Long-term follow-up of CD19 chimeric antigen receptor T cell therapy in acute lymphoblastic leukemia patients relapsed after allogeneic hematopoietic stem cell transplantation

Relapse after allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with B-cell acute lymphoblastic leukemia (B-ALL) is associated with a poor prognosis. Although CD19 chimeric antigen receptor T (CAR-T) cell therapy has shown promise in this population, its long-term efficacy and safety remain unclear. To address this, we conducted a retrospective multicenter study to evaluate the long-term survival outcomes of autologous and allogeneic CD19 CAR-T cell therapies in 55 B-ALL patients who relapsed after allo-HSCT. Following CAR-T cell infusion, 37 patients (67.3%) achieved complete remission (CR). The 3-year leukemia-free survival rate among CR patients was 37.8%. The 3-year overall survival rate for both CR and non-remission patients was 36.2%. Cytokine release syndrome was the most common adverse event, occurring in 74.5% of patients. No significant differences in efficacy or safety were found between autologous and allogeneic CAR-T cell groups (all P > 0.05). This study demonstrates the promising 3-year survival and safety profile of both autologous and allogeneic CD19 CAR-T cell therapies, and further supports CD19 CAR-T cell therapy as a valuable treatment for patients with relapsed B-ALL after allo-HSCT.