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Kolyadko VN. Pathogenic but sweet: factor VIII inhibitor hits the hot spot. J Thromb Haemost 2024; 22:2416-2418. [PMID: 39174227 DOI: 10.1016/j.jtha.2024.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 08/24/2024]
Affiliation(s)
- Vladimir N Kolyadko
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.
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2
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Childers KC, Cowper B, Vaughan JD, McGill JR, Davulcu O, Lollar P, Doering CB, Coxon CH, Spiegel PC. Structural basis for inhibition of coagulation factor VIII reveals a shared antigenic hotspot on the C1 domain. J Thromb Haemost 2024; 22:2449-2459. [PMID: 38849084 PMCID: PMC11343672 DOI: 10.1016/j.jtha.2024.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 05/13/2024] [Accepted: 05/22/2024] [Indexed: 06/09/2024]
Abstract
BACKGROUND Hemophilia A arises from dysfunctional or deficient coagulation factor (F)VIII and leads to inefficient fibrin clot formation and uncontrolled bleeding events. The development of antibody inhibitors is a clinical complication in hemophilia A patients receiving FVIII replacement therapy. LE2E9 is an anti-C1 domain inhibitor previously isolated from a mild/moderate hemophilia A patient and disrupts FVIII interactions with von Willebrand factor and FIXa, though the intermolecular contacts that underpin LE2E9-mediated FVIII neutralization are undefined. OBJECTIVES To determine the structure of the complex between FVIII and LE2E9 and characterize its mechanism of inhibition. METHODS FVIII was bound to the antigen binding fragment (Fab) of NB2E9, a recombinant construct of LE2E9, and its structure was determined by cryogenic electron microscopy. RESULTS This report communicates the 3.46 Å structure of FVIII bound to NB2E9, with its epitope comprising FVIII residues S2040 to Y2043, K2065 to W2070, and R2150 to H2155. Structural analysis reveals that the LE2E9 epitope overlaps with portions of the epitope for 2A9, a murine-derived inhibitor, suggesting that these residues represent a shared antigenic region on the C1 domain between FVIII-/- mice and hemophilia A patients. Furthermore, the FVIII:NB2E9 structure elucidates the orientation of the LE2E9 glycan, illustrating how the glycan sterically blocks interactions between the FVIII C1 domain and the von Willebrand factor D' domain. A putative model of the FVIIIa:FIXa complex suggests potential clashing between the NB2E9 glycan and FIXa light chain. CONCLUSION These results describe an antigenic "hotspot" on the FVIII C1 domain and provide a structural basis for engineering FVIII replacement therapeutics with reduced antigenicity.
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Affiliation(s)
- Kenneth C Childers
- Chemistry Department, Western Washington University, Bellingham, Washington, USA
| | - Ben Cowper
- Medicines and Healthcare products Regulatory Agency, South Mimms Laboratories, Potters Bar, Hertfordshire, UK
| | - Jordan D Vaughan
- Chemistry Department, Western Washington University, Bellingham, Washington, USA
| | - Juliet R McGill
- Chemistry Department, Western Washington University, Bellingham, Washington, USA
| | - Omar Davulcu
- Pacific Northwest Center for Cryo-EM, Oregon Health & Science University, Portland, Oregon, USA; Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, Richland, Washington, USA
| | - Pete Lollar
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, Georgia, USA; Department of Pediatrics, Emory University, Atlanta, Georgia, USA
| | - Christopher B Doering
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Atlanta, Georgia, USA; Department of Pediatrics, Emory University, Atlanta, Georgia, USA; Expression Therapeutics, Inc, Tucker, Georgia, USA
| | - Carmen H Coxon
- Medicines and Healthcare products Regulatory Agency, South Mimms Laboratories, Potters Bar, Hertfordshire, UK
| | - Paul C Spiegel
- Chemistry Department, Western Washington University, Bellingham, Washington, USA.
