A Clinical Study Exploring the Safety, Efficacy and Cell Metabolic Kinetics of Universal Car-t Cell Injection in CD19 and / or CD20 Positive Relapsed / Refractory B-cell Acute Lymphoblastic Leukemia in Adolescents, Children and Adults

This study is testing a new type of immune cell therapy called Universal CAR-T cells — lab-engineered immune cells designed to attack leukemia cells carrying the proteins CD19 and/or CD20 — in adolescents and adults with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL), a fast-growing blood cancer that has not responded to or came back after standard treatment. **You may be eligible if...** - You are between 12 and 75 years old - You have B-ALL that has not responded to standard chemotherapy, or came back after achieving remission - Your leukemia cells test positive for CD19 and/or CD20 - At least 5% of your bone marrow or blood is made up of leukemia cells (blasts) - You have adequate kidney, liver, heart, and lung function **You may NOT be eligible if...** - You are pregnant or breastfeeding - You have active HIV, syphilis, hepatitis B, or hepatitis C - You have an active uncontrolled infection (including active tuberculosis) - You have an active autoimmune disease - You have a history of severe neurological conditions (seizures, stroke, severe brain injury) - You received a stem cell transplant within the past 12 weeks - You have received certain chemotherapy or immune therapy drugs within a specified washout window before cell infusion Talk to your doctor to see if this trial is right for you.