What changed in this filing

/stocks — the workspaceLOADING

Item 5. Other Information

2026-08-10 compared with 2026-05-13 · 57 added, 59 removed, 14 unchanged (89% of the section changed)

1 unchanged sentence

Trading Plans

During the quarter ended March 31, 2026, no director

or Section 16 officer adopted or terminated any Rule 10b5-1 trading arrangements or non-Rule 10b5-1 trading arrangements (in each case,

as defined in Item 408(a) of Regulation S-K), except as disclosed below.

On February 11, 2026 , Arjun Agarwal , our Senior Vice President –

Finance and Treasurer , adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) for the

sale of shares of our common stock over a period ending upon the earlier of when all shares under the plan are sold, or February 26, 2027 ,

subject to certain conditions.

This plan covers the sale of up to (i) 97,965 shares (ii) 100% of net vested RSUs from gross RSU grants

of up to 4,375 shares and (iii) 100% of shares purchased pursuant to the ESPP on June 8, 2026 and December 8, 2026.

On February 19, 2026 , Carl Dambkowski , a director

in our company, adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of

up to 140,000 shares of our common stock over a period ending upon the earlier of when all shares under the plan are sold, or May 31,

2027 , subject to certain conditions.

During the quarter ended

June 30, 2026, no director or Section 16 officer adopted or terminated any Rule 10b5-1 trading arrangements or non-Rule 10b5-1 trading

arrangements (in each case, as defined in Item 408(a) of Regulation S-K), except as disclosed below.

On May 14, 2026 , Lawrence

Klein , our President and Chief Executive Officer , adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense

of Rule 10b5-1(c) for the sale of up to 350,000 shares of our common stock over a period ending upon the earlier of when all shares under

the plan are sold, or August 4, 2027 , subject to certain conditions.

On May 15, 2026 , Paul Quinlan ,

our General Counsel , adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) for the

sale of up to 120,000 shares of our common stock over a period ending upon the earlier of when all shares under the plan are sold, or

August 20, 2027 , subject to certain conditions.

The exhibits filed or furnished as part of this

Quarterly Report are set forth below.

Agreement and Plan of Merger and Reorganization, dated as of April 3, 2024, by and among ARCA biopharma, Inc., Atlas Merger Sub Corp., Atlas Merger Sub II, LLC and Oruka Therapeutics, Inc.

April 3, 2024

Second Amended and Restated Certificate of Incorporation of the Company, filed September 3, 2024.

September 5, 2024

Amended and Restated Bylaws of the Company.

September 5, 2024

Form of Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Preferred Stock.

Certificate of Elimination of Series A Convertible Preferred Stock, effective August 29, 2024.

September 5, 2024

Certificate of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock.

September 5, 2024

Certificate of Designation of Preferences, Rights and Limitations of Series A Non-Voting Convertible Preferred Stock.

September 13, 2024

Description of Securities.

March 6, 2025

Form of Pre-Funded Warrant, dated August 29, 2024.

March 6, 2025

Form of Pre-Funded Warrant, dated September 13, 2024.

September 13, 2024

Form of Pre-Funded Warrant, dated September 19, 2025.

September 22, 2025

Paruka Warrant, dated December 31, 2024

Paruka Warrant, dated December 12, 2025

March 12, 2026

Certification of the Principal Executive Officer pursuant to Rule 13a-14(a) or 15d-14(a) promulgated under the Securities Exchange Act of 1934

Certification of the Principal Financial Officer pursuant to Rule 13a-14(a) or 15d-14(a) promulgated under the Securities Exchange Act of 1934

Certification of the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C.

Section 1350 and Rule 13a-14(B) promulgated under the Securities Exchange Act of 1934

Inline XBRL Instance Document

Inline XBRL Taxonomy Extension Schema with Embedded Linkbases Document

Inline XBRL Taxonomy Extension Calculation Linkbase Document.

Inline XBRL Taxonomy Extension Definition Linkbase Document.

Inline XBRL Taxonomy Extension Label Linkbase Document.

Inline XBRL Taxonomy Extension Presentation Linkbase Document.

