ARCA biopharma, Inc. and Dr. Michael Bristow, President, Chief Executive Officer and a member of the board of directors of ARCA have mutually agreed to conclude Dr. Bristow's employment and service as a director, effective April 3, 2024. In connection with Dr. Bristow's separation, ARCA and Dr. Bristow entered into a separation agreement on April 3, 2024. Effective as of April 3, 2024, the Board appointed Thomas A. Keuer, the Company's Chief Operating Officer, to serve as ARCA's President and principal executive officer.

Mr. Keuer has been with ARCA since 2006, and as its Chief Operating Officer for the last nine years, a position he will continue to serve in. Mr. Keuer will not receive any additional compensation in connection with his appointment as President and principal executive officer. Mr. Keuer's position will end upon closing of the merger transaction with Oruka Therapeutics, Inc. as previously disclosed on a Current Report on Form 8-K filed with the SEC on April 3, 2024.