PD-1/PD-L1 Immune Checkpoint Inhibitors after Platinum-based Chemotherapy in Metastatic or Locally Advanced Urothelial Bladder Carcinoma: A Systematic Review and Meta-analysis

Abstract

Objective: This study aimed to assess the effect of anti-programmed cell death-1/programmed cell death-ligand-1 (PD-1/PD-L1) agents compared with second-line therapy in patients with metastatic or locally advanced urothelial bladder carcinoma following previous platinum-containing chemotherapy.Material and Methods: We systematically searched three electronic databases. The protocol of the study was registered in Prospero (CRD42019142494). Using the Grading of Recommendations Assessment, Development, and Evaluation approach, the certainty of evidence (CoE) was estimated.Results: The search results initially found 8168 publications. For qualitative synthesis, two publications were included. Pooled results indicated that patients treated with anti-PD-1/PD-L1 agents had significantly prolonged overall survival (hazard ratio (HR) 0.80; 95% confidence interval (CI) 0.7-0.9; I2 21.0%; moderate CoE). According to positive PD-L1 expression, PD-1/PD-L1 inhibitors had significantly more survival than chemotherapy (HR 0.75; 95% CI 0.5-0.9, I2 57.0%, low CoE). Furthermore, there was no significant difference in adverse events (AE) between the anti-PD-1/PDL1 agents and second-line chemotherapy (risk ratio 0.68; 95% CI 0.3-1.4; I2 97.0%, low CoE).Conclusion: The present meta-analysis and systematic review provide strong evidence that anti-PD-1/PD-L1 agents could improve overall survival and have similar results in AEs compared with second-line chemotherapy. Further studies will confirm the power of immunotherapy for the treatment of metastatic or locally advanced urothelial bladder carcinoma.