A Phase II study of S-1 and irinotecan combination therapy in previously treated patients with advanced non-small cell lung cancer

Objective: This Phase II studywas conducted to evaluate the efficacy and safety of S-1 and irinotecan combination therapy as a second-line treatment in patients with advanced non-small cell lung cancer. Methods: Irinotecan was administered at 60 mg/m² on Days 1 and 8. Oral S-1 was administered on Days 1-14 every 3 weeks at 80 mg/day for patients with a body surface area of <1.25 m², 100 mg/day for patients with a body surface area of 1.25-1.5 m2 and 120 mg/day for patients with a body surface area of >1.5 m². The primary endpoint was response rate, while the secondary endpoints were progression-free survival, overall survival and safety. Results: Thirty-one patientswere enrolled in this study. The response and disease control rateswere 6.5 and 58.1%, respectively. Progression-free survival and median survival time were 2.8 and 12.6 months, respectively. Grade 3-4 adverse events were reported for 29.0% of the patients. Hematological toxicities of Grade 3 or 4 included leukopenia (9.7%), neutropenia (9.7%), febrile neutropenia (3.2%), thrombopenia (3.2%) and anemia (6.5%). Non-hematological toxicities of Grade 3 or 4 included pneumonitis (6.5%), diarrhea, colitis, dyspnea, rash, oral mucositis, anorexia and pulmonary thromboembolism/deep vein thrombosis (3.2% each). Conclusions: S-1 and irinotecan combination therapy at the present dose and schedule exhibited only modest efficacy with mild toxicities in previously treated patients with non-small cell lung cancer. No further clinical investigation with current dose and schedules is warranted for patients with non-small cell lung cancer who failed first-line platinum-based doublet chemotherapy.