ALX Oncology Holdings Inc., ("ALX Oncology") (NASDAQ: ALXO), a clinical-stage immuno-oncology company developing therapies to block the CD47 checkpoint pathway, today announced the presentation of initial clinical data from its ongoing trial evaluating evorpacept in combination with azacitidine for the treatment of patients wiALX Oncology Holdings Inc., (“ALX Oncology”) (NASDAQ:ALXO), a clinical-stage immuno-oncology company developing therapies to block the CD47 checkpoint pathway, today announced the presentation of initial clinical data from its ongoing trial evaluating evorpacept in combination with azacitidine for the treatment of patients with previously untreated higher-risk (“HR”) or relapsed or refractory (“r/r”) myelodysplastic syndrome (“MDS”). The new results, shared in a poster at the 63rd American Society of Hematology (“ASH”) Annual Meeting [Abstract #2601], show that the combination of evorpacept and azacitidine is active and well tolerated. As of October 25, 2021, 22 patients with either previously untreated HR or r/r MDS have been treated with evorpacept in the Phase 1 dose escalation part of the study, administered at 20 mg/kg or 30 mg/kg once every 2 weeks (“Q2W”) or 60 mg/kg once every 4 weeks (“Q4W”) together with standard dosing of azacitidine. Median follow-up is 3.4 months, and accrual is ongoing.

Evorpacept in combination with azacitidine was well tolerated (N=22) with no dose limiting toxicities, no observed treatment related serious adverse events, and a maximum administered dose of 60 mg/kg Q4W.
In 6 previously untreated HR MDS response-evaluable patients, 3 patients achieved an objective response (“OR”) (2 complete response (“CR”), 1 marrow CR), and 2 patients achieved stable disease (“SD”). Two out of 4 transfusion dependent patients achieved transfusion independence on study.
Among 5 previously untreated HR MDS patients with TP53 mutation and complex cytogenetic abnormalities, 3 achieved an OR (2 CR and 1 marrow CR).
Five of 9 patients with response-evaluable relapsed or refractory MDS that had progressed upon prior hypomethylating agents achieved an OR (5 marrow CRs). In addition, 2 patients achieved SD.

“Evorpacept’s preliminary clinical activity seen in patients with a difficult to treat subset of MDS including disease with TP53 mutation, poor risk cytogenetics, and progression on prior hypomethylating agent regimens, is encouraging,” said Guillermo Garcia-Manero M.D., Professor, Department of Leukemia, at MD Anderson Cancer Center, Houston, TX. “Additionally, evorpacept’s favorable initial tolerability profile in combination with azacitidine suggests it may be safely added without worsening cytopenias, which is particularly notable for this patient population.”

“The initial tolerability and activity of evorpacept seen in ASPEN-02 further support CD47 as a relevant therapeutic target in patients with MDS,” said Sophia Randolph M.D., Ph.D., Chief Medical Officer, ALX Oncology. “Evaluation of evorpacept in our myeloid malignancy program including studies in both MDS and acute myeloid leukemia is built on a strong scientific rationale and we are pleased to now also see initial clinical data supporting its role in enhancing the innate immune anti-cancer response.”

Conference Call on December 13th at 8:00 a.m. EST

ALX Oncology will host a conference call on Monday, December 13, 2021 at 8:00 a.m. EST to further discuss the initial MDS data from ASPEN-02. In addition to ALX Oncology’s executive management team, Dr. Guillermo Garcia-Manero, Professor, Department of Leukemia, at MD Anderson Cancer Center, Houston, TX will be featured on the call to discuss the emerging clinical data in MDS patients.

To access the conference call, please dial (844) 467-7655 (U.S./Canada) or (409) 983-9840 (international) at least 10 minutes prior to the start time and refer to conference ID 7598031. Presentation slides will be available to download under “News & Events” (see “Events”) in the Investors section of the ALX Oncology website at www.alxoncology.com.