Azacitidine and Pembrolizumab in Treating Patients With Myelodysplastic Syndrome

PRIMARY OBJECTIVES: I. To assess the safety of the combination of azacitidine and MK3475 (pembrolizumab) in patients with higher risk myelodysplastic syndrome (MDS). II. To explore the clinical activity (response, survival effect) of the combination of azacitidine with MK-3475 in patients with higher risk MDS. EXPLORATORY OBJECTIVES: I. To study the biological effects of the combination of azacitidine and pembrolizumab in patients with MDS treated on this study. OUTLINE: Patients receive azacitidine intravenously (IV) over 10-40 minutes or subcutaneously (SC) on days 1-7, and pembrolizumab IV over 30 minutes every 3 weeks. Cycles repeat every 4 weeks in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up within 30 days, every 12 weeks for 1 year, then annually thereafter.