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Holle LA, Pantazis JC, Turecek PL, Wolberg AS. Clot formation and fibrinolysis assays reveal functional differences among hemostatic agents in hemophilia A plasma. Res Pract Thromb Haemost 2024; 8:102337. [PMID: 38426025 PMCID: PMC10901841 DOI: 10.1016/j.rpth.2024.102337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Revised: 12/21/2023] [Accepted: 01/16/2024] [Indexed: 03/02/2024] Open
Abstract
Background Measuring the activity of hemostatic agents used to treat hemophilia A often requires drug-specific assays. In vitro assays show hemophilic clots have abnormal characteristics, including prolonged clotting time and decreased resistance to fibrinolysis. The ability of certain agents to correct these parameters in vitro is associated with hemostatic efficacy in vivo. Objectives To compare effects of established and emerging hemostatic agents on clot formation and fibrinolysis in hemophilia A plasma. Methods Pooled and individual hemophilia A platelet-poor plasmas were spiked with replacement (recombinant factor VIII [rFVIII], PEGylated rFVIII, polysialylated rFVIII, and porcine rFVIII) or bypassing (emicizumab, rFVIIa, and activated prothrombin complex concentrate) products. Effects on tissue factor-initiated clot formation and fibrinolysis were measured by turbidity. Results Compared to normal pooled plasma, hemophilia-pooled plasma showed reduced clot formation and increased fibrinolysis, and all replacement agents improved these characteristics. rFVIII and PEGylated rFVIII produced similar effects at similar concentrations, whereas polysialylated rFVIII produced slightly higher and porcine rFVIII slightly lower effects at these concentrations. Bypassing agents enhanced clot formation and stability, but patterns differed from replacement agents. The clotting rate showed a concentration-response relationship for all agents. High concentrations of all products produced effects that exceeded the normal range in at least some parameters. Responses of individual donors varied, but all agents improved clot formation and stability in all donors tested. Conclusion Clotting and fibrinolysis assays reveal hemostatic effects of replacement and bypassing therapies at clinically relevant concentrations. These assays may help characterize hemostatic agents and optimize dosing.
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Affiliation(s)
- Lori A. Holle
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Jacob C. Pantazis
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Peter L. Turecek
- Plasma-Derived Therapies R&D, Baxalta Innovations GmbH – Takeda, Vienna, Austria
| | - Alisa S. Wolberg
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
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2
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Chen R, Huang M, Xu P. Polyphosphate as an antithrombotic target and hemostatic agent. J Mater Chem B 2023; 11:7855-7872. [PMID: 37534776 DOI: 10.1039/d3tb01152f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Polyphosphate (PolyP) is a polymer comprised of linear phosphate units connected by phosphate anhydride bonds. PolyP exists in a diverse range of eukaryotes and prokaryotes with varied chain lengths ranging from six to thousands of phosphate units. Upon activation, human platelets and neutrophils release short-chain PolyP, along with other components, to initiate the coagulation pathway. Long-chain PolyP derived from cellular or bacterial organelles exhibits higher proinflammatory and procoagulant effects compared to short-chain PolyP. Notably, PolyP has been identified as a low-hemorrhagic antithrombotic target since neutralizing plasma PolyP suppresses the thrombotic process without impairing the hemostatic functions. As an inorganic polymer without uniform steric configuration, PolyP is typically targeted by cationic polymers or recombinant polyphosphatases rather than conventional antibodies, small-molecule compounds, or peptides. Additionally, because of its procoagulant property, PolyP has been incorporated in wound-dressing materials to facilitate blood hemostasis. This review summarizes current studies on PolyP as a low-hemorrhagic antithrombotic target and the development of hemostatic materials based on PolyP.
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Affiliation(s)
- Ruoyu Chen
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
| | - Mingdong Huang
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
- College of Chemistry, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China
| | - Peng Xu
- College of Biological Science and Engineering, Fuzhou University, Fuzhou, Fujian, 350108, P. R. China.
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3
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Reitsma SE, Holle LA, Bouck EG, Monroe DM, Mast AE, Burthem J, Bolton-Maggs PHB, Gidley GN, Wolberg AS. Tissue factor pathway inhibitor is a potential modifier of bleeding risk in factor XI deficiency. J Thromb Haemost 2023; 21:467-479. [PMID: 36696199 PMCID: PMC10111213 DOI: 10.1016/j.jtha.2022.10.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 09/26/2022] [Accepted: 10/06/2022] [Indexed: 01/26/2023]
Abstract
BACKGROUND Factor (F) XI deficiency is associated with increased bleeding risk in some individuals. Neither FXI levels nor clinical clotting assays predict the bleeding risk. Compared with controls, FXI-deficient bleeders have reduced clot formation, decreased fibrin network density, and increased susceptibility to fibrinolysis. Tissue factor pathway inhibitor (TFPI) was recently implicated as a modifying factor in individuals with bleeding of unknown cause. OBJECTIVES To determine the potential of TFPI in modifying the bleeding risk in FXI-deficient individuals. METHODS The effects of TFPI on thrombin generation and clot formation, structure, and fibrinolysis in FXI-deficient plasma were measured in vitro in the absence or presence of inhibitory anti-TFPI antibody or exogenous recombinant TFPIα. Total plasma TFPI concentration was measured in 2 independent cohorts of controls and FXI-deficient individuals classified as bleeders or nonbleeders (cohort 1: 10 controls and 16 FXI-deficient individuals; cohort 2: 48 controls and 57 FXI-deficient individuals) and correlated with ex vivo plasma clot formation and fibrinolysis parameters associated with bleeding risk. RESULTS In an in vitro FXI deficiency model, inhibition of TFPI enhanced thrombin generation and clot formation, increased the network density, and decreased fibrinolysis, whereas an increase in TFPI had the opposite effects. Compared with controls, plasma from FXI-deficient bleeders had higher TFPI concentration. Total plasma TFPI concentrations correlated with parameters from ex vivo clotting and fibrinolysis assays that differentiate FXI-deficient bleeders and nonbleeders. CONCLUSION Coagulation and fibrinolysis parameters that differentiate FXI-deficient nonbleeders and bleeders were altered by plasma TFPIα. Total plasma TFPI was increased in FXI-deficient bleeders. TFPI may modify the bleeding risk in FXI-deficient individuals.
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Affiliation(s)
- Stéphanie E Reitsma
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Lori A Holle
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Emma G Bouck
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Dougald M Monroe
- Department of Medicine and UNC Blood Research Center, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Alan E Mast
- Versiti Blood Research Institute, Milwaukee, Wisconsin, USA
| | - John Burthem
- Department of Haematology, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, UK; Institute of Cancer Sciences, The University of Manchester, Manchester, UK
| | | | - Gillian N Gidley
- Institute of Cancer Sciences, The University of Manchester, Manchester, UK; Department of Haematology, St James' Hospital, Leeds Teaching Hospitals Trust, UK
| | - Alisa S Wolberg
- Department of Pathology and Laboratory Medicine and UNC Blood Research Center, University of North Carolina, Chapel Hill, North Carolina, USA.
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4
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Valke LLFG, Rijpma S, Meijer D, Schols SEM, van Heerde WL. Thrombin generation assays to personalize treatment in bleeding and thrombotic diseases. Front Cardiovasc Med 2022; 9:1033416. [PMID: 36440026 PMCID: PMC9684194 DOI: 10.3389/fcvm.2022.1033416] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/26/2022] [Indexed: 07/30/2023] Open
Abstract
Treatment of bleeding and thrombotic disorders is highly standardized and based on evidence-based medicine guidelines. These evidence-based treatment schemes are well accepted but may lead to either insufficient treatment or over-dosing, because the individuals' hemostatic properties are not taken into account. This can potentially introduce bleeding or thrombotic complications in individual patients. With the incorporation of pharmacokinetic (PK) and pharmacodynamic (PK-PD) parameters, based on global assays such as thrombin generation assays (TGAs), a more personalized approach can be applied to treat either bleeding or thrombotic disorders. In this review, we will discuss the recent literature about the technical aspects of TGAs and the relation to diagnosis and management of bleeding and thrombotic disorders. In patients with bleeding disorders, such as hemophilia A or factor VII deficiency, TGAs can be used to identify patients with a more severe bleeding phenotype and also in the management with non-replacement therapy and/or bypassing therapy. These assays have also a role in patients with venous thrombo-embolism, but the usage of TGAs in patients with arterial thrombosis is less clear. However, there is a potential role for TGAs in the monitoring of (long-term) antithrombotic therapy, for example with the use of direct oral anticoagulants. Finally this review will discuss controversies, limitations and knowledge gaps in relation to the introduction of TGAs to personalize medicine in daily medical practice.
