A multicenter phase II study of belotecan, new camptothecin analogue, in patients with previously untreated extensive stage disease small cell lung cancer.

Belotecan (Camtobell, CKD602) is a new camptothecin derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this phase II study was to evaluate the efficacy and safety of single agent belotecan in patients with small cell lung cancer (SCLC). Patients with previously untreated extensive stage disease (ED) SCLC were entered into the study. Belotecan was given by daily intravenous infusion at 0.5mg/m(2)/day for 5 consecutive days, every 3 weeks. 62 patients were enrolled in this study. The overall response rate to chemotherapy on an intention-to-treat basis was 53.2%. The median overall survival was 10.4 months, the median time to progression 4.6 months, and the 1-year survival rate 49.9%. The most common toxicity was hematologic. Grade 3/4 neutropenia occurred in 71.0% of patients and grade 3/4 thrombocytopenia 12.9%. Non-hematologic toxicity of grade 3 or 4 was low. The results suggest that belotecan is relatively active and well tolerable as single agent in patients with ED SCLC. Further investigations with platinum or other active agents are needed.