Phase 3 Randomized, Open-Label Study of Guadecitabine vs Treatment Choice in Previously Treated Acute Myeloid Leukemia

This Phase 3, randomized, open-label, parallel-group multicenter study of the efficacy and safety of guadecitabine in adults with previously treated acute myeloid leukemia (AML) will be conducted in approximately 20 countries. There will be a 14-day screening period, a treatment period, a safety follow-up visit, and a long-term follow-up period. The study is expected to last approximately 2 years. Duration of individual participant participation will vary, and participants may continue to receive treatment for as long as they continue to benefit. Approximately 404 participants from approximately 100 study centers will be randomly assigned to either guadecitabine or treatment choice (TC) in a 1:1 ratio (approximately 202 participants per group). TC is as follows: * High intensity: intermediate or high dose cytarabine (HiDAC); mitoxantrone, etoposide, and cytarabine (MEC); or fludarabine, cytarabine, G-CSF, +/- idarubicin (FLAG/FLAG-Ida). * Low intensity: low dose cytarabine (LDAC), decitabine, or azacitidine. * Best Supportive Care (BSC). Guadecitabine will be given subcutaneous (SC) at a dose of 60 microgram per meter square (mg/m\^2) 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).