Bridging Allogeneic Hematopoietic Stem Cell Transplantation or Not After CD19 CAR - T (S1904) Cell Therapy for r/r B-cell Acute Lymphoblastic Leukemia

Traditional salvage chemotherapy has low efficacy and poor long-term prognosis for relapsed or refractory (R/R) B-cell acute lymphoblastic leukemia (B-ALL). Targeted CD19 CAR-T cell immunotherapy is an effective means of treating R/R B-ALL. Several clinical studies have shown that its remission rate for R/R B-ALL can reach 68-93%. However, long-term follow-up found that the remission time after CD19 CAR-T treatment is short and the relapse rate is high. Therefore, how to ensure the long-term survival of R/R B-ALL patients after remission by CAR-T therapy is an urgent problem to be solved. Some studies have shown that timely bridging allo-HSCT after CAR-T treatment can overcome the risk of relapse and further improve the long-term survival of patients. However, there is currently no randomized controlled study on whether to bridge transplantation after CAR-T. The purpose of this study is to evaluate the efficacy and safety of S1904 in the treatment of relapsed or refractory CD19-positive B-cell acute lymphoblastic leukemia with or without bridging to allogeneic hematopoietic stem cell transplantation after remission.