Definition

A preparation of T lymphocytes that have been genetically modified to express a chimeric antigen receptor (CAR) consisting of an anti-CD19 scFv (single chain variable fragment) fused to the extracellular, transmembrane and intracellular signaling domains of the T-cell co-stimulatory receptor CD28 and the cytoplasmic signaling domain of the zeta chain of the TCR/CD3 complex (CD3-zeta) (19-28z), a truncated form of the human epidermal growth factor receptor (EGFRt), and the human pro-inflammatory cytokine interleukin-12 (IL-12), with potential immunostimulating and antineoplastic activities. Upon administration, EGFRt/19-28z/IL-12 CAR T lymphocytes are directed to and induce selective toxicity in CD19-expressing tumor cells. In addition, the administered T cells secrete IL-12 which induces the secretion of interferon-gamma (IFN-g), promotes the activation of natural killer cells (NKs), and induces cytotoxic T-lymphocyte (CTL) responses against tumor cells, which may result in immune-mediated tumor cell death and inhibition of tumor cell proliferation. CD19 antigen is a B-cell specific cell surface antigen expressed in all B-cell lineage malignancies. The CD28 co-stimulatory molecule signaling domain enhances activation and signaling after recognition of CD19. The inclusion of the CD28 signaling domain may increase proliferation of the T-cells and their antitumor activity compared with the inclusion of the CD3-zeta chain alone. Devoid of both ligand binding domains and tyrosine kinase activity, EGFRt facilitates both the in vivo detection of the administered T cells and the elimination of the administered T cells through a cetuximab-induced antibody dependent cellular cytotoxicity (ADCC) response.