Response to Platinum-based Chemotherapy Rechallenge for Patients With Pembrolizumab-refractory Urothelial Carcinoma.

BACKGROUND: This study aimed to investigate the response to platinum-based chemotherapy rechallenge in patients with pembrolizumab-refractory urothelial carcinoma. PATIENTS AND METHODS: We retrospectively reviewed 14 patients with pembrolizumab-refractory urothelial carcinoma. Each patient received a regimen that they had not previously received (paclitaxel plus carboplatin in 10, gemcitabine plus docetaxel and carboplatin in four). Tumor response and adverse events were assessed. We evaluated overall survival from the chemotherapy rechallenge start date until death. RESULTS: The median overall survival was 11.2 months. The disease-control rate was 85.7%. Partial responses occurred in the metastases in lymph nodes in three (37.5%) patients, lung in one (25%), peritoneal in three (75%), and liver in three (100%). Neutropenia of grade ≥3 occurred in 13 (92.9%) patients. CONCLUSION: The activity of platinum-based chemotherapy rechallenge after pembrolizumab was maintained. Neutropenia was observed in most patients.