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Affiliation(s)
- Lars L. F. G. Valke
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
| | - Sanna Rijpma
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Danielle Meijer
- Department of Laboratory Medicine, Laboratory of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
| | - Saskia E. M. Schols
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
| | - Waander L. van Heerde
- Department of Hematology, Radboud University Medical Center, Nijmegen, Netherlands
- Hemophilia Treatment Center, Nijmegen, Netherlands
- Enzyre BV, Novio Tech Campus, Nijmegen, Netherlands
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5
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Swan D, Mahlangu J, Thachil J. Non‐factor therapies for bleeding disorders: A primer for the general haematologist. EJHAEM 2022; 3:584-595. [PMID: 36051064 PMCID: PMC9422036 DOI: 10.1002/jha2.442] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 03/31/2022] [Accepted: 04/04/2022] [Indexed: 11/09/2022]
Abstract
Management of patients with severe bleeding disorders, particularly haemophilia A and B, and to a lesser extent, von Willebrand disease, has come on leaps and bounds over the past decade. Until recently, patients relied upon the administration of factor concentrates to prevent or treat bleeding episodes. Factor administration requires intravenous access and, in up to one‐third of patients, leads to the development of neutralising antibodies, or inhibitors, which are associated with more frequent bleeding episodes and higher morbidity. Novel non‐factor therapies may offer a solution to these unmet needs. In this review, we discuss the factor mimetics, particularly emicizumab, and the rebalancing agents, which inhibit antithrombin, tissue factor pathway inhibitor and activated protein C, and novel treatments to enhance von Willebrand factor levels. We review the available trial data, unanswered questions and challenges associated with these new treatment modalities. Finally, we provide practical management algorithms to aid the general haematologist when faced with a patient receiving emicizumab who requires surgery or may develop bleeding.
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Affiliation(s)
- Dawn Swan
- National University Ireland Galway Republic of Ireland
| | - Johnny Mahlangu
- Department of Molecular Medicine and Haematology School of Pathology Faculty of Health Sciences University of the Witwatersrand and NHLS Johannesburg South Africa
| | - Jecko Thachil
- Department of Haematology Manchester University Hospitals NHS Foundation Trust Manchester UK
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6
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Hernández-Jiménez M, Martín-Vílchez S, Ochoa D, Mejía-Abril G, Román M, Camargo-Mamani P, Luquero-Bueno S, Jilma B, Moro MA, Fernández G, Piñeiro D, Ribó M, González VM, Lizasoain I, Abad-Santos F. First-in-human phase I clinical trial of a TLR4-binding DNA aptamer, ApTOLL: Safety and pharmacokinetics in healthy volunteers. MOLECULAR THERAPY. NUCLEIC ACIDS 2022; 28:124-135. [PMID: 35402075 PMCID: PMC8938885 DOI: 10.1016/j.omtn.2022.03.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 03/03/2022] [Indexed: 02/05/2023]
Abstract
ApTOLL is an aptamer that antagonizes Toll-like receptor 4 and improves functional outcomes in models of ischemic stroke and myocardial infarction. The aim of this study was to characterize the safety and pharmacokinetics of ApTOLL in healthy volunteers. A first-in-human dose-ascending, randomized, placebo-controlled phase I clinical trial to assess safety and pharmacokinetics of ApTOLL (30-min infusion intravenously) was performed in 46 healthy adult male volunteers. The study was divided into two parts: part A included seven single ascending dose levels, and part B had one multiple dose cohort. Safety and pharmacokinetic parameters were evaluated. No serious adverse events or biochemistry alterations were detected at any dose nor at any administration pattern studied. Maximum concentration was detected at the end of the infusion and mean half-life was 9.3 h. Interestingly, exposure increased in the first four levels receiving doses from 0.7 mg to 14 mg (AUC of 2,441.26 h∗ng/mL to 23,371.11 h∗ng/mL) but remained stable thereafter (mean of 23,184.61 h∗ng/mL after 70 mg). Consequently, the multiple dose study did not show any accumulation of ApTOLL. These results show an excellent safety and adequate pharmacokinetic profile that, together with the efficacy demonstrated in nonclinical studies, provide the basis to start clinical trials in patients.
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Affiliation(s)
- Macarena Hernández-Jiménez
- AptaTargets S.L., Avda. Cardenal Herrera Oria 298, 28035 Madrid, Spain
- Corresponding author AptaTargets S.L., Avda. Cardenal Herrera Oria 298, 28035 Madrid, Spain.
| | - Samuel Martín-Vílchez
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Dolores Ochoa
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Gina Mejía-Abril
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Manuel Román
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Paola Camargo-Mamani
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Sergio Luquero-Bueno
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
| | - Bernd Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, 1090 Vienna, Austria
| | - María A. Moro
- Centro Nacional de Investigaciones Cardiovasculares Carlos III (F.S.P.), 28029 Madrid, Spain
- Unidad de Investigación Neurovascular, Department of Pharmacology and Toxicology, Faculty of Medicine, Universidad Complutense, 28040 Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), 28041 Madrid, Spain
| | - Gerónimo Fernández
- Aptus Biotech S.L., Avda. Cardenal Herrera Oria 298, 28034 Madrid, Spain
| | - David Piñeiro
- AptaTargets S.L., Avda. Cardenal Herrera Oria 298, 28035 Madrid, Spain
| | - Marc Ribó
- AptaTargets S.L., Avda. Cardenal Herrera Oria 298, 28035 Madrid, Spain
| | - Víctor M. González
- Aptus Biotech S.L., Avda. Cardenal Herrera Oria 298, 28034 Madrid, Spain
- Grupo de Aptámeros, Departamento de Bioquímica-Investigación, IRYCIS-Hospital Ramón y Cajal, 28034 Madrid, Spain
| | - Ignacio Lizasoain
- Unidad de Investigación Neurovascular, Department of Pharmacology and Toxicology, Faculty of Medicine, Universidad Complutense, 28040 Madrid, Spain
- Instituto de Investigación Hospital 12 de Octubre (i+12), 28041 Madrid, Spain
| | - Francisco Abad-Santos
- Clinical Pharmacology Department, Hospital Universitario de La Princesa, Universidad Autónoma de Madrid (UAM), Instituto de Investigación Sanitaria La Princesa (IP), 28006 Madrid, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain
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7
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Verhagen MJA, Valke LLFG, Schols SEM. Thrombin generation for monitoring hemostatic therapy in hemophilia A: A narrative review. J Thromb Haemost 2022; 20:794-805. [PMID: 35034413 PMCID: PMC9305107 DOI: 10.1111/jth.15640] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 12/17/2021] [Accepted: 01/10/2022] [Indexed: 11/29/2022]
Abstract
Patients with severe hemophilia A (HA) have an increased risk of spontaneous and trauma-related bleeding because of a congenital absence of factor VIII (FVIII). Most severe HA patients use prophylactic FVIII concentrate, the effect of which can be monitored with FVIII activity level measurement. However, FVIII activity level is less valuable in predicting the potential clinical bleeding risk. Some patients still experience breakthrough bleeds despite adequate FVIII trough levels, whereas others do not bleed with trough levels below threshold. This difference may be caused by inter-individual differences in pro- and anticoagulant factors, the so-called hemostatic balance. Thrombin generation assays (TGAs) measure the hemostatic balance as a whole. Thereby, the TGAs may be a better tool in the guidance and monitoring of treatment in HA patients. In addition, TGAs offer the opportunity to determine the response to bypassing agents and treatment with non-factor replacement therapy, in which FVIII activity assays are not suitable for monitoring. This review summarizes the current knowledge about monitoring different HA treatment modalities by TGA, as a single treatment option and when used in a concomitant fashion.
