Randomized Open-Label Study of INCB047986 in Subjects With Primary Myelodysplastic Syndrome (MDS)

Inclusion Criteria: * Subjects 18 years of age or older. * Subjects must be diagnosed with MDS according to the World Health Organization (WHO) classification for de novo or primary MDS (Vardiman et al 2009). * Subjects who require RBC transfusions or are either refractory to or unlikely to respond to ESA therapy should meet one of the following criteria: * ESA failure as defined by no improvement in Hgb of at least 1.5 g/dL after 8 weeks of at least 40,000 IU per week of EPO (or equivalent). * Have a serum erythropoietin (EPO) of ≥ 500 IU and Hgb level \< 10.0 g/dL. * Transfusion dependence defined as requiring at least 4 units of packed red blood cells (RBCs) for a Hgb of \< 9 g/dL over the 8 weeks prior to screening. * Subjects may not have received hypomethylating agents or immunosuppressive therapy for their MDS prior to this study. Exclusion Criteria: * Subjects at high risk for transformation to acute leukemia as evidenced by poor karyotype or peripheral blood blasts \> 10%. * Subjects with severely compromised bone marrow function as evidenced by trilineage cytopenias with anemia (Hgb \< 10 g/L, platelets \< 100 × 109/L, and absolute neutrophil count (ANC) \< 1.8 × 109/L). * Subjects who harbor the 5q deletion chromosomal aberration. * Subjects with chronic myelomonocytic leukemia (CMML). * Women who are pregnant or breastfeeding, and men and women who cannot comply with requirements to avoid fathering a child or becoming pregnant, respectively. * Subjects with impaired liver function, end stage renal disease on dialysis, or clinically significant concurrent infections requiring therapy. * Subjects with unstable cardiac function. * Invasive malignancies over the previous 2 years except treated basal or squamous carcinomas of the skin, completely resected intraepithelial carcinoma of the cervix, Stage 1 or 2 treated prostate