 - Patients with chronic phase CML will be either refractory failed to achieve hematologic or cytogenetic response or resistant responded initially but subsequently lost hematologic or cytogenetic response to prior imatinib mesylate therapy. Failure to achieve cytogenetic response is defined as follows: no cytogenetic response after 3 months of therapy with imatinib mesylate, no major cytogenetic response at 12 months of therapy, loss of complete cytogenetic response documented twice, or loss of major cytogenetic response at least once. 