Alexis Leonard, MD

Biography

Alexis Leonard, MD, is a pediatric hematologist and physician–scientist at St. Jude Children’s Research Hospital, where she is an assistant member in the Department of Hematology and co-director of the Hematology Gene and Cell Therapy Program. Her clinical care and research focus on advancing gene therapy and transplantation for patients with sickle cell disease. She received her medical degree from Tufts University School of Medicine and completed her pediatric residency and pediatric hematology/oncology fellowship at Children’s National Hospital. During fellowship, she joined Dr. John Tisdale’s laboratory at the National Institutes of Health, where she studied methods to improve gene therapy for sickle cell disease. She subsequently joined the hematology faculty at Children’s National while continuing her research at the NIH. Since joining St. Jude in 2023, Dr. Leonard has focused on improving stem cell collection, developing gene therapy approaches, and supporting patients and families through treatment decisions and long-term follow-up.