ALX Oncology Reports Positive Interim Phase 2 ASPEN-06 Clinical Trial Results

SOUTH SAN FRANCISCO, Calif., Oct. 03, 2023 (GLOBE NEWSWIRE) — 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 positive prespecified interim Phase 2 data from its ASPEN-06 clinical trial, a randomized multi-center international study evaluating evorpacept, the Company’s CD47 blocking therapeutic, in combination with trastuzumab, CYRAMZA® (ramucirumab) and paclitaxel for the treatment of patients with HER2-positive gastric/gastroesophageal junction (“GEJ”) cancer. This prespecified interim analysis represents results from 54 randomized patients with second and third line gastric/GEJ cancer, including a meaningful number of patients previously treated with ENHERTU® (trastuzumab deruxtecan) and checkpoint inhibitors. Patients were treated with evorpacept at 30 mg/kg every two weeks, mirroring the treatment cycle of trastuzumab, CYRAMZA and paclitaxel.

Phase 2 ASPEN-06 Interim Analysis Results:

  • A confirmed overall response rate (“ORR”) of 52% was demonstrated for evorpacept in combination with trastuzumab + CYRAMZA + paclitaxel compared to 22% for the control group of trastuzumab + CYRAMZA + paclitaxel.
  • Median duration of response (“mDOR”) was not reached for the evorpacept combination treatment arm compared to 7.4 months for the control group.
  • The safety profile of evorpacept was consistent with previous clinical trials and was well-tolerated.
  • These interim results compare favorably to the efficacy reported for CYRAMZA + paclitaxel in the RAINBOW study (ORR of 28% and mDOR of 4.4 months), which is the regulatory benchmark and global standard of care for second line gastric/GEJ cancer.

“The ASPEN-06 clinical trial validates the potential of evorpacept both in solid tumors and in combination with anti-cancer antibodies and these data highlight the drug’s potential as a first-in-class foundational immunotherapy,” said Sophia Randolph, M.D., Ph.D., Chief Medical Officer, ALX Oncology. “We are highly encouraged by these initial randomized efficacy and safety results in gastric cancer that build upon the activity previously seen in our first-in-human study and represent the first positive randomized clinical trial data presented for any CD47 blocker. In addition, ASPEN-06 is the first global randomized study in HER2-positive gastric cancer where prior KEYTRUDA® (pembrolizumab) and ENHERTU were allowed. We look forward to reporting the final analysis from the ongoing Phase 2 ASPEN-06 study in Q2 2024 and plan to initiate the Phase 3 portion of ASPEN-06 in late 2024.”

“These data in gastric cancer represent the first positive initial result in a randomized trial setting of blocking the CD47 immune checkpoint pathway with a CD47 blocker that has an inactive Fc effector function in order to treat patients living with advanced gastric cancer,” said Keun Wook Lee, M.D., Ph.D., Professor at Seoul National University College of Medicine and ASPEN-06 Principal Investigator. “Patients with advanced disease face poor outcomes following progression on initial treatment with HER2-directed therapy. Evorpacept could represent a breakthrough in therapy and a potential paradigm shift in the gastric cancer care continuum.”