A Study of Imatinib Versus Nilotinib in Adult Patients With Newly Diagnosed Philadelphia Chromosome Positive (Ph+) Chronic Myelogenous Leukemia in Chronic Phase (CML-CP)

Key Inclusion criteria: * Chronic myelogenous leukemia in chronic phase patients within the first 6 months of diagnosis. * Diagnosis of chronic myelogenous leukemia in chronic phase with confirmation of Philadelphia chromosome of (9:22) translocations Key Exclusion criteria: * Previously documented T315I mutation * Treatment with a tyrosine kinase inhibitor prior to study entry is not allowed except for no more than 2 weeks in duration of imatinib * Any medical treatment for CML prior to study entry for longer than 2 weeks with the exception of hydroxyurea and/or anagrelide * Impaired cardiac function. * Severe or uncontrolled medical conditions (i.e. uncontrolled diabetes, active or uncontrolled infection). * Use of therapeutic coumarin derivatives (i.e., warfarin, acenocoumarol, phenprocoumon) * Currently receiving treatment with any medications that have the potential to prolong the QT interval.