Recombinant factor VIIa reverses the inhibitory effect of aspirin or aspirin plus clopidogrel on in vitro thrombin generation

SummaryRecombinant factor VIIa (rVIIa) has been reported to be clinically effective and safe in haemophilic patients with inhibitor antibodies. Compared to activated prothrombin complex concentrates the risk of thrombotic complications seems to be very low after rVIIa administration. Determination of free thrombin generation has been shown to identify hypercoagulability. Therefore, free thrombin and prothrombinase activity (Xa generation) were assessed after extrinsic activation of rVIIa supplemented factor VIII and factor IX deficient plasma. Free thrombin generation was also determined after supplementation of (activated) prothrombin complex concentrates. Addition of 150 U rVIIa/ml shortened the clotting times markedly in control, factor VIII, and factor IX deficient plasma. In contrast, free thrombin and Xa generation were not different in the absence or presence of 150 U rVIIa/ml. Addition of (activated) prothrombin complex concentrates resulted in a marked increase of free thrombin generation in all investigated plasmas. Although in vitro studies cannot reflect specific clinical circumstances our results support the notion that rVIIa does not induce a hypercoagulable state as sporadically observed after administration of (activated) prothrombin complex concentrates.

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Monitoring low dose recombinant factor VIIa therapy in patients with severe factor XI deficiency undergoing surgery

Thrombosis and Haemostasis ◽

10.1160/th10-12-0816 ◽

2011 ◽

Vol 106 (09) ◽

pp. 521-527 ◽

Cited By ~ 29

Author(s):

Anne Riddell ◽

Rezan Abdul-Kadir ◽

Debra Pollard ◽

Edward Tuddenham ◽

Keith Gomez

Keyword(s):

Thrombin Generation ◽

Low Dose ◽

Recombinant Factor Viia ◽

Factor Viia ◽

Venous Blood ◽

Optimal Dose ◽

Factor Xi ◽

Factor Xi Deficiency

SummaryAlthough factor XI (FXI) concentrate is an effective replacement therapy in severe FXI deficiency without inhibitors, some patients are unwilling to receive it because it is plasma-derived. We report on the use and monitoring of low dose, recombinant factor VIIa (rFVIIa, NovoSeven®), to cover surgery (caesarean section, cholecystectomy and abdominoplasty) in four female patients (FXI:C 2–4 IU/dl, aged 32–51 years) who wished to avoid exposure to plasma. None of our patients had inhibitors to FXI. Our aim was to find the optimal dose of rFVIIa by in vitro spiking of patient samples and to correlate this with the response to rFVIIa in vivo. Prior to surgery, venous blood was collected into sodium citrate with corn trypsin inhibitor and spiked with 0.25–1.0 μg/ml rFVIIa in vitro, equivalent to a 15–70 μg/kg dose of rFVIIa in vivo. Analysis using thromboelastometry and thrombin generation assays, triggered with tissue factor, showed that the thrombin generation assay was insufficiently sensitive to the haemostatic defect in these patients. A concentration of 0.5 μg/ml was as effective as 1.0 μg/ml FVIIa in normalising thromboelastometry in vitro in all four patients. Therefore, patients received 15–30 μg/kg rFVIIa at 2–4 hourly intervals with tranexamic acid 1g every six hours. Post treatment samples were taken at 10–240 minutes and showed initial normalisation of thromboelastometry with gradual return to baseline after 2–4 hours. In conclusion, low-dose rFVIIa therapy was successfully used in four patients with severe FXI deficiency undergoing surgery to prevent bleeding and can be monitored using thromboelastometry.

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Recombinant Factor VIIa Partially Reverses the Effects of Anticoagulants and Antiplatelet Agents on Thrombin Generation and Thromboelastography.

Blood ◽

10.1182/blood.v106.11.4143.4143 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4143-4143

Author(s):

Mariam L. Abdullatif ◽

Elizabeth Donnachie ◽

Miguel Escobar

Keyword(s):

