Inclusion Criteria

Inclusion criteria:

- Ability to provide written informed consent prior to participation to the study.

- Male or female patients ≥ 18 and ≤ 75 years of age

- Patients with CML-CP within 6 months of diagnosis (date of initial diagnosis is the
date of first cytogenetic analysis). FISH analysis will not be accepted.

- Diagnosis of CML in chronic phase with cytogenetic confirmation of Philadelphia
chromosome of (9;22) translocations and presence of Bcr-Abl

- Documented chronic phase CML as defined by:

- < 15% blasts in peripheral blood and bone marrow

- < 30% blasts plus promyelocytes in peripheral blood and bone marrow

- < 20% basophils in the peripheral blood

- ≥ 100 x 109/L (≥ 100,000 /mm3) platelets

- No evidence of extramedullary leukemic involvement, with the exception of
hepatosplenomegaly

- Adequate end organ function as defined by:

- total bilirubin < 1.5 x ULN

- SGOT and SGPT < 2.5 x UNL

- creatinine < 1.5 x ULN

- Female patients of childbearing potential must have a negative serum pregnancy test
within 7 days before initiation of study drug

Exclusion criteria:

- Patients in late chronic phase, accelerated phase, or blastic phase are excluded

- Patients who have received other investigational agents

- Patients who received imatinib for any duration prior to study entry

- Patient received any treatment for CML prior to study entry for longer than 2 weeks
with the exception of hydroxyurea and/or anagrelide

- Patients with another primary malignancy except if the other primary malignancy is
neither currently clinically significant or requiring active intervention

- Patients who are:

- pregnant

- breast feeding

- of childbearing potential without a negative pregnancy test prior to baseline

- male or female of childbearing potential unwilling to use barrier contraceptive
precautions throughout the trial

- Post-menopausal women must be amenorrheic for at least 12 months to be considered of
non-childbearing potential

- Patient with a severe or uncontrolled medical condition (i.e., uncontrolled diabetes,
chronic renal disease)

- Patient previously received radiotherapy to ≥ 25% of the bone marrow

- Patient had major surgery within 4 weeks prior to study entry, or who have not
recovered from prior major surgery

- Patients with an ECOG Performance Status Score ≥ 3

- Patients with International normalized ratio (INR) or partial thromboplastin time
(PTT) > 1.5 x IULN, with the exception of patients on treatment with oral
anticoagulant

- Patients with known positivity for human immunodeficiency virus (HIV)

- baseline testing for HIV is not required

- Patients with any significant history of non-compliance to medical regimens or with
inability to grant a reliable informed consent

- Patients with identified sibling donors where allogeneic bone marrow transplant is
elected as first line treatment

- Patients who are chronic users of acetaminophen or medications containing
acetaminophen.

- Patients who received acetaminophen or medications containing acetaminophen within 72
hours prior to study entry.

Other protocol-defined inclusion/exclusion criteria may apply