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

"Phase I: Patients will receive a single infusion of autologous CD19/CD22 dual CAR-T cells at one of three dose levels (0.3 × 10⁶ cells/kg, 1.0 × 10⁶ cells/kg, or 2.0 × 10⁶ cells/kg) following fludarabine (25-30mg/m2\*3d) and cyclophosphamide (250-300mg/m2\*3d) (FC) lymphodepleting chemotherapy.~Phase II: Patients will receive autologous CD19/CD22 dual CAR-T cells at the RP2D following FC lymphodepleting chemotherapy."