Phase II study of amrubicin at a dose of 45 mg/m2 in patients with previously treated small-cell lung cancer

Most of the previous studies of amrubicin in patients with previously treated small-cell lung cancer were conducted at a dose of 40 mg/m(2). The aim of this study was to assess the efficacy and safety of amrubicin at a dose of 45 mg/m(2) in patients with relapsed or refractory small-cell lung cancer. Previously treated small-cell lung cancer patients were eligible. Amrubicin at a dose of 45 mg/m(2) was administered on Days 1-3 every 3 weeks. The primary endpoint was the response rate. From June 2003 to January 2005, 35 patients were enrolled, of whom 34 received this study treatment. Four cycles or more could be administered in 21 patients (62%). Dose reduction was required in 15 (52%) of the 29 patients who had received two cycles or more. Three complete responses and 15 partial responses were observed among the 34 treated patients, yielding a response rate of 53% (95% confidence interval, 35-71%). Median progression-free survival of the patients was 4.4 months (95% confidence interval, 2.4-5.1 months). Median survival time was 8.2 months (95% confidence interval, 6.6-10.0 months) and 1-year survival rate was 24% (95% confidence interval, 9-39%). Grade 3/4 leukopenia, neutropenia and thrombocytopenia were observed in 76, 97 and 38% of the patients, respectively. Febrile neutropenia occurred in 12 patients (35%), and one patient died from pneumonia. While amrubicin at a dose of 45 mg/m(2) showed high response rate for both sensitive and refractory relapse, the incidence of febrile neutropenia was also high. The utility of amrubicin at 45 mg/m(2) might accordingly be limited.