Definition

A humanized immunoglobulin G1 kappa (IgG1kappa) monoclonal antibody directed against V-set and immunoglobulin domain-containing 4 (VSIG4), with potential immunomodulating and antineoplastic activities. Upon administration, anti-VSIG4 monoclonal antibody EU103 targets, binds to and inhibits the activity of VSIG4 expressed on immunosuppressive M2 macrophages. This induces repolarization of these tumor-associated macrophages (TAMs) and leads to macrophage conversion of M2 into M1 macrophages. This improves the tumor microenvironment (TME), blocks VSIG4-mediated T-cell suppression, and leads to a cytotoxic T-cell-mediated anti-tumor immune response. VSIG4, one of the B7 family-related proteins, is overexpressed in various tumor cell types. Its overexpression negatively regulates T-cell proliferation and is correlated with poor prognosis.