Whole Blood ◽

Thrombin Generation ◽

Recombinant Factor Viia ◽

Factor Viia ◽

Antiplatelet Agents ◽

Adult Patients ◽

Bleeding Complications ◽

Time To Peak ◽

Patient Groups

Abstract Commonly used anticoagulants and anti-platelet agents have the potential drawback of bleeding complications and some lack an antidote for their quick reversal. Recombinant factor VIIa (rFVIIa) has recently been suggested as a general hemostatic agent but its use has only been approved for hemophiliacs with inhibitors. The purpose of this study was to evaluate the in-vitro ability of rFVIIa to reverse the effects of the following anticoagulant and/or anti-platelet agents: aspirin/plavix (n=12), heparin/aspirin/plavix (n=10), and coumadin (n=10). The criteria for patient selection were as follows: adult patients receiving coumadin; INR≥2, adult patients receiving heparin; aPTT≥ 50 seconds. After IRB approval and informed consent, blood was collected from patients receiving these medications and the effects of rFVIIa were studied using the thrombin generation assay and rotational thromboelastography (RoTEG®). Primary hemostasis in whole blood was assessed using the Multiplate® platelet analyzer following stimulation with collagen (final concentration was 3.2 μg/ml). Patients in the aspirin/plavix and heparin/aspirin/plavix groups, but not the coumadin group, had significantly decreased platelet activation compared to the control group. In platelet-poor plasma, the lagtime for thrombin generation was increased in all patient groups receiving anticoagulants and/or antiplatelet agents but the time-to-peak thrombin concentration was increased only in the heparin/ASA/plavix and coumadin goups. The addition of rFVIIa (2 and 6 μg/ml) shortened the lagtime in all patient groups so that it was not significantly different from controls. In the coumadin group, the time-to-peak thrombin concentration was reversed with rFVIIa at 2 μg/ml but was not reversed in the heparin/aspirin/plavix group even at 6 μg/ml. The endogenous thrombin potential (ETP) was decreased only in patients receiving coumadin and could not be reversed at the highest concentration of rFVIIa (6 μg/ml). In whole-blood thromboelastography, the clotting time (CT) in the heparin/aspirin/plavix and coumadin groups were increased compared to controls. Addition of rFVIIa (6 ug/ml) reversed this anticoagulant effect in the coumadin group but not the heparin/aspirin/plavix group. The mean clot firmness (MCF) was decreased only in the heparin/aspirin/plavix group and addition of rFVIIa (6 ug/ml) reversed this effect. Although the number of patients collected in the heparin/aspirin /plavix group was 10, only 4 could be used in the final analysis for thrombin generation and thromboelastography since those with aPTTs>85 seconds did not achieve a CT nor did they generate sufficient thrombin to be evaluated in the allotted time (30 minutes for thromboelastography and 90 minutes for thrombin generation) The in vitro addition of rFVIIa (2 and 6 μg/ml) did not reverse this effect. This study shows that rFVIIa accelerates thrombin generation and CT, but does not completely reverse the effects of these agents on thrombin generation and thromboelastography.

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In vitro evidence of a tissue factor-independent mode of action of recombinant factor VIIa in hemophilia

Blood ◽

10.1182/blood-2014-05-576892 ◽

2014 ◽

Vol 124 (20) ◽

pp. 3172-3174 ◽

Cited By ~ 17

Author(s):

Cecilia Augustsson ◽

Egon Persson

Keyword(s):

Tissue Factor ◽

Mode Of Action ◽

Thrombin Generation ◽

Hemophilia A ◽

Recombinant Factor Viia ◽

Negative Impact ◽

Factor Viia ◽

Key Points ◽

Independent Mode

Key Points The negative impact on thrombin generation of zymogen FVII competing with rFVIIa for TF is counteracted by FVII (auto)activation. Correction of hemophilia A occurs in a rFVIIa concentration range where detectable effects of FVII competition are minimal or absent.

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Biochemical and Pharmacological Properties of SANORG 34006, a Potent and Long-Acting Synthetic Pentasaccharide

Blood ◽

10.1182/blood.v91.11.4197 ◽

1998 ◽

Vol 91 (11) ◽

pp. 4197-4205 ◽

Cited By ~ 151

Author(s):

J.M. Herbert ◽

J.P. Hérault ◽

A. Bernat ◽

R.G.M. van Amsterdam ◽

J.C. Lormeau ◽

...

Keyword(s):

