CAR T-cell Therapy Directed to CD70 for Pediatric Patients With Hematological Malignancies

This study tests a new CAR T-cell therapy targeting a protein called CD70 for children and young adults with blood cancers (like AML, MDS, or ALL) that have come back after treatment or stopped responding. CAR T-cell therapy engineers immune cells to hunt down and destroy cancer cells that carry a specific marker — in this case, CD70. **You may be eligible if...** - You are 21 years old or younger - You have a CD70-positive blood cancer that has relapsed or is refractory (not responding to chemo) - For B-cell ALL: your cancer no longer expresses CD19 (making standard CD19-targeted therapies ineffective), or you are in 2nd or greater relapse - For T-cell ALL or AML/MDS: your cancer is CD70-positive and has returned after multiple treatments or transplant **You may NOT be eligible if...** - Your cancer does not express CD70 - You have uncontrolled infections or organ failure - You do not meet health thresholds for participating in an experimental therapy Talk to your doctor to see if this trial is right for you.