ARC-7: Randomized phase 2 study of domvanalimab + zimberelimab ± etrumadenant versus zimberelimab in first-line, metastatic, PD-L1-high non-small cell lung cancer (NSCLC).

Abstract

397600 Background: While PD-1 inhibitors demonstrated survival benefit compared to chemotherapy in patients (pts) with PD-L1-high, NSCLC, less than half of pts respond to monotherapy. Novel therapeutics or combinations are necessary to improve outcomes. Domvanalimab (D) is an Fc-silent humanized IgG1 monoclonal antibody (mAb) that blocks T cell Immunoglobulin and ITIM domain (TIGIT), thereby reducing immunosuppression of T/NK cells and promoting antitumor activity. Etrumadenant (E) is a selective dual antagonist of both A2a and A2b receptors (R) expressed on immune cells thereby reducing immunosuppressive extracellular adenosine. ARC-7 evaluates whether inhibition of TIGIT and adenosine pathways augments activity of zimberelimab (Z) (anti-PD-1 mAb) in pts with PD-L1-high NSCLC. Methods: ARC-7 (NCT04262856) is a randomized, open-label phase 2 clinical trial which enrolled treatment-naïve pts with Stage IV, squamous or non-squamous NSCLC with locally assessed high PD-L1 expression (TPS ≥ 50%), no EGFR or ALK alterations, and ECOG PS ≤1. Pts were randomized (1:1:1) to: Arm 1 (Z): Z 360 mg intravenously (IV) every 3 weeks (Q3W); Arm 2 (DZ): D 15 mg/kg IV Q3W + Z; Arm 3 (EDZ): E 150 mg orally once daily + DZ. Pts in Arm 1 with confirmed progression had the option to cross over to EDZ. Co-primary endpoints were overall response rate (ORR) and progression-free survival (PFS) per RECIST v1.1. Results: As of 31 August 2022, 149 pts received at least one dose of study treatment. Efficacy for this interim analysis included 133 pts randomized at least 13 weeks prior to data cut-off (ITT-13), allowing for ≥ 2 post-baseline scans. With median follow-up of 11.8 months (mo), D-containing arms, demonstrated improved ORR and PFS compared to Z. In the safety population, grade ≥3 treatment-emergent adverse events occurred in 58% (Z), 47% (DZ), and 52% (EDZ). All cases of rash were grade 1-2, manageable with topical corticosteroids, and more common in EDZ (Table). Conclusions: In the first published, randomized dataset evaluating an Fc-silent TIGIT mAb, both D containing arms demonstrated clinically meaningful improvement in ORR and PFS compared to Z. Treatment with Z, DZ and EDZ was well tolerated, and the safety profiles of D-containing arms were similar to Z. Ongoing phase 3 trials are evaluating DZ compared to standard of care in metastatic NSCLC. Clinical trial information: NCT04262856. [Table: see text]