SEPARATION AGREEMENT AND RELEASE

This Separation Agreement and Release (“Agreement”) is made by and between Michael Bristow (“Executive”) and ARCA biopharma, Inc. (formerly known as ARCA Discovery, Inc.) (the “Company”) (collectively referred to as the “Parties” or individually referred to as a “Party”).

RECITALS

WHEREAS, Executive was employed at-will by the Company;

WHEREAS, Executive signed an Amended and Restated Employment and Retention Agreement with the Company on June 4, 2008, which was amended by the Parties on June 13, 2013 (the “Employment Agreement”);

WHEREAS, Executive signed an Employee Intellectual Property, Confidentiality and Non-Compete Agreement with the Company on January 3, 2005 (the “Confidentiality Agreement”);

WHEREAS, the Company granted Executive certain stock options to purchase shares of the Company’s common stock (the “Options”), as set forth in the table below (the “Options Table”), with each such Option subject to the terms and conditions of either the Company’s 2013 Equity Incentive Plan, as amended (the “2013 Plan”) or the Company’s 2020 Equity Incentive Plan (the “2020 Plan,” and collectively with the 2013 Plan, each an “Equity Plan”), as set forth below, and an option agreement under the applicable Equity Plan (collectively, the Equity Plans and applicable option agreements, the “Stock Agreements”):

WHEREAS, the Company expects to enter into an Agreement and Plan of Merger and Reorganization (the “Merger Agreement”) with Oruka Therapeutics, Inc. (“Target”), pursuant to which Target is expected to become a wholly owned subsidiary of the Company and the stockholders of Target will acquire majority control of the Company (with the transactions referred to in the Merger Agreement, the “Merger,” and the date of the closing of the Merger, the “Closing”);

WHEREAS, Executive resigned from employment with the Company effective April 3, 2024 (the “Separation Date”);

WHEREAS, Executive and the Company executed a Consulting Agreement effective as of the Separation Date (the “Consulting Agreement”), whereby Executive will continue to provide services to the Company as a consultant; and

WHEREAS, the Parties wish to resolve any and all disputes, claims, complaints, grievances, charges, actions, petitions, and demands that Executive may have against the Company and any of the Releasees as defined below, including, but not limited to, any and all claims arising out of or in any way related to Executive’s employment with or separation from the Company;

NOW, THEREFORE, in consideration of the mutual promises made herein, the Company and Executive hereby agree as follows:

COVENANTS

a. any and all claims relating to or arising from Executive’s employment relationship with the Company and the termination of that relationship, as well as any all claims relating to or arising from the Merger;

b. any and all claims relating to, or arising from, Executive’s right to purchase, actual purchase, or ownership of shares of stock of the Company, including, without limitation, any claims for fraud, misrepresentation, breach of fiduciary duty, breach of duty under applicable state corporate law, and securities fraud under any state or federal law;

c. any and all claims for wrongful discharge of employment; termination in violation of public policy; discrimination; harassment; retaliation; breach of contract, both express and implied; breach of covenant of good faith and fair dealing, both express and implied; promissory estoppel; negligent or intentional infliction of emotional distress; fraud; negligent or intentional misrepresentation; negligent or intentional interference with contract or prospective economic advantage; unfair business practices; defamation; libel; slander; negligence; personal injury; assault; battery; invasion of privacy; false imprisonment; conversion; and disability benefits;

d. any and all claims for violation of any federal, state, or municipal statute, including, but not limited to, Title VII of the Civil Rights Act of 1964; the Civil Rights Act of 1991; the Rehabilitation Act of 1973; the Americans with Disabilities Act of 1990; the Equal Pay Act; the Fair Labor Standards Act; the Fair Credit Reporting Act; the Age Discrimination in Employment Act of 1967; the Older Workers Benefit Protection Act; the Employee Retirement Income Security Act of 1974; the Worker Adjustment and Retraining Notification Act; the Family and Medical Leave Act; the Uniformed Services Employment and Reemployment Rights Act; the Colorado Anti-Discrimination Act; the Colorado Religious Discrimination Rules; the Colorado Disability Discrimination Rules; the Colorado Age Discrimination Rules; the Colorado Workplace Harassment Rules; the Colorado Sex Discrimination Rules; the Colorado Marital Status Discrimination Law; the Colorado Equal Pay Law; the Colorado Law Prohibiting Discrimination by Labor Organizations; the Colorado Whistleblower Law; the Colorado Overtime Pay Law; the Colorado Workplace Accommodations for Nursing Mothers Act; the Colorado Civil Union Act; the Colorado Family Care Act; the Colorado Job History Law; the Colorado Crime Victim Leave Law; the Colorado Military Leave Law; the Colorado Military Service Discrimination Law; the Colorado Labor Relations Act; and the Colorado Labor Peace Act;

e. any and all claims for violation of the federal or any state constitution;

f. any and all claims arising out of any other laws and regulations relating to employment or employment discrimination;

g. any claim for any loss, cost, damage, or expense arising out of any dispute over the nonwithholding or other tax treatment of any of the proceeds received by Executive from the Company; and

h. any and all claims for attorneys’ fees and costs.