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3
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Joubert J, Meiring SM, Janse van Rensburg WJ. The thrombin generation capability of the Chacma baboon (Papio ursinus): implications for haemostatic disease models. Sci Rep 2023; 13:22968. [PMID: 38151511 PMCID: PMC10752904 DOI: 10.1038/s41598-023-50341-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 12/19/2023] [Indexed: 12/29/2023] Open
Abstract
Baboon models are often used to investigate haemostatic diseases, such as acquired thrombotic thrombocytopenic purpura or bacterial sepsis-induced disseminated intravascular coagulation, and their potential treatment with novel drugs. Thrombin generation is vital for these models, and an important potential therapeutic target. We investigated the thrombin generation profile of the Chacma baboon (Papio ursinus - a common pre-clinical model) including the effects of sex and ABO blood group. Thrombin generation curves, lag times, peak heights, times-to-peak, velocity indexes and Endogenous Thrombin Potentials (ETPs) of 40 adult Chacma baboons were assessed and compared with normal human plasma, using a low concentration of tissue factor (1 pM) and phospholipids. Reference intervals were calculated, and results compared between O and non-O ABO blood groups, and between males and females. Lag times of all baboons fell within the human reference interval. Most animals (n = 32; 80%) had times-to-peak above, and velocity indexes and peak heights markedly below (n = 27; 68%) the human range. However, 97.5% of baboons had an ETP above the human reference interval, indicating greater overall thrombin generation. ABO blood group had no effect, but males (n = 14; 35%) had less potent thrombin generation than females (n = 26; 65%), with significantly longer lag times (p = 0.0475), lower peak thrombin concentrations (p = 0.0203), and lower ETPs (p = 0.0238). Chacma baboons have greater overall endogenous thrombin generation potentials than humans, which is even more prominent in females. This should be considered when designing future baboon model experiments involving the haemostatic system, or when evaluating novel therapies in these animals.
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Affiliation(s)
- J Joubert
- Department of Haematology and Cell Biology, School of Pathology, Faculty of Health Sciences, University of the Free State, 205 Nelson Mandela Drive, PO Box 339 (G2), Bloemfontein, 9300, South Africa.
- National Health Laboratory Service, Universitas Academic Laboratories, Haematology, Bloemfontein, South Africa.
| | - S M Meiring
- Department of Haematology and Cell Biology, School of Pathology, Faculty of Health Sciences, University of the Free State, 205 Nelson Mandela Drive, PO Box 339 (G2), Bloemfontein, 9300, South Africa
- National Health Laboratory Service, Universitas Academic Laboratories, Haematology, Bloemfontein, South Africa
| | - W J Janse van Rensburg
- Human Molecular Biology Unit, School of Biomedical Sciences, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa
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Yin Q, Zhang X, Liao S, Huang X, Wan CC, Wang Y. Potential anticoagulant of traditional chinese medicine and novel targets for anticoagulant drugs. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2023; 116:154880. [PMID: 37267694 DOI: 10.1016/j.phymed.2023.154880] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 05/04/2023] [Accepted: 05/12/2023] [Indexed: 06/04/2023]
Abstract
BACKGROUND Anticoagulants are the main drugs used for the prevention and treatment of thrombosis. Currently, anticoagulant drugs are primarily multitarget heparin drugs, single-target FXa inhibitors and FIIa inhibitors. In addition, some traditional Chinese drugs also have anticoagulant effects, but they are not the main direction of treatment at present. But the anticoagulant drugs mentioned above, all have a common side effect is bleeding. Many other anticoagulation targets are under investigation. With further exploration of coagulation mechanism, how to further determine new anticoagulant targets and how to make traditional Chinese medicine play anticoagulant role have become a new field of exploration. PURPOSE The purpose of the study was to summarize the recent research progress on coagulation mechanisms, new anticoagulant targets and traditional Chinese medicine. METHODS A comprehensive literature search was conducted using four electronic databases, including PubMed, Embase, CNKI, Wanfang database and ClinicalTrials.gov, from the inception of the study to 28 Feb 2023. Key words used in the literature search were "anticoagulation", "anticoagulant targets", "new targets", "coagulation mechanisms", "potential anticoagulant", "herb medicine", "botanical medicine", "Chinese medicine", "traditional Chinese medicine", "blood coagulation factor", keywords are linked with AND/OR. Recent findings on coagulation mechanisms, potential anticoagulant targets and traditional Chinese medicine were studied. RESULTS The active components extracted from the Chinese medicinal herbs, Salvia miltiorrhiza, Chuanxiong rhizoma, safflower and Panax notoginseng have obvious anticoagulant effects and can be used as potential anticoagulant drugs, but the risk of bleeding is unclear. TF/FVIIa, FVIII, FIX, FXI, FXII, and FXIII have all been evaluated as targets in animal studies or clinical trials. FIX and FXI are the most studied anticoagulant targets, but FXI inhibitors have shown stronger advantages. CONCLUSION This review of potential anticoagulants provides a comprehensive resource. Literature analysis suggests that FXI inhibitors can be used as potential anticoagulant candidates. In addition, we should not ignore the anticoagulant effect of traditional Chinese medicine, and look forward to more research and the emergence of new drugs.
