BCX 1470 methanesulfonate inhibits the esterolytic activity of factor D (IC₅₀=96 nM) and C1s (IC₅₀=1.6 nM), 3.4- and 200-fold better, respectively, than that of trypsin. IC50 & Target: IC50: 96 nM (Factor D); 1.6 nM (C1s); 326 nM (Trypsin) In Vitro: BCX 1470 methanesulfonate is serine protease inhibitor. BCX 1470 methanesulfonate blocks the esterolytic and hemolytic activities of the complement enzymes Cls and factor D in vitro, also blocked development of RPA-induced edema in the rat.