Executive agrees that the release set forth in this Section shall be and remain in effect in all respects as a complete general release as to the matters released. This release does not extend to any obligations incurred under this Agreement. This release does not release claims that cannot be released as a matter of law. This release does not extend to any right Executive may have to unemployment compensation benefits. Executive represents that Executive has made no assignment or transfer of any right, claim, complaint, charge, duty, obligation, demand, cause of action, or other matter waived or released by this Section.

(a) Executive has read this Agreement;

(b) Executive has been represented in the preparation, negotiation, and execution of this Agreement by legal counsel of Executive’s own choice or has elected not to retain legal counsel;

(c) Executive understands the terms and consequences of this Agreement and of the releases it contains; and

(d) Executive is fully aware of the legal and binding effect of this Agreement.

IN WITNESS WHEREOF, the Parties have executed this Agreement on the respective dates set forth below.

MICHAEL BRISTOW, an individual

ARCA BIOPHARMA, INC.

Certain identified information marked with [***] has been excluded from this exhibit because it is not material and is of the type that the registrant treats as private and confidential.

ARCA BIOPHARMA, INC.

CONSULTING AGREEMENT

This Consulting Agreement (this “Agreement”) is made and entered into as of April 3, 2024 (the “Effective Date”) by and between ARCA biopharma, Inc. (the “Company”), and Dr. Michael Bristow (“Consultant”) (each herein referred to individually as a “Party,” or collectively as the “Parties”).

The Company desires to retain Consultant as an independent contractor to perform consulting services for the Company, and Consultant is willing to perform such services, on the terms described below. In consideration of the mutual promises contained herein, the Parties agree as follows:

Consultant shall perform the services described in Exhibit A (the “Services”) for the Company (or its designee), and the Company agrees to pay Consultant the compensation described in Exhibit A for Consultant’s performance of the Services.

Upon the termination of this Agreement, or upon the Company’s earlier request, Consultant will immediately deliver to the Company, and will not keep in Consultant’s possession, recreate, or deliver to anyone else, any and all Company property, including, but not limited to, Confidential Information, tangible embodiments of the Inventions, all devices and equipment belonging to the Company, all electronically-stored information and passwords to access such property, those records maintained pursuant to Section 3(c) and any reproductions of any of the foregoing items that Consultant may have in Consultant’s possession or control.

Consultant agrees to indemnify and hold harmless the Company and its affiliates and their directors, officers and employees from and against all taxes, losses, damages, liabilities, costs and expenses, including attorneys’ fees and other legal expenses, arising directly or indirectly from or in connection with (i) any negligent, reckless or intentionally wrongful act of Consultant or Consultant’s assistants, employees, contractors or agents, (ii) a determination by a court or agency that the Consultant is not an independent contractor, (iii) any failure of Consultant to perform the Services in accordance with all applicable laws, rules and regulations, or (iv) any violation or claimed violation of a third party’s rights resulting in whole or in part from the Company’s use of the Inventions or other deliverables of Consultant under this Agreement.

IN NO EVENT SHALL THE COMPANY BE LIABLE TO CONSULTANT OR TO ANY OTHER PARTY FOR ANY INDIRECT, INCIDENTAL, SPECIAL OR CONSEQUENTIAL DAMAGES, OR DAMAGES FOR LOST PROFITS OR LOSS OF BUSINESS, HOWEVER CAUSED AND UNDER ANY THEORY OF LIABILITY, WHETHER BASED IN CONTRACT, TORT (INCLUDING NEGLIGENCE) OR OTHER THEORY OF LIABILITY, REGARDLESS OF WHETHER THE COMPANY WAS ADVISED OF THE POSSIBILITY OF SUCH DAMAGES AND NOTWITHSTANDING THE FAILURE OF ESSENTIAL PURPOSE OF ANY LIMITED REMEDY. IN NO EVENT SHALL THE COMPANY’S LIABILITY ARISING OUT OF OR IN CONNECTION WITH THIS AGREEMENT EXCEED THE AMOUNTS PAID BY THE COMPANY TO CONSULTANT UNDER THIS AGREEMENT FOR THE SERVICES, DELIVERABLES OR INVENTION GIVING RISE TO SUCH LIABILITY.

10170 Church Ranch Way, Suite 100

Westminster, CO 80021

Attention: Mr. Thomas Keuer

IN WITNESS WHEREOF, the Parties hereto have executed this Consulting Agreement as of the date first written above.

CONSULTANT ARCA BIOPHARMA, INC.

Address for Notice:

[***]

EXHIBIT A

SERVICES AND COMPENSATION

Name: Mr. Thomas A. Keuer

Title: President

Email: [***]

Phone: [***]

Contract consulting services, including the following:

Final completion of these services is expected on or before August 1, 2024 unless otherwise approved by an authorized agent of the Company.

This Exhibit A is accepted and agreed upon as of April 3, 2024.

CONSULTANT ARCA BIOPHARMA, INC.