SCHEDULE 13G/A 0000950170-25-072010 0001493215 XXXXXXXX LIVE 1 Ordinary Shares, par value GBP 0.008 per share 06/30/2025 0001738021 Compass Therapeutics, Inc. 20451W101 80 GUEST STREET BOSTON MA 02135 Rule 13d-1(b) RTW Investments, LP DE 0.00 0.00 0.00 0.00 0.00 0.0 IA PN Explanatory Note: This Amendment No. 1 to Schedule 13G (this "Amendment") is being filed to correct an administrative error in connection with the filing earlier today of a Schedule 13G by RTW Investments, LP and Roderick Wong (the "Reporting Persons"), which was inadvertently filed with the Securities and Exchange Commission with respect to Compass Therapeutics, Inc. As of June 30, 2025 the Reporting Persons did not own any shares of Compass Therapeutics, Inc. and this amendment is being filed to correct this administrative error. Roderick Wong X1 0.00 0.00 0.00 0.00 0.00 0.0 HC IN Explanatory Note: This Amendment No. 1 to Schedule 13G (this "Amendment") is being filed to correct an administrative error in connection with the filing earlier today of a Schedule 13G by RTW Investments, LP and Roderick Wong (the "Reporting Persons"), which was inadvertently filed with the Securities and Exchange Commission with respect to Compass Therapeutics, Inc. As of June 30, 2025 the Reporting Persons did not own any shares of Compass Therapeutics, Inc. and this amendment is being filed to correct this administrative error. Compass Therapeutics, Inc. 80 GUEST STREET, BOSTON, MA, 02135. This statement is filed by: (i) RTW Investments, LP ("RTW Investments"), a Delaware limited partnership and the investment adviser to certain funds (the "RTW Funds"), with respect to Ordinary Shares, par value GBP 0.008 per share (the "Shares") of COMPASS Pathways plc (the "Company") directly held by the RTW Funds; and (ii) Roderick Wong, M.D. ("Dr. Wong"), the Managing Partner and Chief Investment Officer of RTW Investments, with respect to the Shares directly held by the RTW Funds. The foregoing persons are hereinafter sometimes collectively referred to as the "Reporting Persons." The filing of this statement should not be construed as an admission that any of the foregoing persons or any Reporting Person is, for the purposes of Section 13 of the Securities Exchange Act of 1934, as amended, the beneficial owner of the Shares reported herein. The address of the business office of each of the Reporting Persons is 40 10th Avenue, Floor 7, New York, New York 10014. RTW Investments is a Delaware limited partnership. Dr. Wong is a citizen of the United States. N IA HC The information required by Item 4(a) is set forth in Rows 5 - 9 of the cover page for each of the Reporting Persons and is incorporated herein by reference. RTW Investments: 0% Dr. Wong: 0% RTW Investments: 0 Dr. Wong: 0 RTW Investments: 0 Shares Dr. Wong: 0 Shares RTW Investments: 0 Dr. Wong: 0 RTW Investments: 0 Shares Dr. Wong: 0 Shares N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. RTW Investments, LP /s/ Roderick Wong, M.D. 08/14/2025 Roderick Wong s/ Roderick Wong, M.D. 08/14/2025