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Affiliation(s)
- Marieke J. A. Verhagen
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
| | - Lars L. F. G. Valke
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
| | - Saskia E. M. Schols
- Department of HematologyRadboud University Medical CenterNijmegenThe Netherlands
- Hemophilia Treatment CenterNijmegen‐Eindhoven‐MaastrichtNijmegenThe Netherlands
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8
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Mahlangu JN. Progress in the Development of Anti-tissue Factor Pathway Inhibitors for Haemophilia Management. Front Med (Lausanne) 2021; 8:670526. [PMID: 34026796 PMCID: PMC8131856 DOI: 10.3389/fmed.2021.670526] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 03/24/2021] [Indexed: 12/28/2022] Open
Abstract
The unprecedented progress in addressing unmet needs in haemophilia care to date includes developing several novel therapies that rebalance haemostasis by restoring thrombin generation in patients with haemophilia A or B with and without inhibitors. These novel therapies are FVIII mimetics, antithrombin interference RNA therapy and several monoclonal antibodies directed against the tissue factor pathway inhibitor (anti-TFPI). In this review, we provide an update on the progress made in developing anti-TFPI therapie. Phase 1 data from the three anti-TFPI studies showed acceptable safety profiles, and currently, available phase 2 data are encouraging. While these data support these molecules' further development progression, there is uncertainty on several aspects of their evolution. Two of the three anti-TFPIs have shown drug-related thrombosis, with one study consequently terminated. None of the thrombotic events is predictable with current monitoring tools, and none correlate with known coagulation parameters. All three anti-TFPIs undergo target mediated drug disposition, which impacts the formulation of dosing regimen fo these therapies. They would require more frequent dosing than some of the extended half-life clotting factor products and antithrombin RNAi therapy. There is no assay to measure the TFPI as the physiological levels are very low, which makes monitoring the impact of the anti-TFPI a challenge. The anti-TFPIs have several advantages, including their bioavailability when administered subcutaneously, their stable pharmacokinetics and their ability to prevent bleeds in haemophilia A or B patients with and without inhibitors. Whether these advantages can be realized will depend on the outcome of the currently ongoing studies.
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Affiliation(s)
- Johnny N. Mahlangu
- Haemophilia Comprehensive Care Centre, Charlotte Maxeke Johannesburg Academic Hospital, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
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9
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Overview of the Therapeutic Potential of Aptamers Targeting Coagulation Factors. Int J Mol Sci 2021; 22:ijms22083897. [PMID: 33918821 PMCID: PMC8069679 DOI: 10.3390/ijms22083897] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/11/2022] Open
Abstract
Aptamers are single-stranded DNA or RNA sequences that bind target molecules with high specificity and affinity. Aptamers exhibit several notable advantages over protein-based therapeutics. Aptamers are non-immunogenic, easier to synthesize and modify, and can bind targets with greater affinity. Due to these benefits, aptamers are considered a promising therapeutic candidate to treat various conditions, including hematological disorders and cancer. An active area of research involves developing aptamers to target blood coagulation factors. These aptamers have the potential to treat cardiovascular diseases, blood disorders, and cancers. Although no aptamers targeting blood coagulation factors have been approved for clinical use, several aptamers have been evaluated in clinical trials and many more have demonstrated encouraging preclinical results. This review summarized our knowledge of the aptamers targeting proteins involved in coagulation, anticoagulation, fibrinolysis, their extensive applications as therapeutics and diagnostics tools, and the challenges they face for advancing to clinical use.
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10
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Franchini M, Marano G, Pati I, Veropalumbo E, Vaglio S, Pupella S, Masiello F, Cruciani M, Mengoli C, Liumbruno GM. Investigational drugs to treat hemophilia. Expert Opin Investig Drugs 2020; 29:295-301. [DOI: 10.1080/13543784.2020.1722999] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Massimo Franchini
- Italian National Blood Centre, National Institute of Health, Rome, Italy
- Department of Hematology and Transfusion Medicine, Carlo Poma Hospital, Mantua, Italy
| | - Giuseppe Marano
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Ilaria Pati
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Eva Veropalumbo
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Stefania Vaglio
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Simonetta Pupella
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Francesca Masiello
- Italian National Blood Centre, National Institute of Health, Rome, Italy
| | - Mario Cruciani
- Italian National Blood Centre, National Institute of Health, Rome, Italy
- Infection Control Committee and Antibiotic Stewardship Programme, AULSS9 Scaligera, Verona, Italy
| | - Carlo Mengoli
- Italian National Blood Centre, National Institute of Health, Rome, Italy
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11
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Spadarella G, Di Minno A, Milan G, Franco N, Polimeno M, Castaldo F, Di Minno G. Paradigm shift for the treatment of hereditary haemophilia: Towards precision medicine. Blood Rev 2019; 39:100618. [PMID: 31676141 DOI: 10.1016/j.blre.2019.100618] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Revised: 10/07/2019] [Accepted: 10/08/2019] [Indexed: 12/17/2022]
Abstract
Patients with haemophilia A (HA) or B (HB) experience spontaneous limb- or life-threatening bleedings which are prevented by regular prophylactic intravenous infusions of the deficient coagulation factor (FVIII or FIX). Prophylaxis with subcutaneous long-acting non-factor products that improve in vivo thrombin generation is now under intensive investigation (concizumab, fitusiran) or successfully employed (emicizumab) in haemophilia patients. Both haemophilia patients with/without inhibitors take advantage of non-factor products employed alone. In those who also need bypassing agents (or FVIII concentrates) for breakthrough bleeds, thromboembolic events and/or thrombotic microangiopathy may occur. By enhancing thrombin generation, prothrombotic mutations co-segregating with FVIII/FIX gene mutations may trigger thrombotic episodes in HA patients carrying acquired thrombogenic factors (e.g. venous catheters). A thorough knowledge of individual needs increasingly contributed to improve comprehensive care and personalize treatments in haemophilia. Integrating genomics, lifestyle and environmental data is expected to be key to: 1) identify which haemophilia patients are less likely to benefit from a given intervention; 2) define optimal dosing and scheduling of bypassing agents (or FVIII) to employ in combination with non-factor products; 3) establish tests to monitor in vivo thrombin generation; 4) improve communication and deliver results to individuals. As individual outcomes will be improved and the risk of adverse events minimized, non-factor products will come into wider use within the haemophilia community, and patients will hopefully have no more risks of breakthrough bleeds. The risks of a normal life for a "former haemophilia patient" is likely to change the treatment landscape and the structure of haemophilia Centers.
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Affiliation(s)
- Gaia Spadarella
- Postgraduation School in Radiodiagnostics, Università degli studi di Milano, Italy
| | - Alessandro Di Minno
- Dipartimento di Farmacia, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Graziella Milan
- Centro Geriatrico "Frullone" ASL Napoli-1 Centro, Naples, Italy.
| | - Nicoletta Franco
- Dipartimento di Medicina Clinica e Chirurgia, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Mariateresa Polimeno
- Dipartimento di Medicina Clinica e Chirurgia, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Francesco Castaldo
- Dipartimento di Farmacia, Università degli Studi di Napoli "Federico II", Naples, Italy
| | - Giovanni Di Minno
- Dipartimento di Medicina Clinica e Chirurgia, Università degli Studi di Napoli "Federico II", Naples, Italy.
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12
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Li W, Zhao M, Yan H, Wang K, Lan XI. Aptamer Oligonucleotides as Potential Therapeutics in Hematologic Diseases. Mini Rev Med Chem 2019; 19:788-795. [PMID: 28969551 DOI: 10.2174/1389557517666171002160526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 06/22/2017] [Accepted: 08/05/2017] [Indexed: 11/22/2022]
Abstract
Aptamers are single-stranded DNA or RNA oligonucleotides generated by a novel in vitro selection technique termed Systematic evolution of ligands by exponential enrichment (SELEX). During the past two decades, various aptamer drugs have been developed and many of them have entered into clinical trials. In the present review, we focus on aptamers as potential therapeutics for hematological diseases, including anemia of chronic inflammation (ACI) and anemia of chronic disease (ACD), hemophilia, thrombotic thrombocytopenic purpura (TTP) or VWD type-2B, and sickle cell disease (SCD), in particular, those that have entered into clinical trials.
