Multi-institutional Prospective Research of Expanded Multi-antigen Specifically Oriented Lymphocytes for the Treatment of VEry High Risk Hematopoietic Malignancies

This trial is testing a type of immune cell therapy called TAA-T (Tumor-Associated Antigen T cells) — specially trained immune cells grown from the patient's stem cell donor — to prevent leukemia (AML and MDS) from coming back after a stem cell transplant. **You may be eligible if...** - You are between 6 months and 80 years old - You have high-risk AML or MDS and have received, or are planning to receive, a stem cell transplant from a donor - Your cancer has not relapsed after the transplant - Your general health is acceptable (Karnofsky/Lansky score at least 50) - You are willing to use contraception during the study (if age-appropriate) **You may NOT be eligible if...** - You have an uncontrolled active infection - You have significant graft-versus-host disease (a complication where the transplanted cells attack your body) - You are pregnant - Your organ function does not meet the minimum requirements at the time of cell infusion Talk to your doctor to see if this trial is right for you.