Phase I study of weekly cisplatin, bolus fluorouracil and escalating doses of irinotecan in advanced solid tumors.

Objective: We performed a phase I study of 5-fluorouracil (5-FU), cisplatin and irinotecan.

Methods: Twenty-nine patients received cisplatin 25 mg/m(2) and bolus 5-FU 425 mg/m(2), along with irinotecan at 40, 50, and 65 mg/m(2) weekly for 4 out of 6 weeks.

Results: The maximum tolerated dose (MTD) for untreated patients was irinotecan 65 mg/m(2) while the MTD for previously treated patients was irinotecan 40 mg/m(2). Neutropenia and diarrhea were the major dose-limiting toxicities. Antitumor activity was noted in gastric, esophageal and pancreatic cancers.

Conclusions: Because of the toxicity profile, combinations with continuous infusion 5-FU or capecitabine should be explored.