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Affiliation(s)
- Weibin Li
- Institute for Laboratory Medicine, Fuzhou General Hospital, Second Military Medical University, No 156 North Xi-er Huan Road, Fuzhou 350025, Fujian Province, China
| | - Meng Zhao
- Institute for Laboratory Medicine, Fuzhou General Hospital, Second Military Medical University, No 156 North Xi-er Huan Road, Fuzhou 350025, Fujian Province, China
| | - Huihui Yan
- Institute for Laboratory Medicine, Fuzhou General Hospital, Second Military Medical University, No 156 North Xi-er Huan Road, Fuzhou 350025, Fujian Province, China
| | - Kaiyu Wang
- Institute for Laboratory Medicine, Fuzhou General Hospital, Second Military Medical University, No 156 North Xi-er Huan Road, Fuzhou 350025, Fujian Province, China
| | - XIaopeng Lan
- Institute for Laboratory Medicine, Fuzhou General Hospital, Second Military Medical University, No 156 North Xi-er Huan Road, Fuzhou 350025, Fujian Province, China
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13
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Ferrarese M, Baroni M, Della Valle P, Spiga I, Poloniato A, D'Angelo A, Pinotti M, Bernardi F, Branchini A. Missense changes in the catalytic domain of coagulation factor X account for minimal function preventing a perinatal lethal condition. Haemophilia 2019; 25:685-692. [PMID: 30994257 DOI: 10.1111/hae.13761] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Revised: 03/23/2019] [Accepted: 03/23/2019] [Indexed: 11/26/2022]
Abstract
INTRODUCTION Inherited deficiencies in the coagulation pathway provide diversified models to investigate the molecular bases of perinatal lethality associated with null-like variants. Differently from X-linked haemophilias, homozygous/doubly heterozygous null variants in the rare autosomally inherited deficiency of factor X (FX) might be incompatible with perinatal survival. AIM To provide experimental evidence about the null/close-to-null FX function. METHODS The residual secreted (ELISA) and functional (thrombin generation assays) protein levels associated with the novel nonsense (c.1382G>A; p.Trp461Ter) and missense (c.752T>C; p.Leu251Pro) variants, found in the proposita with life-threatening symptoms at birth, were characterized through recombinant (r)FX expression. RESULTS The rFX-461Ter showed very low secretion and undetectable function. Expression and function of the predicted readthrough-deriving missense variants (rFX-461Tyr, rFX-461Gln) were also severely impaired. These unfavourable features, due to nucleotide and protein sequence constraints, precluded functional readthrough over the 461 stop codon. Differently, the poorly secreted rFX-251Pro variant displayed residual function that was characterized by anti-TFPI aptamer-based amplification or selective inhibition of activated FX function by fondaparinux in plasma and found to be reduced by approximately three orders of magnitude. Similarly to the rFX-251Pro, a group of catalytic domain missense variants cause poorly secreted molecules with modest function in FX-deficient patients with life-threatening symptoms. CONCLUSIONS Our data, contributing to the knowledge of the very severe FX deficiency forms, support life-saving requirement of trace FX function, clearly exemplified by the dysfunctional but not completely inactive rFX-251Pro variant that, albeit with severely reduced function, is compatible with a residual activity ensuring minimal haemostasis and permitting perinatal survival.
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Affiliation(s)
- Mattia Ferrarese
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Marcello Baroni
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Patrizia Della Valle
- Coagulation Service and Thrombosis Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Ivana Spiga
- Clinical Molecular Biology Laboratory, IRCCS San Raffaele Hospital, Milan, Italy
| | - Antonella Poloniato
- Neonatology Unit, Mother-Child Department, IRCCS San Raffaele Hospital, Milan, Italy
| | - Armando D'Angelo
- Coagulation Service and Thrombosis Research Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Mirko Pinotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Francesco Bernardi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Alessio Branchini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
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14
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Post-transcriptional, post-translational and pharmacological regulation of tissue factor pathway inhibitor. Blood Coagul Fibrinolysis 2018; 29:668-682. [PMID: 30439766 DOI: 10.1097/mbc.0000000000000775] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
: Tissue factor (TF) pathway inhibitor (TFPI) is an endogenous natural anticoagulant that readily inhibits the extrinsic coagulation initiation complex (TF-FVIIa-Xa) and prothrombinase (FXa, FVa and calcium ions). Alternatively, spliced TFPI isoforms (α, β and δ) are expressed by vascular and extravascular cells and regulate thrombosis and haemostasis, as well as cell signalling functions of TF complexes via protease-activated receptors (PARs). Proteolysis of TFPI plays an important role in regulating physiological roles of the TF pathway in host defense and possibly haemostasis. Elimination of TFPI inhibition has therefore been proposed as an approach to improve haemostasis in haemophilia patients. In this review, we focus on posttranscription and translational modification of TFPI and its function in thrombosis and how pharmacological inhibitors and endogenous proteases interfere with TFPI and alter haemostasis.
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15
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Abstract
Regular prophylactic treatment with factor VIII (FVIII) and factor IX (FIX) concentrates in hemophilia A and B, respectively, is introduced in early infancy and has resulted in dramatic improvement of the conditions. Recombinant FVIII and FIX concentrates have been available for > 25 years and have been modified and refined through the years; however, unfortunately frequent intravenous administrations are still necessary. The half-lives of these products have now been extended (EHL) by fusion with albumin, the Fc-portion of IgG, or by being PEGylated. This has been very successful for EHL-FIX, with 3-5 times longer half-life, and to a lesser degree for EHL-FVIII with a half-life extension of only 1.5 times the conventional products. New treatment principles using FVIII mimetics or monoclonal antibodies that rebalance the pro- and anti-coagulation system by interfering with production of anti-thrombin or tissue factor pathway inhibitor have the benefits of long-lasting activity, subcutaneous administration, and being useful in patients both with and without neutralizing antibodies. As the ultimate treatment, recent progress has also been made with gene therapy of both hemophilia A and B.
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Affiliation(s)
- Rolf C R Ljung
- Department of Clinical Sciences-Paediatrics, Lund University, Lund, Sweden.
- Centre for Thrombosis and Haemostasis, Skåne University Hospital, Malmö, Sweden.
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16
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Kovacevic KD, Gilbert JC, Jilma B. Pharmacokinetics, pharmacodynamics and safety of aptamers. Adv Drug Deliv Rev 2018; 134:36-50. [PMID: 30321620 DOI: 10.1016/j.addr.2018.10.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 10/10/2018] [Accepted: 10/11/2018] [Indexed: 12/15/2022]
Abstract
Aptamers are synthetic molecules structured as single-stranded DNA or RNA oligonucleotides that can be designed to mimic the functional properties of monoclonal antibodies. They bind to the target molecules (typically soluble or cell-bound proteins) with high affinity (with picomolar to low nanomolar range) and specificity, and therefore can be an alternative to therapeutic antibodies or peptide ligands. This paper reviews published data regarding pharmacokinetics, pharmacodynamics and safety of aptamers from preclinical and clinical studies. Aptamers have been developed for the treatment of a variety of diseases, including cancer, macular degeneration,g cardiovascular disease, diabetes and anaemia of chronic diseases. There are several preclinical studies with unmodified aptamers, but the vast majority of aptamer trials in humans have been conducted with modified aptamers, because unmodified aptamers demonstrate metabolic instability, as well as rapid renal filtration and elimination. Various strategies have been developed to improve the pharmacokinetic profile of aptamers. Aside from chemical modification of nucleotides in order to stabilize them against nuclease degradation, the main modification to extend the half-life is pegylation. Therefore, the process of pegylation as well as its benefits and possible shortcomings will briefly be discussed.
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17
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Attempting to remedy sub-optimal medication adherence in haemophilia: The rationale for repeated ultrasound visualisations of the patient's joint status. Blood Rev 2018; 33:106-116. [PMID: 30146094 DOI: 10.1016/j.blre.2018.08.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 07/14/2018] [Accepted: 08/17/2018] [Indexed: 01/01/2023]
Abstract
Haemophilia is marked by joint bleeding (haemarthrosis) leading to cartilage damage (arthropathy). Lifelong prophylaxis-initiated after the first bleeding episode-leads to a dramatic decrease in arthropathy in haemophilia patients. However, adherence to continuous intravenous administrations of factor VIII (FVIII) or FIX products is challenging, and patients potentially suffer from breakthrough bleedings while on prophylaxis. Newer FVIII/FIX products with enhanced convenience attributes and/or easier infusion procedures are intended to improve adherence. However, pharmacokinetic data should be harmonised with information from individual attitudes and treatment needs, to tailor intravenous dosing and scheduling in patients who receive extended half-life products. Nor is there sound evidence as to how subcutaneous non-FVIII/FIX replacement approaches (concizumab; emicizumab; fitusiran) or single intravenous injections of adeno-associated viral vectors (when employing gene therapy) will revolutionize adherence in haemophilia. In rheumatoid arthritis, repeated ultrasound examination of a patient's major joints is a valuable tool to educate patients and parents to understand the disease and provide an objective framework for clinicians to acknowledge patient's adherence. Joint ultrasound examination in haemophilia significantly correlates with cartilage damage, effusion, and synovial hypertrophy evaluated by magnetic resonance imaging. Furthermore, in patients with haemophilia undergoing prophylaxis with an extended half-life product for a ≈ 2.8 year period, a significant continued improvement in joint health is detected at the physical examination. This provides the rationale for studies on repeated ultrasound examinations of joint status to attempt to remedy sub-optimal medication adherence and help identify which approach is most suited on which occasion and for which patient.
