GT719 Injection for the Treatment of Recurrent/Refractory CD19 Positive Adult B-cell Malignancies

This study is testing an experimental cell therapy called GT719 for adults with B-cell blood cancers (such as certain types of leukemia or lymphoma) that have come back or stopped responding to other treatments. GT719 is designed to target a protein called CD19 found on these cancer cells. **You may be eligible if...** - You are an adult diagnosed with a CD19-positive B-cell blood cancer - Your cancer has relapsed (come back) or is refractory (no longer responding to treatment) - You are in relatively good physical condition and can perform normal daily activities (ECOG score 0 or 1) - You are willing to follow the study protocol and provide informed consent **You may NOT be eligible if...** - You have a primary immune deficiency disorder - You have had a blood clot (deep vein thrombosis or pulmonary embolism) in the past 6 months requiring blood thinners - You have another medical condition that could interfere with the safety or effectiveness assessments of the study Talk to your doctor to see if this trial is right for you.