A bispecific humanized monoclonal antibody against human CD3, a T-cell surface antigen, and human G-protein coupled receptor family C group 5 member D (GPRC5D), a tumor-associated antigen (TAA), with potential antineoplastic activity. Upon administration, talquetamab binds to both CD3 on T-cells and GPRC5D expressed on certain tumor cells. This results in the cross-linking of T-cells and tumor cells, and induces a potent cytotoxic T-lymphocyte (CTL) response against GPRC5D-expressing tumor cells. GPRC5D is overexpressed on certain tumors, such as multiple myeloma, while minimally expressed on normal, healthy cells, and plays a key role in tumor cell proliferation.