Inclusion Criteria:

          -  Participants must have pathologically confirmed AML in CR1 as defined by:

               -  Bone marrow biopsy with < 5% blasts

               -  No clusters or collections of blast cells

               -  No extramedullary leukemia

               -  Absolute neutrophil count ≥ 1000/µL (achieved post-induction at some point)

               -  Please note that full platelet recovery is not necessary, and thus, patients
                  achieving CRp are eligible.

          -  Participants must be designated to undergo reduced intensity allogeneic peripheral
             blood hematopoietic stem cell transplantation (HCT). Consent will be obtained prior to
             admission for HCT. The following HCT 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 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/m2 IV total dose and
                       melphalan is 100-140 mg/m2 IV total dose. Exact logistics of administration
                       are at the discretion of institutional standard.

                    -  Fludarabine / Busulfan where fludarabine is ≥ 90 mg/m2 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/m2 IV total dose and
                       busulfan is dosed to achieve AUC of 4000 µmol/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 HCT and methotrexate given
                       after HCT on days +1, +3 and +6 ± +11 at a dose of 5-10 mg/m2 IV. Exact
                       logistics are at the discretion of the treating institution.

          -  Age ≥ 60 and ≤ 80 years old

          -  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.

          -  Patients without normal organ function defined as follows:

               -  Platelet count of ≤50,000/ μL, hemoglobin of ≤8g/dL, or ANC of ≤1000 AST (SGOT),
                  ALT (SGPT) and Alkaline Phosphatase ≥5 × institutional Upper Limit of Normal
                  (ULN)

               -  Direct 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 any history of documented diastolic or systolic dysfunction
             (LVEF < 40%, as measured by 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 HIV-positive and on combination antiretroviral therapy because of the potential for
             pharmacokinetic interactions with ruxolitinib. In addition, these participants are at
             increased risk of lethal infections when treated with marrow-suppressive therapy.

          -  Have a systemic infection requiring IV antibiotic therapy, nor any other severe
             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