Triplet schedule of weekly 5-fluorouracil and alternating irinotecan or oxaliplatin in advanced colorectal cancer: a dose-finding and phase II study.

A weekly administration of alternating irinotecan or oxaliplatin associated to 5-Fluorouracil in advanced colorectal cancer was planned in order to evaluate a new schedule maintaining dose intensities of each drug as in double combinations and tolerability of the triplet association. The following weekly schedule was administered: irinotecan, days 1 and 15; oxaliplatin, days 8 and 22; 5-fluorouracil (5-FU) over 12-h (from 10:00 p.m. to 10:00 a.m.) timed flat infusion, days 1-2, 8-9, 15-16 and 22-23, every 4 weeks. Dose- finding and phase II study were planned. Thirteen patients were enrolled in the dose-finding study and 23 in the phase II study. The recommended doses of our study are: irinotecan 160 mg/m(2); oxaliplatin 80 mg/m(2); 5-FU 900 mg/m(2). The dose-limiting toxicity was diarrhea (35% of patients) but no cases of febrile neutropenia were observed. In 30 patients assessable for response two complete (6.7%) and 18 partial (60%) responses were observed, for an overall response rate of 66.7% (alpha 0.05, CI+/-17). The triplet association using this weekly alternating schedule is an active and well-tolerated outpatient regimen. Surgical removal of residual disease was considered in 5 patients and a radical resection was performed in 5 patients (147 %).