Randomized double-blind phase 2 trial of 3 doses of TAS-108 in patients with advanced or metastatic postmenopausal breast cancer.

Background: The objective of this study was to evaluate 3 different doses of (7α)-21-(4-[(diethylamino)methyl]-2 methoxyphenoxy)-7 methyl-19 norpregna-1,3,5(10)-trien-3-ol 2-hydroxy-1,2,3-propanetricarboxylate (TAS-108) in patients with recurrent, hormone-responsive breast cancer.

Methods: In this randomized, double-blind, multicenter study, TAS-108 was administered daily at a dose of 40 mg, 80 mg, or 120 mg to postmenopausal patients with locally advanced, or inoperable, or metastatic hormone-receptor positive breast cancer. The primary efficacy outcome was clinical benefit (CB), defined as the total number of patients who achieved a complete response, a partial response, or stable disease for ≥24 weeks.

Phase I and pharmacokinetic study of S-1 administered for 14 days in a 21-day cycle in patients with advanced upper gastrointestinal cancer.

Purpose: S-1 is a novel oral fluoropyrimidine that combines tegafur with CDHP and oxonic acid. To decrease the incidence of late onset, severe diarrhea observed in a previous study, a phase I study was conducted to determine the maximum tolerated dose (MTD) of S-1 utilizing a 14-day schedule, repeated every 21 days, in patients with chemotherapy-refractory upper gastrointestinal malignancies.

Methods: S-1 was administered orally, twice-daily, at an initial dose level of 30 mg/m2/dose; doses were escalated by 5 mg/m2 at each level.

Phase I pharmacokinetic study of S-1 plus cisplatin in patients with advanced gastric carcinoma.

Purpose: The conversion rate of tegafur (a component of S-1) to fluorouracil (FU) differs in Asians and whites because of polymorphic differences in the CYP2A6 gene. S-1 with cisplatin is considered highly active in Japanese gastric cancer patients. Therefore, we initiated a phase I pharmacokinetic study of this combination in our gastric cancer patients.