Phase I trial of oral S-1 plus gemcitabine in elderly patients with nonsmall cell lung cancer.

We conducted a phase I study to determine the maximum tolerated dose, the recommended dose and the safety profile of S-1 and gemcitabine combination regimen in the treatment of elderly patients (> or = 70 years) with advanced nonsmall cell lung cancer (NSCLC). Chemotherapy-naive patients with advanced NSCLC were treated with S-1 and gemcitabine. S-1 was administered orally twice daily for 14 days and gemcitabine on days 1 and 15 of each cycle, and this was repeated every 4 weeks. Doses of each drug were planned as follows: level 1, 800/60; level 2, 1000/60; level 3, 1000/70; and level 4, 1000/80 [gemcitabine (mg/m2/ day)/S-1 (mg/m2/day)]. The dose-limiting toxicity (DLT) of the regimen was assessed during the first chemotherapy cycle. Sixteen patients were enrolled in this study. The main grade 3 toxicities observed during the first cycle were neutropenia (43.7%), leukopenia (18.7%), and hyperglycemia. One of six patients in level 3 had DLT. Although no patients in level 4 experienced DLT, this level was considered the maximum tolerated dose. Level 4 was selected as the recommended dose. Objective responses were seen in four patients (response rate, 42.9%). The combination of S-1 plus gemcitabine is a feasible and well-tolerated regimen for the treatment of elderly patients with advanced NSCLC.