A DLT included events that started within 28 days of the first dose of CC-486 in a 28-day cycle, constituted a change from baseline irrespective of outcome, as decided by the investigator to be related to CC-486 including: * ≥ Grade (GR) 3 nausea, diarrhea, or vomiting despite the use of medical support * Other significant nonhematologic toxicity of ≥ GR 3 considered not related to the disease or intercurrent illness • Absolute neutrophil count (ANC) \< 0.5 x 10\^9/L for \> 1 week despite growth factor support * Platelets \< 25 x 10\^9/L for \> 1 week despite transfusion support * Failure of recovery to an ANC ≥ 1.0 x 10\^9/L and/or platelets ≥ 50 x 10\^9/L with a hypocellular marrow by 56 days after the start of a cycle of CC-486 not due to relapse or progressive disease. The maximum tolerated dose is defined as the cohort delivering the highest dose in which no more than 33% of the evaluable subjects had a DLT The safety population included subjects who received ≥ 1 dose of CC-486

A TEAE was defined as any AE with an onset date on or after the first dose of IP or any event already present that worsened in severity or increased in frequency after exposure to IP up to 28 days after the last dose. In addition, an AE that occurred beyond the timeframe and was assessed by the doctor as possibly related to IP was considered to be treatment-emergent. Severity was assessed using National Cancer Institute Common Toxicity Terminology Criteria for AEs (NCI CTCAE) version 4.0, where 1= Mild; 2= Moderate; 3= Severe; 4= Life-threatening; 5= Death related to AE. Serious AEs resulted in death, were life-threatening, required or prolonged inpatient hospitalization, resulted in persistent or significant disability/incapacity, congenital anomaly, or resulted in a medical event that may have jeopardized the patient or required medical or surgical intervention to prevent one of the outcomes above.