Ruxolitinib Phosphate in Treating Older Patients with Acute Myeloid Leukemia in Complete Remission or Myelodysplastic Syndrome after Donor Stem Cell Transplant

Inclusion Criteria

• Participants must meet either of the following: * Have pathologically confirmed acute myeloid leukemia (AML) in complete remission (CR) as defined by: ** Bone marrow biopsy with < 5% blasts ** No clusters or collections of blast cells ** No extramedullary leukemia ** Absolute neutrophil count >= 1000/uL (achieved post-induction at some point) ** Please note that full platelet recovery is not necessary, and thus, patients achieving pathological complete remission (CRp) are eligible * Or have pathologically confirmed myelodysplastic syndrome (MDS) as defined by: ** Bone marrow biopsy with < 10% blasts ** Patients receiving MDS-directed therapy must be off treatment for > 2 weeks prior to start of conditioning
• Participants must be designated to undergo reduced intensity allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT); consent will be obtained prior to admission for HSCT; the following HSCT conditions must be planned: * Donors must be 8/8 HLA-matched (at the allele level) as defined by matching at HLA-A, -B, -DR and –C who pass institutional standard to serve as a peripheral blood stem cell donor * Donor grafts must be granulocyte colony-stimulating factor (G-CSF) mobilized peripheral blood stem cells with dose and apheresis logistics at the discretion of institutional standard * Conditioning therapy will be one of the following 3 options: ** Fludarabine/melphalan where fludarabine is >= 90 mg/m^2 intravenously (IV) total dose and melphalan is 100-140 mg/m^2 IV total dose; exact logistics of administration are at the discretion of institutional standard ** Fludarabine/busulfan where fludarabine is >= 90 mg/m^2 IV total dose and busulfan = 6.4 mg/kg IV total dose; exact logistics of administration are at the discretion of institutional standard ** Fludarabine/busulfan where fludarabine is >= 90 mg/m^2 IV total dose and busulfan is dosed to achieve area under the curve (AUC) of 4000 umol/min based on a pharmacokinetics determined from a test dose; exact logistics are at the discretion of institutional standard * GVHD prophylaxis is comprised of tacrolimus/short course methotrexate as defined by tacrolimus started prior to day 0 of HSCT and methotrexate given after HSCT on days +1, +3 and +6 +/- +11 at a dose of 5-10 mg/m^2 IV; exact logistics are at the discretion of the treating institution
• Age >= 60 and =< 80 years old
• Eastern Cooperative Oncology Group (ECOG) performance status 0–2
• Male participants must agree to use an acceptable method for contraception during the entire study treatment period and through 6 months after the last dose of treatment
• Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria

• Have had a prior allogeneic HSCT
• Aspartate aminotransferase (AST) (serum glutamic-oxaloacetic transaminase [SGOT]), alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase [SGPT]) and alkaline phosphatase >= 3 x institutional upper limit of normal (ULN)
• Total bilirubin > 2.0 mg/dL
• Adequate renal function as defined by calculated creatinine clearance =< 40 mL/min (Cockcroft-Gault formula)
• Have a history of other malignancy(ies) unless: They have been disease-free for at least 5 years and are deemed by the treating investigator to be at low risk for recurrence of that malignancy, or the only cancer they have had is cervical cancer in situ, or basal cell or squamous cell carcinoma of the skin
• Have a chronic or active infection that requires systemic antibiotics, antifungal or antiviral treatment
• Have current or a history of congestive heart failure New York Heart Association (NYHA) class 3 or 4, or current documented diastolic or systolic dysfunction (left ventricular ejection fraction [LVEF] < 40%, as measured by multigated acquisition [MUGA] scan or echocardiogram)
• Have an uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements
• Be human immunodeficiency virus (HIV)-positive
• Have active uncontrolled infection; an active uncontrolled infection is defined as hemodynamic instability attributable to sepsis or new symptoms, worsening physical signs, or radiographic findings attributable to infection; persisting fever without signs or symptoms will not be interpreted as an active uncontrolled infection
• Planned use of ex vivo or in vivo T-cell depletion
• Have current or a history of ventricular or life-threatening arrhythmias or diagnosis