Apixaban

Biological Activity

Apixaban is a direct Human Factor Xa inhibitor with Ki of 0.08 nM. Apixaban 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 in vitro. Apixaban significantly inhibits factor Xa activity with IC50 of 0.22 μM in rabbit ex vivo.

Protocol

Cell Experiment
Cell lines
Preparation method	Platelet aggregation assays Platelet aggregation was measured in citrated human and rabbit platelet-rich plasma (PRP) in vitro with a platelet aggregometer (Model PAP-4D, BioData, Horsham, PA, USA). PRP was obtained from citrated blood after centrifuging at 250 · g for 6 min. Citrated PRP (250 μL) was mixed with 20 μL of vehicle, DMP802 at 3 μM or apixaban at 1–10 μM, and incubated for 3 min at 37℃. DMP802, a glycoprotein (GP)IIb/IIIa receptor antagonist, was included as a positive control (IC50 = 29 nM against human platelet aggregation response to 10 μM ADP). Peak platelet aggregation was determined after the addition of 20 μL of the agonist (ADP at 10 μM, c-thrombin at 35 nM, and collagen at 10 μg mL)1, final concentration).
Concentrations	1-10 μM
Incubation time	3 min

Animal Experiment
Animal models	rat AVST model
Formulation	10% N,N-dimethylacetamide; 30% 1,2-propanediol; 60% water
Dosages	0.03, 0.1, 0.3, 1mg/kg/h
Administration	intravenously

Conversion of different model animals based on BSA (Value based on data from FDA Draft Guidelines)

Species	Mouse	Rat	Rabbit	Guinea pig	Hamster	Dog
Weight (kg)	0.02	0.15	1.8	0.4	0.08	10
Body Surface Area (m2)	0.007	0.025	0.15	0.05	0.02	0.5
Km factor	3	6	12	8	5	20

Animal A (mg/kg) = Animal B (mg/kg) multiplied by	Animal B Km
	Animal A Km

For example, to modify the dose of resveratrol used for a mouse (22.4 mg/kg) to a dose based on the BSA for a rat, multiply 22.4 mg/kg by the K_m factor for a mouse and then divide by the K_m factor for a rat. This calculation results in a rat equivalent dose for resveratrol of 11.2 mg/kg.

Chemical Information

References

Analysis of the projected utility of dabigatran, rivaroxaban, and apixaban and their future impact on existing Hematology and Cardiology Anticoagulation Clinics at The Johns Hopkins Hospital.
Carter et al. J Thromb Thrombolysis. 2012 Aug 4. PMID: 22865256.

Safety and efficacy of apixaban in the treatment of atrial fibrillation.
Martin et al. Clin Med Insights Cardiol. 2012;6:103-9. PMID: 22844196.

Apixaban: a new player in the anticoagulant class.
Agrawal et al. Curr Drug Targets. 2012 Jun;13(6):863-75. PMID: 22250655.

Apixaban in patients with atrial fibrillation.
Connolly et al. N Engl J Med. 2011 Mar 3;364(9):806-17. PMID: 21309657.

Apixaban, an oral, direct and highly selective factor Xa inhibitor: in vitro, antithrombotic and antihemostatic studies.
Wong PC, et al. J Thromb Haemost. 2008 May;6(5):820-9. PMID: 18315548.