Inclusion Criteria:
- Patients ≥ 18 years of age
- ECOG (Eastern Cooperative Oncology Group) Performance Status 0, 1, or 2
- Must have a diagnosis of Philadelphia chromosome positive (Ph+) chronic myeloid leukemia (CML) in chronic phase, with no previous evidence of accelerated or blast-phase disease.
- Must be actively receiving treatment for their CML with a tyrosine kinase inhibitor (TKI): imatinib, dasatinib, nilotinib or bosutinib, and must be on stable dose for > 1 year.
- Must have an ongoing complete hematologic response (CHR) on a TKI
- Must have an ongoing complete cytogenetic response (CCyR) on a TKI
- Must be in a major molecular remission (MMR) on a TKI for a minimum of 1 year leading up to enrollment.
- Adequate end organ function
- Adequate electrolytes
- Adequate platelet count
- Adequate neutrophil count
- Written informed consent prior to any screening procedures
Exclusion Criteria:
- Patients in complete molecular remission (CMR) on a TKI.
- Patients who have failed nilotinib or not tolerated nilotinib in the past
- Certain cardiovascular disorders
- Currently receiving treatment with strong CYP3A4 inhibitors which cannot be discontinued prior to starting study drug
- Actively receiving herbal medicines that are strong CYP3A4 inhibitors and/or inducers and treatment cannot be discontinued prior to starting study drug
- Currently receiving treatment with any medications that have the potential to prolong the QT interval that cannot be discontinued prior to starting study drug
- Impaired gastrointestinal (GI) function or GI disease that may significantly alter the absorption of the drug
- Acute or chronic pancreatic disease within the last year
- Cytopathologically confirmed Central Nervous System (CNS) infiltration
- Another primary malignancy that requires systemic chemotherapy or radiation
- Acute or chronic liver disease or severe renal disease considered unrelated to the cancer
- History of significant congenital or acquired bleeding disorder unrelated to cancer
- Major surgery within 4 weeks prior to Day 1 of the study or who have not recovered from prior surgery
- Past treatment with ruxolitinib
- Treatment with other investigational agent within 30 days of Day 1
- Inability to grant consent or history of non-compliance to medical regimens
- Women who are breastfeeding
- Women of child-bearing potential, unless they are using highly effective contraception
| Maximum Eligible Age: | N/A |
| Minimum Eligible Age: | 18 Years |
| Eligible Gender: | All |
| Healthy Volunteers: | No |