Thrombin Generation ◽

Ex Vivo ◽

Thrombus Formation ◽

Factor Xa ◽

Therapeutic Index ◽

Inhibitory Effect ◽

Experimental Models ◽

Treatment And Prevention ◽

Long Acting

Abstract SANORG 34006 is a new sulfated pentasaccharide obtained by chemical synthesis. It is an analog of the “synthetic pentasaccharide” (SR 90107/ ORG 31540) which represents the antithrombin (AT) binding site of heparin. SANORG 34006 showed a higher affinity to human AT than SR 90107/ORG 31540 (kd = 1.4 ± 0.3 v 48 ± 11 nmol/L), and it is a potent and selective catalyst of the inhibitory effect of AT on factor Xa (1,240 ± 15 anti–factor Xa U/mg v850 ± 27 anti-factor Xa U/mg for SR 90107/ORG 31540). In vitro, SANORG 34006 inhibited thrombin generation occurring via both the extrinsic and intrinsic pathway. After intravenous (IV) or subcutaneous (SC) administration to rabbits, SANORG 34006 displayed a long-lasting anti–factor Xa activity and inhibition of thrombin generation (TG) ex vivo. SANORG 34006 was slowly eliminated after IV or SC administration to rats, rabbits, and baboons, showed exceptionally long half-lives (between 9.2 hours in rats and 61.9 hours in baboons), and revealed an SC bioavailability near 100%. SANORG 34006 displayed antithrombotic activity by virtue of its potentiation of the anti–factor Xa activity of AT. It strongly inhibited thrombus formation in experimental models of thromboplastin/stasis-induced venous thrombosis in rats (IV) and rabbits (SC) (ED50values = 40.0 ± 3.4 and 105.0 ± 9.4 nmol/kg, respectively). The duration of its antithrombotic effects closely paralleled the ex vivo anti–factor Xa activity. SANORG 34006 enhanced rt-PA–induced thrombolysis and inhibited accretion of125I-fibrinogen onto a preformed thrombus in the rabbit jugular vein suggesting that concomitant use of SANORG 34006 during rt-PA therapy might be helpful in facilitating thrombolysis and preventing fibrin accretion onto the thrombus under lysis. Contrary to standard heparin, SANORG 34006 did not enhance bleeding in a rabbit ear incision model at a dose that equals 10 times the antithrombotic ED50 in this species and, therefore, exhibited a favorable therapeutic index. We suggest that SANORG 34006 is a promising compound in the treatment and prevention of various thrombotic diseases.

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Management of the Bleeding Patient Receiving New Oral Anticoagulants: A Role for Prothrombin Complex Concentrates

BioMed Research International ◽

10.1155/2014/583794 ◽

2014 ◽

Vol 2014 ◽

pp. 1-7 ◽

Cited By ~ 31

Author(s):

Lisa M. Baumann Kreuziger ◽

Joseph C. Keenan ◽

Colleen T. Morton ◽

David J. Dries

Keyword(s):

Recombinant Factor Viia ◽

Factor Viia ◽

Oral Anticoagulants ◽

New Oral Anticoagulants ◽

Coagulation Cascade ◽

Clotting Factors ◽

Prothrombin Complex Concentrates ◽

Clotting System ◽

Clinical Trial Evidence

Ease of dosing and simplicity of monitoring make new oral anticoagulants an attractive therapy in a growing range of clinical conditions. However, newer oral anticoagulants interact with the coagulation cascade in different ways than traditional warfarin therapy. Replacement of clotting factors will not reverse the effects of dabigatran, rivaroxaban, or apixaban. Currently, antidotes for these drugs are not widely available. Fortunately, withholding the anticoagulant and dialysis are freqnently effective treatments, particularly with rivaroxaban and dabigatran. Emergent bleeding, however, requires utilization of Prothrombin Complex Concentrates (PCCs). PCCs, in addition to recombinant factor VIIa, are used to activate the clotting system to reverse the effects of the new oral anticoagulants. In cases of refractory or emergent bleeding, the recommended factor concentrate in our protocols differs between the new oral anticoagulants. In patients taking dabigatran, we administer an activated PCC (aPCC) [FELBA] due to reported benefit in human in vitro studies. Based on human clinical trial evidence, the 4-factor PCC (Kcentra) is suggested for patients with refractory rivaroxaban- or apixaban-associated hemorrhage. If bleeding continues, recombinant factor VIIa may be employed. With all of these new procoagulant agents, the risk of thrombosis associated with administration of factor concentrates must be weighed against the relative risk of hemorrhage.

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A Variant of Recombinant Factor VIIa With Enhanced Procoagulant and Antifibrinolytic Activities in an In Vitro Model of Hemophilia

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/01.atv.0000257204.82396.2b ◽

2007 ◽

Vol 27 (3) ◽

pp. 683-689 ◽

Cited By ~ 57

Author(s):

Geoffrey A. Allen ◽

Egon Persson ◽

Robert A. Campbell ◽

Mirella Ezban ◽

Ulla Hedner ◽

...

