- Chronic myelogenous leukemia- chronic phase failing imatinib mesylate therapy (either progressive disease or failure to achieve a major cytogenetic response at 1 year following initiation of therapy), accelerated phase failing to achieve a complete cytogenetic remission at 1 year following initiation of therapy, accelerated phase failing to achieve any cytogenetic response at 6 months of therapy, accelerated phase with progressive disease as demonstrated by worsening cytogenetic response in two consecutive analyses separated by 4 weeks or CML in blast crisis. Patients with blast phase of CML must have < 10% blasts in bone marrow.