This phase 1/2 study will determine the safety, feasibility, and efficacy of CD33 CART cells following lymphodepleting chemotherapy in patients with acute myeloid leukemia (AML). Patients who are between ages 1 to 30 years with relapsed or refractory AML will be eligible for this study.

This study involves taking a study drug called venetoclax with or without standard of care chemotherapy. The overall goal of this study is to see if adding venetoclax to standard chemotherapy leads to improved survival for children and young adults with relapsed acute myeloid leukemia (AML). The study may last up to 9 years and will enroll male and female patients from the ages of 29 days to 21 years of age.