement by October 15, 2025. Certain additional shares issuable upon exercise or conversion are excluded from the reported totals because they would exceed the contractual ownership caps.

Positive

• Material investment: Reporting persons now beneficially own 11,162,741 shares (19.99%) of ORKA, a significant stake.
• PIPE participation: Fund II purchased 333,340 shares at $15.00 per share for an aggregate of $5,000,100, adding committed capital.
• Registration rights: The investors obtained a Registration Rights Agreement requiring the company to file an initial resale registration statement by October 15, 2025, enabling resale of PIPE shares.

Negative

• Beneficial ownership caps: Pre-funded warrants and Series B preferred conversions are subject to ownership limitations (9.99% and 19.99% respectively), and certain issuable shares are excluded from the reported totals because they would exceed those caps.
• Concentrated stake near threshold: The combined position at 19.99% is close to common regulatory/market thresholds that can prompt additional scrutiny or strategic reactions by other stakeholders.

Insights

Securities Analyst

TL;DR: Fairmount and affiliates acquired a near-20% economic stake via direct holdings, warrants and convertible preferreds and participated in a $15/share PIPE.

Fairmount's combined reported position at 19.99% is material for shareholders because it aggregates multiple instrument types (common shares, pre-funded warrants and convertible preferred stock) and sits just below a 20% threshold that often attracts heightened market and regulatory attention. The PIPE participation (333,340 shares for $5.0 million) and associated registration rights provide liquidity pathways for those newly issued shares. Beneficial ownership limitations on the pre-funded warrants and preferred conversions constrain immediate further accumulation of common shares and affect the reported share count.

Corporate Governance Specialist

TL;DR: This Schedule 13D/A signals significant investor influence potential and includes standard registration rights from the PIPE.

The filing shows coordinated reporting among an investment manager and its funds, with shared voting and dispositive power. The Registration Rights Agreement obligates the issuer to register PIPE shares by October 15, 2025, which reduces resale friction for investors and could affect near-term float. The presence of ownership caps on warrant exercise and preferred conversion is important governance detail: it limits dilution from those instruments unless thresholds change, and it clarifies which issuances are excluded from beneficial ownership calculations.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13D

Under the Securities Exchange Act of 1934

(Amendment No. 4)

ORUKA THERAPEUTICS, INC.

(Name of Issuer)

Common Stock, $0.001 par value

(Title of Class of Securities)

687604108

(CUSIP Number)

Ms. Erin O'Connor
Fairmount Funds Management LLC, 200 Barr Harbor Drive, Suite 400
West Conshohocken, PA, 19428
(267) 262-5300

(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)

09/17/2025

(Date of Event Which Requires Filing of This Statement)

If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box.

The information required on the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13D

CUSIP No. 687604108

1

Name of reporting person

Fairmount Funds Management LLC

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,162,741.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,162,741.00

11

Aggregate amount beneficially owned by each reporting person

11,162,741.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

19.99 %

14

Type of Reporting Person (See Instructions)

IA

Comment for Type of Reporting Person:

The securities (a) include (i) 1,131,954 shares of common stock, $0.001 par value per share (the "Common Stock"), 1,253,572 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants and 6,203,907 shares of Common Stock issuable upon conversion of 74,447 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 (i) 4,044,092 shares of Common Stock issuable upon exercise of Pre-Funded Warrants and (ii) 5,224,242 shares of Common Stock issuable upon conversion of 62,691 shares of Series B Preferred Stock, in each case 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 and conversion of shares of Series B Preferred Stock in excess of such beneficial ownership limitations. 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 55,841,629 shares of Common Stock outstanding as of September 17, 2025, consisting of (i) 37,450,745 shares of Common Stock outstanding as of July 31, 2025, as reported in the Company's most recent Quarterly Report on Form 10-Q, (ii) a total of 10,933,405 shares of Common Stock issued in the Company's private placement on September 17, 2025, as reported by the Company, (iii) the 1,253,572 shares of Common Stock underlying the Pre-Funded Warrants, and (iv) the 6,203,907 shares of Common Stock underlying the 74,447 shares of Series B Preferred Stock owned by the Reporting Persons, subject to the respective beneficial ownership limitations.

