Pilot CAR-T Cells Therapy for Children/Young Adults With CD19+ R/R Leukemia/Lymphoma

This pilot study is testing CAR-T cell therapy — a type of immunotherapy using genetically engineered immune cells — in children and young adults with CD19-positive relapsed or refractory leukemia or lymphoma (cancer that came back or didn't respond to prior treatment). **You may be eligible if...** - You have CD19-positive leukemia or lymphoma that has relapsed or not responded to prior treatment - You have sufficient T-cells in your blood (above 150 cells/µL) - Your performance score is 70 or above (able to carry out normal activities with some effort) **You may NOT be eligible if...** - You have a primary immune deficiency or genetic syndrome - You have a neurological disease or autoimmune disease - You have an uncontrolled active infection - You have active graft-versus-host disease (grade 2–4) - You have significant liver or kidney dysfunction - You are HIV positive, have active Hepatitis B or C, or are pregnant Talk to your doctor to see if this trial is right for you.