POS-040 BCX9930, AN ORAL FACTOR D INHIBITOR IN DEVELOPMENT FOR THE TREATMENT OF COMPLEMENT-MEDIATED KIDNEY DISEASES, INHIBITS COMPLEMENT ALTERNATIVE PATHWAY ACTIVITY IN HEALTHY SUBJECTS

Abstract

Complement Factor D, a serine protease, is the rate-limiting enzyme of the alternative pathway (AP) and has the lowest concentration in plasma among all the complement proteins. Factor D is essential for the formation of AP C3 convertase, as well as for the amplification of complement activity initiated by all 3 complement pathways, including amplification of up to 80% of classical and lectin pathways’ complement responses (Harboe et al, Clin Exp Immunol 2004). BCX9930 is an orally administered, potent and selective inhibitor of Factor D under development for the treatment of complement-mediated kidney diseases, including C3 glomerulopathy, IgA nephropathy, and primary membranous nephropathy.