Southwest Oncology Group phase II study of irinotecan in patients with advanced transitional cell carcinoma of the urothelium that progressed after platinum-based chemotherapy.

Purpose: The purpose of this study was to characterize the activity and toxicity of irinotecan in metastatic platinum-refractory urothelial carcinoma.

Patients And Methods: In a prospective multi-institutional phase II clinical trial, we evaluated the activity and safety of irinotecan 350 mg/m2 (300 mg/m2 in patients with previous radiation therapy to the pelvis) intravenously given every 21 days in patients with metastatic urothelial carcinoma and evidence of progression following one previous systemic chemotherapy regimen for metastatic disease that included cisplatin or carboplatin. The primary goal of this study was to evaluate the probability of confirmed complete or partial response.

Results: Forty eligible patients were registered between December 2003 and December 2006. One patient had a complete response, and 1 had a partial response (overall response rate, 5%; 95% CI, 1%-17%). Median progression-free survival was 2.1 months (95% CI, 1.8-2.3 months). Median overall survival was 5.4 months (95% CI, 3.4-7.1 months). Toxicity was similar to that reported previously for this schedule of irinotecan.

Conclusion: The response rate seen in this study is insufficient to recommend further evaluation of irinotecan in urothelial cancer that relapsed following initial platinum based chemotherapy. Investigation of novel agents for this patient population remains a priority.