Clinical outcomes and treatment status in patients alive at 5 years by tumor PD-L1 expression level. PFS in randomly assigned patients with (A) tumor PD-L1 expression ≥ 1% or (B) tumor PD-L1 expression < 1%; ORR and DOR in randomly assigned patients with (C) tumor PD-L1 expression ≥ 1% or (D) tumor PD-L1 expression < 1%; treatment status at 5 years in treateda patients with (E) tumor PD-L1 expression ≥ 1% or (F) tumor PD-L1 expression < 1%. Kaplan-Meier curves are not shown for the PD-L1 < 1% chemotherapy arms because of small sample sizes. Ninety-five percent CIs for the nivolumab plus ipilimumab, nivolumab (PD-L1 ≥ 1%) or nivolumab plus chemotherapy (PD-L1 < 1%), and chemotherapy (PD-L1 ≥ 1% only) arms at 5-year landmarks, respectively, (A) 37 to 60, 36 to 64, and 4 to 28; (B) 30 to 68 and 23 to 71; (C) 40 to 66, 39 to 73, and 4 to 36; and (D) 14 to 66 and 23 to 72. aOne patient in the PD-L1 ≥ 1% nivolumab arm and 1 patient in the PD-L1 ≥ 1% chemotherapy arm were randomly assigned but not treated and are not included in the analysis of subsequent treatments. DOR, duration of response; HR, hazard ratio; NA, not available; NR, not reached; ORR, objective response rate; PD-L1, programmed death ligand 1; PFS, progression-free survival., In an early-phase study involving patients with advanced non–small-cell lung cancer (NSCLC), the response rate was better with nivolumab plus ipilimumab than with nivolumab monotherapy , Abstract Purpose: We present 5-year results from CheckMate 227 Part 1, in which nivolumab plus ipilimumab improved overall survival (OS) versus chemotherapy in patients with metastatic non-small-cell lung cancer, regardless of tumor programmed death ligand 1 (PD-L1) status..