A Study of Secondary Infusion of Relmacabtagene Autoleucel Injection for Relapsed or Refractory B-cell Lymphoma

CD19-targeted chimeric antigen receptor T-cell therapy has shown remarkable efficacy in relapsed or refractory B-cell malignancies. However, CD19 CAR-T cells are still unable to induce durable remissions in some patients. Further therapeutic strategies remain to be explored for patients who fail to achieve complete remission (CR) or who relapse after CAR-T treatment. the mechanisms underlying the failure of CAR-T cell therapy may be diverse and not yet fully understood. It may be due to the patient's own poor T-cell function, immunosuppressive tumour microenvironment, loss of tumour-targeting antigen expression with antitumour therapy, and compromised CAR-T renewal in vivo, or T-cell depletion due to the tumour microenvironment. It has recently been demonstrated that CAR-T cells become functionally depleted, or CAR lost, with sustained exposure to tumour antigen stimulation (Good, C, 2021). Extensive clinical experience suggests that CAR-T cell expansion and persistence are required to achieve a durable response. In patients requiring follow-up therapy after failure of the first CAR-T cell infusion (CART1), one option is a second infusion of CD19 CAR-T cells (CART2) for retreatment, and a second infusion of CD19 CAR-T cells (CART2) is considered a possible approach to improve prognosis.