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Affiliation(s)
- Qinan Yin
- Department of Pharmacy, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China; Personalized Drug Therapy Key Laboratory of Sichuan Province, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China
| | - Xiaoqin Zhang
- Department of Critical Care Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China
| | - Suqing Liao
- Department of Critical Care Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China
| | - Xiaobo Huang
- Department of Critical Care Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China
| | - Chunpeng Craig Wan
- College of Agronomy, Jiangxi Agricultural University, Jiangxi Key Laboratory for Post-Harvest Technology and Nondestructive Testing of Fruits & Vegetables, Nanchang 330045, PR. China.
| | - Yi Wang
- Department of Critical Care Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu 610072, PR. China.
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Dimitropoulos G, Rahim SMZ, Moss AS, Lip GYH. New anticoagulants for venous thromboembolism and atrial fibrillation: what the future holds. Expert Opin Investig Drugs 2017; 27:71-86. [DOI: 10.1080/13543784.2018.1416090] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Gerasimos Dimitropoulos
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - S. M. Zubair Rahim
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - Alexandra Sophie Moss
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Cardiology Department, City Hospital, Birmingham, UK
| | - Gregory Y. H. Lip
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
- Aalborg Thrombosis Research Unit, Department of Clinical Medicine, Aalborg University, Aalborg, Denmark
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van Montfoort M, Meijers J. Anticoagulation beyond direct thrombin and factor Xa inhibitors: indications for targeting the intrinsic pathway? Thromb Haemost 2017; 110:223-32. [DOI: 10.1160/th12-11-0803] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Accepted: 05/07/2013] [Indexed: 11/05/2022]
Abstract
SummaryAntithrombotic drugs like vitamin K antagonists and heparin have been the gold standard for the treatment and prevention of thromboembolic disease for many years. Unfortunately, there are several disadvantages of these antithrombotic drugs: they are accompanied by serious bleeding problems, it is necessary to monitor the therapeutic window, and there are various interactions with food and other drugs. This has led to the development of new oral anticoagulants, specifically inhibiting either thrombin or factor Xa. In terms of effectiveness, these drugs are comparable to the currently available anticoagulants; however, they are still associated with issues such as bleeding, reversal of the drug and complicated laboratory monitoring. Vitamin K antagonists, heparin, direct thrombin and factor Xa inhibitors have in common that they target key proteins of the haemostatic system. In an attempt to overcome these difficulties we investigated whether the intrinsic coagulation factors (VIII, IX, XI, XII, prekallikrein and high-molecular-weight kininogen) are superior targets for anticoagulation. We analysed epidemiological data concerning thrombosis and bleeding in patients deficient in one of the intrinsic pathway proteins. Furthermore, we discuss several thrombotic models in intrinsic coagulation factor-deficient animals. The combined results suggest that intrinsic coagulation factors could be suitable targets for anticoagulant drugs.
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Denas G, Pengo V. Investigational anticoagulants for hematological conditions: a new generation of therapies. Expert Opin Investig Drugs 2013; 22:1281-94. [PMID: 23876036 DOI: 10.1517/13543784.2013.821463] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
INTRODUCTION The introduction of novel anticoagulants has had contrasting effects on the agents in the pipeline, fueling the development of some and sinking the others. The complexity of the coagulation cascade offers interesting inhibition choices that might become valid treatment options. AREAS COVERED This review will highlight some of the anticoagulants in the pipeline. Following the success of the direct thrombin and FXa inhibitors already in the market, new agents are being tested. These include AZD0837, betrixaban, letaxaban, darexaban, and LY517717. Targeting other components of the hemostatic pathway might lead to better safety profiles without influencing efficacy. Inhibitors to FVIIa-tissue factor (FVIIa/TF) complex, FIX, FXI, and FXII are being assessed. New inspiring inhibitors are antisense oligonucleotides (ASOs) and aptamers. These are highly specific agents with readily reversible effect and might be engineered to inhibit any coagulation factor. Currently tested ASOs and aptamers are inhibitors of FXI, FXII, thrombin, FIXa, and platelet GPIV. EXPERT OPINION Some of the agents in the pipeline offer valid treatment option for long-term therapy, overcoming some of the drawbacks of the novel anticoagulants. Research is being driven by an expanding market in the anticoagulation field that has been unexploited for a long time.
