Gilead Sciences, Inc. and Arcus Biosciences, Inc. announced updated results from an interim analysis of the ARC-7 study in patients with first-line, metastatic non-small cell lung cancer (NSCLC) with PD-L1 tumor proportion score (TPS) =50% without epidermal growth factor receptor (EGFR) or anaplastic lymphoma kinase (ALK) mutations. ARC-7 is the first Phase 2, randomized, open-label study evaluating the combinations of Fc-silent anti-TIGIT monoclonal antibody domvanalimab plus anti-PD-1 monoclonal antibody zimberelimab (doublet) and domvanalimab plus zimberelimab and etrumadenant, an A2a/b adenosine receptor antagonist (triplet), versus zimberelimab monotherapy. These results will be presented on June 3, 2023, during the ASCO Plenary Series: Rapid Abstract Updates session by Melissa L. Johnson, M.D., Director, Lung Cancer Research, Sarah Cannon Research Institute, and Lead Investigator for the ARC-7 study.

Arcus will post the updated ARC-7 results, which will include the data presented at Dr. Johnson's session, as well as additional data, on its website on the corporate presentation page at 5:30pm PDT. At the time of data cutoff (DCO), February 7, 2023, safety and efficacy were evaluated in all patients randomized and treated (n=150). With a median follow-up time of approximately 18 months, both domvanalimab-containing study arms demonstrated sustained, clinically meaningful improvements in progression-free survival (PFS) compared to zimberelimab monotherapy, with a 33% reduction in risk of disease progression or death for the doublet and 28% for the triplet.

No unexpected safety signals were observed across the three study arms at the time of DCO. The domvanalimab-containing study arms appeared to be generally well tolerated and showed an overall safety profile consistent with the known safety profiles of each individual molecule to date. Incidence of infusion-related reactions was low across all treatment arms: 4%, 4% and 12% for zimberelimab monotherapy and the domvanalimab-doublet and -triplet arms, respectively.

The addition of domvanalimab to zimberelimab did not increase the incidence of infusion-related reactions, consistent with the Fc-silent design of domvanalimab. Domvanalimab, zimberelimab and etrumadenant are investigational molecules. Neither Gilead nor Arcus has received approval from any regulatory authority for any use globally, and their safety and efficacy for the treatment of lung cancer have not been established.