G-protein coupled receptor family C group 5 member D (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. A humanized T-cell redirecting bispecific antibody targeting both GPRC5D and CD3 antigen is being developed for the treatment of multiple myeloma. The antibody binds to both CD3 on T cells and GPRC5D expressed on certain tumor cells to result in the cross-linking of T cells and tumor cells, thereby inducing a potent cytotoxic T-lymphocyte (CTL) response against GPRC5D-expressing tumor cells.