Efficacy and Toxicity of Belotecan for Relapsed or Refractory Small Cell Lung Cancer Patients

Introduction: Belotecan (Camtobell, CKD602) is a new camptothecin-derivative antitumor agent that belongs to the topoisomerase inhibitors. The aim of this study was to evaluate the efficacy and safety of belotecan monotherapy as a second-line therapy in patients with relapsed or refractory small cell lung cancer (SCLC). Methods: Between June 2008 and August 2011, a total of 50 patients with relapsed or refractory SCLC were treated with belotecan 0.5mg/m(2) for 5 consecutive days, every 3 weeks. We evaluated the overall response rate (ORR), the progression-free survival (PFS), and the overall survival (OS), and toxicity according to sensitivity to initial chemotherapy. Results: The median age was 66 years (range, 43-84 years) and Eastern Cooperative Oncology Group performance was 0 or 1 in 34 patients (68%) and 2 in 16 patients (32%). Twenty patients (40%) had sensitive relapse and 30 patients (60%) had refractory disease. The ORR, PFS, and OS for sensitive patients were 20% (95% confidence interval [CI], 8-40), 2.8 months (95% CI, 0.53-5.06), and 6.5 months (95% CI, 1.58-11.42), respectively. In the refractory group, the ORR, PFS, and OS were 10% (95% CI, 1-21), 1.5 months (95% CI, 1.25-1.75), and 4.0 months (95% CI, 3.40-4.60), respectively. Most commonly reported grade-3 or -4 adverse events included neutropenia (54%), thrombocytopenia (38%), and anemia (32%). Conclusion: Belotecan showed modest activity with an acceptable safety profile as a second-line therapy in patients with relapsed or refractory SCLC.