Irinotecan and UFT/leucovorin in patients with advanced cancers.

The combination of irinotecan and fluorouracil (5-FU) is synergistic when applied to human colon cancer cell lines in vitro and appears to be schedule-dependent: maximal activity occurs when irinotecan is administered prior to 5-FU. In this phase I study, irinotecan is administered in combination with UFT and leucovorin in patients with advanced solid tumors. Irinotecan is given as a 90-minute intravenous infusion on day 1 followed by twice-daily UFT plus oral leucovorin on days 2 through 15. Cycles are repeated every 21 days. Five patients have been treated to date; four are evaluable for toxicity. Starting doses were irinotecan 200 mg/m2/day, UFT 200 mg/m2/day, and leucovorin 60 mg/day. Preliminary results indicate that irinotecan in combination with UFT plus leucovorin is well tolerated at the initial doses (described in this article).