Setipiprant

Setipiprant is an orally available, selective CRTH2 antagonist (IC50: 6.0 nM). CRTH2 is a G protein-coupled receptor for prostaglandin (PGD2). PGD2 is produced by the mast cells and is a key mediator in various inflammatory diseases, including allergy and asthma. Binding of PGD2 to CRTH2, which are expressed on the surface of blood-borne cells, induces chemotaxis of Th2 cells, basophils, and eosinophils, and stimulates cytokine release from these cells.(In Vitro):Setipiprant (0-10 μM; 90 min) interacts with hCRTH2 receptor in the absence and presence of Human Serum Albumin (HSA) in the assay buffer with IC50 values of 6 and 340 nM, respectively.Setipiprant (0-10 μM; 5-20 min) inhibits hCRTH2 receptor based intracellular calcium liberation, intracellular cAMP and shape change of human eosinophils with IC50 values of 30, 80 and 235 nM, respectively.Setipiprant (0-10 μM) inhibits prostanoid receptors hDP1, hEP2 and hEP4 with IC50 values of 1290, 2600 and ＞10000 nM, respectively.(In Vivo):Pharmacokinetic Properties of Setipiprant in Rats and Dogs.