Definition

A preparation of T lymphocytes that have been genetically modified to express chimeric antigen receptors (CARs) targeting the tumor-associated antigens (TAAs) human epidermal growth factor 2 (HER2; ErbB2; HER-2) and the immunosuppressive ligand programmed cell death-1 ligand 1 (PD-L1; cluster of differentiation 274; CD274), with potential immunostimulating and antineoplastic activities. Upon administration, anti-HER2/anti-PD-L1 CAR T cells target and bind to HER2- and PD-L1-expressing tumor cells, thereby inducing selective toxicity in HER2- and PD-L1-expressing tumor cells. HER2 is overexpressed in a variety of cancer cell types and is associated with increased tumor cell proliferation. PD-L1 is overexpressed by many human cancer cell types and plays a key role in the downregulation of the immune system and tumor evasion from host immunity.