Inclusion Criteria

Inclusion:

- Histologically confirmed diagnosis of CML chronic 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
chronic phase with the exception of hydroxyurea

- Age >/= 2 years

- Bilirubin
- 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 high dose within 28 days; etoposide, anthracyclines, or mitoxantrone within 21
days; busulfan within the past six weeks

- Patients who had received hematopoietic stem cell transplantation within 6 weeks of
Day 1 decitabine therapy

- Patients with Grade 3/4 cardiac disease or any other serious concurrent medical
condition.

- Patients who are pregnant or nursing. All patients of childbearing potential must
practice effective methods of contraception while on study.

- Patients with mental illness or other condition precluding their ability to give
informed consent or to comply with study requirements

- Patients with systemic, uncontrolled infections