Current evidence of PD-1 and PD-L1 immune checkpoint inhibitors for esophageal cancer: an updated meta-analysis and synthesis of ongoing clinical trials.

Abstract

Esophageal cancer (EC) is the sixth leading cause of cancer mortality worldwide, with a poor prognosis and a 5-year survival rate of 5% in advanced cases. To evaluate the efficacy of programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors in EC patients by analyzing phase III clinical trials. A meta-analysis following the PRISMA Statement 2020 guidelines. PubMed/MEDLINE, Web of Science, and Embase were searched through 6 December 2022, and the analysis was conducted using Review Manager 5.4.3 (Cochrane). Out of 387 studies, 13 phase III clinical trials with 6519 participants were pooled. Overall survival (OS) favored PD-1/PD-L1 inhibitors with a Cohen's d of 0.28 (95% CI: 0.12-0.43; p = 0.0006), and the likelihood of achieving objective response also favored these inhibitors (OR: 2.04, 95% CI: 1.68-2.48; p < 0.0001). This meta-analysis provides strong evidence that PD-1/PD-L1 inhibitors combined with chemotherapy improve OS and objective response rate among patients with advanced EC but do not affect progression-free survival. Open Science Framework: osf.io/y27rx.