Nanobody-Based CD19/CD22 Tandem Dual CAR-T Therapy for R/R B-ALL

This study tests a new CAR-T cell therapy that targets two proteins — CD19 and CD22 — found on B-cell leukemia cells. It uses nanobody-based technology (very small, precise targeting molecules) to attack cancer cells. The therapy is for people with relapsed or refractory B-cell acute lymphoblastic leukemia (B-ALL) — a blood cancer that has returned or stopped responding to treatment. **You may be eligible if:** - You are between 3 and 65 years old - You have been diagnosed with B-ALL that has relapsed or is refractory (not responding to treatment) - Your cancer has been confirmed to have more than 5% blast cells in bone marrow, leukemic cells in spinal fluid, or measurable tumors outside the bone marrow - You have an expected survival of at least 12 weeks and are in good general health **You may NOT be eligible if:** - You are under 3 or over 65 years old - You do not have B-ALL (e.g., you have T-cell ALL) - Your cancer does not meet the relapsed/refractory criteria - You have serious organ dysfunction or active uncontrolled infection - You are pregnant Talk to your doctor to see if this trial is right for you.