S-1 plus cisplatin versus S-1 alone for first-line treatment of advanced gastric cancer (SPIRITS trial): a phase III trial

Summary Background Phase I/II clinical trials of S-1 plus cisplatin for advanced gastric cancer have yielded good responses and the treatment was well tolerated. In this S-1 Plus cisplatin versus S-1 In RCT In the Treatment for Stomach cancer (SPIRITS) trial, we aimed to verify that overall survival was better in patients with advanced gastric cancer treated with S-1 plus cisplatin than with S-1 alone. Methods In this phase III trial, chemotherapy-naive patients with advanced gastric cancer were enrolled betweeen March 26, 2002, and Nov 30, 2004, at 38 centres in Japan, and randomly assigned to S-1 plus cisplatin or S-1 alone. In patients assigned to S-1 plus cisplatin, S-1 (40–60 mg depending on patient's body surface area) was given orally, twice daily for 3 consecutive weeks, and 60 mg/m 2 cisplatin was given intravenously on day 8, followed by a 2-week rest period, within a 5-week cycle. Those assigned to S-1 alone received the same dose of S-1 twice daily for 4 consecutive weeks, followed by a 2-week rest period, within a 6-week cycle. The primary endpoint was overall survival. Secondary endpoints were progression-free survival, proportions of responders, and safety. Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00150670. Findings 305 patients were enrolled; seven patients were ineligible or withdrew consent, therefore, 148 patients were assigned to S-1 plus cisplatin and 150 patients were assigned to S-1 alone. Median overall survival was significantly longer in patients assigned to S-1 plus cisplatin (13·0 months [IQR 7·6–21·9]) than in those assigned to S-1 alone (11·0 months [5·6–19·8]; hazard ratio for death, 0·77; 95% CI 0·61–0·98; p=0·04). Progression-free survival was significantly longer in patients assigned to S-1 plus cisplatin than in those assigned to S-1 alone (median progression-free survival 6·0 months [3·3–12·9] vs 4·0 months [2·1–6·8]; p Interpretation S-1 plus cisplatin holds promise of becoming a standard first-line treatment for patients with advanced gastric cancer.