Dramatic Response to Enfortumab Vedotin in Soft-tissue Metastases from Urothelial Carcinoma: A Case Report

Abstract Soft-tissue metastasis from urothelial carcinoma is a rare but advanced disease entity. We report a patient with muscle-invasive bladder cancer who experienced rapid disease recurrence following radical surgery and adjuvant platinum-based chemotherapy. Despite further treatment with taxane-based chemotherapy and immune checkpoint inhibitors, the patient developed diffuse soft-tissue metastases, including in the skin, muscles of the extraocular area, extremities, and trunk. Salvage treatment with enfortumab vedotin (EV) was administered along with local radiation therapy to the orbital metastasis for better symptom control. Unexpectedly, the soft-tissue metastases showed a dramatic response after the first cycle of EV. However, after two cycles of EV treatment, the skin and extremity muscular metastases progressed, while the extraocular metastasis remained controlled. Four months after EV treatment, the patient died due to systemic progression and infection.