Ipilimumab in Treating Patients With Relapsed or Refractory High-Risk Myelodysplastic Syndrome or Acute Myeloid Leukemia

PRIMARY OBJECTIVES: I. Evaluate the safety and toxicity associated with the administration of ipilimumab in terms of dose limiting toxicities (DLT), and maximally-tolerated dose (MTD) in a cohort of patients with high risk myelodysplastic syndrome who failed hypomethylating therapy, and patients with acute myeloid leukemia (AML) who underwent induction therapy but are not planned for further intensive chemotherapy. (Dose-escalation) II. Determine the optimal dose of ipilimumab for the dose-expansion phase of the trial. (Dose-escalation) III. Better define immunologic profiles associated with ipilimumab use in terms of regulatory T-cells (T-regs) dynamic changes in 2 separate cohorts of myelodysplastic syndrome (MDS) and AML patients at the optimal dose level. (Dose-expansion) IV. Obtain preliminary efficacy data of ipilimumab in terms of complete response (CR), partial response (PR), and hematological improvement (HI) in both cohorts. (Dose-expansion) SECONDARY OBJECTIVES: I. Define immunologic profiles associated with ipilimumab use in terms of T-regs dynamic changes at different dose levels. (Dose-escalation) II. Define toxicity profiles of ipilimumab at the optimal dose in both patient cohorts. (Dose-expansion) III. Obtain preliminary data on potential correlations between noted ipilimumab-induced immunologic changes and observed toxicity and clinical responses. (Dose-expansion) OUTLINE: This is a dose-escalation study. INDUCTION: Patients receive ipilimumab intravenously (IV) on day 1. Treatment repeats every 21 days for up to 4 courses in the absence of disease progression or unacceptable toxicity. MAINTENANCE: Beginning 12 weeks after last dose of induction ipilimumab, patients receive ipilimumab IV on day 1. Treatment repeats every 12 weeks for up to 4 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up at least monthly for 6 months.