PD-1 inhibitors in advanced esophageal squamous cell carcinoma: a survival analysis of reconstructed patient-level data.

Background: Recently, a sum of trials of programmed cell death-1 (PD-1) inhibitors combined with chemotherapy have shown excellent efficacy compared to chemotherapy alone in patients with previously untreated, advanced esophageal squamous cell carcinoma (ESCC). However, there is no head-to-head comparison and consensus on which immunotherapy regimen results in better survival outcomes. This study aimed to evaluate the survival efficacy of various PD-1 inhibitor-based therapies in the first-line treatments for patients with advanced ESCC.

Methods: Data collected prior to 31 July 2023 were searched in the PubMed, Cochrane Library, Embase, Medline, and Web of Science databases. Overall survival (OS) and progression-free survival curves were pooled using the MetaSurv package. Survival data were compared by reconstructed individual patient data.

Results: A total of 4,162 patients and seven randomized controlled trials were included. After synthesizing, PD-1 inhibitors prolonged median OS from 11.3 months (95% CI (confidence interval) 10.7-11.7) to 15.6 months (95% CI 14.7-16.3). Based on reconstructed patient-level data, the toripalimab, tislelizumab, and sintilimab group achieved the longest OS, whereas the sintilimab and tislelizumab group had the lowest risk of recurrence than other treatments. In patients with a combined positive score of ≥10, sintilimab had better OS efficacy than pembrolizumab (HR: 0.71, 95% CI: 0.52-0.96). In terms of tumor proportion score of ≥1%, camrelizumab, nivolumab, and toripalimab showed proximate survival benefits in both OS and progression-free survival.

Conclusion: PD-1 inhibitor combined with chemotherapy significantly improved the survival time of patients with advanced ESCC. Toripalimab, tislelizumab, and sintilimab plus chemotherapy showed the best OS benefit. Longer progression-free benefits might be generated from adding tislelizumab and sintilimab to chemotherapy. Sintilimab was strongly recommended for patients with high programmed cell death-ligand 1 abundance.

Systematic Review Registration: [https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42024501086].