Phase II Trial of Decitabine in Patients With Chronic Myelogenous Leukemia Blast Phase Who Are Refractory to Imatinib Mesylate (Gleevec)

Inclusion: * Histologically confirmed diagnosis of CML blast phase * Ph chromosome-positive * Previous treatment with imatinib mesylate resulting in: i) Hematologic Resistance / Hematologic Refractory: Based on a physician's (documented) decision to discontinue imatinib mesylate treatment due to failure of continued benefit or no benefit to the patient, ii) Imatinib Mesylate Intolerance: any toxicity resulting in a physician's (documented) decision to discontinue imatinib mesylate treatment. * Patients must have recovered from the side effects of previous CML therapy for blast phase with the exception of hydroxyurea * Age \>/= 2 years * Bilirubin \</= 3 x the upper limit of normal (ULN), SGOT and SGPT \</= 3 x ULN, except \</= 5 x ULN in leukemic involvement of the liver, serum creatinine \</= 2 x ULN * WHO performance status 0-3 * A negative serum hCG pregnancy test in patients of childbearing potential * Able to give signed informed consent directly or through a parent or guardian for minors Exclusion: * Leukemic involvement of the central nervous system * Active malignancy other than CML or non-melanoma cancer of the skin * Previous treatment for CML with another investigational agent within 28 days of study entry * At study entry, patients who were treated with: imatinib mesylate within the past 48 hours, interferon-alpha within the past 48 hours; homoharringtonine within the past 14 days; low-dose cytosine arabinoside within 7 days, moderate dose within 14 days, or hi…