First-line PD-1/PD-L1 inhibitor plus chemotherapy vs chemotherapy alone for negative or < 1% PD-L1-expressing metastatic non-small-cell lung cancers

Aims Single-agent anti-PD-1/PD-L1 clinical efficacy against < 1% PD-L1-expressing non-small-cell lung cancers (NSCLCs) is controversial. Methods This meta-analysis examined randomized-trial data comparing first-line PD-1/PD-L1-inhibitor + chemotherapy (CT) vs CT alone for advanced < 1% PD-L1 NSCLCs. Outcome measures included overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). Results IMpower (atezolizumab + CT), Keynote (pembrolizumab + CT) and CheckMate (nivolumab + CT) trials included 2037 NSCLCs (1246 PD-L1-negative; 791 < 1% PD-L1 expression). Anti-PD-1/PD-L1 + CT was significantly associated (hazard ratio [95% confidence interval]) with prolonged OS (0.75 [0.63-0.89]; p = 0.0008) and PFS (0.72 [0.65-0.80]; p < 0.0001), and higher ORR (odds ratio 2.06 [1.50-2.83]; p < 0.0001). Conclusions First-line anti-PD-1/PD-L1 + CT combination appears superior to CT alone for advanced, < 1% PD-L1-expressing NSCLCs for OS, PFS and ORR.