Definition

A hinge-stabilized human immunoglobulin G4 (IgG4) bispecific antibody directed against both the tumor-associated antigen (TAA) CD22 and the co-stimulatory T-cell-specific surface glycoprotein CD28, with potential immunostimulating and antineoplastic activities. Upon administration, anti-CD22/anti-CD28 bispecific antibody REGN5837 targets and binds to both CD28 expressed on T cells and CD22 expressed on tumor cells, which crosslinks the T cells to the tumor cells. This may result in the activation of a cytotoxic T-lymphocyte (CTL) response against the CD22-expressing tumor cells. CD22 is exclusively expressed on B cells and is often overexpressed in B-lymphocytic malignancies. It negatively regulates the B-cell receptor.