Abstract
Nivolumab is a programmed cell death 1 (PD-1) receptor inhibitor antibody that enhances immune system antitumor activity. Although it is used for treating advanced non-small-cell lung cancer (NSCLC), its actual efficacy has not been determined. We searched PubMed, the Cochrane Library, Embase, MEDLINE, and Web of Science for related noncomparative clinical studies and randomized controlled trials (RCTs) to assess nivolumab benefit and risk in NSCLC. The main outcomes were objective response rate (ORR), 1-year overall survival rate (1-yOS rate), and progression-free survival rate at 24 weeks (PFS at 24 weeks rate), any-grade adverse effects rate (any-grade AEs%), and grade 3-4 AE rate (grade 3-4 AEs%). Relative risk (RR) was used to compare ORR in patients with positive and negative programmed cell death ligand 1 (PD-L1) expression. Random-effects models were used to determine pooled effect size and two-sided 95% confidence intervals (95% CI). We included 20 studies (17 noncomparative open-label cohort studies, three RCTs) involving 3404 patients in our meta-analysis. The modified nivolumab ORR was 18% (95% CI: 15-20%), the 1-yOS rate was 45% (95% CI: 40-50%), PFS at 24 weeks rate was 42% (95% CI: 37-48%), any-grade AEs% was 61% (95% CI: 50-73%), and grade 3-4 AEs% was 12% (95% CI: 9-16%). PD-L1 expression was related with the nivolumab ORR. Nivolumab potentially causes ongoing response, long-term PFS, and reduced treatment-related AEs. PD-L1 expression predicts the outcome of nivolumab immunotherapy. More high-quality and well-designed RCTs with large sample sizes are warranted to prove our findings.