Phase II study of irinotecan and S-1 combination therapy in patients (pts) with advanced non-small cell lung cancer (NSCLC): (WJTOG3505)

Abstract

8084 Background: S-1 is an oral anticancer drug combining tegafur, oxonic acid, and CDHP. We have conducted a phase II trial to evaluate the efficacy and toxicity of irinotecan in combination with S-1 for patients with advanced NSCLC. Methods: Chemotherapy-naïve pts with advanced stage (IIIB/IV) NSCLC, ECOG PS of 0–1, and adequate organ functions were treated with i.v. irinotecan 150 mg/m2 on day 1 and oral S-1 80 mg/m2/day on days 1 to 14 every 3 weeks. The primary objective of this study was to determine the objective response rate. With the target activity level of 35% and the lowest response rate of interest set at 20%, 50 eligible patients were required with an 80% power to accept the hypothesis and a 5% significance level to reject the hypothesis. Results: Of 59 pts enrolled in the study, 56 pts (median age, 63 years; range, 40–74 years) were eligible and analyzed. The median number of cycles administered was 5 (range, 1–15). The overall response rate was 31% (95% CI, 19–45%) and the progression free survival was 4.9 months (95% CI, 4.0–6.4 months). The median survival time was 15 months and 1-year survival rate was 62.5% (95% CI, 49.8–75.2%). The most common grade 3 to 4 hematologic toxicities were neutropenia (25%), leukopenia (8.9%) anemia (3.6%) and thrombocytopenia (3.6%). Nonhematologic toxicity of grade 3 or 4 included anorexia (14.3%), fatigue (8.9%), diarrhea (8.9%) and febrile neutropenia (7.1%). Conclusions: The combination of irinitecan/S-1 chemotherapy showed a promising effectiveness with acceptable toxicity rates in patients with advanced NSCLC. These results warrant further investigation of this regimen including a randomized controlled trial for its use as a first line treatment for NSCLC. No significant financial relationships to disclose.