SCHEDULE 13G/A 0001214659-25-000855 0001232621 XXXXXXXX LIVE 3 Common Stock, par value $0.0001 per share 09/30/2025 0001738021 Compass Therapeutics, Inc. 20454B104 80 Guest Street Suite 601 Boston MA 02135 Rule 13d-1(c) TANG CAPITAL MANAGEMENT, LLC DE 0.00 17176510.00 0.00 17176510.00 17176510.00 N 9.99 OO Tang Capital Management, LLC ("TCM") beneficially owns 17,176,510 shares of the Issuer's Common Stock, which consists of: (i) 16,811,963 shares of the Issuer's Common Stock and (ii) 364,547 shares currently issuable upon exercise of Warrants (the "Warrants," as defined in the Issuer's Registration Statement filed on Form 424B5 with the Securities and Exchange Commission on August 13, 2025). The percentages used herein are based on 171,937,045 shares of Common Stock outstanding which is comprised of: (i) 171,572,498 shares of Common Stock outstanding as of August 11, 2025, as set forth in the Issuer's Prospectus filed on Form 424B5 that was filed with the Securities and Exchange Commission on August 13, 2025 and (ii) 364,547 shares currently issuable upon exercise of Warrants. TCM shares voting and dispositive power over such shares with Tang Capital Partners, LP ("TCP"), Tang Capital Partners International, LP ("TCPI"), Tang Capital Partners III, Inc. ("TCP III"), Tang Capital Partners IV, Inc. ("TCP IV") and Kevin Tang. KEVIN TANG X1 0.00 17176510.00 0.00 17176510.00 17176510.00 N 9.99 IN Kevin Tang beneficially owns 17,176,510 shares of the Issuer's Common Stock, which consists of: (i) 16,811,963 shares of the Issuer's Common Stock and (ii) 364,547 shares currently issuable upon exercise of Warrants. Kevin Tang shares voting and dispositive power over such shares with TCP, TCPI, TCP III and TCM. TANG CAPITAL PARTNERS, LP DE 0.00 10274944.00 0.00 10274944.00 10274944.00 N 5.98 PN TCP beneficially owns 10,274,944 shares of the Issuer's Common Stock, which consists of: (i) 10,069,923 shares of the Issuer's Common Stock and (ii) 205,021 shares currently issuable upon exercise of Warrants. TCP owns 3,773,704 of the Issuer's Pre-funded Warrants, which are each exercisable for one share of the Issuer's Common Stock. TCP may not exercise any portion of the Investor Warrants for shares of Common Stock if, as a result of the exercise, TCP, together with its affiliates and any other person or entity acting as a group, would own more than 9.99% of the Issuer's outstanding shares of Common Stock after exercise. However, TCP may increase such percentage to any other percentage, not in excess of 19.99% (to the extent such limit is required under applicable Nasdaq rules), by providing written notice to the Issuer, provided that any increase in such percentage shall not be effective until 61 days after notice is provided to the Issuer. The foregoing limitations remain in effect with respect to the Warrants, and, accordingly, only 205,021 shares are currently issuable upon exercise of the Warrants. TCP shares voting and dispositive power over such shares with TCM and Kevin Tang. TANG CAPITAL PARTNERS INTERNATIONAL, LP DE 0.00 5568566.00 0.00 5568566.00 5568566.00 N 3.24 PN TCPI beneficially owns 5,568,566 shares of the Issuer's Common Stock, which consists of: (i) 5,409,040 shares of the Issuer's Common Stock and (ii) 159,526 shares currently issuable upon exercise of Warrants. TCPI owns 2,936,296 of the Issuer's Pre-Funded Warrants, which are each exercisable for one share of the Issuer's Common Stock. Based on the ownership limitations described above, only 159,526 shares are currently issuable upon exercise of the Warrants. TCPI shares voting and dispositive power over such shares with TCM and Kevin Tang. TANG CAPITAL PARTNERS III, INC NV 0.00 999750.00 0.00 999750.00 999750.00 N 0.58 CO TCP III shares voting and dispositive power over such shares with TCM and Kevin Tang. TANG CAPITAL PARTNERS IV, INC NV 0.00 333250.00 0.00 333250.00 333250.00 N 0.19 CO TCP IV shares voting and dispositive power over such shares with TCM and Kevin Tang. Compass Therapeutics, Inc. 80 Guest Street, Suite 601, Boston, MA, 02135 This Statement on Schedule 13G (this "Statement") is filed by TCM, the general partner of TCP and TCPI; Kevin Tang, the manager of TCM and Chief Executive Officer of TCP III and TCP IV; TCP; TCPI; TCP III; and TCP IV. The address of TCM, Kevin Tang, TCP and TCPI is 4747 Executive Drive, Suite 210, San Diego, CA 92121. The address of TCP III and TCP IV is 400 S. 4th Street, 3rd Floor, Las Vegas, NV 89101. TCM is a Delaware limited liability company. Mr. Tang is a United States citizen. TCP and TCPI are Delaware limited partnerships. TCP III and TCP IV are Nevada corporations that are indirectly wholly owned by TCP. Y 17,176,510 9.99% 0 shares 17,176,510 shares 0 shares 17,176,510 shares 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 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. TANG CAPITAL MANAGEMENT, LLC /s/ Kevin Tang 11/14/2025 KEVIN TANG /s/ Kevin Tang 11/14/2025 TANG CAPITAL PARTNERS, LP /s/ Kevin Tang 11/14/2025 TANG CAPITAL PARTNERS INTERNATIONAL, LP /s/ Kevin Tang 11/14/2025 TANG CAPITAL PARTNERS III, INC /s/ Kevin Tang 11/14/2025 TANG CAPITAL PARTNERS IV, INC /s/ Kevin Tang 11/14/2025