X0206 3 2024-09-12 0 0001953926 Zenas BioPharma, Inc. ZBIO 0001802528 Fairmount Funds Management LLC 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN PA 19428 1 0 1 0 0001769651 Fairmount Healthcare Fund II L.P. 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN PA 19428 1 0 1 0 0001830177 Kiselak Tomas 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN PA 19428 1 0 1 0 0001663607 Harwin Peter Evan 200 BARR HARBOR DRIVE SUITE 400 WEST CONSHOHOCKEN PA 19428 1 0 1 0 Common Stock 287915 I By Fairmount Healthcare Fund II LP Series Seed Convertible Preferred Stock Common Stock 41130 I By Fairmount Healthcare Fund II LP Series A Convertible Preferred Stock Common Stock 252890 I By Fairmount Healthcare Fund II LP Series B Convertible Preferred Stock Common Stock 709794 I By Fairmount Healthcare Fund II LP Series C Convertible Preferred Stock Common Stock 301077 I By Fairmount Healthcare Fund II LP Fairmount Funds Management LLC ("Fairmount") is the investment manager for Fairmount Healthcare Fund II L.P. ("Fund II"). The general partner of Fairmount is Fairmount Funds Management GP LLC ("Fairmount GP"), of which Peter Harwin and Tomas Kiselak are the managing members. Fairmount, Fairmount GP, Mr. Harwin, and Mr. Kiselak disclaim beneficial ownership of any of the reported securities, except to the extent of their pecuniary interest therein. Each share of Series Seed Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 8.6831-for-1 basis and has no expiration date. The Series Seed Convertible Preferred Stock will automatically convert into common stock upon the closing of the Company's initial public offering. Each share of Series A Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 8.6831-for-1 basis and has no expiration date. The Series A Convertible Preferred Stock will automatically convert into common stock upon the closing of the Company's initial public offering. Each share of Series B Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 8.6831-for-1 basis and has no expiration date. The Series B Convertible Preferred Stock will automatically convert into common stock upon the closing of the Company's initial public offering. Each share of Series C Convertible Preferred Stock is convertible into shares of the Issuer's Common Stock on a 8.6831-for-1 basis and has no expiration date. The Series C Convertible Preferred Stock will automatically convert into common stock upon the closing of the Company's initial public offering. Fairmount may be deemed a director by deputization of the Issuer by virtue of the fact that Tomas Kiselak serves on the board of directors of the Issuer and is a Managing Member of Fairmount. /s/ Tomas Kiselak, Managing Member of Fairmount Funds Management LLC 2024-09-12 /s/ Tomas Kiselak, Managing Member of Fairmount Healthcare Fund II LP 2024-09-12 /s/ Tomas Kiselak 2024-09-12 /s/ Peter Harwin 2024-09-12