Bispecific BCMA/CD24 CAR-T cells control multiple myeloma growth

Area of Science:

• Immunotherapy
• Oncology
• Cellular Biology

Background:

• Anti-B cell maturation antigen (BCMA)-specific chimeric antigen receptor (CAR) T-cell therapy offers high response rates for multiple myeloma but rarely achieves durable cures.
• Relapse is often driven by minimal residual myeloma cells with less-differentiated, stem-like features, including CD24 expression.
• CD24-positive myeloma cells constitute a significant fraction of residual disease post-BCMA-CAR-T therapy.

Purpose of the Study:

• To develop and evaluate CD24-specific CAR T-cells for targeting and eliminating residual multiple myeloma cells.
• To investigate the mechanism by which CD24-CAR-T cells enhance myeloma cell clearance.
• To assess the efficacy of a dual-targeted BCMA-CD24-CAR-T therapy compared to monospecific approaches.

Main Methods:

• Development of CD24-specific CAR T-cells.
• Assessment of CD24-CAR-T cell interactions with myeloma cells and macrophages.
• Evaluation of macrophage polarization and phagocytic activity.
• Comparison of dual-targeted BCMA-CD24-CAR-T cells against monospecific BCMA-CAR-T cells in vitro/in vivo models.

Main Results:

• CD24-CAR-T cells effectively block the CD24-Siglec-10 pathway, enhancing macrophage-mediated phagocytosis of myeloma cells.
• CD24-CAR-T cell treatment promotes the polarization of macrophages towards an M1-like phenotype.
• Dual-targeted BCMA-CD24-CAR-T cells demonstrate superior efficacy compared to BCMA-CAR-T cells alone.

Conclusions:

• CD24-CAR-T cells represent a novel immunotherapeutic strategy to target residual multiple myeloma.
• This approach enhances anti-myeloma immunity by promoting macrophage-mediated tumor cell clearance.
• Dual targeting of BCMA and CD24 offers a promising avenue for improving durable responses in multiple myeloma treatment.