X0306 4 2020-12-14 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 2020-12-14 4 P 0 20000 76.00 A 995000 I See footnote Common Stock 2161981 I See footnote 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. 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. /s/ Peter Garcia, by power of attorney 2020-12-15