[CAS NO. 618385-01-6]  Vorapaxar (MK-5348)

SCH 530348 is a synthetic tricyclic 3-phenylpyridine and an orally active himbacine-based thrombin-receptor antagonist. SCH 530348 shows potent inhibition of thrombin-induced platelet aggregation with an IC50 of 47 nM and haTRAP-induced platelet aggregation with an IC50 of 25 nM, whereas it shows no inhibition of platelet aggregation induced by other agonists such as ADP, collagen and a PAR-4 agonist peptide. SCH 530348 also has no affect on the prothrombin time (PT), partial thromboplastin time (PTT), or activated partial thromboplastin time (aPTT). Moreover, SCH 530348 causes no increase in the bleeding time or in surgical bleeding compared with inactive control. SCH530348 is found to be selective for PAR-1 when tested over a number of ion channels and receptors, including PAR-4 receptor.