A quantitative systems pharmacology model of blood coagulation network describes in vivo biomarker changes in non-bleeding subjects.
Essentials Baseline coagulation activity can be detected in non-bleeding state by in vivo biomarker levels. A detailed mathematical model of coagulation was developed to describe the non-bleeding state. Optimized model described in vivo biomarkers with recombinant activated factor VII treatment. Sensitivity analysis predicted prothrombin fragment 1 + 2 and D-dimer are regulated differently.



Background Prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin III complex (TAT) and D-dimer can be detected in plasma from non-bleeding hemostatically normal subjects or hemophilic patients. They are often used as safety or pharmacodynamic biomarkers for hemostatis-modulating therapies in the clinic, and provide insights into in vivo coagulation activity. Objectives To develop a quantitative systems pharmacology (QSP) model of the blood coagulation network to describe in vivo biomarkers, including F1 + 2, TAT, and D-dimer, under non-bleeding conditions. Methods The QSP model included intrinsic and extrinsic coagulation pathways, platelet activation state-dependent kinetics, and a two-compartment pharmacokinetics model for recombinant activated factor VII (rFVIIa). Literature data on F1 + 2and D-dimer at baseline and changes with rFVIIa treatment were used for parameter optimization. Multiparametric sensitivity analysis (MPSA) was used to understand key proteins that regulate F1 + 2, TAT and D-dimer levels. Results The model was able to describe tissue factor (TF)-dependent baseline levels of F1 + 2, TAT and D-dimer in a non-bleeding state, and their increases in hemostatically normal subjects and hemophilic patients treated with different doses of rFVIIa. The amount of TF required is predicted to be very low in a non-bleeding state. The model also predicts that these biomarker levels will be similar in hemostatically normal subjects and hemophilic patients. MPSA revealed that F1 + 2and TAT levels are highly correlated, and that D-dimer is more sensitive to the perturbation of coagulation protein concentrations. Conclusions A QSP model for non-bleeding baseline coagulation activity was established with data from clinically relevant in vivo biomarkers at baseline and changes in response to rFVIIa treatment. This model will provide future mechanistic insights into this system.
PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA.
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D
Lee
Pharmacometrics, Global Innovative Pharma Business, Pfizer Inc., Cambridge, MA, USA.
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0000-0001-7225-1317
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Nayak
Pharmacometrics, Global Innovative Pharma Business, Pfizer Inc., Cambridge, MA, USA.
S W
SW
Martin
PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA.
A C
AC
Heatherington
Pharmacokinetics, Dynamics and Metabolism - New Biological Entities, Pfizer Inc., San Diego, CA, USA.
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P
Vicini
PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA.
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F
Hua
D015415:Biomarkers / Q000097:blood*; D001777:Blood Coagulation; D015942:Factor VIIa; D005338:Fibrin Fibrinogen Degradation Products / Q000737:chemistry; D006487:Hemostasis; D006801:Humans; D008962:Models, Theoretical; D015539:Platelet Activation; D011516:Prothrombin / Q000737:chemistry; D011994:Recombinant Proteins / Q000097:blood; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013925:Thromboplastin
D015415:Biomarkers; D005338:Fibrin Fibrinogen Degradation Products; D011994:Recombinant Proteins; C036309:fibrin fragment D; D011516:Prothrombin; D013925:Thromboplastin; C103587:recombinant FVIIa; D015942:Factor VIIa
blood coagulation; factor VIIa; hemophilia; prothrombin fragment 1 + 2; systems biology