AZD1981 is a selective, orally bioavailable and potent antagonist of the chemoattractant receptor-homologous expressed on Th2 lymphocytes receptor (CRTh2 or DP2) with an IC50 value of 4 nM [1].
AZD1981 has shown to inhibit eosinophil migration with a pIC50 value of 7.6±0.1. AZD1981 could block chemotaxis of DP2+ T-cell lines with a pIC50 value of 7.5±0.1. AZD1981 has been demonstrated to inhibit PGD2 binding to mouse, rat, rabbit, dog, guinea pig and human DP2. AZD1981 could inhibit shape change induced by DP2 in dog and guinea pig granulocytes as well as in human eosinophils and basophils in blood [2].
References:
[1] Luker T1, Bonnert R, Brough S, Cook AR, Dickinson MR, Dougall I, Logan C, Mohammed RT, Paine S, Sanganee HJ, Sargent C, Schmidt JA,Teague S, Thom S. Substituted indole-1-acetic acids as potent and selective CRTh2 antagonists-discovery of AZD1981. Bioorg Med Chem Lett. 2011 Nov 1;21(21):6288-92.
[2] Schmidt JA1, Bell FM, Akam E, Marshall C, Dainty IA, Heinemann A, Dougall IG, Bonnert RV, Sargent CA. Biochemical and pharmacological characterization of AZD1981, an orally available selective DP2 antagonist in clinical development for asthma. Br J Pharmacol. 2013 Apr;168(7):1626-38.