Phase I study of a novel taxane BMS-188797 in adult patients with solid malignancies

Preclinical studies show that BMS-188797 has a broad spectrum of antitumor activity in in vitro cytotoxicity assays and tumor xenograft models. We did a phase I trial designed to determine the maximum tolerated dose and the pharmacokinetics of BMS-188797 when administered i.v.

BMS-188797 was administered i.v. over 60 minutes once every 21 days to 51 patients. The initial dose cohort of 3.75 mg/m(2) was set at approximately one third the lethal dose in dogs. Doses were subsequently escalated in cohorts according to a modified Fibonacci design.

Fifty-one patients received a total of 160 cycles of therapy. The dose-limiting toxicity of febrile neutropenia occurred in two patients at the 200 mg/m(2) cohort. Moderate to severe sensory neuropathy occurred in 12 patients (24%). Four radiographic partial responses based on the Response Evaluation Criteria in Solid Tumors occurred: two in subjects with breast cancer, one in a subject with non-small cell lung cancer, and one in a subject with renal cell carcinoma. The duration of the partial responses observed were 24.1 months (renal cell carcinoma), 5.7 and 4.3 months (breast cancer), and 4.5 months (non-small cell lung cancer). Pharmacokinetics appear linear at doses through 110 mg/m(2) but not at higher doses.

The dose-limiting toxicity in this single-agent study of BMS-188797 was febrile neutropenia. The recommended phase II dose of BMS-188797 as a single agent is 175 mg/m(2) i.v. for 1 hour administered every 3 weeks.