Trial of 3-weekly Versus 5-weekly Schedule of S-1 Plus Cisplatin in Gastric Cancer: SOS

The urgent need for a new effective therapy with better safety profile for the metastatic gastric cancer patients and promising results observed so far in the studies with S-1 plus cisplatin combination in advanced gastric cancer (AGC) strongly warrants the comparison of a 3-weekly schedule to a 5-weekly schedule of S-1 plus cisplatin as a standard regimen in the first-line treatment for AGC patients. The objectives of this study are to compare a 3-weekly schedule to a 5-weekly schedule of S-1 plus Cisplatin combination in terms of efficacy, quality of life and safety in patients with previously untreated advanced or recurrent unresectable gastric cancer. Primary endpoint is progression-free survival. This is an open label, randomized, multi-center, non-inferiority/superiority (of 3-weekly regimen over 3-weekly regimen) hybrid study.