Allogeneic CD19-targeted CAR-γδT Cell Infusion Therapy in Relapsed/Refractory B Cell Acute Lymphoblastic Leukemia

dose escalation (3+3) : dose 1 (3 × 10\^8cells/kg) ,dose 2 (1 × 10\^9 cells/kg) ,dose 3 (3 × 10\^9cells/kg)

Intravenous fludarabine 30mg/m2 on days-6 to -3,the infusion dose is adjusted according to the subject's condition

Intravenous cyclophosphamide 1000mg/m2 on days -5 to -3, the infusion dose is adjusted according to the subject's condition