Efficacy and safety of enfortumab vedotin in older patients with metastatic urothelial carcinoma: A multicenter retrospective study

Introduction: We aimed to evaluate the efficacy and safety of enfortumab vedotin therapy for a cohort of older Japanese patients with metastatic urothelial carcinoma compared to younger patients. Materials and Methods: We retrospectively evaluated patients with metastatic urothelial carcinoma treated with enfortumab vedotin and recruited between April 2019 and February 2023. Older patients were defined as being ≥75 years old. Efficacy was evaluated by comparing overall survival, progression-free survival, and objective response rates between groups. Adverse events and relative dose intensity were also compared. Moreover, the prognostic factor for overall survival in the entire cohort was evaluated using multivariate analysis. Results: Of the 57 patients treated with enfortumab vedotin, 37 were younger and 20 were older, (median ages of 67.6 and 79.2, respectively). Median overall survival in older and younger patients was 407 and 365 days, respectively (P = 0.48). The objective response rate was 60.0 % and 54 % (P = 0.68) and median progression-free survival 228 and 223 days in older and younger patients, respectively (P = 0.76). Adverse events were equivalent between groups except for liver dysfunction, which frequently occurred in younger patients. The dose intensity for the older and younger patients did not differ (65.7 % vs. 63.5 %, P = 0.37, respectively). In multivariate analysis, neutrophil-to-lymphocyte ratio of 3 or more was the only risk factor for worse overall survival in the entire cohort (P = 0.04). Discussion: Our data demonstrated that enfortumab vedotin therapy can benefit older patients with metastatic urothelial carcinoma equivalent to younger patients without compromising safety profiles.