Organ-Specific Tumor Response to Enfortumab Vedotin for Metastatic Urothelial Carcinoma: A Multicenter Retrospective Study

Abstract

IntroductionTo evaluate the organ-specific therapeutic effect of enfortumab vedotin (EV) after chemotherapy and immunotherapy failed for advanced urothelial carcinoma. Materials methodsAt 6 institutions between December 2021 and July 2023, we retrospectively analyzed patients with metastatic upper and lower urinary tract cancer who received EV monotherapy after platinum-based chemotherapy and immune checkpoint blockade therapy. Objective response rate (ORR) and organ-specific response rate (OSRR) were evaluated according to the Response Evaluation Criteria in Solid Tumors, version 1.1. ResultsThis study analyzed 58 patients with 210 tumor lesions, of which 24% were females and 48% had upper urinary tract cancer. The ORR and disease control rate were 53.5% and 74.1%. Moreover, we found 15 target lesions in the primary site, 7 in local recurrence, 93 in the lymph nodes, 46 in the lung, 29 in the liver, and 20 in the bone, with OSRRs of 40%, 71.4%, 61.1%, 70.6%, 90.9%, and 18.2%, respectively. Over time from baseline, the reduction rate (median) in tumor burden was 50% or more in the lymph node, lung, and liver metastases. ConclusionThe organ-specific tumor response to EV in patients with metastatic urothelial carcinoma was almost favorable. The antitumor activity of EV monotherapy may be less in bone metastasis than in other organ sites. Conversely, EV showed remarkably high efficacy against liver metastasis.