First-line Pembrolizumab Versus Pembrolizumab Plus Chemotherapy Versus Chemotherapy Alone in Non–small-cell Lung Cancer: A Systematic Review and Network Meta-analysis

This study aimed to comprehensively review the available evidence regarding the efficacy of first-line pembrolizumab for advanced/metastatic non-small-cell lung cancer (NSCLC), and to compare pembrolizumab monotherapy versus pembrolizumab plus chemotherapy versus chemotherapy alone.A search of the PubMed, EMBASE, and Cochrane Library databases was performed in July 2018, and abstracts from the American Society of Clinical Oncology meetings (2015-2018) were reviewed. Summaries of the results were pooled using a random-effect model to determine the pooled hazard ratio (HR) for progression-free survival (PFS), overall survival (OS), and their 95% confidence intervals (CIs). A network meta-analysis was used to indirectly compare pembrolizumab monotherapy with pembrolizumab plus chemotherapy.A total of 4 relevant phase III trials comprising 2754 patients were identified. Pembrolizumab (with or without chemotherapy) led to significant improvements in OS and PFS, irrespective of the programmed cell death ligand 1 (PD-L1) tumor proportion score (TPS). In particular, for the subgroup with PD-L1 TPS ≥ 50%, the HR of PFS was 0.49 (95% CI, 0.32-0.76; P = .001), and that of OS was 0.57 (95% CI, 0.45-0.73; P < .001). In terms of PFS, pembrolizumab plus chemotherapy was superior to pembrolizumab monotherapy with an HR of PFS 0.52 (95% CI, 0.27-0.99; P = .048) for the subgroup with PD-L1 TPS ≥ 50%.For patients with NSCLC with PD-L1 TPS ≥ 50%, pembrolizumab plus chemotherapy has a better PFS than pembrolizumab monotherapy in this meta-analysis. To confirm this finding, a prospective phase III trial that directly compares the treatments is warranted.