The patients received sequential infusion of CD22 and CD19 CAR-T cells (co-stimulatory molecule was 4-1BB and infusion dose was 5*10^6/kg respectively) after standard induction and consolidation chemotherapy. Autologous stem cells mobilization and collection were performed 6-8 weeks after CAR-T infusion. Standard BuCy as conditioning regimen for Auto-HSCT was used 4 weeks after successful stem cell collection. CD22 and CD19 CAR-T cells were re-infused 2 days after Auto-HSCT. Patients were followed up and minimal residual diseases (MRD) was monitored by flow cytometry and second-generation gene sequencing of IgH rearrangement.
Chimeric antigen receptor T-cell (CAR-T) therapy has achieved remarkable efficacy in B-cell acute lymphoblastic leukemia (B-ALL). However, relapse after CAR-T has been a major issue. Multi-antigen CAR T and combination with other regimens may reduce the relapse rate. The investigators first conducted CD22/CD19 CAR T-cells and auto-HSCT sandwich  strategy as consolidation therapy in patients with B-ALL. The main Purpose of this study was to observe the safety and efficacy of this new strategy.