This trial is testing an experimental treatment called DFP-10917 against standard treatments for relapsed or refractory acute myeloid leukemia (AML). Patients in the experimental arm will receive DFP-10917 by continuous intravenous infusion for 14 days, followed by a 14-day resting period, for up to 6 cycles. Patients in the control arm will receive standard treatments, which may include non-intensive reinduction or intensive reinduction, depending on the patient's prior induction treatment.