[Phase I study of orally administered UFT plus l-leucovorin]

A Phase I study of UFT plus l-LV was conducted in 29 patients (pts) with G.I. cancer on a multicenter cooperative study. UFT and l-LV were given orally in two divided doses for 28 consecutive days, followed by a 14 day-rest period. UFT was fixed in three doses, 250, 313 and 375 mg/m2/day, and l-LV was increased in dose from 25 to 50 and to 100 mg/body/days. Dose-limiting toxicities were anorexia, diarrhea, and nausea/vomiting. The maximum tolerated dose of UFT was 375 mg/m2/day, and l-LV 25 mg/body/day. Severe myelotoxicity was not observed. There were three responders (PR) out of 21 pts with measurable disease at UFT doses of 313 mg/m2/day and l-LV 50 and 100 mg/body/day. Responses observed were abdominal mass (rectal ca), liver metastasis (pancreas ca) and metastasis of liver and lymph-node (gastric ca). As a result of pharmacokinetics, plasma concentrations of 5-methyl-THF were maintained > 1.0 microM for over 5 hours that was considered to have a modulating effect on the plasma concentration. In doses of 50 mg and 100 mg/body/day of l-LV. No accumulations in plasma were observed in patient treated in 28 days by l-LV/UFT therapy. It was suggested UFT and l-LV did not interfere with each other's absorption. A Phase II study is recommended, with doses of 313 mg/m2/day of UFT and 50 or 100 mg/body/day of l-LV.