SCHEDULE 13D

CUSIP No. 687604108

1

Name of reporting person

Fairmount Healthcare Fund II L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 8,589,433.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 8,589,433.00

11

Aggregate amount beneficially owned by each reporting person

8,589,433.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

15.38 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person:

The securities (a) include 1,131,954 shares of Common Stock, 1,253,572 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants, and 6,203,907 shares of Common Stock issuable upon conversion of 74,447 shares of Series B Preferred Stock and (b) exclude 4,044,092 shares of Common Stock issuable upon exercise of Pre-Funded Warrants and 5,224,242 shares of Common Stock issuable upon conversion of 62,691 shares of Series B Preferred Stock. 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 and conversion of shares of Series B Preferred Stock in excess of such beneficial ownership limitations. 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 55,841,629 shares of Common Stock outstanding as of September 17, 2025, consisting of (i) 37,450,745 shares of Common Stock outstanding as of July 31, 2025, as reported in the Company's most recent Quarterly Report on Form 10-Q, (ii) a total of 10,933,405 shares of Common Stock issued in the Company's private placement on September 17, 2025, as reported by the Company, (iii) the 1,253,572 shares of Common Stock underlying the Pre-Funded Warrants, and (iv) the 6,203,907 shares of Common Stock underlying the 74,447 shares of Series B Preferred Stock owned by Fund II, subject to the respective beneficial ownership limitations.

SCHEDULE 13D

CUSIP No. 687604108

1

Name of reporting person

Fairmount Healthcare Co-Invest III L.P.

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 2,573,308.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 2,573,308.00

11

Aggregate amount beneficially owned by each reporting person

2,573,308.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

5.32 %

14

Type of Reporting Person (See Instructions)

PN

Comment for Type of Reporting Person:

The securities include 2,573,308 shares of Common Stock. Row 13 is based on 48,384,150 shares of Common Stock outstanding as of September 17, 2025, consisting of (i) 37,450,745 shares of Common Stock outstanding as of July 31, 2025, as reported in the Company's most recent Quarterly Report on Form 10-Q, and (ii) a total of 10,933,405 shares of Common Stock issued in the Company's private placement on September 17, 2025, as reported by the Company.

SCHEDULE 13D

CUSIP No. 687604108

1

Name of reporting person

Peter Evan Harwin

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

UNITED STATES

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,162,741.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,162,741.00

11

Aggregate amount beneficially owned by each reporting person

11,162,741.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

19.99 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

The information in the "Comments" to the cover page for Fairmount Funds Management LLC above is hereby incorporated by reference.

SCHEDULE 13D

CUSIP No. 687604108

1

Name of reporting person

Tomas Kiselak

2

Check the appropriate box if a member of a Group (See Instructions)

(a)
(b)

3

SEC use only

4

Source of funds (See Instructions)

AF

5

Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

6

Citizenship or place of organization

SLOVAKIA

Number of Shares Beneficially Owned by Each Reporting Person With:

7	Sole Voting Power 0.00
8	Shared Voting Power 11,162,741.00
9	Sole Dispositive Power 0.00
10	Shared Dispositive Power 11,162,741.00

11

Aggregate amount beneficially owned by each reporting person

11,162,741.00

12

Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

13

Percent of class represented by amount in Row (11)

19.99 %

14

Type of Reporting Person (See Instructions)

IN

Comment for Type of Reporting Person:

The information in the "Comments" to the cover page for Fairmount Funds Management LLC above is hereby incorporated by reference.

