Patients (with or without prior taxane exposure) receive ixabepilone IV over 1 hour on days 1-5. An additional cohort of 37 patients who have received prior taxane therapy are then accrued to receive ixabepilone IV over 1 hour on days 1-3 at a higher starting dose. For all patients, courses repeat every 3 weeks in the absence of disease progression or unacceptable toxicity. Patients who receive more than 6 courses with satisfactory response may be treated every 4-5 weeks.