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18
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Kaur H, Bruno JG, Kumar A, Sharma TK. Aptamers in the Therapeutics and Diagnostics Pipelines. Theranostics 2018; 8:4016-4032. [PMID: 30128033 PMCID: PMC6096388 DOI: 10.7150/thno.25958] [Citation(s) in RCA: 225] [Impact Index Per Article: 37.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/16/2018] [Indexed: 12/17/2022] Open
Abstract
Aptamers are short single-stranded DNA or RNA oligonucleotides that can selectively bind to small molecular ligands or protein targets with high affinity and specificity, by acquiring unique three-dimensional structures. Aptamers have the advantage of being highly specific, relatively small in size, non-immunogenic and can be easily stabilized by chemical modifications, thus allowing expansion of their diagnostic and therapeutic potential. Since the invention of aptamers in the early 1990s, great efforts have been made to make them clinically relevant for diseases like macular degeneration, cancer, thrombosis and inflammatory diseases. Furthermore, owing to the aforementioned advantages and unique adaptability of aptamers to point-of-care platforms, aptamer technology has created a stable niche in the field of in vitro diagnostics by enhancing the speed and accuracy of diagnoses. The aim of this review is to give an overview on aptamers, highlight the inherent therapeutic and diagnostic opportunities and challenges associated with them and present various aptamers that have reached therapeutic clinical trials, diagnostic markets or that have immediate translational potential for therapeutics and diagnostics applications.
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Affiliation(s)
| | - John G. Bruno
- Operational Technologies Corporation, 4100 NW Loop 410, Suite 100, San Antonio, Texas 78229, USA
| | - Amit Kumar
- Discipline of Biosciences and Biomedical Engineering, Indian Institute of Technology Indore, Simrol, Indore, 453552, India
| | - Tarun Kumar Sharma
- Center for Biodesign and Diagnostics, Translational Health Science and Technology Institute (THSTI), Faridabad-121001, Haryana, India
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19
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Korte W, Graf L. The Potential Close Future of Hemophilia Treatment - Gene Therapy, TFPI Inhibition, Antithrombin Silencing, and Mimicking Factor VIII with an Engineered Antibody. Transfus Med Hemother 2018; 45:92-96. [PMID: 29765291 DOI: 10.1159/000488152] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 03/06/2018] [Indexed: 12/21/2022] Open
Abstract
Summary Hemophilia is one of the best researched monogenic diseases. Hemophilia A will affect approximately 1:5,000 male live births. In recent decades, great progress has been made with the introduction of recombinant proteins in the 1990s for therapy and prophylaxis, securing adequate availability and, with the introduction of the prophylaxis concept, reducing the negative impact of hemophilia on morbidity (especially arthropathy). Despite this progress, there are still challenges to overcome to secure adequate prophylaxis and treatment: for the time being, causal pharmacological hemophilia prophylaxis and therapy requires repeated i.v. application on a regular basis. Although this approach leads to a reduced comorbidity, it does not yet represent an optimized approach with continuous reversal of the hemophilic defect, which would be the ideal solution. This review summarizes the very new treatment strategies for the treatment of hemophilia A and B.
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Affiliation(s)
- Wolfgang Korte
- Center for Laboratory Medicine, Hemostasis and Hemophilia Center, St. Gallen, Switzerland
| | - Lukas Graf
- Center for Laboratory Medicine, Hemostasis and Hemophilia Center, St. Gallen, Switzerland
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20
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Thomassen S, Mastenbroek TG, Swieringa F, Winckers K, Feijge MAH, Schrijver R, Cosemans JMEM, Maroney SA, Mast AE, Hackeng TM, Heemskerk JWM. Suppressive Role of Tissue Factor Pathway Inhibitor-α in Platelet-Dependent Fibrin Formation under Flow Is Restricted to Low Procoagulant Strength. Thromb Haemost 2018; 118:502-513. [PMID: 29452445 DOI: 10.1055/s-0038-1627453] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Tissue factor pathway inhibitor-alpha (TFPI-α) is a Kunitz-type serine protease inhibitor, which suppresses coagulation by inhibiting the tissue factor (TF)/factor VIIa complex as well as factor Xa. In static plasma-phospholipid systems, TFPI-α thus suppresses both factor Xa and thrombin generation. In this article, we used a microfluidics approach to investigate how TFPI-α regulates fibrin clot formation in platelet thrombi at low wall shear rate. We therefore hypothesized that the anticoagulant effect of TFPI-α in plasma is a function of the local procoagulant strength-defined as the magnitude of thrombin generation under flow, due to local activities of TF/factor VIIa and factor Xa. To test this hypothesis, we modulated local coagulation by microspot coating of flow channels with 0 to 100 pM TF/collagen, or by using blood from patients with haemophilia A or B. For blood or plasma from healthy subjects, blocking of TFPI-α enhanced fibrin formation, extending from a platelet thrombus, under flow only at <2 pM coated TF. This enhancement was paralleled by an increased thrombin generation. For mouse plasma, genetic deficiency in TFPI enhanced fibrin formation under flow also at 0 pM TF microspots. On the other hand, using blood from haemophilia A or B patients, TFPI-α antagonism markedly enhanced fibrin formation at microspots with up to 100 pM coated TF. We conclude that, under flow, TFPI-α is capable to antagonize fibrin formation in a manner dependent on and restricted by local TF/factor VIIa and factor Xa activities.
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Affiliation(s)
- Stella Thomassen
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Tom G Mastenbroek
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Frauke Swieringa
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands.,Department of Protein Dynamics, ISAS Leibnitz Institute Dortmund, Dortmund, Germany
| | - Kristien Winckers
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Marion A H Feijge
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Roy Schrijver
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Judith M E M Cosemans
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Susan A Maroney
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin, United States
| | - Alan E Mast
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin, United States.,Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Michigan, United States
| | - Tilman M Hackeng
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
| | - Johan W M Heemskerk
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, The Netherlands
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21
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Abstract
Nucleic acid aptamers, often termed 'chemical antibodies', are functionally comparable to traditional antibodies, but offer several advantages, including their relatively small physical size, flexible structure, quick chemical production, versatile chemical modification, high stability and lack of immunogenicity. In addition, many aptamers are internalized upon binding to cellular receptors, making them useful targeted delivery agents for small interfering RNAs (siRNAs), microRNAs and conventional drugs. However, several crucial factors have delayed the clinical translation of therapeutic aptamers, such as their inherent physicochemical characteristics and lack of safety data. This Review discusses these challenges, highlighting recent clinical developments and technological advances that have revived the impetus for this promising class of therapeutics.
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Affiliation(s)
- Jiehua Zhou
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA 91010, USA
| | - John Rossi
- Department of Molecular and Cellular Biology, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA 91010, USA
- Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute of City of Hope, 1500 E. Duarte Rd, Duarte, CA 91010, USA
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22
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Schoergenhofer C, Buchtele N, Schwameis M, Bartko J, Jilma B, Jilma-Stohlawetz P. The use of frozen plasma samples in thromboelastometry. Clin Exp Med 2017; 17:489-497. [PMID: 28210886 PMCID: PMC5653723 DOI: 10.1007/s10238-017-0454-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 01/19/2017] [Indexed: 12/11/2022]
Abstract
Thromboelastometry is increasingly used in the clinical and scientific setting. The use of frozen plasma samples may be useful in overcoming certain limitations such as local and timely availability. Whole blood (WB) samples of 20 healthy volunteers were obtained, and plasma was generated. NATEM (n = 20), EXTEM (n = 20) and INTEM (n = 8) analyses were performed in WB, fresh plasma and frozen and thawed plasma. Dabigatran (500, 1000 ng/ml), rivaroxaban (100, 200 ng/ml) or alteplase (333 ng/ml) were added ex vivo to WB, and thromboelastometry was performed in WB and in frozen and thawed plasma samples. Clot formation time, mean clot firmness and the area under the curve were significantly altered in plasma compared to WB. In INTEM and EXTEM analysis, clotting time (CT) was comparable between WB (100%) and fresh (INTEM 114% and EXTEM 93%, ratio of the means) and frozen plasma samples (85 and 99%), whereas in NATEM analysis, the CT increased in fresh (193%) and frozen plasma samples (130%). Dabigatran dose-dependently increased the CT approximately 5- and 9-fold in WB and even more pronounced 10- and 26-fold in plasma. Accordingly, rivaroxaban dose-dependently increased the CT 2- and 2.7-fold in WB, and 3.5- and 4-fold in plasma samples. Hyperfibrinolysis was achieved by addition of alteplase in all WB samples and was reproducible in plasma samples. In conclusion, thromboelastometry, especially INTEM and EXTEM analyses, is possible using frozen and stored plasma samples with comparable results to the corresponding whole blood samples.
