Phase I study of irinotecan and gemcitabine in previously untreated patients with advanced non-small cell lung cancer

BACKGROUND: Irinotecan and gemcitabine are effective against non-small cell lung cancer. We conducted a phase I study of the combined use of irinotecan and gemcitabine in previously untreated patients with advanced non-small cell lung cancer to determine dose-limiting toxicities and maximum tolerated dose. METHODS: Patients were treated with irinotecan followed by gemcitabine on days 1 and 8 every 3 weeks. Gemcitabine dose was fixed at 1000 mg/m2, and irinotecan dose was increased from 60 mg/m2. RESULTS: A total of 16 patients was enrolled. Maximum tolerated dose of irinotecan was determined up to level 3 (irinotecan 100 mg/m2). In Japan, the maximum approved weekly dose of irinotecan is 100 mg/m2, so this was the dose that was used. Only very mild hematological and non-hematological toxicities were noted. CONCLUSION: Use of 100 mg/m2 irinotecan followed by 1000 mg/m2 gemcitabine on days 1 and 8 every 3 weeks warrants a phase II study.