ALX Oncology Strengthens IP Portfolio; Announces End of Post-Grant Review Period for Issued U.S. Patent Covering ALX148

• The post-grant review period for U.S. Patent 10,696,730 covering the composition of matter of ALX148 ended on March 30, 2021.

• This patent provides coverage of ALX148 until at least 2036, not including term adjustments or extensions.

BURLINGAME, Calif., April 05, 2021 (GLOBE NEWSWIRE) — ALX Oncology Holdings Inc., (“ALX Oncology”) (Nasdaq: ALXO), a clinical-stage immuno-oncology company developing therapies that block the CD47 checkpoint pathway, announces that the post-grant review period for granted U.S. Patent No. 10,696,730 ended on March 30, 2021. This patent covers the lead product candidate ALX148, a next generation CD47-blocking therapeutic that combines a high-affinity signal regulatory protein-alpha (“SIRP“) CD47-binding domain fused with an inactivated, proprietary Fc domain. The U.S. patent is not expected to expire before August 5, 2036, excluding patent term adjustments or extensions.

ALX Oncology’s engineered fusion protein ALX148 is designed to enhance the activity of a wide range of leading anti-cancer agents and has shown promising clinical activity in both solid tumors and hematologic malignancies. ALX148’s proprietary inactive Fc domain maintains antibody-like pharmacokinetics, while improving tolerability when compared to other CD47 blocking approaches and their associated cytopenias.

ALX148 has a lower molecular weight compared to a typical antibody, which enables it to deliver the molar equivalent of an antibody at one half the dose. This may facilitate increased solid tumor penetration and, coupled with ALX148’s very high affinity for CD47, may provide greater potency within the tumor microenvironment.

The U.S. Patent and Trademark Office (“USPTO”) issued U.S. Patent No. 10,696,730 on June 30, 2020, which is part of a portfolio covering ALX148 that includes U.S. Patent No. 10,259,859 granted on April 16, 2019. The latter patent covers sequences for a wide variety of high-affinity SIRP domains fused to inactivated Fc domains.

Jaume Pons, Ph.D., Founder, President and Chief Executive Officer of ALX Oncology commented, “We are excited about the grant of the ‘730 patent and the expiration of the post-grant review period as we prepare to initiate randomized Phase 2 studies in myelodysplastic syndromes, gastric/gastroesophageal junction cancer, and head and neck squamous cell carcinoma. The USPTO’s issuance of this patent reinforces the strength of our intellectual property portfolio, and further supports our ongoing and planned clinical trials in treating patients with cancer.”

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 checkpoint pathway and bridge the innate and adaptive immune system. ALX Oncology’s lead product candidate, ALX148, is a next generation CD47 blocking therapeutic that combines a high-affinity CD47 binding domain with an inactivated, proprietary Fc domain. ALX148 has demonstrated promising clinical responses across a range of hematologic and solid malignancies in combination with a number of leading anti-cancer agents. ALX Oncology intends to continue clinical development of ALX148 for the treatment of a range of solid tumor indications as well as MDS and AML. For more information, please visit ALX Oncology’s website at www.alxoncology.com.

Cautionary Note Regarding Forward-Looking Statements
This press release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, as amended. Such forward-looking statements are based on ALX Oncology’s beliefs and assumptions and on information currently available to it on the date of this press release. Forward-looking statements may involve known and unknown risks, uncertainties and other factors that may cause ALX Oncology’s actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. These and other risks are described more fully in ALX Oncology’s filings with the Securities and Exchange Commission (“SEC”), including ALX Oncology’s Annual Report on Form 10-K, filed with the SEC on March 18, 2021, and other documents ALX Oncology subsequently files with the SEC from time to time. Except to the extent required by law, ALX Oncology undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.