ALX Oncology Announces Two Evorpacept Abstracts Accepted for Poster Presentation at 2024 ASCO Annual Meeting

ALX Oncology Holdings Inc., (“ALX Oncology” or “the Company”) (Nasdaq: ALXO), an immuno-oncology company developing therapies that block the CD47 immune checkpoint pathway, today announced the acceptance of two abstracts for poster presentation at the American Society of Cancer Oncology (“ASCO”), which will be held in Chicago from May 31-June 4, 2024.

Session titles and information for the two abstracts are listed below and are now available on the ASCO online program planner.

Evorpacept plus enfortumab vedotin in patients with locally advanced or metastatic urothelial carcinoma: Phase 1a dose escalation results Session Type and Title: Poster Presentation – Genitourinary Cancer – Kidney and Bladder Session Date and Time: Sunday, June 2, 2024, 9:00 AM – 12:00 PM CDT Location: Hall A Abstract Number: 4575ALX Oncology Sponsored Clinical Trial

Results of a Phase 2 study of evorpacept (ALX148), and cetuximab, and pembrolizumab in patients with refractory microsatellite stable metastatic colorectal cancer Session Type and Title: Poster Presentation – Gastrointestinal Cancer – Colorectal and Anal Session Date and Time: Saturday, June 1, 2024, 1:30 PM – 4:30 PM CDT Location: Hall A Abstract Number: 3530Investigator-Sponsored Trial at the University of Colorado Cancer Center

Copies of the presentations will be available on the Publications section of ALX Oncology’s website following presentation at the meeting.

About ALX Oncology

ALX Oncology is a publicly traded, clinical-stage immuno-oncology company focused on helping patients fight cancer by developing therapies that block the CD47 immune checkpoint inhibitor and bridge the innate and adaptive immune system. ALX Oncology’s lead product candidate, evorpacept, is a next generation CD47 blocking therapeutic that combines a high-affinity CD47 binding domain with an inactivated, proprietary Fc domain. To date, evorpacept has been dosed in over 500 subjects and has demonstrated promising activity and favorable tolerability profile across a range of hematologic and solid malignancies in combination with various leading anti-cancer antibodies. ALX Oncology is currently focusing on combining evorpacept with anti-cancer antibodies, antibody-drug conjugates (“ADCs”), and PD-1/PD-L1 immune checkpoint inhibitors.

Investor and Media Contact:

Caitlyn DohertyManager, Investor Relations and Corporate Communications, ALX [e-mail][phone]