SPX-104

SPX-104 is a monoclonal antibody targeting Leukocyte Immunoglobulin-Like Receptor Subfamily B Member 2 (LILRB2), also known as ILT4, developed by SparX Biotech. LILRB2 is an inhibitory receptor primarily expressed on myeloid cells, including macrophages and dendritic cells, where it acts as a checkpoint to suppress immune activation. In the tumor microenvironment, LILRB2 signaling promotes the polarization of macrophages toward an immunosuppressive M2 phenotype. SPX-104 functions as an antagonist, blocking the interaction of LILRB2 with its ligands, such as HLA-G and MHC class I molecules. This blockade redirects macrophage polarization from an M2 to a pro-inflammatory M1 phenotype, thereby enhancing anti-tumor immune responses and T-cell activation. SPX-104 served as the parental antibody for the development of SPX-303, a bispecific antibody targeting both LILRB2 and PD-L1.

Other names

anti-LILRB2 antibodyanti-LILRB-2 antibodyanti-LILRB 2 antibodyILT4 antibodyILT-4 antibodyILT 4 antibody