Imatinib Mesylate, Busulfan, Fludarabine, and Antithymocyte Globulin for CML Patients

Inclusion Criteria:

1. Diagnosis of Ph+ chronic myelogenous leukemia (CML) in first chronic phase without a complete hematologic response after 3 months of Imatinib mesylate therapy, or \>=35% Ph+ cells despite \> 6 months of Imatinib mesylate treatment, or after disease progression from a complete or partial response. Any patient with accelerated phase or blast crisis who achieves a subsequent chronic phase is eligible. Patients must have an HLA matched related or unrelated donor or one antigen mismatched related donor.
2. Patients should be less than 70 years of age. Patients less than 30 years of age who achieve a hematologic remission with imatinib therapy are eligible regardless of cytogenetic response.
3. Patients are stratified as Group 1: First chronic phase, Group 2 Accelerated phase or blast crisis that achieved a hematologic remission with imatinib mesylate-based treatment.

Exclusion Criteria:

1. Zubrod Performance Scale (PS) \>=2, uncontrolled infection, Creatinine \> 2.0 mg/dl; Ejection fraction \< 40%; Carbon Monoxide Diffusing Capacity (DLCO) \< 45% of predicted; Serum bilirubin \> 2 gm/dl; GPT (Glutamic-pyruvic transaminase) or GOT (glutamic-oxaloacetic transaminase)\> 3 times normal values. Patients should not be human immunodeficiency virus (HIV) seropositive or pregnant.
2. Patients should not have progressed to accelerated phase or blast crisis while receiving imatinib mesylate containing therapy.