- Recently, a Phase I study was completed, indicating recommended dose as S-1 100 mg/m2/day1-14 and oxaliplatin (130 mg/m2/day1), repeated every 3 weeks. However, in the phase II study using the above recommended dose, delayed toxicities of thrombocytopenia and anemia were observed. These delayed toxicities were also reported in a phase II study using S-1 90 mg/m2/day plus oxaliplatin 130 mg/m2/day1 in advanced gastric cancer. At 2007 GI ASCO, the interim data of S-1(80 mg/m2/day1-14) plus oxaliplatin (130 mg/m2/day1) combination, repeated every 3 weeks, was presented, showing promising antitumor activity with favourable safety profile. Among 18 patients, there were only two patients with Grade 3 thrombocytopenia and one with Grade 3 neutropenia. Response rate was 57.1 % and disease control rate was 92.9 %. Considering these results and Japanese data which showed that enhanced efficacy was not observed with S-1 over 90 mg/m2/day and oxaliplatin combination, S-1 80 mg/m2/day 1-14 and oxaliplatin 130 mg/m2/D1, repeated every 3 weeks, will be tested in this study.