Phase II Study of S-1 Combined with Irinotecan (CPT-11) in Patients with Advanced Colorectal Cancer

Abstract

Objective: To determine the efficacy and tolerability of oral fluoropyrimidine S-1 plus irinotecan in patients with previously untreated advanced colorectal cancer. Methods: S-1 was administered orally at 80 mg/m²/day for 21 consecutive days followed by a 2-week rest. CPT-11 was given intravenously on days 1 and 15 of each course, at a dose of 80 mg/m²/day. Courses were repeated every 5 weeks, unless disease progression or severe toxicities were observed. Results: A total of 282 courses of treatment were administered to 40 patients, achieving complete response in 1 and partial responses in 24 with an overall response rate of 62.5% (95% CI: 47.5–77.5%). Median progression-free survival was 7.8 months (95% CI: 6.7–9.6 months). The rates of grade 3 or 4 toxicities were as follows: neutropenia 12.5%, anorexia 12.5%, fatigue 10%, and diarrhea 7.5%. Conclusion: Combined treatment with S-1 and irinotecan is an effective, well-tolerated and convenient regimen in patients with advanced colorectal cancer which is easily maintained.