S-1 Combined with Weekly Paclitaxel in Patients with Advanced Gastric Cancer: Masahiro Gotoh, Shin-ichiro Kawabe and Hiroya Takiuchi (Dept. of Gastroenterology, Osaka Medical College) Summary Both paclitaxel and S-1 have been identified as an effective agent for the treatment of gastric cancer. Furthermore, weekly paclitaxel was found to have a better toxicity profile and to be as effective as an equivalently dosed conventional schedule of delivery every 3 weeks. Osaka Gastrointestinal Cancer Chemotherapy Study Group (OGSG) conducted the phase I/II study of weekly paclitaxel combined with S-1. S-1 was given orally at a fixed dosage of 40 mg/m2 bid for 14 consecutive days, followed by a week rest. Paclitaxel was scheduled to be given intravenously on days 1 and 8. The MTD of paclitaxel was presumed to be 60 mg/m2 because 50.0% of patients (2/4) developed DLTs (mainly grade 3 anorexia). Therefore, the RD of paclitaxel was estimated to be 50 mg/m2. This combination treatment was demonstrated to exhibit a tolerable toxicity profile with a high antitumor activity of 48% (14/29) and MST of 417 days. This regimen is investigated in a randomized phase II trial and may yet become a test arm in future phase III trials.