Effectiveness and safety profile of pembrolizumab for metastatic urothelial cancer: A retrospective single-center analysis in Japan

Background The paradigm of medical treatment for metastatic urothelial carcinoma is dramatically changing through the introduction of pembrolizumab. Aim We investigated the treatment effectiveness, the safety profile, and the prognostic factors of pembrolizumab in Japanese real-world clinical practice. Methods and results The medical records of 74 consecutive Japanese patients with metastatic urothelial cancer (UC), who started pembrolizumab as a second- or later-line treatment at our institution between January 2018 and March 2020, were reviewed and statistically analyzed. The median follow-up period after initiation of pembrolizumab was 8.5 (interquartile range: 3.5-15.7) months. The objective response rate was 30.2%, the median progression-free survival period was 4.9 months, and the median overall survival (OS) period was 13.3 months. Evaluation revealed that 39 (52.9%) patients experienced adverse events (AEs), among whom eight patients (10.9%) had severe AEs (grade 3 or more), including grade 5 hemophagocytic syndrome. Multivariate analysis indicated that the presence of liver metastasis, worse performance status (>= 2), elevated serum lactate dehydrogenase, and increased C-reactive protein were predictive of shorter OS. Conclusion We studied the effectiveness and safety profile of pembrolizumab therapy in Japanese UC patients. We believe that the data presented here will be useful for clinical physicians.