Keyword(s):

In Vitro Model ◽

Recombinant Factor Viia ◽

Factor Viia ◽

Vitro Model

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The glycoprotein Ib-IX-V complex contributes to tissue factor–independent thrombin generation by recombinant factor VIIa on the activated platelet surface

Blood ◽

10.1182/blood-2008-02-139113 ◽

2008 ◽

Vol 112 (8) ◽

pp. 3227-3233 ◽

Cited By ~ 56

Author(s):

Cees Weeterings ◽

Philip G. de Groot ◽

Jelle Adelmeijer ◽

Ton Lisman

Keyword(s):

Tissue Factor ◽

Cho Cells ◽

Thrombin Generation ◽

Recombinant Factor Viia ◽

Factor Viia ◽

Affinity Constant ◽

Activate Factor ◽

Platelet Surface ◽

Static Conditions ◽

Lines Of Evidence

Abstract Several lines of evidence suggest that recombinant factor VIIa (rFVIIa) is able to activate factor X on an activated platelet, in a tissue factor-independent manner. We hypothesized that, besides the anionic surface, a receptor on the activated platelet surface is involved in this process. Here, we showed that, in an ELISA setup, a purified extracellular fragment of GPIbα bound to immobilized rFVIIa. Surface plasmon resonance established a affinity constant (Kd) of approximately 20 nM for this interaction. In addition, CHO cells transfected with the GPIb-IX-V complex could adhere to immobilized rFVIIa, whereas wild-type CHO cells could not. Furthermore, platelets sti-mulated with a combination of collagen and thrombin adhered to immobilized rFVIIa under static conditions. Platelet adhesion was inhibited by treatment with O-sialoglycoprotein endopeptidase, which specifically cleaves GPIbα from the platelet surface. In addition, rFVIIa-mediated thrombin generation on the activated platelet surface was inhibited by cleaving GPIbα from its surface. In summary, 3 lines of evidence showed that rFVIIa interacts with the GPIb-IX-V complex, and this interaction enhanced tissue factor-independent thrombin generation mediated by rFVIIa on the activated platelet surface. The rFVIIa-GPIbα interaction could contribute to cessation of bleeding after administration of rFVIIa to patients with bleeding disorders.

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Inhibition of fibrinolysis by recombinant factor VIIa in plasma from patients with severe hemophilia A

Blood ◽

10.1182/blood.v99.1.175 ◽

2002 ◽

Vol 99 (1) ◽

pp. 175-179 ◽

Cited By ~ 117

Author(s):

Ton Lisman ◽

Laurent O. Mosnier ◽

Thierry Lambert ◽

Evelien P. Mauser-Bunschoten ◽

Joost C. M. Meijers ◽

...

Keyword(s):

Hemophilia A ◽

Recombinant Factor Viia ◽

Factor Viia ◽

In Vitro Study ◽

Clot Lysis ◽

Severe Hemophilia ◽

Large Variability ◽

Lysis Time ◽

Clot Lysis Time

Recombinant factor VIIa (rFVIIa) is a novel prohemostatic drug for patients with hemophilia who have developed inhibitory antibodies. The postulation has been made that hemophilia is not only a disorder of coagulation, but that hyperfibrinolysis due to a defective activation of thrombin activatable fibrinolysis inhibitor (TAFI) might also play a role. In this in vitro study, the potential of rFVIIa to down-regulate fibrinolysis via activation of TAFI was investigated. rFVIIa was able to prolong clot lysis time in plasmas from 17 patients with severe hemophilia A. The prolongation of clot lysis time by rFVIIa was completely abolished by addition of an inhibitor of activated TAFI. The concentration of rFVIIa required for half maximal prolongation of clot lysis time (Clys½-VIIa) varied widely between patients (median, 73.0 U/mL; range, 10.8-250 U/mL). The concentration of rFVIIa required for half maximal reduction of clotting time (Cclot½-VIIa) was approximately 10-fold lower than the Clys½-VIIa value (median, 8.4 U/mL; range, 1.7-22.5 U/mL). Inhibition of TFPI with a polyclonal antibody significantly decreased Clys½-VIIa values (median, 2.6 U/mL; range, 0-86.9 U/mL), whereas Cclot½-VIIa values did not change (median, 7.2 U/mL; range, 2.2-22.5 U/mL). On addition of 100 ng/mL recombinant full-length TFPI, a nonsignificant increase of Clys½-VIIa values was observed (median, 119.2 U/mL; range, 12.3-375.0 U/mL), whereas Cclot½-VIIa values did not change (median, 8.8 U/mL; range, 2.6-34.6 U/mL). In conclusion, this study shows that rFVIIa both accelerates clot formation and inhibits fibrinolysis by activation of TAFI in factor VIII-deficient plasma. However, a large variability in antifibrinolytic potential of rFVIIa exists between patients.

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