Definition

A human, Fc-attenuated immunoglobulin G1 (IgG1) monoclonal antibody targeting the immune checkpoint immunoglobulin superfamily member 8 (IGSF8; PGRL; PG regulatory-like protein, KCT-4, CD81 partner 3; LIR-D1; KASP; KAI/CD82 associated protein; EWI-2; Glu-Trp-Ile EWI motif-containing protein 2), with potential immune checkpoint inhibitory, immunostimulating and antineoplastic activities. Upon administration, anti-IGSF8 monoclonal antibody GV20-0251 targets and binds to IGSF8 expressed on various immune cells, thereby preventing the binding of IGSF8 to beta 1 integrins and various tetraspanins. This inhibits IGSF8-mediated signaling and abrogates the IGSF8-mediated inhibition on immune activation. This may stimulate a T-cell-mediated immune response against cancer cells. IGSF8, a transmembrane adhesion protein and member of the Ig super family (IgSF), is an immune inhibitory receptor that plays a key role in cancer cell motility and suppression of T-cell proliferation and activation. It is involved in tumor cell immune evasion and the inhibition of immune responses.