X0306 4 2021-04-19 0 0001810182 ALX ONCOLOGY HOLDINGS INC ALXO 0001816977 Pons Jaume C/O ALX ONCOLOGY HOLDINGS INC. 866 MALCOLM ROAD, SUITE 100 BURLINGAME CA 94010 1 1 0 0 President & CEO Common Stock 2021-04-19 4 S 0 5330 56.4227 D 556016 D Common Stock 2021-04-19 4 S 0 6956 57.7298 D 549060 D Common Stock 2021-04-19 4 S 0 2914 58.3576 D 546146 D Common Stock 2021-04-19 4 S 0 663 59.5174 D 545483 D Common Stock 2021-04-19 4 S 0 837 60.4753 D 544646 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on January 28, 2021. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $56.10 to $57.08, 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 $57.11 to $58.09, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $58.125 to $58.90, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $59.21 to $60.20, inclusive. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $60.27 to $61.01, inclusive. /s/ Peter Garcia, by power of attorney 2021-04-21