DISCUSSION
tumor, PD‐L1
TUMOR
We performed updated analyses of treatment‐naïve patients with advanced nsNSCLC without driver mutations who were enrolled in a placebo‐controlled randomized trial in three Asian countries. At the data cutoff at which time the minimum follow‐up was 19.4 months, the nivolumab arm showed longer OS vs. placebo (HR 0.74, 95% CI 0.58–0.94). This compares with an HR of 0.85 in the primary analysis, which had a shorter minimum follow‐up (7.4 months). These findings expand on our prior analysis,To our knowledge, this is the first randomized, placebo‐controlled trial to reveal a survival benefit of an anti–PD‐1 antibody (nivolumab) administered together with bevacizumab and chemotherapy as initial, first‐line therapy of advanced nsNSCLC. An improvement in the tumor microenvironment may be conferred through synergistic effects of bevacizumab and nivolumab.When patients were divided into subgroups by tumor PD‐L1 expression level, we observed a significant OS benefit in the PD‐L1 1%–49% group and a fair OS benefit in the <1%/indeterminate and ≥ 50% groups. This is inconsistent with the prior data showing that the PFS benefit was observed regardless of the PD‐L1 expression level, and that the PD‐L1 1%–49% group had the lowest numerical PFS benefit.The effects of first‐line atezolizumab combined with PCB for treating wild‐type metastatic nsNSCLC were recently reported in a Phase III study.The main limitation of this updated survival analysis is that only OS data were obtained; PFS and safety data were not updated. Further follow‐up of OS, PFS, and safety and future analyses are needed to comprehensively discuss the benefits of nivolumab.In conclusion, nivolumab plus PCB provided superior OS vs. placebo plus PCB for the initial (first‐line) treatment of patients with metastatic nsNSCLC. Therefore, we believe that nivolumab plus PCB is a viable new option for the initial treatment of metastatic nsNSCLC without driver mutations in 