A Clinical Study Evaluating the Safety and Efficacy of GT719 Universal Cell Injection in Adult Participants With Relapsed/Refractory CD19-positive B-cell Malignant Hematological Tumors

This study is testing a new type of cell therapy called GT719 — made from donated immune cells — for people with aggressive blood cancers (B-cell leukemia or B-cell lymphoma) that have come back or stopped responding to treatment. **You may be eligible if...** - You are 18–75 years old - You have been diagnosed with relapsed or treatment-resistant B-cell acute lymphoblastic leukemia or B-cell lymphoma - Lab tests show your cancer cells carry a marker called CD19 - You are otherwise reasonably healthy and active (able to do light activity) - Your heart, kidneys, and liver are functioning adequately - At least 2 weeks have passed since your last cancer treatment **You may NOT be eligible if...** - Your cancer has spread to the brain, spinal fluid, or testicles - You have had another cancer in the past 5 years (some exceptions apply) - You had a stem cell transplant within the last 6 weeks - You have an active, uncontrolled infection - You are pregnant or unwilling to use contraception for 1 year after treatment Talk to your doctor to see if this trial is right for you.