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Affiliation(s)
- Gentian Denas
- Padua University Hospital, Cardiology Clinic, Department of Cardiac, Thoracic, and Vascular Sciences , Via Giustiniani 2, 35128 Padova , Italy +390498215658 ; +390498215658 ;
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Verhamme P, Gunn S, Sonesson E, Peerlinck K, Vanassche T, Vandenbriele C, Ageno W, Glazer S, Prins M, Buller H, Tangelder M. Single-dose TB-402 or rivaroxaban for the prevention of venous thromboembolism after total hip replacement. A randomised, controlled trial. Thromb Haemost 2013; 109:1091-8. [PMID: 23615791 DOI: 10.1160/th13-01-0066] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2013] [Accepted: 03/29/2013] [Indexed: 11/05/2022]
Abstract
TB-402 is a long-acting monoclonal antibody that partially inhibits factor VIII. A single administration of TB-402 was effective and well-tolerated for the prevention of venous thromboembolism (VTE) after total knee replacement. In this study, the efficacy and safety of a single administration of TB-402 for the extended prophylaxis of VTE after total hip replacement (THR) was investigated. This was a phase II, randomised, active-controlled, double-blind study that included patients undergoing elective THR surgery. Patients were randomised to TB-402 25 mg or TB-402 50 mg, administered as a single intravenous administration 2-4 hours postoperatively, or to rivaroxaban 10 mg once daily for 35 days. The primary efficacy outcome was total VTE defined as symptomatic VTE and asymptomatic deep-vein thrombosis (DVT) detected by bilateral venography at day 35. The principal safety outcome was the incidence of major bleeding and clinically relevant non-major bleeding until day 35. Total VTE was similar in all groups: 5.3% (95%CI 2.9-9.6), 5.2% (95%CI 2.8-9.3) and 4.7% (95%CI 2.5-8.7) for TB-402 25 mg, TB-402 50 mg and rivaroxaban, respectively. All were asymptomatic DVTs. Major or clinically relevant non-major bleedings were observed in 5.8% (95%CI 3.3-9.9), 7.2% (95%CI 4.4-11.6) and 1.4% (95%CI 0.5-4.2) for TB-402 25 mg, TB-402 50 mg and rivaroxaban, respectively. In conclusion, TB-402, administered as a single postoperative dose, had a similar efficacy compared to rivaroxaban for the prevention of VTE after THR. The incidence of major and clinically relevant non-major bleeding was higher in the TB-402 groups than in the rivaroxaban group.
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Affiliation(s)
- Peter Verhamme
- Center for Molecular and Vascular Biology, KU Leuven, Herestraat 49 / box 911, B-3000 Leuven, Belgium.
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Tangelder M, Long C, Emmerechts J, Jacquemin M, Peerlinck K, Vanassche T, Glazer S, Giesen P, Hoylaerts M, Verhamme P. Antidote strategies to reverse anticoagulation with TB-402, a long-acting partial inhibitor of factor VIII. J Thromb Haemost 2012; 10:1371-8. [PMID: 22540161 DOI: 10.1111/j.1538-7836.2012.04762.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND TB-402 is a partially inhibiting antibody of factor VIII that is under development as a long-acting anticoagulant. PATIENTS AND METHODS The reversibility of FVIII inhibition by TB-402 was evaluated in vitro after spiking with recombinant human FVIII (rhFVIII), human plasma-derived FVIII (hpdFVIII), recombinant activated human FVII (rhFVIIa), FVIII inhibitor bypassing activity (FEIBA), and prothrombin complex concentrate (PCC). Twelve subjects were randomized to placebo or 35 or 70 IU kg(-1) rhFVIII 48 h after a single dose of 620 μg kg(-1) TB-402. TB-402 concentrations, FVIII activity (FVIII:C), activated partial thromboplastin time (APTT) and thrombin generation were measured over a period of 8 weeks. RESULTS In spiked samples, TB-402 inhibited FVIII:C by 30%, prolonged APTT by 4.5 s, and reduced the peak height in the thrombin generation assay to 56% ± 13% of the control value. In the presence of 10 μg mL(-1) TB-402, rhFVIII restored FVIII:C and APTT to the values obtained in the absence of TB-402. The inhibitory effect of TB-402 on thrombin generation was entirely reversed by rhFVIII, hpdFVIII, rhFVIIa, FEIBA, and PCC. In men, the mean half-life (t(1/2) ) of TB-402 was 14.2 days. TB-402 lowered the endogenous thrombin potential by 23% for ~ 35 days. Infusion of 35 IU kg(-1) rhFVIII had a marginal effect, whereas 70 IU kg(-1) rhFVIII restored FVIII:C, reduced APTT back to baseline for 9 h, and restored thrombin generation for ~ 3 h. CONCLUSIONS TB-402 resulted in a stable long-term anticoagulant effect. rhFVIII and other procoagulants counteracted the effect of TB-402 temporarily, and may be effective antidotes for future clinical practice.
