Objective: To compare the relative efficacy of immune checkpoint inhibitors (ICIs) or chemotherapy (CT) alone, or their combination modality in the first-line treatment of advanced nonsmall cell lung cancer (NSCLC).
Methods: This meta-analysis was performed on the eligible randomized controlled trials (RCTs) after searching web databases and meeting abstracts. The main research endpoints were the comparisons of median overall survival (mOS), the OS rate of 6 months (OSR6m), 1 year (OSR1y) and 2 years (OSR2y), median progression-free survival (mPFS), the PFS rate of 6 months (PFSR6m) and 1-year (PFSR1y), objective response rates (ORR), and treatment-related adverse events (TRAEs).
Results: Eleven RCTs comprising 6278 cases were included. In the subgroup of programmed death-ligand 1 (PD-L1) ≥50%, compared with chemotherapy, the ICIs showed similar OSR6m (P > 0.05), but significantly improved efficacy in mOS, OSR1y, OSR2y, and ORR (all P < 0.05), also had less grade ≥ 3 TRAEs. Compared with pembrolizumab alone, pembrolizumab plus CT in the subgroup of PD-L1 ≥ 50% had similar mOS, OSR6m, OSR1y, and PFSR1y (all P > 0.05), but significantly improved mPFS, PFSR6m, and ORR (all P < 0.05 for interaction). Compared with the CT group, ICIs plus CT group with PD-L1 ≥ 50% or <1% showed significant benefit in OS, PFS, and ORR (all P < 0.05). However, in the ICIs plus CT group with 1% ≤ PD-L1 ≤ 49%, only PFS and ORR showed significant benefit compared with CT group (all P < 0.05), but not for results of OS.
Conclusions: The findings support the rationale for using pembrolizumab alone in the first-line treatment of PD-L1 ≥ 50% advanced NSCLC due to the similar OS and lower grade ≥ 3 TRAEs. However, the combination of ICIs and chemotherapy is strongly recommended in patients with PD-L1 ≤ 49% for significant survival benefit.
Keywords: chemotherapy; immunotherapy; meta-analysis; nonsmall cell lung cancer; programmed death-ligand 1.
© 2019 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.