Durable complete metabolic response to enfortumab vedotin plus pembrolizumab in metastatic upper tract urothelial carcinoma: a case report

Upper tract urothelial carcinoma (UTUC) accounts for approximately 5–10% of urothelial malignancies and is frequently associated with advanced stage and aggressive clinical behavior. In metastatic disease, platinum-based chemotherapy has historically represented standard first-line therapy; however, long-term outcomes remain limited. The combination of enfortumab vedotin and pembrolizumab has recently demonstrated superior survival outcomes compared with platinum-based chemotherapy in advanced urothelial carcinoma. Nevertheless, the depth and durability of response following early discontinuation of antibody–drug conjugate therapy remain incompletely characterized. A 38-year-old woman with advanced UTUC developed metastatic progression involving liver, lymph nodes, peritoneum, ovary, and bone following platinum-based chemotherapy and surgery. She received three cycles of enfortumab vedotin plus pembrolizumab. Cross-sectional imaging demonstrated near-complete radiologic response with resolution of hepatic metastases and marked regression of thoracic and abdominal lymphadenopathy. Enfortumab vedotin was discontinued because of treatment-related peripheral neuropathy and dermatologic toxicity, and pembrolizumab monotherapy was continued. At the sixth cycle of pembrolizumab, FDG PET/CT revealed complete metabolic response. The patient remains progression-free for more than eight months after documentation of complete metabolic response. This case demonstrates sustained complete metabolic response following short-course enfortumab vedotin combined with pembrolizumab in metastatic UTUC and highlights the potential for durable disease control despite early discontinuation of enfortumab vedotin.