Phase I/II study of amrubicin, a novel 9-aminoanthracycline, in patients with advanced non-small-cell lung cancer

Abstract

Purpose: Amrubicin is a novel, totally synthetic 9-aminoanthracycline. The present phase I/II study was performed to define its maximum-tolerated dose (MTD), efficacy and toxicity in the treatment of previously untreated patients with advanced non-small-cell lung cancer (NSCLC). Patients and Methods: Chemonaive patients were required to have cytologically or histologically proven measurable NSCLC, an Eastern Cooperative Oncology Group (ECOG) performance status (PS) of 0 to 2, and adequate organ functions. Amrubicin was administered by daily intravenous injection for 3 consecutive days every 3 weeks. Results: In a phase I study, four patients were enrolled at dose level 1 (40 mg/m²/day) and four at dose level 2 (45 mg/m²/day). No dose limiting toxicity (DLT), which was defined as toxicity consisting of grade 4 neutropenia and leukopenia lasting four days or more, and grade 3 or 4 toxicity other than neutropenia, leukopenia, anorexia, nausea/vomiting, and alopecia, was observed at these dose levels. Subsequently, at dose level 3 (50 mg/m²/day), 3 of 5 patients experienced DLTs (leukopenia, neutropenia, thrombocytopenia, or gastrointestinal complications). The MTD and recommended dose (RD) were determined to be 50 mg/m²/day and 45 mg/m²/day, respectively. Three partial responses (PRs) were achieved in 13 patients (response rate, 23.1%) in a phase I study. In a phase II study, 15 patients were assessable for efficacy and toxicity at the RD, and four PRs were obtained (response rate, 26.7%). The major toxicities were leukopenia and neutropenia, while non-hematologic toxicities were mild. The overall response rate in the combined patient population of the phase I/II study was 25.0% (7 PRs in 28 patients), with a 95% confidence interval of 10.7% to 44.9%. Conclusion: Amrubicin exerted promising antitumor activity on NSCLC with acceptable toxicity.