Phase I Study Of Flavopiridol In Combination With Imatinib Mesylate (STI571, Gleevec) In Bcr/Abl+ Hematological Malignancies

OBJECTIVES:

• Determine the maximum tolerated dose and recommended phase II dose of flavopiridol and imatinib mesylate in patients with Bcr/Abl+ hematological malignancies.
• Determine the toxic effects of this regimen in these patients.
• Determine the disease-related effects of this regimen in these patients.
• Determine the pharmacokinetics and pharmacodynamics of this regimen in these patients.
• Correlate response to this regimen with mechanisms of imatinib mesylate resistance in patients previously treated with imatinib mesylate.

OUTLINE: This is a dose-escalation, multicenter study. Patients are stratified according to percentage of blasts in the peripheral blood and bone marrow (less than 15% vs at least 15%) and recent myelosupressive treatment (no vs yes).

Patients receive oral imatinib mesylate daily and flavopiridol IV over 1 hour on days 2, 9, and 16. Courses repeat every 28 days in the absence of disease progression or unacceptable toxicity.

Cohorts of 3-6 patients receive escalating doses of imatinib mesylate and flavopiridol until the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 3 or 2 of 6 patients experience dose-limiting toxicity.