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Affiliation(s)
- M Tangelder
- Research and Development, ThromboGenics NV, Heverlee, Belgium.
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Weitz JI, Eikelboom JW, Samama MM. New antithrombotic drugs: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012; 141:e120S-e151S. [PMID: 22315258 DOI: 10.1378/chest.11-2294] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
This article focuses on new antithrombotic drugs that are in or are entering phase 3 clinical testing. Development of these new agents was prompted by the limitations of existing antiplatelet, anticoagulant, or fibrinolytic drugs. Addressing these unmet needs, this article (1) outlines the rationale for development of new antithrombotic agents; (2) describes the new antiplatelet, anticoagulant, and fibrinolytic drugs; and (3) provides clinical perspectives on the opportunities and challenges faced by these novel agents.
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Affiliation(s)
- Jeffrey I Weitz
- Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, ON, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, Canada.
| | - John W Eikelboom
- Thrombosis and Atherosclerosis Research Institute and Department of Medicine, McMaster University, Hamilton, ON, Canada
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Emmerechts J, Vanassche T, Loyen S, Van Linthout I, Cludts K, Kauskot A, Long C, Jacquemin M, Hoylaerts M, Verhamme P. Partial versus complete factor VIII inhibition in a mouse model of venous thrombosis. Thromb Res 2012; 129:514-9. [DOI: 10.1016/j.thromres.2011.06.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/20/2011] [Accepted: 06/29/2011] [Indexed: 10/17/2022]
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12
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Procoagulant activity induced by vascular injury determines contribution of elevated factor VIII to thrombosis and thrombus stability in mice. Blood 2011; 118:3960-8. [PMID: 21828144 DOI: 10.1182/blood-2011-06-362814] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Studies have correlated elevated plasma factor VIII (FVIII) with thrombosis; however, it is unclear whether elevated FVIII is a proinflammatory biomarker, causative agent, or both. We raised FVIII levels in mice and measured the time to vessel occlusion (TTO) after ferric chloride-induced injury. Compared with control (saline-infused) mice, elevated FVIII had no effect after longer (3-minute) carotid artery injury, but it shortened the TTO after shorter (2-minute) injury (P < .008). After injury, circulating thrombin-antithrombin (TAT) complexes were lower after short versus long injury (P < .04), suggesting short treatment produced less coagulation activation. TAT levels in FVIII-infused mice were higher than in controls after short, but not longer, injury. Accordingly, elevated FVIII had no effect on in vitro thrombin generation or platelet aggregation triggered by high tissue factor, but it increased thrombin generation rate and peak (2.4- and 1.5-fold, respectively), and it accelerated platelet aggregation (up to 1.6-fold) when initiated by low tissue factor. Compared with control mice, elevated FVIII stabilized thrombi (fewer emboli) after short injury, but it had no effect after longer injury. TTO and emboli correlated with TATs. These results demonstrate dependence of FVIII activity on extent of vascular injury. We propose elevated plasma FVIII is an etiologic, prothrombotic agent after moderate but not extensive vascular damage.
