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

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.