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Affiliation(s)
- Christian Schoergenhofer
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Nina Buchtele
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Michael Schwameis
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Johann Bartko
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria
| | - Bernd Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, Währinger Gürtel 18-20, 1090, Vienna, Austria.
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23
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Meeks SL, Batsuli G. Hemophilia and inhibitors: current treatment options and potential new therapeutic approaches. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2016; 2016:657-662. [PMID: 27913543 PMCID: PMC6142469 DOI: 10.1182/asheducation-2016.1.657] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The immune response to infused factor concentrates remains a major source of morbidity and mortality in the treatment of patients with hemophilia A and B. This review focuses on current treatment options and novel therapies currently in clinical trials. After a brief review of immune tolerance regimens, the focus of the discussion is on preventing bleeding in patients with hemophilia and inhibitors. Recombinant factor VIIa and activated prothrombin complex concentrates are the mainstays in treating bleeds in patients with inhibitors. Both agents have been shown to reduce bleeding episodes to a similar degree when infused prophylactically; however, individual patients may respond better to one agent over the other at any given time. The international immune tolerance trial revealed that a high-dose factor VIII regimen provided significantly better bleeding protection than the low-dose regimen. Given the high cost of treatment and the potential for a high-dose immune tolerance regimen to prevent bleeding in some patients, we discuss how we treat patients to maximize the prevention of bleeds while minimizing cost. Novel approaches to treatment of these patients are in development. These include agents that mimic factor VIII or augment thrombin generation by bypassing the inhibitor, as well as agents that inhibit the natural anticoagulants.
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Affiliation(s)
- Shannon L Meeks
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Emory University, Atlanta, GA
| | - Glaivy Batsuli
- Aflac Cancer and Blood Disorders Center, Children's Healthcare of Atlanta, Emory University, Atlanta, GA
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24
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Hamedani NS, Rühl H, Zimmermann JJ, Heiseler T, Oldenburg J, Mayer G, Pötzsch B, Müller J. In Vitro Evaluation of Aptamer-Based Reversible Inhibition of Anticoagulant Activated Protein C as a Novel Supportive Hemostatic Approach. Nucleic Acid Ther 2016; 26:355-362. [PMID: 27736370 DOI: 10.1089/nat.2016.0645] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Activated protein C (APC) is a critical regulator of thrombin formation and thereby protects against thrombosis. On the other hand, overwhelming formation of APC increases the risk of bleeding such as in trauma-induced coagulopathy. Thus, pharmacological inhibition of APC activity may improve blood clottability in certain clinical situations. In this study, we demonstrate that the DNA aptamer HS02-52G binds with fast onset (1.118 ± 0.013 × 105 M-1 s-1) to APC and possesses a long residence time of 13.5 min within the aptamer-APC complex. Functional analysis revealed HS02-52G as a highly potent and specific inhibitor of APC in plasma and whole blood with IC50 values ≤30 nM, whose activity can be readily neutralized by the short complementary DNA molecule AD22. These features qualify the novel aptamer-antidote pair as a candidate treatment option for acute APC-related bleedings.
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Affiliation(s)
- Nasim Shahidi Hamedani
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
| | - Heiko Rühl
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
| | - Julia Janina Zimmermann
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
| | | | - Johannes Oldenburg
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
| | - Günter Mayer
- 3 Life and Medical Sciences Institute, University of Bonn , Bonn, Germany
| | - Bernd Pötzsch
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
| | - Jens Müller
- 1 Institute of Experimental Hematology and Transfusion Medicine, University of Bonn Medical Center , Bonn, Germany
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25
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Rice NT, Szlam F, Varner JD, Bernstein PS, Szlam AD, Tanaka KA. Differential Contributions of Intrinsic and Extrinsic Pathways to Thrombin Generation in Adult, Maternal and Cord Plasma Samples. PLoS One 2016; 11:e0154127. [PMID: 27196067 PMCID: PMC4873248 DOI: 10.1371/journal.pone.0154127] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 04/09/2016] [Indexed: 11/18/2022] Open
Abstract
Background Thrombin generation (TG) is a pivotal process in achieving hemostasis. Coagulation profiles during pregnancy and early neonatal period are different from that of normal (non-pregnant) adults. In this ex vivo study, the differences in TG in maternal and cord plasma relative to normal adult plasma were studied. Methods Twenty consented pregnant women and ten consented healthy adults were included in the study. Maternal and cord blood samples were collected at the time of delivery. Platelet-poor plasma was isolated for the measurement of TG. In some samples, anti-FIXa aptamer, RB006, or a TFPI inhibitor, BAX499 were added to elucidate the contribution of intrinsic and extrinsic pathway to TG. Additionally, procoagulant and inhibitor levels were measured in maternal and cord plasma, and these values were used to mathematically simulate TG. Results Peak TG was increased in maternal plasma (393.6±57.9 nM) compared to adult and cord samples (323.2±38.9 nM and 209.9±29.5 nM, respectively). Inhibitory effects of RB006 on TG were less robust in maternal or cord plasma (52% vs. 12% respectively) than in adult plasma (81%). Likewise the effectiveness of BAX499 as represented by the increase in peak TG was much greater in adult (21%) than in maternal (10%) or cord plasma (12%). Further, BAX499 was more effective in reversing RB006 in adult plasma than in maternal or cord plasma. Ex vivo data were reproducible with the results of the mathematical simulation of TG. Conclusion Normal parturient plasma shows a large intrinsic pathway reserve for TG compared to adult and cord plasma, while TG in cord plasma is sustained by extrinsic pathway, and low levels of TFPI and AT.
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Affiliation(s)
- Nicklaus T. Rice
- Department of Obstetric and Gynecology, Vanderbilt Medical Center, Nashville, Tennessee, United States of America
| | - Fania Szlam
- Department of Anesthesiology, Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Jeffrey D. Varner
- School of Chemical Engineering, Purdue University, West Lafayette, Indiana, United States of America
| | - Peter S. Bernstein
- Department of Clinical Obstetric & Gynecology and Women’s Health, Albert Einstein College of Medicine/Montefiore Medical Center, Bronx, New York, United States of America
| | - Arthur D. Szlam
- Department of Mathematics, CCNY, New York, United States of America
| | - Kenichi A. Tanaka
- Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- * E-mail:
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26
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Maier KE, Levy M. From selection hits to clinical leads: progress in aptamer discovery. Mol Ther Methods Clin Dev 2016; 5:16014. [PMID: 27088106 PMCID: PMC4822646 DOI: 10.1038/mtm.2016.14] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 12/23/2015] [Accepted: 12/29/2015] [Indexed: 12/23/2022]
Abstract
Aptamers were discovered more than 25 years ago, yet only one has been approved by the US Food and Drug Administration to date. With some noteworthy advances in their chemical design and the enzymes we use to make them, aptamers and aptamer-based therapeutics have seen a resurgence in interest. New aptamer drugs are being approved for clinical evaluation, and it is certain that we will see increasingly more aptamers and aptamer-like drugs in the future. In this review, we will discuss the production of aptamers with an emphasis on the advances and modifications that enabled early aptamers to succeed in clinical trials as well as those that are likely to be important for future generations of these drugs.