Cover Page Interactive Data File (embedded within the Inline XBRL document)

Filed herewith.

Furnished herewith.

The certifications on Exhibit 32.1 hereto are deemed not “filed” for purposes of Section 18 of the Exchange Act or otherwise subject to the liability of that Section.

Such certifications will not be deemed incorporated by reference into any filing under the Securities Act or the Exchange Act.

Exhibits and/or schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K.

The Company hereby undertakes to furnish supplementally copies of any of the omitted exhibits and schedules upon request by the SEC;

provided, however, that the Company may request confidential treatment pursuant to Rule 24b-2 under the Exchange Act for any exhibits or schedules so furnished.

Certain portions of this exhibit (indicated by “***”) have been omitted because they are both (i) not material and (ii) is the type of information that the registrant both customarily and actually treats as private and confidential.

and Plan of Merger and Reorganization, dated as of April 3, 2024, by and among ARCA biopharma, Inc., Atlas Merger Sub Corp., Atlas

Merger Sub II, LLC and Oruka Therapeutics, Inc.

Amended and Restated Certificate of Incorporation of the Company, filed September 3, 2024.

and Restated Bylaws of the Company.

of Certificate of Designation of Preferences, Rights and Limitations of Series A Convertible Preferred Stock.

of Elimination of Series A Convertible Preferred Stock, effective August 29, 2024.

of Designation of Preferences, Rights and Limitations of Series B Non-Voting Convertible Preferred Stock.

of Designation of Preferences, Rights and Limitations of Series A Non-Voting Convertible Preferred Stock.

of Securities.

of Pre-Funded Warrant, dated August 29, 2024.

of Pre-Funded Warrant, dated September 13, 2024.

of Pre-Funded Warrant, dated September 19, 2025.

Warrant, dated December 31, 2024.

Warrant, dated December 12, 2025.

First Amendment to IL-23 License Agreement, dated May 29, 2026.

Certification

of the Principal Executive Officer pursuant to Rule 13a-14(a) or 15d-14(a) promulgated under the Securities Exchange Act of 1934.

Certification

of the Principal Financial Officer pursuant to Rule 13a-14(a) or 15d-14(a) promulgated under the Securities Exchange Act of 1934.

Certification

of the Principal Executive Officer and Principal Financial Officer pursuant to 18 U.S.C.

Section 1350 and Rule 13a-14(b) promulgated

under the Securities Exchange Act of 1934.

XBRL Instance Document.

XBRL Taxonomy Extension Schema with Embedded Linkbases Document.

XBRL Taxonomy Extension Calculation Linkbase Document.

XBRL Taxonomy Extension Definition Linkbase Document.

XBRL Taxonomy Extension Label Linkbase Document.

XBRL Taxonomy Extension Presentation Linkbase Document.

Page Interactive Data File (embedded within the Inline XBRL document).

The certifications on Exhibit 32.1 hereto are deemed not “filed” for purposes of Section 18 of the Exchange Act

or otherwise subject to the liability of that Section.

Such certifications will not be deemed incorporated by reference into any filing

under the Securities Act or the Exchange Act.

and/or schedules have been omitted pursuant to Item 601(a)(5) of Regulation S-K.

The Company hereby undertakes to furnish supplementally

copies of any of the omitted exhibits and schedules upon request by the SEC;

provided, however, that the Company may request confidential

treatment pursuant to Rule 24b-2 under the Exchange Act for any exhibits or schedules so furnished.

Certain portions of this exhibit

(indicated by “***”) have been omitted because they are both (i) not material and (ii) is the type of information that the

registrant both customarily and actually treats as private and confidential.

Pursuant to the requirements

1 unchanged sentence

duly authorized.

Oruka Therapeutics, Inc.

/s/ Lawrence Klein

Oruka Therapeutics,

August 10, 2026

Lawrence Klein

1 unchanged sentence

(Principal Executive Officer)

/s/ Arjun Agarwal

August 10, 2026

Arjun Agarwal

Senior Vice President, Finance and Treasurer

2 unchanged sentences

Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.

What changed 10-Q

Item 5. Other Information