X0306 4 2020-07-21 0 0001810182 ALX ONCOLOGY HOLDINGS INC ALXO 0001750698 Vivo Capital IX, LLC C/O VIVO CAPITAL LLC 192 LYTTON AVENUE PALO ALTO CA 94301 0 0 1 0 0001750117 Vivo Capital Fund IX, L.P. C/O VIVO CAPITAL LLC 192 LYTTON AVENUE PALO ALTO CA 94301 0 0 1 0 0001728970 Vivo Opportunity, LLC C/O VIVO CAPITAL LLC 192 LYTTON AVENUE PALO ALTO CA 94301 0 0 1 0 0001726403 Vivo Opportunity Fund, L.P. C/O VIVO CAPITAL LLC 192 LYTTON AVENUE PALO ALTO CA 94301 0 0 1 0 Common Stock 2020-07-21 4 P 0 789474 19.00 A 789474 I See footnote Common Stock 2020-07-21 4 C 0 3245048 A 4034522 I See footnote Common Stock 2020-07-21 4 P 0 185526 19.00 A 185526 I See footnote Series C Convertible Preferred Stock 2020-07-21 4 C 0 3158851 D Common Stock 3158851 0 I See footnote The shares are held of record by Vivo Capital Fund IX, L.P. (VIVO IX LP). Vivo Capital IX, LLC (VIVO IX LLC) is the General Partner of VIVO IX LP. As the managing members of Vivo Capital IX, LLC, Frank Kung, Albert Cha, Edgar Engleman, Shan Fu and Chen Yu share voting and dispositive power with respect to the shares held of record by VIVO IX LP but each disclaims beneficial ownership of such shares except to the extent of his individual pecuniary interest therein. Each share of Series C Convertible Preferred Stock automatically converted into Common Stock on a 1:1 basis immediately prior to the completion of the Issuer's initial public offering of Common Stock and had no expiration date. Includes 86,197 shares of Common Stock issued as payment of accrued dividends upon conversion of the preferred stock on July 21, 2020. The shares are held of record by Vivo Opportunity Fund, L.P. (VOF). Vivo Opportunity, LLC is the general partner of VOF. As the managing members of Vivo Opportunity, LLC, Albert Cha, Gaurav Aggarwal, Shan Fu, Frank Kung and Michael Chang share voting and dispositive power with respect to the shares held of record by VIVO IX LP but each disclaims beneficial ownership of such shares except to the extent of his individual pecuniary interest therein. /s/ Albert Cha, as a managing member of Vivo Capital IX, LLC 2020-07-21 /s/ Albert Cha, as a managing member of Vivo Capital IX, LLC, the general partner of VIVO IX LP 2020-07-21 /s/ Albert Cha, as a managing member of Vivo Opportunity, LLC 2020-07-21 /s/ Albert Cha, as a managing member of Vivo Opportunity, LLC, the general partner of Vivo Opportunity Fund, L.P. 2020-07-21