Outcomes of metastatic urothelial carcinoma following discontinuation of enfortumab-vedotin.

ABSTRACT Background Enfortumab vedotin (EV) is approved to treat metastatic urothelial carcinoma (mUC) following platinum and PD1/L1 inhibitors. Since the outcomes and patterns of therapy of patients following discontinuation of EV are unknown, we conducted a retrospective study to assess this issue. Methods Data were retrospectively obtained from patients with mUC following discontinuation of EV after prior platinum-based chemotherapy and PD1/L1 inhibitors. Objective response rate (ORR) was evaluated in those who received therapy post-EV. Statistical analyses were performed to describe the overall survival (OS) and compare patient characteristics and outcomes of those who did or did not receive treatment post-EV. Results Data were available for 63 patients from 6 institutions: 46 (73%) were male and median age was 68 years (range 43-83). The median OS was 32 weeks. Thirty-two patients (51%) received therapy after EV. The OS of those who did vs did not receive post-EV therapy was significantly different (median 43.1 vs. 16.9 weeks, p=0.015). Longer duration of prior EV therapy was associated with receipt of post-EV therapy (p=0.0437) as well as OS in both the treated (p=0.045) and untreated groups (p=0.012). Objective response was observed in 3 of 32 patients (9.4%) who received therapy post-EV. Conclusion Outcomes of patients with mUC following discontinuation of EV are dismal and only 51% received therapy after discontinuation of EV. This study identifies benchmarks for the interpretation of activity of new agents following EV and raises the hypothesis for duration of EV as a potential prognostic factor following discontinuation of EV. MICROABSTRACT This retrospective study demonstrates poor outcomes of metastatic urothelial carcinoma patients following discontinuation of Enfortumab Vedotin (EV). Only 51% received therapy after discontinuation of EV. Benchmarks for the interpretation of activity of new agents following EV were identified. The duration of EV was identified as a potential prognostic factor following discontinuation of EV.