Exhibit A

JOINT FILING AGREEMENT

The undersigned agree that this Schedule 13G dated August 13, 2025 relating to the Common Stock, $0.0001 par value per share, of Compass Therapeutics, Inc. shall be filed on behalf of the undersigned.

SUVRETTA CAPITAL MANAGEMENT, LLC

By: /s/ Andrew Nathanson

 Name: Andrew Nathanson

Title: General Counsel and Chief Compliance Officer

AVERILL MASTER FUND, LTD.

By: /s/ Andrew Nathanson

Name: Andrew Nathanson

Title:   Authorized Signatory

AARON COWEN

By: /s/ Aaron Cowen