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13
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Verhamme P, Tangelder M, Verhaeghe R, Ageno W, Glazer S, Prins M, Jacquemin M, Büller H. Single intravenous administration of TB-402 for the prophylaxis of venous thromboembolism after total knee replacement: a dose-escalating, randomized, controlled trial. J Thromb Haemost 2011; 9:664-71. [PMID: 21284801 DOI: 10.1111/j.1538-7836.2011.04221.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND TB-402 is a novel anticoagulant monoclonal antibody with a prolonged antithrombotic effect resulting from its partial factor (F)VIII inhibition and long half-life. We evaluated the efficacy and safety of a single administration of TB-402 for the prevention of venous thromboembolism (VTE) after total knee replacement (TKR). PATIENTS AND METHODS This was a phase II, dose-escalating, randomized, enoxaparin-controlled, open-label study. Patients were post-operatively assigned to a single dose of TB-402 (0.3, 0.6 or 1.2 mg kg(-1)) or enoxaparin 40 mg for at least 10 days (n = 75 per group; 3:1 TB-402 to enoxaparin). The primary efficacy outcome was total VTE defined as asymptomatic deep vein thrombosis (DVT) detected by bilateral venography and symptomatic VTE by day 7 to 11. The principal safety outcome was the incidence of major bleeding and clinically relevant non-major bleeding. RESULTS Total VTE was lower in all TB-402 groups compared with enoxaparin: 16.7%(95% CI 9.8-26.9), 23.9%(95% CI 15.3-35.3), 24.1%(95% CI 16.0-34.5) and 39.0%(95% CI 28.8-50.1) for TB-402 0.3, 0.6, 1.2 mg kg(-1) and enoxaparin, respectively (P = 0.003 for TB-402 0.3 mg kg(-1) vs. enoxaparin). The incidence of total VTE in the pooled TB-402 groups was 21.6% (95%CI 16.6-27.5), an absolute risk reduction vs. enoxaparin of 17.4% (95% CI 5.2-29.6). Major or clinically relevant non-major bleeding was observed in 3/75(4.0%), 4/74(5.4%), 7/87(8.0%) and 3/79(3.8%) patients for TB-402 0.3, 0.6, 1.2 mg kg(-1) and enoxaparin, respectively. CONCLUSIONS TB-402, as a single post-operative administration, was associated with a lower rate of VTE in all doses tested, compared with enoxaparin. The incidence of major and clinically relevant non-major bleeding was similar to enoxaparin 40 mg for TB-402 0.3 and 0.6 mg kg(-1).
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Affiliation(s)
- P Verhamme
- Center for Molecular and Vascular Biology, University of Leuven, Belgium.
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14
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Gómez-Outes A, Suárez-Gea ML, Lecumberri R, Rocha E, Pozo-Hernández C, Vargas-Castrillón E. New parenteral anticoagulants in development. Ther Adv Cardiovasc Dis 2010; 5:33-59. [PMID: 21045018 DOI: 10.1177/1753944710387808] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The therapeutic armamentarium of parenteral anticoagulants available to clinicians is mainly composed by unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), fondaparinux, recombinant hirudins (i.e. bivalirudin, desirudin, lepirudin) and argatroban. These drugs are effective and safe for prevention and/or treatment of thromboembolic diseases but they have some drawbacks. Among other inconveniences, UFH requires regular anticoagulant monitoring as a result of variability in the anticoagulant response and there is a risk of serious heparin-induced thrombocytopaenia (HIT). LMWH, fondaparinux and recombinant hirudins are mainly cleared through the kidneys and their use in patients with severe renal insufficiency may be problematic. LMWH is only partially neutralized by protamine while fondaparinux and recombinant hirudins have no specific antidote. Novel anticoagulants in development for parenteral administration include new indirect activated factor Xa (FXa) inhibitors (idrabiotaparinux, ultra-low-molecular-weight heparins [semuloparin, RO-14], new LMWH [M118]), direct FXa inhibitors (otamixaban), direct FIIa inhibitors (flovagatran sodium, pegmusirudin, NU172, HD1-22), direct FXIa inhibitors (BMS-262084, antisense oligonucleotides targeting FXIa, clavatadine), direct FIXa inhibitors (RB-006), FVIIIa inhibitors (TB-402), FVIIa/tissue factor inhibitors (tifacogin, NAPc2, PCI-27483, BMS-593214), FVa inhibitors (drotrecogin alpha activated, ART-123) and dual thrombin/FXa inhibitors (EP217609, tanogitran). These new compounds have the potential to complement established parenteral anticoagulants. In the present review, we discuss the pharmacology of new parenteral anticoagulants, the results of clinical studies, the newly planned or ongoing clinical trials with these compounds, and their potential advantages and drawbacks over existing therapies.
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Affiliation(s)
- Antonio Gómez-Outes
- Division of Pharmacology and Clinical Evaluation, Medicines for Human Use, Spanish Agency for Medicines and Health Care Products (AEMPS), Parque Empresarial Las Mercedes, Edificio 8, C/Campezo 1, Madrid, 28022, Spain.
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Tolerability and pharmacokinetics of TB-402 in healthy male volunteers. Clin Ther 2010; 32:1205-20. [DOI: 10.1016/j.clinthera.2010.06.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2010] [Indexed: 11/19/2022]
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