SCHEDULE 13D

Item 1.	Security and Issuer
(a)	Title of Class of Securities: Common Stock, $0.001 par value
(b)	Name of Issuer: ORUKA THERAPEUTICS, INC.
(c)	Address of Issuer's Principal Executive Offices: 855 Oak Grove Avenue, Suite 100, Menlo Park, CALIFORNIA , 94025.
Item 1 Comment: This Amendment No. 4 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, and Amendment No. 3 on March 10, 2025 (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. 4 shall have the meanings ascribed to them in the Statement. Unless amended or supplemented below, the information in the Statement remains unchanged.
Item 3.	Source and Amount of Funds or Other Consideration
	Item 3 of the Statement is hereby amended and supplemented as follows: In aggregate, the Reporting Persons have voting and dispositive power over 11,162,741 shares of Common Stock of the Company, which is comprised of (a) 3,705,262 shares of Common Stock, (b) Pre-Funded Warrants to purchase up to 1,253,572 shares of Common Stock, the exercise of which is subject to a beneficial ownership limitation of 9.99% of the outstanding Common Stock (and excluding shares of Common Stock issuable upon exercise of the Pre-Funded Warrants in excess of the beneficial ownership limitation), and (c) 6,203,907 shares of Common Stock issuable upon conversion of 74,447 shares of Series B Preferred Stock, the conversion of which is subject to a beneficial ownership limitation of 19.99% of the outstanding Common Stock (and excluding shares of Common Stock issuable upon conversion of the Series B Preferred Stock in excess of the beneficial ownership limitation). On September 17, 2025, Fund II purchased a total of 333,340 shares of Common Stock through a private placement with the Company for an aggregate of $5,000,100. The shares were purchased with working capital.
Item 4.	Purpose of Transaction
	Item 4 of the Statement is hereby amended and supplemented as follows: Subscription Agreement On September 17, 2025, the Company entered into a securities purchase agreement (the "Subscription Agreement") for a private investment in public equity ("PIPE") with certain institutional and accredited investors, including Fund II. The PIPE closed on September 19, 2025. Pursuant to the terms of the Subscription Agreement, Fund II purchased a total of 333,340 shares of Common Stock for investment purposes at a purchase price of $15.00 per share. The foregoing description of the Subscription Agreement does not purport to be complete and is qualified in its entirety by reference to the form of the Subscription Agreement, which the Reporting Persons anticipate will be filed as an exhibit to the Company's upcoming Current Report on Form 8-K. Registration Rights Agreement In connection with the PIPE, the Company and investors participating in the PIPE, including Fund II, entered into a registration rights agreement (the "Registration Rights Agreement"), pursuant to which the Company is required to prepare and file an initial registration statement with the U.S. Securities and Exchange Commission no later than October 15, 2025 registering for resale under the Securities Act of 1933, as amended, the shares of Common Stock purchased by the investors in the PIPE. The Registration Rights Agreement also provides that the Company is required to pay certain expenses relating to such registrations and indemnify the applicable securityholders against certain liabilities. The foregoing summary of the Registration Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the form of Registration Rights Agreement, which the Reporting Persons anticipate will be filed as an exhibit to the Company's upcoming Current Report on Form 8-K.
Item 5.	Interest in Securities of the Issuer
(a)	The information in rows 11 and 13 of each of the cover pages (including the explanatory note in the "Comments") of this Amendment No. 4 is incorporated by reference herein.
(b)	The information in rows 7 through 10 of each of the cover pages of this Amendment No. 4 is incorporated by reference herein. The Reporting Persons' securities (a) include (i) 1,131,954 shares of Common Stock, 1,253,572 shares of Common Stock issuable upon the exercise of Pre-Funded Warrants and 6,203,907 shares of Common Stock issuable upon conversion of 74,447 shares of Series B Preferred Stock, directly held by Fund II, and (ii) 2,573,308 shares of Common Stock directly held by Co-Invest, and (b) exclude (i) 4,044,092 shares of Common Stock issuable upon exercise of Pre-Funded Warrants and (ii) 5,224,242 shares of Common Stock issuable upon conversion of 62,691 shares of Series B Preferred Stock, in each case 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 and conversion of shares of Series B Preferred Stock in excess of such beneficial ownership limitations. 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%.
(c)	On September 17, 2025, Fund II purchased a total of 333,340 shares of Common Stock in the PIPE at a price of $15.00 per share, for an aggregate of $5,000,100.
(d)	Fairmount is the investment manager to Fund II and Co-Invest and has voting and dispositive power over shares of Common Stock held on behalf of Fund II and Co-Invest.
Item 7.	Material to be Filed as Exhibits.
	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).

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Fairmount Funds Management LLC

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin, Managing Member
Date:	09/19/2025

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak, Managing Member
Date:	09/19/2025

Fairmount Healthcare Fund II L.P.

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin, Managing Member
Date:	09/19/2025

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak, Managing Member
Date:	09/19/2025

Fairmount Healthcare Co-Invest III L.P.

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin, Managing Member
Date:	09/19/2025

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak, Managing Member
Date:	09/19/2025

Peter Evan Harwin

Signature:	/s/ Peter Harwin
Name/Title:	Peter Harwin
Date:	09/19/2025

Tomas Kiselak

Signature:	/s/ Tomas Kiselak
Name/Title:	Tomas Kiselak
Date:	09/19/2025

FAQ

How many ORKA shares do Fairmount and affiliates beneficially own?

They beneficially own 11,162,741 shares, representing 19.99% of outstanding common stock as of September 17, 2025.

What was the PIPE transaction involving ORKA and Fund II?

On September 17, 2025 Fund II purchased 333,340 shares in a PIPE at $15.00 per share, paying $5,000,100; the PIPE closed on September 19, 2025.

Are there registration rights for the PIPE shares?

Yes. The Registration Rights Agreement requires the company to file an initial resale registration statement no later than October 15, 2025 and obligates the company to pay related expenses and provide certain indemnities.

Do the pre-funded warrants and preferred conversions increase the reported stake?

The reported stake includes certain pre-funded warrants and Series B preferred conversion rights but excludes additional issuable shares that would exceed contractual beneficial ownership limitations (9.99% for pre-funded warrants; 19.99% for Series B conversion).

Who has voting and dispositive power over the reported shares?

Fairmount Funds Management LLC, as investment manager, has shared voting and dispositive power over shares held by Fund II and Co-Invest and reported shared voting/dispositive power of 11,162,741 shares.