Definition

An afucosylated human monoclonal antibody directed against the transforming growth factor beta (TGFbeta) activator glycoprotein A repetitions predominant (GARP; leucine-rich repeat-containing protein 32; LRRC32), with potential immunomodulating and antineoplastic activities. Upon administration, anti-GARP monoclonal antibody DS-1055a selectively targets and binds to GARP and depletes GARP-positive regulatory T cells (Tregs). This leads to a reversal of immunosuppression mediated by GARP-positive Tregs and enhances the immune response to tumor cells. GARP, a transmembrane protein highly expressed on activated, immunosuppressive Tregs in the tumor microenvironment (TME), is essential for the expression of TGFbeta on the cell surface of activated Tregs; it plays an important role in regulation of the immune cell function and the immunosuppressive nature of Tregs.