X0306 4 2020-07-21 0 0001810182 ALX ONCOLOGY HOLDINGS INC ALXO 0001777517 Graham G. Walmsley C/O LOGOS GLOBAL MANAGEMENT, LP 1 LETTERMAN DRIVE, BLDG D, SUITE D3-700 SAN FRANCISCO CA 94129 1 0 0 0 Common Stock 2020-07-21 4 C 0 2105901 A 2161981 I See footnote Common Stock 2020-07-21 4 P 0 975000 19.00 A 975000 I See footnote Series C Convertible Preferred Stock 2020-07-21 4 C 0 2105901 D Common Stock 2105901 0 I See footnote 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 56,080 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 Logos Opportunities Fund I, L.P. (LOF I LP). As a managing member of Logos Opportunities GP, LLC, the general partner of LOF I LP, the reporting person shares voting and dispositive power with respect to the shares held of record by LOF I LP but disclaims beneficial ownership of such shares except to the extent of his individual pecuniary interest therein. The shares are held of record by Logos Global Master Fund, L.P. (LGMF LP). As a managing member of Logos GP LLC, the general partner of LGMF LP, the reporting person shares voting and dispositive power with respect to the shares held of record by LGMF LP but disclaims beneficial ownership of such shares except to the extent of his individual pecuniary interest therein. /s/ Peter Garcia, by power of attorney 2020-07-21