FD-IN-1 (Compound 12) is an orally bioavailable and selective factor D ( FD ) inhibitor with an IC 50 of 12 nM. Complement FD, a highly specific S1 serine protease, plays a central role in the alternative complement pathway of the innate immune system. FD-IN-1 also inhibits factor XIa (FXIa) and Tryptase β2 with IC 50 s of 7.7 and 6.5 µM, respectively. In Vitro FD-IN-1 (Compound 12) exhibits functional inhibition of AP activation (IC 50 =0.26 μM) in vitro in a membrane attack complex (MAC) deposition assay using 50% human whole blood (WB). MCE has not independently confirmed the accuracy of these methods. They are for reference only. In Vivo FD-IN-1 (Compound 12) demonstrates systemic suppression of AP activation in a lipopolysaccharide-induced alternative complement pathway (AP) activation model as well as local ocular suppression in intravitreal injection-induced AP activation model in mice expressing human FD . FD-IN-1 (Compound 12) exhibits high oral bioavailability (C57BL6 mice 83%, Beagle dogs 70%) following oral administration (mice and dogs 10 mg/kg) . FD-IN-1 (Compound 12) exhibits terminal elimination half-lives (C57BL6 mice 1.6 h and Beagle dogs 3.8 h) following intravenous administration (mice and dogs 1 mg/kg) . MCE has not independently confirmed the accuracy of these methods. They are for reference only. Animal Model: Human FD knock-in mice Dosage: 3 and 10 mg/kg Administration: Oral gavage Result: The AP pathway was fully inhibited for up to 10 h at the 10 mg/kg dose. Form:Solid