Dose-escalation phase I study in metastatic breast cancer patients with combination of paclitaxel and tegafur·uracil.

The study present the results of the dose-setting study of concomitant weekly administration of paclitaxel and tegafur·uracil (UFT) for metastatic breast cancer. Eligible patients who entered the study underwent two or more courses of weekly paclitaxel + UFT therapy as the protocol therapy. The initial dose (level 1) was paclitaxel, 80 mg/m(2) and UFT, 400 mg/day. At level 2, paclitaxel remained the same, but UFT was increased to 600 mg/day. At level 3, only paclitaxel was increased to 90 mg/m(2). Twelve patients were enrolled in this study between September 2000 and September 2002. Three patients were assigned to level 1. Grade 3 liver dysfunction (increased aspartate aminotransferase and alanine aminotransferase) was noted in one patient and grade 4 neutropenia was noted in one patient, showing that dose-limiting toxicity was detected in 2/3 patients. In accordance with the protocol, UFT was fixed at 400 mg/day and paclitaxel was decreased to 60 mg/m(2) at level -1, and then increased to 70 mg/m(2) at level 0. The overall effective rate after completion of two courses was 33% (3/9) including one case of complete response and two cases of partial responses. The remaining patients presented with stable diseases and no patient had progressive disease. In this study, weekly paclitaxel with concomitant UFT was administered. The recommended doses of paclitaxel and UFT were determined to be 70 mg/m(2) and 400 mg/day, respectively. As the toxicity profile shows, the highest toxicity level of this regimen was neutropenia and liver dysfunction, and dose-limiting toxicity was neutropenia.