ALX Oncology's experimental CD47-blocking therapy, evorpacept, has demonstrated compelling efficacy in treating HER2-positive gastric and gastroesophageal junction tumors, according to updated results from the ASPEN-06 Phase 2 clinical trial presented at the 2025 American Society of Clinical Oncology Gastrointestinal Tumors Symposium.
The trial revealed significant improvements in multiple clinical endpoints when comparing evorpacept to standard treatment. Patients receiving evorpacept achieved an overall response rate (ORR) of 48.9%, nearly triple the 24.5% observed in the control group receiving the standard combination of trastuzumab, ramucirumab, and paclitaxel.
Improved Survival Metrics
The study demonstrated meaningful advances in key survival metrics. Median progression-free survival reached 7.5 months in the evorpacept group, compared to 6.7 months in the control arm. More notably, patients showed a substantially longer duration of response at 15.7 months, significantly exceeding the 9.1 months observed in the control group.
Safety Profile and Clinical Implications
Dr. Kohei Shitara, a principal investigator in the trial, emphasized the therapy's particular significance for patients who have previously undergone HER2-targeted treatments. "These results represent a potentially important advancement in the treatment landscape for HER2-positive gastric cancer patients," noted Dr. Shitara.
The safety analysis revealed that evorpacept was generally well-tolerated, with an adverse event profile comparable to the control regimen. Dr. Alan Sandler, Chief Medical Officer of ALX Oncology, highlighted the treatment's innovative design, noting its efficient combination with anti-HER2 antibodies to enhance therapeutic outcomes.
Regulatory Status and Future Direction
The drug's promising results are backed by significant regulatory support. The U.S. Food and Drug Administration has granted Fast Track designation to evorpacept for second-line treatment of HER2-positive gastric and gastroesophageal junction tumors. Additionally, both the FDA and European Commission have awarded the therapy Orphan Drug Designation for this indication.
Building on these positive results, ALX Oncology plans to initiate regulatory discussions with the FDA to determine the next steps in bringing this potential new treatment option to patients.
