PD-1/PD-L1 inhibitors plus carboplatin and paclitaxel compared with carboplatin and paclitaxel in primary advanced or recurrent endometrial cancer: a systematic review and meta-analysis of randomized clinical trials.

Background: Paclitaxel and carboplatin is the standard chemotherapy for the treatment of advanced or recurrent endometrial cancer. However, the benefit of adding programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors to chemotherapy is still unclear.

Method: We searched PubMed, Scopus, Cochrane, and Web of Science databases for randomized controlled trials that investigated PD-1/PD-L1 inhibitors plus carboplatin and paclitaxel compared with carboplatin and paclitaxel in primary advanced or recurrent endometrial cancer. We computed hazard ratios (HRs) or risk ratios (RRs) for binary endpoints, with 95% confidence intervals (CIs). We used DerSimonian and Laird random-effect models for all endpoints. Heterogeneity was assessed using I statistics. R, version 4.2.3, was used for statistical analyses.

Results: A total of three studies and 1,431 patients were included. Compared with carboplatin plus paclitaxel-based chemotherapy, progression-free survival (PFS) rate (HR 0.32; 95% CI 0.23-0.44; p < 0.001) and overall survival (OS) at 30 months (RR 3.13; 95% CI 1.26-7.78; p = 0.01) were significant in favor of the PD-1/PD-L1 inhibitors plus carboplatin and paclitaxel group in the mismatch repair-deficient subgroup. However, there were no significant differences in the mismatch repair-proficient subgroup for PFS (HR 0.74; 95% CI 0.50-1.08; p = 0.117) or OS at 30 months (RR 2.24; 95% CI 0.79-6.39; p = 0.13).

Conclusion: Immunotherapy plus carboplatin-paclitaxel increased significantly PFS and OS among patients with advanced or recurrent endometrial cancer, with a significant benefit in the mismatch repair-deficient and high microsatellite instability population.