Phase II study of combined belotecan and cisplatin as first-line chemotherapy in patients with extensive disease of small cell lung cancer

To determine the efficacy and safety of belotecan in combination with cisplatin as first-line chemotherapy for extensive disease of small cell lung cancer (ED SCLC).

Patients with chemotherapy-naïve ED SCLC were eligible if the following criteria were met: age ≥18 years; a measurable lesion; Eastern Cooperative Oncology Group Performance Status (PS) 0–2; and adequate organ function. Each cycle consisted of belotecan (0.5 mg/m²/day) on days 1–4 and cisplatin (60 mg/m²) intravenously on day 1. The cycle was repeated every 3 weeks until the completion of the 6th cycle, disease progression, or intolerable toxicity.

Thirty-five patients (median age, 68 years) were enrolled: 32 males (91.4%); and PS = 0 (n = 3), PS = 1 (n = 18), and PS = 2 (n = 14). The median number of cycles delivered was 5 (range, 1–6). The relative dose intensity was 70.1% for belotecan and 83.0% for cisplatin. Of 30 evaluable patients, objective response rate was 71.4% (95% confidence interval [CI], 55.7–87.2) by the intent-to-treat principle. The median duration of follow-up was 14.3 months. The median progression-free survival was 5.7 months (95% CI, 3.9–7.5) and the median overall survival was 10.2 months (95% CI, 9.3–11.1). The frequently reported grade 3 or 4 toxicities included neutropenia in 24 patients (68.6%), thrombocytopenia in 10 (28.6%), and anemia in 7 (20.0%). There was no grade 3 or 4 non-hematologic toxicity except three patients (8.6%) with fatigue.

Belotecan and cisplatin combination therapy showed significant efficacy in ED SCLC with improved non-hematologic toxicities.