Definition

A bispecific gamma delta T-cell engager (TCE) antibody targeting both the tumor-associated antigen (TAA) epidermal growth factor receptor (EGFR; HER1; ErbB1) and Vdelta2-T-cell receptor (TCR) chain of Vgamma9Vdelta2 T cells, with potential immunostimulating and antineoplastic activities. Upon administration, anti-EGFR gamma delta T-cell engaging bispecific antibody SGN-EGFRd2 binds to both EGFR-expressing tumor cells and Vgamma9Vdelta2 T cells. This activates and redirects the Vgamma9Vdelta2 T cells to EGFR-expressing tumor cells, and the Vgamma9Vdelta2 T-cells secrete interferon-gamma (IFN-g) and exert direct killing of tumor cells. In addition, the Vgamma9Vdelta2 T-cells activate the immune system to exert a cytotoxic T-lymphocyte (CTL) response against tumor cells. Gamma delta T lymphocytes play a key role in the activation of the immune system and do not require major histocompatibility complex (MHC)-mediated antigen presentation to exert their cytotoxic effect. The Vdelta2 gamma delta T-cell subset is one of the two major gamma delta T-cell subsets that is almost exclusively paired with the Vgamma9 chain. EGFR, overexpressed by a variety of cancers, plays a key role in tumor cell proliferation and survival.