CD22 CAR-T cells secreting CD19 T-cell engagers

CD22 CAR-T cells secreting CD19 T-cell engagers are a novel, dual-targeted immunotherapy for B-cell malignancies. These are autologous T cells engineered to express a chimeric antigen receptor (CAR) that targets CD22 and simultaneously secrete a bispecific T-cell engager antibody (TCE) against CD19. This design enables the engineered CAR-T cells to directly kill CD22+ tumor cells and also to recruit endogenous T cells to eradicate CD19+ tumor cells. The dual-targeting approach is intended to minimize antigen escape, a common cause of relapse following single-target CAR-T therapy. Preclinical studies indicate this approach provides enhanced and rapid cytotoxicity compared to tandem anti-CD19/CD22 CAR-T cells, especially under conditions where antigen expression is downregulated. Primary indications include relapsed or refractory B-cell malignancies such as B-cell acute lymphoblastic leukemia (B-ALL)[7].