CAR T-cell Long-Term Follow-Up, Quality of Life and Adverse Reactions

This study follows up with young people who received a type of immune cell therapy called CAR T-cell therapy to treat a blood cancer called B-cell acute lymphoblastic leukemia (B-ALL). Researchers want to understand long-term health effects, quality of life, and any lasting side effects years after treatment. **You may be eligible if:** - You were 26 years old or younger at the time of your first CAR T-cell treatment - You received a CD19-targeting CAR T-cell therapy (experimental or commercial) for B-ALL - You received only one type of CAR T-cell product (repeat infusions of the same product are okay) - You have been in remission without needing further treatment after CAR T-cell therapy (a stem cell transplant after CAR T is allowed) - You had no more than one bone marrow transplant in total - It has been at least 2 years since your last CAR T-cell infusion **You may NOT be eligible if:** - You or your legal guardian are unwilling or unable to provide written consent Talk to your doctor to see if this trial is right for you.