Breakthrough Data: Anti-TIGIT Therapy Domvanalimab Combination Extends Survival Beyond One Year in Upper GI Cancer Patients

Gilead Sciences and Arcus Biosciences have unveiled compelling clinical evidence that their investigational treatment regimen significantly improves survival outcomes for patients with advanced upper gastrointestinal cancers. The combination therapy, pairing the anti-TIGIT antibody domvanalimab with anti-PD-1 monoclonal antibody zimberelimab and standard chemotherapy, demonstrated a median progression-free survival exceeding 12 months in the Phase 2 EDGE-Gastric trial—a meaningful improvement over historical anti-PD-1 chemotherapy benchmarks.

Key Clinical Findings

The updated trial data evaluated 41 patients with locally advanced unresectable or metastatic gastric, gastroesophageal junction, or esophageal adenocarcinoma. Results showed that approximately 60% of patients maintained progression-free survival at the one-year mark, with a median treatment duration of 49.4 weeks. Notably, the therapeutic benefit remained consistent across patient subgroups, including those with low PD-L1 expression—a patient population traditionally considered harder to treat with immunotherapy alone.

Advancing Toward Phase 3 Development

These encouraging results from the Phase 2 EDGE-Gastric study have reinforced confidence in the ongoing Phase 3 STAR-221 trial, which evaluates the same three-drug regimen in the same patient population. The Phase 3 trial potentially represents the first anti-TIGIT combination therapy to reach the market for these cancer types, addressing a significant unmet clinical need for patients with advanced upper GI malignancies.

According to Dr. Yelena Y. Janjigian, Chief of Gastrointestinal Oncology at Memorial Sloan Kettering Cancer Center and principal investigator for the EDGE-Gastric study, the consistency of efficacy measures and safety profile observed in the trial provides a solid foundation for confirming these benefits in a larger patient population. The data were presented at the American Society of Clinical Oncology (ASCO) Annual Meeting, underscoring the clinical significance of this immunotherapy combination approach.