Which Is More Suitable for First-Line Treatment of Extensive-Stage Small Cell Lung Cancer, PD-L1 Inhibitors Versus PD-1 Inhibitors? A Systematic Review and Network Meta-Analysis

Abstract

Background: In this network meta-analysis (NMA), the efficiency and safety of PD-1 inhibitors + chemotherapy and PD-L1 inhibitors + chemotherapy were compared in the first-line therapy of patients with extensive-stage small cell lung cancer (ES-SCLC). Methods: We searched research databases, conference abstracts, and trial registries and subsequently chose relevant studies and extracted dates. The NMA was conducted to estimate the efficiency and safety of the PD-1 inhibitors + chemotherapy and PD-L1 inhibitors + chemotherapy on overall survival (OS), progression-free survival (PFS), overall remission rate (ORR), and adverse events (AEs). Studies were assessed for quality. Subgroup analyses were used to evaluate study heterogeneity. Results: We included six randomized trials with a total of 3163 patients. Direct comparisons showed that patients who received either PD-1 inhibitors + chemotherapy (HR: 0.71, 95% CI: 0.57–0.87) or PD-L1 inhibitors + chemotherapy (HR: 0.74, 0.61–0.89) demonstrated significantly longer OS than those who received placebo + chemotherapy. The results of the NMA showed that no significant differences in OS (HR 0.96 95% CI: 0.72–1.3), PFS (HR 0.83, 95% CI: 0.51–1.4), and ORR (OR 1.3 95% CI: 0.66–2.5) were observed for PD-1 inhibitors + chemotherapy compared with PD-L1 inhibitors + chemotherapy, but the Bayesian ranking revealed that patients receiving PD-1 inhibitors + chemotherapy tended to have longer OS, PFS benefit, and better treatment response than patients receiving PD-L1 inhibitors + chemotherapy. In terms of safety, no significant difference was observed in their safety profiles. Conclusion: In comparison to placebo + chemotherapy, PD-L1 inhibitors + chemotherapy and PD-1 inhibitors + chemotherapy significantly improved survival for ES-SCLC. According to the available data, PD-L1 inhibitors + chemotherapy and PD-1 inhibitors + chemotherapy had equivalent efficacy and safety; however, the level of evidence of this type of comparison is limited.