A Phase I Study of Oral Uracil-Tegafur Prior to Weekly Intravenous Gemcitabine in Patients with Advanced Pancreatic Cancer

Abstract

Background: Gemcitabine is widely accepted as the first-line agent for advanced pancreatic cancer. The antitumor cell activity of gemcitabine is higher when administered after 5-fluorouracil (5-FU) rather than before 5-FU in an in vitro study. The present study was conducted to define the maximum tolerated dose and dose-limiting toxicity associated with an oral fluoropyrimidine prodrug that combines uracil and tegafur (UFT), given prior to weekly intravenous gemcitabine in patients with advanced pancreatic cancer. Methods: Over a 21-day cycle, gemcitabine was given intravenously over 30 min on days 8 and 15, while UFT was given orally from days 1 to 14. The dose of UFT used was 400 mg per day, given as two doses. The dose of gemcitabine was escalated in a stepwise fashion from 800 (level 1, n = 3) to 900 mg/m² (level 2, n = 6) and then to 1,000 mg/m² (level 3, n = 3), such that totally 12 patients received the combination chemotherapy. Results: During the first cycle, grade 3 leukopenia was observed in 2 patients at dose level 1. Only 1 patient treated at dose level 2 experienced dose-limiting toxicity (grade 3 elevated transaminase), including additional patients treated at this dose level. No grade 3/4 toxicities occurred in patients treated at dose level 3. A significant response was observed in 1 out of 12 patients (8.3%). Seven patients (58.3%) had stable disease, while 4 patients (33.3%) showed disease progression. Conclusions: The combination chemotherapy of oral UFT and gemcitabine was convenient, well tolerated and may benefit patients with advanced pancreatic cancer. Doses recommended for further study of this schedule are gemcitabine 1,000 mg/m² and UFT 400 mg/day.