Phase II trial of S-1 as second-line therapy in patients with advanced non-small cell lung cancer.

Currently available agents for the treatment of advanced stage non-small cell lung cancer (NSCLC) have limited efficacy. S-1 is a novel formulation of oral fluoropyrimidine shown to be tolerable and active in patients with NSCLC in Japan. We conducted a multicenter phase II study in previously treated patients with NSCLC to evaluate the efficacy of single-agent S-1 in a predominantly non-Asian population.Patients with advanced NSCLC and previously treated with only one line of chemotherapy received oral S-1 at 30 mg/m every 12 hours for 14 consecutive days followed by a 7-day rest until meeting discontinuation criteria. The primary end point was to evaluate the overall response rate.Fifty-seven patients were accrued from 21 centers across the United States. Overall response rates and stable disease according to independent review were 7.1% and 48.2%, respectively, with a disease control rate of 55.3%. Progression-free survival was 2.9 months, median overall survival 7.3 months, and 1-year survival 31.6%. There were no significant differences in survival according to histologic subtype. The treatment was well tolerated, with the most common treatment-related side effects being nausea (54%) and diarrhea (49%).Single-agent S-1 is well tolerated and has activity comparable with the other agents approved for use in recurrent/relapsed NSCLC.