A Multicenter Phase 3, Open-Label Study of Bosutinib Versus Imatinib in Adult Patients With Newly Diagnosed Chronic Phase Chronic Myelogenous Leukemia

The study will be open for enrollment until the planned number of approximately 500
Philadelphia Chromosome Positive (Ph+) patients have been randomized (approximately 250 Ph+
patients in each treatment arm; a total of approximately 530 Ph+ and Ph- patients). All
patients will be treated and/or followed for approximately 5 years (240 weeks) after
randomization until the study has closed. Patients who discontinue study therapy early due to
disease progression or intolerance to study medication will continue to be followed yearly
for survival for up to approximately 5 years (240 weeks) after randomization.

Inclusion Criteria:

1. Molecular diagnosis of CP CML of ≤ 6 months (from initial diagnosis).

2. Adequate hepatic, renal and pancreatic function.

3. Age ≥ 18 years.

Exclusion Criteria:

1. Any prior medical treatment for CML, including tyrosine kinase inhibitors (TKIs), with
the exception of hydroxyurea and/or anagrelide treatment, which are permitted for up
to 6 months prior to study entry (signature of ICF) if suitably approved for use in
the subject's region.

2. Any past or current Central Nervous System (CNS) involvement, including leptomeningeal
leukemia.

3. Extramedullary disease only.

4. Major surgery or radiotherapy within 14 days of randomization.

5. History of clinically significant or uncontrolled cardiac disease.

6. Known seropositivity to human immunodeficiency virus (HIV), current acute or chronic
hepatitis B (hepatitis B surface-antigen positive), hepatitis C, cirrhosis or evidence
of decompensated liver disease. Patients with resolved Hepatitis B can be included.

7. Recent or ongoing clinically significant GI disorder, e.g. Crohn's Disease, Ulcerative
Colitis, or prior total or partial gastrectomy.

8. History of another malignancy within 5 years with the exception of basal cell
carcinoma or cervical carcinoma in situ or stage 1 or 2 cancer that is considered
adequately treated and currently in complete remission for at least l2 months.

9. Current, or recent (within 30 days, or 5 half-lives of investigational product)
participation in other clinical trials of investigational agents and/or containing
interventional procedures deemed contrary to the objectives and conduct of this trial.