Safety and Efficacy Study of Zamtocabtagene Autoleucel (MB-CART2019.1) in Pediatric Patients With R/R B-Cell Neoplasms

This study is testing a CAR T-cell therapy called zamtocabtagene autoleucel (MB-CART2019.1) in children and young adults whose B-cell blood cancers — such as certain types of leukemia or lymphoma — have come back or stopped responding to other treatments. CAR T-cell therapy uses the patient's own immune cells, which are modified in a lab to find and attack cancer cells. **You may be eligible if...** - You are a child or young adult (age requirements based on local regulations) - You have been diagnosed with a relapsed or refractory CD19+ and/or CD20+ B-cell cancer (such as Burkitt lymphoma, diffuse large B-cell lymphoma, or other aggressive B-cell cancers) - Your cancer has come back or has not responded to prior treatment - A parent or guardian can provide consent on your behalf if needed **You may NOT be eligible if...** - Your cancer does not express CD19 or CD20 - You have severe organ problems or active uncontrolled infections - You have certain other medical conditions that make this therapy unsafe Talk to your doctor to see if this trial is right for you.