X0202 SCHEDULE 13G/A 0001404574-25-000007 0001404574 XXXXXXXX LIVE 2 Common Stock, par value $0.0001 per share 03/31/2026 0001442836 Mersana Therapeutics, Inc. 59045L205 840 MEMORIAL DRIVE CAMBRIDGE MA 02139 Rule 13d-1(c) 683 Capital Management, LLC DE 0 0 0 0 0 N 0 IA 683 Capital Partners, LP DE 0 0 0 0 0 N 0 PN Ari Zweiman X1 0 0 0 0 0 N 0 IN Mersana Therapeutics, Inc. 840 MEMORIAL DRIVE, CAMBRIDGE, MASSACHUSETTS 02139 683 Capital Management, LLC 683 Capital Partners, LP Ari Zweiman Each of the foregoing is referred to as a "Reporting Person" and collectively as the "Reporting Persons." The principal business address for each of the Reporting Persons is 1700 Broadway, Suite 4200, New York, New York 10019. 683 Capital Management, LLC - DELAWARE 683 Capital Partners, LP - DELAWARE Ari Zweiman - UNITED STATES Y This Amendment No. 2 constitutes an exit filing for the Reporting Persons (as defined below). Following the consummation of the merger described in the Issuer's current report on Form 8-K, filed on January 6, 2026, the Reporting Persons no longer beneficially own any shares of Common Stock of the Issuer. 0 See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. See Cover Pages Items 5-9. N Y Y Y N See Exhibit A to Schedule 13G filed on November 24, 2025. 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. 683 Capital Management, LLC Ari Zweiman 05/15/2026 683 Capital Partners, LP Ari Zweiman 05/15/2026 Ari Zweiman Ari Zweiman 05/15/2026