Phase II study of sequential triplet chemotherapy, irinotecan and cisplatin followed by amrubicin, in patients with extensive-stage small cell lung cancer: West Japan Thoracic Oncology Group Study 0301.

INTRODUCTION: Combination chemotherapy of irinotecan, a topoisomerase I inhibitor, and cisplatin is a standard treatment in patients with extensive-stage small cell lung cancer (SCLC). Amrubicin, a novel 9-aminoanthracycline, inhibits topoisomerase II. We investigated a sequential triplet chemotherapy consisting of irinotecan and cisplatin followed by amrubicin in patients with extensive-stage SCLC.

METHODS: Eligible patients were aged 20 to 70 years and had Eastern Cooperative Oncology Group performance status of 0 or 1, measurable lesions, and adequate organ functions. Chemotherapy consisted of irinotecan 60 mg/m on days 1 and 8 plus cisplatin 60 mg/m on day 1 every 3 weeks for three cycles and then amrubicin 40 mg/m alone on days 1 to 3 every 3 weeks for three cycles.

RESULTS: From September 2004 to September 2006, 45 patients were enrolled, 43 were evaluable for response and survival, and 44 were evaluable for toxicity. Twenty-eight patients (64%) completed the full planned chemotherapy. One patient achieved complete response and 33 had partial response for an overall response rate of 79%. Median progression-free survival was 6.5 months. Median overall survival was 15.4 months. Major toxicity was myelosuppression. Grade 3 or 4 neutropenia, anemia, thrombocytopenia, and febrile neutropenia occurred in 57%, 7%, 0%, and 7% of patients during irinotecan/cisplatin cycles and in 91%, 27%, 9%, and 15% of patients during amrubicin cycles, respectively.

CONCLUSIONS: The sequential triplet chemotherapy, irinotecan and cisplatin followed by amrubicin, is an effective and well-tolerated treatment in patients with extensive-stage SCLC. Further investigation of this treatment is warranted.