Combination chemotherapy of biweekly irinotecan (CPT-11) plus tegafur/uracil (UFT) and leucovorin (LV) for patients with metastatic colorectal cancer: Phase I/II study in Japanese patients

Purpose: We aimed to evaluate the safety and efficacy of combination chemotherapy with biweekly irinotecan (CPT-11) plus oral tegafur/uracil (UFT) and leucovorin (LV) in patients with previously untreated metastatic colorectal adenocarcinoma in phase I/II setting. Patients and methods: We recruited 37 patients with histologically proven metastatic colorectal adenocarcinoma. UFT (300 mg/m² per day) and LV (75 mg/day) were administered orally on days 1-21. CPT-11 was administered intravenously on day 1 and 15, at an initial dose of 60 mg/m², stepping up to 150 mg/m² in a traditional phase I fashion. The treatment was repeated every 4 weeks. After patients enrolled into a phase II portion, the efficacy and toxicity of this regimen were also assessed. Results: The recommended dose of CPT-11 was determined to be 150 mg/m². Although one patient had a pulmonary embolism after 60 mg/m² of CPT-11, the treatment was well tolerated in general. The overall objective response rate was 37.8% (14/37; 95% CI, 22.5-55.2) in all patients. Median progression-free survival was 226 days (95% CI, 133-276). Conclusions: Biweekly CPT-11 plus UFT and LV had a reasonable safety profile with manageable toxicity, and had a promising activity in patients with metastatic colorectal cancer. Further trials are indicated based on the promising results observed in this study.