Eligible pts with systemic treatment-naïve, advanced or metastatic NSCLC, PD-L1 TPS ≥50%...were enrolled and randomized 2:1 to IBI939 20 mg/kg plus sintilimab 200 mg IV Q3W (arm A) or sintilimab 200 mg monotherapy IV Q3W (arm B)...among 40 response-evaluable NSCLC pts (27 in arm A vs 13 in arm B), the confirmed ORR was 66.7% (95% CI, 46.0-83.5) vs 61.5% (95% CI, 31.6-86.1)(arm A vs B)....The median PFS was not reached (95% CI, 6.8-NA) in arm A vs 6.0 months (95% CI, 1.4-NA) in arm B (HR: 0.43; 95% CI, 0.17-1.10)....IBI939 plus sintilimab demonstrated improved PFS benefit and manageable safety profile in PD-L1 TPS ≥ 50% NSCLC patients with no prior systemic treatment.