Phase I and pharmacokinetic study of BMS-184476, a taxane with greater potency and solubility than paclitaxel

Purpose: To assess the feasibility, toxicity, pharmacokinetics, and preliminary activity of BMS-184476 administered as a 1-hour intravenous (IV) infusion every 3 weeks. Patients and Methods: Patients with advanced solid malignancies were treated with escalating doses of BMS-184476 as a 1-hour IV infusion every 3 weeks without premedication to prevent hypersensitivity reactions (HSR). Plasma sampling and urine collections were performed to characterize the pharmacokinetics and pharmacodynamics of BMS-184474. Results: Thirty-four patients were treated with 78 courses of BMS-184476 at five dose levels ranging from 20 to 80 mg/m². Dose-limiting toxicity (DLT), consisting of severe neutropenia with fever, severe diarrhea, and/or severe mucositis, was experienced during course 1 by six of nine minimally pretreated patients treated at the 70 and 80 mg/m² dose level. In contrast, of 15 assessable patients treated at the 60 mg/m² dose level, which is the maximum-tolerated dose (MTD) of BMS-184476 on this administration schedule, only one heavily pretreated patient developed DLT (grade 4 neutropenia with fever and grade 3 diarrhea). One patient developed a grade 2 HSR during a second course of BMS-184476 at the 40 mg/m² dose level. A previously untreated patient with an advanced cholangiocarcinoma experienced a partial response, and a patient with an untreated carcinoma of the gastroesophageal junction had a minor response. The pharmacokinetics of BMS-184476 seemed linear in the dose range studied. Mean ± SD values for clearance, volume of distribution at steady-state, and terminal half-life were 220 ± 89 mL/min/m², 402 ± 231 L/m², and 40.8 ± 21.8 hours, respectively. Conclusion: The MTD and recommended dose for phase II evaluations of BMS-184476 is 60 mg/m² as a 1-hour IV infusion every 3 weeks. The results of this study suggest that BMS-184476 may have several advantages compared with paclitaxel in terms of toxicity, pharmacokinetics, pharmaceutics, and administration and warrants further clinical development.