MK-8318

MK-8318 is a potent and selective CRTh2 receptor antagonist with a K_i of 5.0 nM. IC50 & Target: Ki: 5.0±1.8 nM (CRTh2 Receptor)
IC50: 3.5±2.1 nM (β-arrestin), 8.0±6.8 nM (cAMP) 50 µM (CYP3A4), 50 µM (CYP2C9), 50 µM (CYP2D6)^[1] In Vitro: MK-8318 also inhibits β-arrestin, cAMP, CYP3A4, CYP2C9, and CYP2D6 with IC₅₀s of 3.5±2.1 nM, 8.0±6.8 nM, 50 µM, 50 µM and 50 µM^[1]. In Vivo: In a sheep model, MK-8318 blocks late airway response (LAR) and airway hyperresponsiveness (AHR) after i.v. infusion at 1 mg/kg. MK-8318 shows 76% LAR efficacy and 114% AHR efficacy. MK-8318 also displays good efficacy on BAL cells/pulmonary function from ovalbumin sensitized and challenged Brown Norway rats at 3, 10, and 30 mg/kg oral dosing^[1].