The purpose of this study is to learn if 5'-Azacitidine will help to lower the risk of the disease coming back after a stem cell transplant in patients with MDS and AML. This study will also be looking at the side effects of this medicine.

5'-Azacitidine is an FDA approved drug for treatment of MDS and AML, as well as patients whose disease came back after transplant, where it helped going into remission. It is unclear if 5'-Azacitidine can prevent the disease from coming back after transplant. This study will help show if getting 5'-Azacitidine soon after transplant can lower the risk of your disease coming back.

Inclusion Criteria:

Patients who have undergone T cell depleted allogeneic hematopoietic stem cell transplantation at MSKCC for:

• De novo myelodysplastic syndromes (MDS): IPSS-1 with poor risk cytogenetics or higher IPSS.
• Acute myelogenous leukemia (AML) in first remission that required more than 1 cycle of treatment to achieve remission or with the following cytogenetic abnormalities: FLT3 mutation, deletion/monosomy of chromosome 5 or 7, MLL gene rearrangement, or more than or equal to 3 cytogenetics abnormalities. Also patients in second or greater remission.
• Patients with Secondary MDS/AML.
• Patients will be considered eligible for the study if after transplant they achieved hematologic (<5% blasts) and cytogenetic remission.
• Patients will be eligible to enter the study between 60-120 days post transplant.
• Age: pediatrics and adults patients - 1 year old-75 years old.
• Karnofsky performance status >=60% for patients >16yo and Lansky performance status >=60% for patients ≤16yo
• Stable blood counts (ANC>1000/uL, Hb>8gr/dL, Plt>50,000/ uL) not supported by transfusions.
• Renal: Serum creatinine <1.5 ULN
• Hepatic: <3xULN ALT and <1.5 total serum bilirubin, unless there is congenital benign hyperbilirubinemia.
• Cardiac: Adequate cardiac function measured by LVEF>50%. If asymptomatic, pretransplant echocardiogram is adequate. If symptomatic, echocardiogram needs to be repeated.
• Each patient must be willing to participate as a research subject and must sign an informed consent form.

Exclusion Criteria:

Patients will be excluded from the trial if at time of enrollment:

• Active uncontrolled bacterial, fungal or viral infection.

• Evidence of uncontrolled graft-versus-host disease.

• Pulmonary: new onset hypoxia

• Known or suspected hypersensitivity to 5'-azacitadine or mannitol.

  • Evidence of residual disease either by increased blasts count (>5%) or persistence of previous known cytogenetics abnormalities.

• Peripheral blood neutrophil chimerism: less than 95% donor.