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Affiliation(s)
- Keith E Maier
- Department of Biochemistry, Albert Einstein College of Medicine , Bronx, New York, USA
| | - Matthew Levy
- Department of Biochemistry, Albert Einstein College of Medicine , Bronx, New York, USA
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Felli A, Zeidler P, Jilma B, Opfermann P, Holaubek C, Zimpfer D, Wadowski PP, Steinlechner B. Different Heparin Contents in Prothrombin Complex Concentrates May Impair Blood Clotting in Outpatients With Ventricular Assist Devices Receiving Phenprocoumon. J Cardiothorac Vasc Anesth 2016; 30:96-101. [DOI: 10.1053/j.jvca.2015.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Indexed: 11/11/2022]
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Woodruff RS, Sullenger BA. Modulation of the Coagulation Cascade Using Aptamers. Arterioscler Thromb Vasc Biol 2015; 35:2083-91. [PMID: 26315404 PMCID: PMC5304947 DOI: 10.1161/atvbaha.115.300131] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/19/2015] [Indexed: 11/16/2022]
Abstract
As a novel class of therapeutics, aptamers, or nucleic acid ligands, have garnered clinical interest because of the ease of isolating a highly specific aptamer against a wide range of targets, their chemical flexibility and synthesis, and their inherent ability to have their function reversed. The following review details the development and molecular mechanisms of aptamers targeting specific proteases in the coagulation cascade. The ability of these anticoagulant aptamers to bind to and inhibit exosite function rather than binding within the active site highlights the importance of exosites in blocking protein function. As both exosite inhibitors and reversible agents, the use of aptamers is a promising strategy for future therapeutics.
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Affiliation(s)
- Rebecca S Woodruff
- From the Bloodworks Northwest Research Institute, Seattle, WA (R.S.W.); Department of Medicine, University of Washington, Seattle (R.S.W.); and Duke Translational Research Institute, Department of Surgery, Duke University Medical Center, Durham, NC (B.A.S.)
| | - Bruce A Sullenger
- From the Bloodworks Northwest Research Institute, Seattle, WA (R.S.W.); Department of Medicine, University of Washington, Seattle (R.S.W.); and Duke Translational Research Institute, Department of Surgery, Duke University Medical Center, Durham, NC (B.A.S.).
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Abstract
Coagulation and anticoagulation system is kept in balance by the orchestrated action of a variety of biological factors, and the disruption of this balance leads to the risk of hemorrhage or thrombosis. Oligonucleotide aptamers are single-stranded DNA (ssDNA) or RNA ligands that are synthesized in vitro and bind to target molecules through dimensional structure with high specificity and affinity, and thus represent attractive candidates for the development of agents to maintain the balance of coagulation and anticoagulation. In this review, we summarize recent progress in aptamer-based application in the modulation of coagulation. The aptamers with specific chemical and biological characteristics have great potential to be explored as agents for the treatment of blood coagulation abnormalities.
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Aimaiti R, Qin L, Cao T, Yang H, Wang J, Lu J, Huang X, Hu Z. Identification and application of ssDNA aptamers against H₃₇Rv in the detection of Mycobacterium tuberculosis. Appl Microbiol Biotechnol 2015; 99:9073-83. [PMID: 26194558 DOI: 10.1007/s00253-015-6815-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 06/30/2015] [Accepted: 07/02/2015] [Indexed: 01/09/2023]
Abstract
Microscopy of direct smear with the Ziehl-Neelsen stain is still broadly used in tuberculosis diagnosis. However, this method suffers from low specificity and is difficult to distinguish Mycobacterium tuberculosis (MTB) from nontuberculosis mycobacterial (NTM), since all mycobacterial species are positive in Ziehl-Neelsen stain. In this study, we utilized whole cell SELEX to obtain species-specific aptamers for increasing the specificity of MTB detection. Whole cell SELEX was performed in MTB reference strain H37Rv by two selection processes based on enzyme-linked plate or Eppendorf tube, respectively. To increase success rate of generating aptamers, the selection processes were systematically monitored to understand the dynamic evolution of aptamers against complex structure of target bacteria. Two preponderant groups and ten high-affinity aptamers were obtained by analyzing the dynamic evolution. Preponderant aptamer MA1 from group I showed relatively high binding affinity with apparent dissociation constant (KD value) of 12.02 nM. Sandwich ELISA assay revealed five aptamer combinations effectively bound MTB strains in preliminary evaluation, especially the combination based on aptamer MA2 (another preponderant aptamer from group II) and MA1. Further evaluated in many other strains, MA2/MA1 combination effectively identified MTB from NTM or other pathogenic bacteria, and displayed the high specificity and sensitivity. Binding analysis of aptamer MA1 or MA2 by fluorescence microscopy observation showed high binding reactivity with H37Rv, low apparent cross-reactivity with M. marinum, and no apparent cross-reactivity with Enterobacter cloacae. Taken together, this study provides attractive candidate species-specific aptamers to effectively capture or discriminate MTB strains.
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Affiliation(s)
- Rusitanmujiang Aimaiti
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Lianhua Qin
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Ting Cao
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Hua Yang
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Jie Wang
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Junmei Lu
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Xiaochen Huang
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China
| | - Zhongyi Hu
- Shanghai Key Laboratory of Tuberculosis, Clinic and Research Center of Tuberculosis, Shanghai Pulmonary Hospital, Tongji University School of Medicine, 507 Zhengmin Road, Shanghai, 200433, China.
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Abstract
Hemophilia, when severe, leads to spontaneous life-threatening bleeding episodes. Current therapy requires frequent intravenous infusions. Most patients must limit their physical activities to avoid bleeding when the factor activity levels are below normal. In 2014, new therapeutic factor VIII and IX products were approved in Canada and the U.S. Over the next couple of years, other new factor products will likely be approved. These new factors have been engineered to have improved pharmacokinetic properties, including extended half-life in circulation, thus providing major therapeutic advances for patients with hemophilia. In the completed clinical trials, over 700 patients have successfully used these longer acting products regularly for more than one year. These promising new therapies should allow patients with hemophilia to use fewer infusions to prevent spontaneous bleeding or to treat bleeding episodes, and to provide appropriate clotting factor levels for different physical activities.
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Affiliation(s)
- J S Powell
- Division of Hematology and Oncology, University of California Davis Medical Center, Sacramento, CA, USA
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Dobrovolskaia MA, McNeil SE. Immunological and hematological toxicities challenging clinical translation of nucleic acid-based therapeutics. Expert Opin Biol Ther 2015; 15:1023-48. [PMID: 26017628 DOI: 10.1517/14712598.2015.1014794] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
INTRODUCTION Nucleic acid-based therapeutics (NATs) are proven agents in correcting disorders caused by gene mutations, as treatments against cancer, microbes and viruses, and as vaccine adjuvants. Although many traditional small molecule NATs have been approved for clinical use, commercialization of macromolecular NATs has been considerably slower, and only a few have successfully reached the market. Preclinical and clinical evaluation of macromolecular NATs has revealed many assorted challenges in immunotoxicity, hematotoxicity, pharmacokinetics (PKs), toxicology and formulation. Extensive review has been given to the PK and toxicological concerns of NATs including approaches designed to overcome these issues. Immunological and hematological issues are a commonly reported side effect of NAT treatment; however, literature exploring the mechanistic background of these effects is sparse. AREAS COVERED This review focuses on the immunomodulatory properties of various types of therapeutic nucleic acid concepts. The most commonly observed immunological and hematological toxicities are described for various NAT classes, with citations of how to circumvent these toxicities. EXPERT OPINION Although some success with overcoming immunological and hematological toxicities of NATs has been achieved in recent years, immunostimulation remains the main dose-limiting factor challenging clinical translation of these promising therapies. Novel delivery vehicles should be considered to overcome this challenge.
