Factor D inhibitor 6

Factor D inhibitor 6 is a potent, highly selective and orally active factor D (FD) inhibitor with an IC₅₀ of 30 nM and a K_d of 6 nM. Factor D inhibitor 6 is inactive against factor B, lassical and lectin complement-pathway activation, and a broad assay panel of receptors, ion channels, kinases and proteases^[1]. IC50 & Target: IC50: 30 nM (Factor D)^[1]
Kd: 6 nM (Factor D)^[1] In Vitro: Factor D inhibitor 6 (compound 6) effectively blocks both alternative pathway (AP)-mediated hemolysis in 10% human serum (IC₅₀ = 6 nM) and AP-induced membrane-attack complex (MAC) formation in lepirudinanticoagulated 50% human whole blood (IC₅₀ = 0.14 μM)^[1].
Factor D inhibitor 6 (compound 6) shows modest inhibition of murine FD (IC₅₀ = 0.86 μM)^[1].
Factor D inhibitor 6 (compound 6) inhibits both hemolysis and component 3 (C3) deposition on the surface of red blood cells (RBCs) with an IC₅₀ value of 70 nM, consistent with inhibition of the AP amplification loop^[1]. In Vivo: Factor D inhibitor 6 (Compound 6; 1-10 mg/kg; Oral gavage; once; C57Bl/6 mice) treatment dosed-ependently inhibits complement activation, with full inhibition at 10 mg/kg. Factor D inhibitor 6 shows sustained inhibition of LPS-induced AP activation for at least 8 h post-dose with an EC₅₀ of 0.034 μM^[1].