Purpose: To evaluate the antitumor effect and feasibility of a combination of irinotecan (CPT-11) and 5-day infusional 5-fluorouracil (5-FU) in a sequential schedule based on our previous combination phase I studies in patients with metastatic colorectal cancer.
Patients and methods: Forty chemotherapy-naive patients with metastatic colorectal cancer received 90-min infusion of CPT-11 at a dose of 150 mg/m(2) on days 1 and 15 and 120-h protracted infusion of 5-FU at 600 mg/m(2)/day on days 3-7, which were repeated every 4 weeks.
Results: The median number of actually administered courses was five, ranging from one to 14. There were 16 (40%) patients who developed grade 3 or 4 neutropenia. Grade 3 or 4 nausea/vomiting and diarrhea were seen in three (8%) and seven (18%) patients, respectively. Only one early death not related to treatment occurred during the study. There was one complete response and 17 partial responses with a response rate of 45% (95% confidence interval: 29.3-61.5%). With a median follow-up period of 22.5 months for survivors, the median survival and median progression-free survival times were 15.9 and 7.0 months, respectively.
Conclusions: Although the toxicities were modest, this sequentially combined regimen is active and feasible in patients with metastatic colorectal cancer.