Definition

A preparation of T lymphocytes that are genetically engineered to express a fourth-generation chimeric antigen receptor (4SCAR) targeting the two tumor-associated antigens (TAAs) CD19 and B-cell antigen receptor complex-associated protein beta chain (CD79b; B-cell-specific glycoprotein B29), with potential immunostimulating and antineoplastic activities. Upon administration, the anti-CD19/anti-CD79b 4SCAR-expressing bispecific T cells are directed to and induce selective toxicity in CD19- and CD79b-expressing tumor cells. CD19 antigen is a B-cell specific cell surface antigen expressed in all B-cell lineage malignancies. CD79b, a B-cell surface antigen and critical receptor for successful B-cell development, is part of the B-cell receptor (BCR) signaling complex. It is widely expressed in certain subtypes of B-cell lymphomas. CD19 and CD79b are expressed at high levels on tumor cells but not at significant levels on normal tissues. Targeting two antigens may protect against antigen escape and may enhance CAR-T cell efficacy.