X0306 4 2021-09-16 0 0001810182 ALX ONCOLOGY HOLDINGS INC ALXO 0001188956 GARCIA PETER S C/O ALX ONCOLOGY HOLDINGS INC. 866 MALCOLM ROAD, SUITE 100 BURLINGAME CA 94010 0 1 0 0 Chief Financial Officer Common Stock 2021-09-16 4 M 0 1426 4.08 A 10757 D Common Stock 2021-09-16 4 S 0 1426 80.4312 D 9331 D Common Stock 2021-09-17 4 M 0 11345 4.08 A 20676 D Common Stock 2021-09-17 4 S 0 1027 77.8427 D 19649 D Common Stock 2021-09-17 4 S 0 7199 78.6112 D 12450 D Common Stock 2021-09-17 4 S 0 1746 79.4584 D 10704 D Common Stock 2021-09-17 4 S 0 273 80.224 D 10431 D Common Stock 2021-09-17 4 S 0 1100 81.19 D 9331 D Employee Stock Option (right to buy) 4.08 2021-09-16 4 M 0 1426 0.00 D 2030-03-09 Common Stock 1426 79042 D Employee Stock Option (right to buy) 4.08 2021-09-17 4 M 0 11345 0.00 D 2030-03-09 Common Stock 11345 67697 D Employee Stock Option (right to buy) 4.08 2030-03-09 Common Stock 95659 95659 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on July 14, 2021. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.00 to $80.88, inclusive. The reporting person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (2) through (6) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $77.05 to $78.045, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $78.05 to $79.045, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $79.05 to $80.02, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $80.05 to $80.51, inclusive. The option is subject to an early exercise provision and is immediately exercisable. One-fourth of the shares subject to the option vest on March 9, 2021 and 1/36th of the remaining shares vest monthly thereafter. The option is subject to an early exercise provision and is immediately exercisable. One-fourth of the shares subject to the option vested on January 2, 2021 and 1/36th of the remaining shares vest monthly thereafter. /s/ Peter Garcia 2021-09-17