Definition

A preparation of T lymphocytes engineered to express chimeric antigen receptor(s) (CAR) targeting the human tumor-associated antigens (TAAs) B-cell maturation antigen (BCMA; tumor necrosis factor receptor superfamily member 17; TNFRSF17) and G-protein coupled receptor family C group 5 member D (GPRC5D) and fused to as of yet not fully elucidated co-stimulatory domains, with potential immunostimulating and antineoplastic activities. Upon administration, the anti-BCMA/anti-GPRC5D CAR T cells OriC321 specifically and simultaneously target and bind to tumor cells expressing BCMA and/or GPRC5D. This induces selective toxicity in tumor cells that express BCMA and/or GPRC5D. BCMA, a receptor for both a proliferation-inducing ligand (APRIL) and B-cell activating factor (BAFF), is a member of the tumor necrosis factor receptor superfamily (TNFRSF). BCMA is found on the surfaces of plasma cells, is overexpressed on malignant plasma cells and plays a key role in plasma cell proliferation and survival. GPRC5D is overexpressed in certain malignancies, such as multiple myeloma, while minimally expressed in normal, healthy cells. It plays a key role in tumor cell proliferation.