Allogeneic Second-generation CD19-CAR T Cells for Pediatric Relapsed/Refractory B-ALL

This study is testing allogeneic (donor-derived) second-generation CD19-CAR T cells — genetically engineered immune cells designed to seek out and destroy cancer cells carrying the CD19 protein — in children with B-cell acute lymphoblastic leukemia (B-ALL) that has come back or has not responded to treatment. **You may be eligible if...** - You are a child with B-ALL that has relapsed after a stem cell transplant from a donor, OR your cancer has relapsed/not responded after standard treatment and at least 2 rescue therapies including a CD19/CD22-targeted antibody treatment - Your cancer cells have CD19 expression (at least 50 CD19+ cells per microliter or detectable minimal residual disease) - A fully matched related donor is available **You may NOT be eligible if...** - Your cancer does not express CD19 - You have not yet tried the required prior treatments - A fully matched related donor is not available Talk to your doctor to see if this trial is right for you.