Guadecitabine will be given SC at a dose of 60 mg/m2 in 28-day cycles. In Cycle 1, guadecitabine will be given for 10 days on Days 1-5 and Days 8-12. Cycle 2 will be either the 5-day regimen (Days 1-5) or 10-day regimen (Days 1-5 and 8-12) based on assessment of disease response and hematologic recovery at the end of Cycle 1. In subsequent cycles, guadecitabine treatment will be for 5 days only (Days 1-5).