M6903

M6903 is a fully human monoclonal antibody of the IgG2 isotype that targets T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), an immune checkpoint receptor. Developed by EMD Serono (Merck KGaA), M6903 is designed to enhance anti-tumor immunity by blocking the interaction between TIM-3 and its known ligands, including galectin-9 (Gal-9), phosphatidylserine (PtdSer), and carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). Unlike many other anti-TIM-3 antibodies, M6903 has been shown to disrupt the binding of all three primary ligands, thereby reversing T-cell exhaustion and promoting the activation of antigen-specific T cells. It is primarily investigated for the treatment of solid tumors, often in combination with other immunotherapies such as bintrafusp alfa, a bifunctional fusion protein targeting the PD-L1 and TGF-β pathways.