ONC201 in Treating Patients With Relapsed or Refractory Acute Leukemia or High-Risk Myelodysplastic Syndrome

This study is testing an experimental drug called ONC201 in adults with leukemia or a pre-leukemia blood disorder (called high-risk MDS) whose cancer has come back or stopped responding to standard treatments. **You may be eligible if...** - You are 18 or older - You have acute leukemia or high-risk MDS that has returned or stopped responding to standard therapies - Your kidney, liver, and blood counts are within acceptable limits - Enough time has passed since your last cancer treatment - If you have had a stem cell transplant, it was more than 6 months ago and you have no active graft-versus-host disease **You may NOT be eligible if...** - You have uncontrolled infections, severe heart failure, or uncontrolled irregular heartbeat - You have been treated for another cancer within the past 3 years (except minor skin cancers) - You are known to have HIV, hepatitis B, or hepatitis C - You currently use drugs or alcohol heavily - The leukemia has spread to your brain or spinal fluid - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.