Background: The epothilone B analog, BMS-247550, is a non-taxane microtubulin-stabilizing agent with preclinical activity in taxane-resistant cell lines and phase I activity in colorectal cancer. We conducted a phase II study of single-agent BMS-247550 in advanced colorectal cancer patients who had disease progression following treatment with irinotecan-5-fluorouracil-leucovorin (IFL).
Patients and methods: Patients were required to have histologically or cytologically confirmed advanced or metastatic colorectal cancer; progressed on or after chemotherapy with IFL; Eastern Cooperative Oncology Group performance status < or =1; peripheral neuropathy grade < or =1; and adequate laboratory parameters. BMS-247550 40 mg/m(2) was administered intravenously over 3 h every 3 weeks. Patients were evaluated for response every 6 weeks.
Results: Twenty-five patients were enrolled; all were evaluable for toxicity and 23 were evaluable for response. There were no complete or partial responses. Thirteen patients (56%) had stable disease after two cycles of therapy; five patients (20%) received six or more cycles. The median time to progression was 11 weeks; median overall survival was 36 weeks. There was considerable grade 3/4 hematological toxicity, including neutropenia (48%) and leukopenia (36%). Grade 3/4 non-hematological toxicities included grade 3 hypersensitivity reaction (12%) and peripheral neuropathy (20%).
Conclusions: Single-agent BMS-247550 (40 mg/m(2)) administered every 21 days demonstrated no activity in advanced colorectal cancer. Peripheral neuropathy was treatment-limiting.