Inclusion Criteria:

- Ph+ CML-CP within 12 months of diagnosis

- Imatinib 400 mg qd for up to 12 months

- Imatinib trough plasma concentration <850 ng/mL

- Patient that have met response milestones including:

1. CHR and at least minor CyR (Ph+ ≤65%) at 3 months from diagnosis

2. At least pCyR at 6 months from diagnosis (Ph+ ≤35%)

3. CCyR at 12 months from diagnosis

Exclusion Criteria:

- Prior documented failure events including:

- Loss of CHR or CCyR

- Less than CHR (stable disease or disease progression) at 3 months after diagnosis

- No CyR at 6 months after diagnosis

- Less than PCyR at 12 months after diagnosis

- Prior accelerated phase or blast phase CML

- Previously documented T315I mutation

- Previous treatment with any other tyrosine kinase inhibitor except for imatinib.

- Patients who had any other treatment for CML (transplant) except imatinib,
hydroxyurea and/or anagrelide

- Impaired cardiac function (refer to Section 5.2 for details)

- Patients receiving therapy with strong inhibitors of CYP3A4 or medications that
prolong the QT interval and cannot be either discontinued or switched to a different
medication prior to starting study drug.

- Any other malignancy that is clinically significant or requires active intervention.

- Major surgery within 4 weeks prior to Day 1 of study or who have not recovered from
prior surgery.

- Treatment with other investigational agents within 30 days of Day 1.