Nivolumab and Ipilimumab after Donor Stem Cell Transplant in Treating Patients with High Risk Refractory or Relapsed Acute Myeloid Leukemia or Myelodysplastic Syndrome

Inclusion Criteria

• Patients with evidence of relapsed or refractory AML or MDS following allogeneic stem cell transplantation (allo-SCT) Evidence of relapse will include: *AML patients: Bone marrow or peripheral blood blast count >/= 5% and/or presence of extramedullary disease (myeloid sarcoma) and/or presence of measurable residual disease by multicolor flow cytometry in the bone marrow *MDS patients: Appearance of dysplastic changes in the bone marrow, with or without increase in bone marrow blast count, which is pathologically consistent with myelodysplastic syndrome.
• Age >/=18 years
• Patients must have received preparative regimens to include either busulfan- or melphalan-based regimens
• Patient must have achieved myeloid engraftment as defined by an absolute neutrophil count >= 500 micro/L on 3 consecutive days
• Eastern Cooperative Oncology Group (ECOG) performance status =< 2
• Direct bilirubin =< 2 times upper limit of normal (x ULN)
• Aspartate aminotransferase or alanine aminotransferase =< 2.5 x ULN
• Serum creatinine =< 2 x ULN or glomerular filtration rate (GFR) >= 50
• Patients must provide written informed consent
• The interval from the infusion of stem cells to time of initiation of nivolumab or ipilimumab will be at least 6 weeks (42 days)
• Females must be surgically or biologically sterile or postmenopausal (amenorrheic for at least 12 months) or if of childbearing potential, must have a negative serum or urine pregnancy test within 72 hours before the start of the treatment
• Women of childbearing potential must agree to use an adequate method of contraception during the study and until 5 months after the last treatment. Male study participants will not be required to use contraceptive measures and/or a latex or other synthetic condom during sexual activity with a woman of childbearing potential (WOCBP) partner

Exclusion Criteria

• Patients with known allergy or hypersensitivity to nivolumab or ipilimumab or any of their components
• Patients with acute GVHD > grade 2 at any time during the post-transplant course
• Patients with a known history of severe interstitial lung disease or severe pneumonitis or active pneumonitis that is uncontrolled in the opinion of the treating physician
• Patients with a known history of any of the following autoimmune diseases are excluded: * Patients with a history of inflammatory bowel disease (including Crohn’s disease and ulcerative colitis) * Patients with a history of rheumatoid arthritis, systemic progressive sclerosis (scleroderma), systemic lupus erythematosus, autoimmune vasculitis (e.g., Wegener’s granulomatosis)
• Patients with solid organ allografts (such as renal transplant) are excluded
• Ongoing immunosuppressive therapy for the treatment of GVHD. Patients receiving GVHD prophylaxis will be allowed on this study
• Patients with symptomatic central nervous system (CNS) leukemia at the time of evaluation or patients with poorly controlled CNS leukemia
• Active and uncontrolled disease/(active uncontrolled infection, uncontrolled hypertension despite adequate medical therapy, active and uncontrolled congestive heart failure New York Heart Association [NYHA] class III/IV, clinically significant and uncontrolled arrhythmia) as judged by the treating physician
• Patients with known human immunodeficiency virus seropositivity will be excluded
• Known to be positive for hepatitis B by surface antigen expression. Known to have active hepatitis C infection (positive by polymerase chain reaction or on antiviral therapy for hepatitis C within the last 6 months)
• Any other medical, psychological, or social condition that may interfere with study participation or compliance, or compromise patient safety in the opinion of the investigator
• Patients unwilling or unable to comply with the protocol
• Pregnant or breastfeeding