Prolonged effect of GlycoPEGylated rFVIIa (40k-PEG-rFVIIa) in rabbits correlates to activity in plasma

Summary

The pharmacokinetics and pharmacodynamics of 40k-PEG-rFVIIa, a GlycoPEGylated derivative of recombinant wild-type FVIIa, were compared with rFVIIa in rabbits. The procoagulant effect was determined as the weight of the clot formed in a defined segment of a facial vein. A time course study was conducted where ligation was made 10 minutes, 12 or 24 hours after i.v. injection of equimolar doses of 40k-PEG-FVIIa or rFVIIa (2 mg/kg). This dose was selected based on a dose response study and a duration of effect study with rFVIIa. The clot weight increased with increasing doses of rFVIIa, and the duration of effect correlated with the plasma FVIIa clot activity. The plasma half-life of 40k-PEG-rFVIIa measured as FVIIa clot activity was found to be 25 hours, which was 5–6 times longer than rFVIIa. The aPTT and PT were reduced, and the measured increase in thrombin-antithrombin correlated to the effect on clot formation. Thus, the effect was similar at ligation 10 minutes after administration of 40k-PEG-rFVIIa or rFVIIa. At 12 hours, the effect of rFVIIa was absent while significant effect was seen 12 and 24 hours post dosing with 40k-PEG-rFVIIa. No consumption of platelets or fibrinogen was found and no thrombi formation was seen in histological examination of various organs. In conclusion, 40k-PEG-rFVIIa has shown prolonged duration of effect that correlated to various plasma markers and FVIIa clot activity. In perspective, the data support further clinical development of 40k-PEG-rFVIIa to potentially become a long-acting recombinant treatment option for prophylaxis in haemophilia patients with inhibitors.

Keywords

Coagulation activity - glycoPEGylated rFVIIa - venous stasis - rabbits

• References

• 1 Konkle BA, Ebbesen LS, Erhardtsen E. et al Randomized, prospective clinical trial of recombinant factor VIIa for secondary prophylaxis in hemophilia patients with inhibitors. J Thromb Haemost 2007; 05: 1904-1913.
• 2 Weimer T, Ostergaard H, Bayer RJ. et al Prolonged in-vivo half-life of factor VIIa derivatives. Thromb Haemost 2008; 99: 659-667.
• 3 Roberts MJ, Bentley MD, Harris JM. Chemistry for peptide and protein PEGylation. Adv Drug Deliv Rev 2002; 54: 459-476.
• 4 Wessler S. Studies in intravascular coagulation. I. Coagulation changes in isolated venous segments. J Clin Invest 1952; 31: 1011-1014.
• 5 Peternel L, Drevensek G, Cerne M. et al Evaluation of two experimental venous thrombosis models in the rat. Thromb Res 2005; 115: 527-534.
• 6 Matthiasson SE, Lindblad B, Matzsch T. et al Effect of low molecular weight heparin, dextran and their combinations on experimental venous thrombosis in rabbits. Thromb Haemost 1994; 71: 363-365.
• 7 Diness V, Bregengaard C, Erhardtsen E. et al Recombinant human factor VIIa (rFVIIa) in a rabbit stasis model. Thromb Res 1992; 67: 233-241.
• 8 Morrissey JH, Macik BG, Neuenschwander PF. et al Quantitation of activated factor VII levels in plasma using a tissue factor mutant selectively deficient in promoting factor VII activation. Blood 1993; 81: 734-744.
• 9 Wildgoose P, Nemerson Y, Hansen LL. et al Measurement of basal levels of factor VIIa in hemophilia A and B patients. Blood 1992; 80: 25-28.
• 10 Pelzer H, Schwarz A, Heimburger N. Determination of human thrombin-anti-thrombin III complex in plasma with an enzyme-linked immunosorbent assay. Thromb Haemost 1988; 59: 101-106.
• 11 Tranholm M, Kristensen K, Kristensen AT. et al Improved hemostasis with super-active analogs of factor VIIa in a mouse model of hemophilia A. Blood 2003; 102: 3615-3620.
• 12 Lauritzen B, Tranholm M, Ezban M. rFVIIa and a new enhanced rFVIIa-analogue, NN1731, reduce bleeding in clopidogrel-treated and in thrombocytopenic rats. J Thromb Haemost 2009; 07: 651-657.
• 13 Tranholm M, Rojkjaer R, Pyke C. et al Recombinant factor VIIa reduces bleeding in severely thrombocytopenic rabbits. Thromb Res 2003; 109: 217-223.
• 14 Sørensen BB, Karpf D, Groth AV, Bysted BV, Hermit MB, Tranholm M et al. Effect of Glycopegylation on the pharmacokinetic properties of FVIIa. J Thromb Haemost 2007 05. (Supp 2): Abstract P-T-012.
• 15 Fridberg MJ, Hedner U, Roberts HR. et al A study of the pharmacokinetics and safety of recombinant activated factor VII in healthy Caucasian and Japanese subjects. Blood Coagul Fibrinolysis 2005; 16: 259-266.
• 16 Erhardtsen E. Pharmacokinetics of recombinant activated factor VII (rFVIIa). Semin Thromb Hemost 2000; 26: 385-391.
• 17 Møss J, Rosholm A, Laurén A. Safety and pharmacokinetics of a long-acting glycopegylated rFVIIa derivative: A first human dose trial in healthy subjects. J Thromb Haemost 2009 07. (Supp 2): Abstract OC-WE-055.
• 18 Hoffman M, Monroe III DM, Roberts HR. Activated factor VII activates factors IX and X on the surface of activated platelets: thoughts on the mechanism of acion of high-dose activated factor VII. Blood Coagul Fibrinolysis 1998; 09 (Suppl. 01) S61-S65.
• 19 Østerud B, Breimo ES, Olsen JO. Blood borne tissue factor revisited. Thromb Res 2008; 122: 432-434.
• 20 Taylor Jr FB, Toh CH, Hoots WK. et al Towards definition, clinical and laboratory criteria, and a scoring system for disseminated intravascular coagulation. Thromb Haemost 2001; 86: 1327-1330.
• 21 Berthelsen LO, Kristensen AT, Wiinberg B. et al Implementation of the ISTH classification of non-overt DIC in a thromboplastin induced rabbit model. Thromb Res 2009; 124: 490-497.
• 22 Roberts HR, Monroe III DM, Hoffman M. Safety profile of recombinant factor VIIa. Semin Hematol 2004; 41: 101-108.
• 23 Abshire T, Kenet G. Safety update on the use of recombinant factor VIIa and the treatment of congenital and acquired deficiency of factor VIII or IX with inhibitors. Haemophilia 2008; 14: 898-902.