Definition

A bispecific antibody directed against both a mutant form of the human epidermal growth factor receptor (EGFR), EGFR variant III (EGFRvIII), and the T-cell surface antigen CD3, with potential immunostimulating and antineoplastic activities. Upon administration, anti-EGFRvIII/CD3 bispecific antibody RO7428731 specifically binds to both CD3 on cytotoxic T-lymphocytes (CTLs) and EGFRvIII on EGFRvIII-expressing tumor cells. This crosslinks T-cells and tumor cells, and activates and redirects CTLs to EGFRvIII-expressing tumor cells. This leads to CTL-mediated killing of EGFRvIII-expressing tumor cells. EGFRvIII, a mutant form of EGFR expressed in certain tumor cell types and frequently seen in malignant glioma, plays a key role in tumor cell proliferation and survival.