Open Label, Phase II Study to Evaluate Efficacy and Safety of Oral Nilotinib in Philadelphia Positive (Ph+) Chronic Myelogenous Leukemia (CML) Pediatric Patients.

Key Inclusion Criteria: * Newly diagnosed and untreated Ph+ CML CP or Ph+ CML CP or AP resistant or intolerant to either imatinib or dasatinib * Karnofsky ≥ 50% for patients \> 10 years of age and Lansky ≥ 50 for patients ≤ 10 years of age * Adequate renal, hepatic and pancreatic function * Potassium, magnesium, phosphorus and total calcium values ≥ LLN (lower limit of normal) * Written informed consent Key Exclusion Criteria: * Treatment with strong CYP3A4 inhibitors or inducers * Use or planned use of any medications that have a known risk or possible risk to prolong the QT interval * Acute or chronic liver, pancreatic or severe renal disease * History of pancreatitis or chronic pancreatitis. * Impaired cardiac function * No evidence of active graft vs host and \<3mo since Stem Cell Transplant * Total body irradiation (TBI) or craniospinal radiation therapy \<6months * Hypersensitivity to the active ingredient or any of the excipients including lactose. * the criteria regarding pregnancy and contraception * Active or systemic bacterial, fungal, or viral infection * known Hepatitis B, Hepatitis C, or HIV infection