Dr. Devine and team are conducting the first trial in children and young adults examining CAR T cell therapy as a treatment for relapsed or refractory acute myeloid leukemia (AML). CAR T cell therapy is when a patient’s T cells (a part of the immune system) are changed so that they will attack cancer cells. In this trial specifically, the patient’s T cells will be modified to anti-CD33 chimeric antigen receptor expressing T cells (CD33CART) which target AML cancer cells. There are two phases in this trial: Phase I will focus on the safety and maximum dosage amount of CD33CART; Phase II will focus on the effectiveness of CD33CART to attack the AML cells – hopefully resulting in remission. If successful, this trial will provide a much-needed new treatment option for children and young adults with AML with the possibility to significantly extend their lives or provide a chance for a cure.