A multicenter phase II study of belotecan, a new camptothecin analogue, as a second-line therapy in patients with 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 as a second-line therapy in patients with small cell lung cancer (SCLC). Patients who were previously treated for SCLC were entered into the study. Belotecan was given by daily intravenous infusion for five consecutive days, every three weeks. Twenty-five patients were enrolled in this study. On an intention-to-treat basis, belotecan induced an overall response rate of 24%, a median overall survival of 9.9 months, a median time to progression of 2.2 months, and a 1-year survival rate of 38.3%. Grade 3/4 neutropenia developed in 88.0% of patients and grade 3/4 thrombocytopenia in 40.0%. Nonhematologic toxicity of grade 3 or 4 was low. The results suggest that belotecan is relatively active and well tolerated as a second-line agent in patients with SCLC.