Apixaban

A highly potent, selective, efficacious, and orally bioavailable inhibitor of factor Xa (FXa) with Ki of 0.08 nM; shows no affinity for thrombin (Ki>3 uM), does not alter human and rabbit platelet aggregation to ADP, gamma-thrombin, and collagen at 10 uM; produces dose-dependent antithrombotic effects with EC50 of 270 nM, 110 nM and 70 nM, respective in the AVST, venous thrombosis (VT) and ECAT rabbit models.Thrombosis Approved (In Vitro) :Apixaban (BMS-562247-01) prolongs the clotting times of normal human plasma with the concentrations (EC2x) of 3.6 μM, 0.37 μM, 7.4 μM, and 0.4 μM, which are required respectively to double the prothrombin time (PT), modified prothrombin time (mPT), activated partial thromboplastin time (APTT) and HepTest. Besides, Apixaban shows the highest potency in human and rabbit plasma, but less potency in rat and dog plasma in both the PT and APTT assays. (In Vivo) :Apixaban (BMS-562247-01) shows the excellent pharmacokinetics with very low clearance (Cl: 0.02 L/kg/h), and low volume of distribution (Vdss: 0.2 L/kg) in the dogs. Besides, Apixaban also exhibits a moderate half-life (T1/2: 5.8 hours) and good oral bioavailability (F: 58%) .In the arteriovenous-shunt thrombosis (AVST), venous thrombosis (VT) and electrically mediated carotid arterial thrombosis (ECAT) rabbit models, Apixaban produces dose-dependent antithrombotic effects with EC50 of 270 nM, 110 nM and 70 nM, respectively.Apixaban significantly inhibits factor Xa activity with IC50 of 0.22 μM in rabbit ex vivo.In chimpanzee, Apixaban also shows small volume of distribution (Vdss: 0.17 L/kg), low systemic clearance (Cl: 0.018 L/kg/h), and good oral bioavailability (F: 59%) .