Empasiprubart (development code ARGX-117) is an investigational, humanized monoclonal antibody designed for the treatment of complement-mediated diseases. It functions as a targeted inhibitor of the classical and lectin pathways of the complement system. Unlike inhibitors that target the terminal pathway (e.g., anti-C5) or the alternative pathway amplification loop (e.g., anti-Factor B), empasiprubart specifically binds to and neutralizes complement component C2. By inhibiting C2, the drug prevents the formation of the C3 convertase in both the classical and lectin pathways, thereby blocking these specific activation routes at an early, upstream point while leaving the alternative pathway intact for baseline immune surveillance.