Randomization and blinding
Eligible patients were randomized 1:1 via blocking using an interactive web response system (RAMOS NG), to receive chemotherapy in combination with either dostarlimab or pembrolizumab. Patients, relevant study staff, and investigators were blinded to study treatment; details of blinding were documented in site-specific blinding plans. Randomization was stratified by PD-L1 status (TPS < 1% vs 1–49% vs ≥50%) and smoking status (never vs former/current).