Organ-Specific Tumor Response to Pembrolizumab in Advanced Urothelial Carcinoma After Platinum-Based Chemotherapy

To evaluate the organ-specific therapeutic effect of pembrolizumab after the failure of platinum-based chemotherapy for advanced urothelial carcinoma (UC). Patients with advanced UC who received pembrolizumab after the failure of platinum-based chemotherapy and who had measurable disease were retrospectively analyzed. The objective response rate (ORR) and organ-specific response rate (OSRR) were evaluated according to Response Evaluation Criteria in Solid Tumors, version 1.1. We analyzed 69 patients (male, n=51; median age, 71 years) with 226 metastases. The ORR was 23.2%. In total, 32, 31, 16, 14, 13 and 7 patients had measurable lung (OSSR 31.3%), lymph node (OSSR 29.0%), local recurrence (OSSR 12.5%), primary tumor organ (OSSR 7.1%), liver (OSSR 23.1%) and bone (OSSR 28.6%) disease, respectively. The median overall survival (OS) for pembrolizumab was 10.9 months (95% confidence interval, 5.9‑13.7 months). Regarding organ-specific OS, a Log rank test significant differences in OS were confirmed between patients with and without primary tumor organ disease (p=0.046) and liver metastasis (p