[ANALYSIS OF THE ASSOCIATION BETWEEN IMMUNE-RELATED ADVERSE EVENTS AND THE EFFICACY OF PEMBROLIZUMAB IN PATIENTS WITH METASTATIC UROTHELIAL CARCINOMA].

(Objectives) We evaluated the association between immune-related adverse events (irAEs) and the efficacy of pembrolizumab therapy in patients with metastatic urothelial carcinoma. (Methods) Data of 42 patients with metastatic urothelial carcinoma treated with pembrolizumab between May 2018 and February 2020 were retrospectively analyzed to determine the association between irAEs and objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). (Results) IrAEs were observed in 19 patients (45.2%). Objective response was observed in 15 patients (35.7%). Thirteen (68.4%) of 19 patients who experienced irAEs showed an objective response, whereas two (8.70%) of 23 patients who did not experience irAEs (odds ratio: 15.0, 95% confidence interval [CI]: 1.70-738, P=0.006). PFS and OS in the irAE group were longer than those in the non-irAE group (PFS: hazard ratio: 0.24, 95% CI: 0.11-0.54, P<0.001; OS: hazard ratio: 0.11, 95% CI: 0.03-0.37, P<0.001). (Conclusions) During pembrolizumab treatment, the occurrence of irAEs was significantly associated with higher response and survival prolongation in patients with metastatic urothelial carcinoma.