4SCAR19 + 4SCAR123

**4SCAR19 + 4SCAR123** is an investigational combination of two fourth-generation chimeric antigen receptor T cell (CAR-T) therapies targeting CD19 and CD123 antigens. Both constructs incorporate a safety switch (inducible caspase 9), costimulatory domains (CD28/CD27), and are designed to improve both efficacy and safety. The combination aims to overcome limitations found in single-antigen CAR-T cell therapies, specifically to prevent antigen-loss relapses in B-cell malignancies (such as B-cell acute lymphoblastic leukemia and B-cell lymphoma), by simultaneously targeting leukemic cells that express either CD19 or CD123. Developed and tested primarily by Shenzhen Geno-Immune Medical Institute, the therapy leverages an allogenic or autologous T cell platform with lentiviral CAR constructs. Both components have shown promising safety and efficacy profiles in early-phase clinical trials, with a notable reduction in relapse caused by antigen loss[1][5][8].