Definition

A preparation of allogeneic T lymphocytes that have been genetically modified to express a chimeric antigen receptor (CAR) targeting the tumor-associated antigen (TAA) CD19 (cluster of differentiation 19), a single short hairpin RNA (shRNA) that disrupts the expression of beta-2 microglobulin (B2M) component of the class 1 major histocompatibility complex (MHC) molecules, and a HLA-E gene, with potential immunostimulating and antineoplastic activities. Upon administration, the allogeneic anti-CD19 CAR T cells PBCAR19B specifically recognize and bind to CD19-expressing tumor cells. This may result in a specific cytotoxic T-lymphocyte (CTL)-mediated killing of CD19-expressing tumor cells. The downregulation of the expression of the class 1 MHC molecule component B2M by shRNA and the HLA-E gene decrease the number of CAR T cells that are rejected and killed by natural killer (NK) and cytotoxic T cells. CD19 antigen is a B-cell-specific cell surface antigen overexpressed in B-cell lineage malignancies.