Gilead, Arcus announce data supporting ongoing Phase 3 STAR-221 study

Gilead Sciences (GILD) and Arcus Biosciences (RCUS) announced longer-term efficacy and safety results from Arm A1 of the Phase 2 EDGE-Gastric study. These updated data show consistent objective response rate and provide mature progression-free survival in patients with locally advanced unresectable or metastatic gastric, gastroesophageal junction or esophageal adenocarcinoma. The ongoing, multi-arm, global Phase 2 EDGE-Gastric study is evaluating the safety and efficacy of various combinations of the Fc-silent anti-TIGIT antibody domvanalimab plus the anti-PD-1 monoclonal antibody zimberelimab and chemotherapy in this patient population. At data cutoff, safety and efficacy were evaluated in all patients enrolled and treated. With a median time on treatment of 49.4 weeks, the domvanalimab plus zimberelimab and chemotherapy regimen demonstrated sustained improvement across efficacy measures, including in those patients who have low PD-L1 expression. No unexpected safety signals were observed at the time of DCO. The domvanalimab plus zimberelimab and chemotherapy regimen was generally well tolerated and showed an overall safety profile consistent with the known safety profiles of each individual molecule to date. Infusion-related reactions were observed in 19.5% of the total subjects, and the majority were related to chemotherapy. The updated data from Arm A1 of the Phase 2 EDGE-Gastric study support the ongoing Phase 3 STAR-221 study, in unresectable or metastatic upper GI cancers, which is expected to complete enrollment mid-year 2024.