Pharmacokinetics and anticoagulant properties of the factor VIIa-tissue factor inhibitor recombinant Nematode Anticoagulant Protein c2 following subcutaneous administration in man

 

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Summary

Recombinant Nematode Anticoagulant Protein c2 (rNAPc2) is a potent (K_i=10 pM), inhibitor of the factor VIIa/tissue factor (fVIIa/TF) complex that requires the prerequisite binding to zymogen or activated factor X (fX). In two double blind, placebo-controlled, sequential dose-escalation phase I studies, rNAPc2 was found to be safe and well tolerated following single and repeat subcutaneous administrations in healthy human male volunteers at doses ranging from 0.3 to 5 µg/kg. There was a dose-dependent elevation of the prothrombin time reaching almost 4-fold above the baseline value in the highest dose group that directly correlated with rNAPc2 plasma concentration. In contrast, there was little or no effect on the activated partial thromboplastin time, thrombin time or template bleeding time. The pharmacokinetic behavior of rNAPc2 revealed a dose-independent and prolonged elimination half-life (t_1/2β) with a mean of >50 hours. A high affinity interaction between rNAPc2 and plasma fX was shown to be essential for the prolonged t_1/2β in man using crossed immunoelectrophoresis and was confirmed by exploiting the considerably weaker interaction between rNAPc2 and bovine fX which resulted in an attenuated t_1/2β of ~1.5 hours in calves. The accumulated data suggests that rNAPc2 is safe and well tolerated following repeat subcutaneous administrations at doses up to 5 µg/kg in healthy volunteers. In addition, the in vivofate of rNAPc2 in man appears to be governed by its high affinity interaction with circulating fX. This data supports the continued development of this novel anticoagulant for the prevention and treatment of acute thrombotic disorders.

• References

• 1 Stanssens P, Bergum PW, Gansemans Y. et al Anticoagulant repertoire of the hookworm Ancylostoma caninum . Proc Natl Acad Sci USA 1996; 93: 2149-54.
  CrossrefPubMedGoogle Scholar
• 2 Bergum PW, Cruikshank A, Maki SL. et al Role of zymogen and activated factor X as scaffolds for the inhibition of the blood coagulation factor VIIa-tissue factor complex by recombinant nematode anticoagulant protein c2. J Biol Chem 2001; 276: 10063-71.
  CrossrefPubMedGoogle Scholar
• 3 Buddai SK, Toulokhonova L, Bergum PW. et al Nematode anticoagulant protein c2 reveals a site on factor Xa that is important for macromolecular substrate binding to human pro-thrombinase. J Biol Chem 2002; 277: 26689-98.
  CrossrefPubMedGoogle Scholar
• 4 Lee A, Agnelli G, Buller H. et al Dose-response study of recombinant factor VIIa/tissue factor inhibitor recombinant nematode anticoagulant protein c2 in prevention of postoperative venous thromboembolism in patients undergoing total knee replacement. Circulation 2001; 104: 74-8.
  CrossrefPubMedGoogle Scholar
• 5 Moons AH, Peters RJ, Bijsterveld NR. et al Recombinant nematode anticoagulant protein c2, an inhibitor of the tissue factor/factor VIIa complex, in patients undergoing elective coronary angioplasty. J Am Coll Cardiol 2003; 41: 2147-53.
  CrossrefPubMedGoogle Scholar
• 6 Zivelin A, Gitel S, Griffin JH. et al Extensive venous and arterial thrombosis associated with an inhibitor to activated protein C. Blood 1999; 94: 895-901.
  PubMedGoogle Scholar
• 7 Gibaldi M, Perrier D. Pharmacokinetics 2^ndedition. Marcel Decker 1982
  Google Scholar
• 8 Fair DS, Edgington TS. Heterogeneity of hereditary and acquired factor X deficiencies by combined immunochemical and functional analysis. Brit J Haematol 1985; 59: 235-48.
  CrossrefPubMedGoogle Scholar
• 9 Henkens CM, Bom VJJ, van der Schaaf W. et al Plasma levels pf protein S, protein C and factor X: effects of sex, hormonal state and age. Thromb Haemost 1995; 74: 1271-5.
  Article in Thieme ConnectPubMedGoogle Scholar
• 10 Morrissey JH. Tissue factor: an enzyme cofactor and a true receptor. Thromb Haemost 2001; 86: 66-74.
  Article in Thieme ConnectPubMedGoogle Scholar
• 11 Mann KG. Biochemistry and physiology of blood coagulation. Thromb Haemost 1999; 82: 165-74.
  Article in Thieme ConnectPubMedGoogle Scholar
• 12 Konigsberg W, Kirchhofer D, Riederer MA. et al The TF:VIIa complex: clinical significance, structure-function relationships and its role in signaling and metastasis. Thromb Haemost 2001; 86: 757-71.
  Article in Thieme ConnectPubMedGoogle Scholar
• 13 Bichler J, Fichtl B, Siebeck M. et al Pharmacokinetics and pharmacodynamics of hirudin in man after a single subcutaneous and intravenous bolus administration. Drug Res 1988; 38: 704-10.
  PubMedGoogle Scholar
• 14 Marbet GA, Verstraete M, Kienast J. et al Clinical pharmacology of intravenously administered recombinant desulfatohirudin (CGP 39393) in healthy volunteers. J Cardiovascular Pharmacology 1993; 22: 364-72.
  PubMedGoogle Scholar
• 15 van der Meer J, Hemker HC, Loeliger EA. Pharmacological aspects of vitamin K₁. A clinical and experimental study in man. Thromb Diath Haemorrh 1968; 19: 1-95.
  PubMedGoogle Scholar
• 16 Friederich PW, Levi M, Bauer KA. et al Ability of recombinant factor VIIa to generate thrombin during inhibition of tissue factor in human subjects. Circulation 2001; 103: 2555-9.
  CrossrefPubMedGoogle Scholar
• 17 Hedner U. NovoSeven as a universal haemo-static agent. Blood Coagul Fibrinolysis 2000; 11: S107-S111.
  CrossrefPubMedGoogle Scholar
• 18 Bijsterveld NR, Moons AH, Boekholdt AM. et al Ability of recombinant factor VIIa to reverse the anticoagulant effect of pentasaccharide fondaparinux in healthy volunteers. Circulation 2002; 106: 2550-4.
  CrossrefPubMedGoogle Scholar
• 19 Greinacher A, Eichler P, Albrecht D. et al Antihirudin antibodies following low-dose subcutaneous treatment with desirudin for thrombosis prophylaxis after hip-replacement sugery: incidence and clinical relevance. Blood 2003; 101: 2617-9.
  CrossrefPubMedGoogle Scholar
• 20 Eichler P, Friesen HJ, Lubenow N. et al Antihirudin antibodies in patients with heparin-induced thrombocytopenia treated with lepiudin: incidence, effects on aPTT and clinical relevance. Blood 2000; 96: 2373-8.
  PubMedGoogle Scholar