Definition

A bispecific T-cell engager (BiTE) antibody composed of two single-chain variable fragments (scFv), one directed against the tumor-associated antigen (TAA) human B-cell maturation antigen (BCMA; TNFRSF17), fused to one that is directed against the CD3 antigen found on T lymphocytes, with potential immunostimulating and antineoplastic activities. Upon administration of anti-BCMA/CD3 BiTE antibody AMG 701, this bispecific antibody binds to both CD3 on cytotoxic T lymphocytes (CTLs) and BCMA found on BCMA-expressing tumor cells. This activates and redirects CTLs to BCMA-expressing tumor cells, which results in the CTL-mediated cell 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.