On February 22, 2022, Brett Kaplan, M.D., a member of the Board of Directors (the “Board”) of Compass Therapeutics, Inc. (the “Company”), notified the Company of his resignation from the Board and all committees thereof, effective February 25, 2022. Dr. Kaplan's resignation was not the result of a disagreement with the Company on any matter relating to the Company's operations, policies or practices.