Definition

A bispecific T-cell engager antibody directed against both the tumor-associated antigen (TAA) delta-like protein 3 (DLL3) and the CD3 antigen found on T lymphocytes, with potential immunostimulating and antineoplastic activities. Upon administration, anti-DLL3/CD3 bispecific antibody BI 764532 binds to both the CD3 antigen on cytotoxic T lymphocytes (CTLs) and the DLL3 antigen on DLL3-expressing tumor cells. This activates and redirects CTLs to DLL3-expressing tumor cells, which results in the CTL-mediated cell death of DLL3-expressing tumor cells. DLL3, a Notch pathway protein, is overexpressed on a variety of cancer cell types. It plays a key role in embryonic development and in tumor initiation and proliferation.