Description

Multiple myeloma (MM) is the second most common malignant hematological cancer in the world, which begins with the malignant proliferation of plasma cells in bone marrow. It has been a difficult disease to treat, and most patients will eventually relapse, especially for those with high-risk genotypes. At present, the therapeutic drugs for MM include glucocorticoids, cytotoxic drugs, immunosuppressants, protease inhibitors, monoclonal antibodies and cell therapies. Among those, immunotherapy has been proven to be a revolutionary treatment with great potential of curing this disease. The frequently targeted MM antigens include CD38, CD138, CD19 and BCMA, and recently, GPRC5D.

BCMA, the B cell maturation antigen, also known as CD269 or TNFRSF17, is a member of tumor necrosis factor receptor superfamily, which is highly expressed on the surface of plasma cells and partially expressed on plasma cell-like dendritic cells. It has been an ideal target for MM immunotherapy.

GPRC5D, the G-protein-coupled receptor C57 subtype D and a seven-transmembrane protein, is highly expressed on the surface of plasma cells but not in other healthy cells, and thus it has become a potential target for the treatment of MM. The expression of GPRC5D is unrelated to BCMA, so the combination therapy targeting these antigens may bring a complementary and synergistic therapeutic outcome in patients.

This trial is aimed to test the safety and efficacy of combining these different CAR-T cells targeting BCMA and GPRC5D, and in combination with well-established therapeutics as a frontline treatment for the high-risk MM or plasmacytoma patients. Another goal of this study is to investigate the persistence and function of these CAR-T cells in the body.