OBJECTIVES: This study involves meta-analysis aiming to evaluate the effectiveness and safety of pembrolizumab monotherapy as first-line treatment for programmed death-ligand 1 (PD-L1) positive advanced or metastatic non-small cell lung cancer (NSCLC).

METHODS: Data was collected from eligible studies identified through a systematic search of PubMed, Europe PMC, ClinicalTrials.gov, Google Scholar, conference proceedings from ASCO, ESMO, and WCLC congress (2021-2023), and references of relevant systematic reviews up to November 2023. The observational studies evaluating the overall survival (OS), progression-free survival (PFS), objective response rate (ORR), or safety were included. However, the studies assessing only geriatric patients or patients with extremely high PD-L1 tumor proportion scores were excluded. The National Institutes of Health (NIH) quality assessment tool for observational studies was used to assess the quality of included studies. A single-arm meta-analysis was performed in R software using a standard random-effects model. Cochran’s Q-test and I² statistics were estimated to assess heterogeneity across studies.

RESULTS: Twenty-five studies with 7,293 patients were included in the meta-analysis. The pooled OS rates at 6, 12, and 36 months were 69%, 45%, and 38%, respectively. The corresponding pooled PFS rates were 60%, 33%, and 20%. The pooled ORR was 46%. The evidence revealed all-grade treatment-related adverse events (TRAEs), immune-related adverse events (IRAEs), and pneumonitis to be 37%, 54%, and 22%, respectively. The respective incidence rates of grade ≥3 adverse events (AEs) were 12%, 7%, and 5%. Fifteen percent of patients discontinued pembrolizumab due to AEs. The funnel plots revealed no to minimal levels of publication bias visually.

CONCLUSIONS: Real-world evidence for the effectiveness and safety of pembrolizumab is consistent with the findings of KEYNOTE-024 and KEYNOTE-042 trials. The congruence of results lends support to the use of pembrolizumab monotherapy as a first-line treatment for improving outcomes in advanced or metastatic NSCLC.