A bispecific T-cell engager (BiTE) antibody directed against both the tumor-associated antigen (TAA) human B-cell maturation antigen (BCMA; TNFRSF17) and the T-cell surface antigen CD3, with potential immunostimulating and antineoplastic activities. Upon administration, alnuctamab binds bivalently to BCMA expressed on tumor cells and monovalently to CD3 expressed on cytotoxic T-lymphocytes (CTLs). This activates and redirects CTLs to BCMA-expressing tumor cells, which results in the CTL-mediated death of BCMA-expressing tumor cells. BCMA, a member of the tumor necrosis factor receptor superfamily that is specifically overexpressed on malignant plasma cells, plays a key role in promoting plasma cell survival.