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Affiliation(s)
- Marina A Dobrovolskaia
- Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Nanotechnology Characterization Laboratory, Cancer Research Technology Program , P.O. Box B, Frederick, MD 21702 , USA +1 301 846 6939 ; +1 301 846 6399 ;
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33
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Franchini M. Next-generation treatment of acquired hemophilia A. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1017470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Powell JS. Lasting power of new clotting proteins. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2014; 2014:355-363. [PMID: 25696879 DOI: 10.1182/asheducation-2014.1.355] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Hemophilia is a genetic disease caused by a deficiency of one of the coagulation proteins. The term usually refers to either hemophilia A, factor VIII (FVIII), with an incidence of ∼1 in 5000 male births, or hemophilia B, factor IX (FIX), with an incidence of ∼1 in 30 000 male births. When severe, the disease leads to spontaneous life-threatening bleeding episodes. Current therapy requires frequent intravenous infusions of therapeutic factor concentrates. Most patients administer the infusions at home every few days and must limit their physical activities to avoid bleeding when the factor activity levels are below normal. In March 2014, a new therapeutic FIX preparation was approved for clinical use in Canada and the United States and, in June 2014, a new FVIII preparation was approved for clinical use in the United States. Over the next couple of years, other new factor products for FIX, FVIIa, and FVIII, which are currently in late stages of clinical trials, will likely also be approved. These new factors have been engineered to extend their half-life in circulation, thus providing major therapeutic advances for patients with hemophilia primarily by allowing treatment with fewer infusions per month. In the clinical trials so far, >500 patients have successfully used these extended half-life products regularly for >1 year to prevent spontaneous bleeding, to treat successfully any bleeding episodes, and to provide effective coagulation for major surgery. Essentially all infusions were well tolerated and effective. These promising new therapies should allow patients to use fewer infusions to maintain appropriate clotting factor activity levels in all clinical settings.
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Affiliation(s)
- Jerry S Powell
- Division of Hematology and Oncology, University of California Davis Medical Center, Sacramento, CA
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Ducore JM, Miguelino MG, Powell JS. Alprolix (recombinant Factor IX Fc fusion protein): extended half-life product for the prophylaxis and treatment of hemophilia B. Expert Rev Hematol 2014; 7:559-71. [DOI: 10.1586/17474086.2014.951322] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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36
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Abstract
Recent studies of the anticoagulant activities of the tissue factor (TF) pathway inhibitor (TFPI) isoforms, TFPIα and TFPIβ, have provided new insight into the biochemical and physiological mechanisms that underlie bleeding and clotting disorders. TFPIα and TFPIβ have tissue-specific expression patterns and anticoagulant activities. An alternative splicing event in the 5' untranslated region allows for translational regulation of TFPIβ expression. TFPIα has 3 Kunitz-type inhibitor domains (K1, K2, K3) and a basic C terminus, whereas TFPIβ has the K1 and K2 domains attached to a glycosylphosphatidyl inositol-anchored C terminus. TFPIα is the only isoform present in platelets, whereas endothelial cells produce both isoforms, secreting TFPIα and expressing TFPIβ on the cell surface. TFPIα and TFPIβ inhibit both TF-factor VIIa-dependent factor Xa (FXa) generation and free FXa. Protein S enhances FXa inhibition by TFPIα. TFPIα produces isoform-specific inhibition of prothrombinase during the initiation of coagulation, an anticoagulant activity that requires an exosite interaction between its basic C terminus and an acidic region in the factor Va B domain. Platelet TFPIα may be optimally localized to dampen initial thrombin generation. Similarly, endothelial TFPIβ may be optimally localized to inhibit processes that occur when endothelial TF is present, such as during the inflammatory response.
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37
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Inhibition of tissue factor pathway inhibitor increases the sensitivity of thrombin generation assay to procoagulant microvesicles. Blood Coagul Fibrinolysis 2013; 24:567-72. [PMID: 23807485 DOI: 10.1097/mbc.0b013e328360a56e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Patients with cancer have a seven-fold to 10-fold increased risk of developing venous thromboembolism (VTE). Circulating microvesicles could be a predictive biomarker for VTE in cancer. Thrombin generation assay (TGA) is a useful technique to detect procoagulant activity of microvesicles. However, TGA suffers from a lack of sensitivity due to the presence of tissue factor pathway inhibitor (TFPI) in plasma. The aim of the study was to improve the sensitivity of TGA to tissue factor by limiting the interference of TFPI. Serial dilutions of MDA-MB231 cells were incubated for 45 min at 37°C to generate microvesicles. Samples were then centrifuged and supernatants that contain microvesicles were used for TGA. Normal pooled plasma was incubated with inhibitor of TFPI or was diluted twice to decrease plasma level of TFPI. Lagtime was used as a surrogate marker of TGA to detect procoagulant activity of microvesicles. Inhibition of TFPI decreased twice the cell concentration needed for a significant reduction of lagtime and decreased 2.4-fold the intraassay variability. Plasma dilution had no impact on the TGA sensitivity when TGA was triggered by microvesicles derived from MDA-MB-231. Thrombin generation is a very sensitive method to study the procoagulant activity of tissue factor bearing microvesicles. The sensitivity can be increased by inhibition of TFPI with specific monoclonal antibody against its Kunitz domain I. A two times plasma dilution is an interesting cheaper alternative to study the procoagulant activity of microvesicles by TGA with a good sensitivity, especially when low plasma quantities are available.
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38
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Parunov LA, Soshitova NP, Fadeeva OA, Balandina AN, Kopylov KG, Kumskova MA, Gilbert JC, Schaub RG, McGinness KE, Ataullakhanov FI, Panteleev MA. Drug-drug interaction of the anti-TFPI aptamer BAX499 and factor VIII: studies of spatial dynamics of fibrin clot formation in hemophilia A. Thromb Res 2013; 133:112-9. [PMID: 24263002 DOI: 10.1016/j.thromres.2013.10.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Revised: 10/25/2013] [Accepted: 10/28/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND In recent years, a number of tissue factor pathway inhibitor (TFPI) antagonists have been developed to serve as bypassing agents to improve hemostasis in hemophilia A. Since TFPI antagonists and FVIII concentrates are procoagulants, their combined effect on spatial clot formation could be potentially pro-thrombotic. OBJECTIVE To investigate the cooperative effect of TFPI inhibition and supplementation of FVIII in hemophilia A in a spatial, reaction-diffusion experiment in vitro. METHODS Plasma was collected at different time points from hemophilia A patients undergoing prophylaxis and was supplemented in vitro with TFPI inhibitor BAX499 (formerly ARC19499) at concentrations from 0 up to 600nM. Clotting propagation in recalcified plasma activated by a surface with immobilized tissue factor (TF) was monitored by videomicroscopy. RESULTS Increasing concentration of BAX499 improved coagulation for all hemophilia A plasma samples activated with TF at 1.6pmole/m(2) by shortening lag time and increasing initial clot growth velocity and clot size. In contrast, plasma concentration of FVIII had little effect on lag time, but increased spatial clot growth velocity. There was a decrease in the BAX499 efficiency as FVIII concentration increased (lag time shortened by 50% if FVIII:C<5%, but the effect was only 25% if FVIII:C>30%). CONCLUSIONS The results indicate that BAX499 has an effect on clotting in hemophilia A plasma at low FVIII concentrations, however has little effect at high FVIII concentrations.
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Affiliation(s)
- Leonid A Parunov
- Center for Theoretical Problems of Physicochemical Pharmacology, 4 Kosygina Street, Moscow 119991, Russia.
| | - Natalia P Soshitova
- National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia
| | - Olga A Fadeeva
- National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia
| | - Anna N Balandina
- Center for Theoretical Problems of Physicochemical Pharmacology, 4 Kosygina Street, Moscow 119991, Russia; National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia; Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Mashely, Moscow , Russia
| | - Konstantin G Kopylov
- National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia; Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Mashely, Moscow , Russia
| | - Maria A Kumskova
- National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia; Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Mashely, Moscow , Russia
| | | | | | | | - Fazoil I Ataullakhanov
- Center for Theoretical Problems of Physicochemical Pharmacology, 4 Kosygina Street, Moscow 119991, Russia; National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia; Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Mashely, Moscow , Russia; Department of Physics, Moscow State University, 1 Vorobyevy Gory, Moscow 119991, Russia
| | - Mikhail A Panteleev
- Center for Theoretical Problems of Physicochemical Pharmacology, 4 Kosygina Street, Moscow 119991, Russia; National Research Center for Hematology, 4 Novyi Zykovskii Passage, Moscow 125167, Russia; Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Mashely, Moscow , Russia; Department of Physics, Moscow State University, 1 Vorobyevy Gory, Moscow 119991, Russia
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Tissue factor pathway inhibitor-alpha inhibits prothrombinase during the initiation of blood coagulation. Proc Natl Acad Sci U S A 2013; 110:17838-43. [PMID: 24127605 DOI: 10.1073/pnas.1310444110] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Tissue factor (TF) pathway inhibitor (TFPI) is a well-characterized activated factor X (FXa)-dependent inhibitor of TF-initiated coagulation produced in two alternatively spliced isoforms, TFPIα and TFPIβ. The TFPIα C terminus has a basic sequence nearly identical to a portion of the factor V (FV) B domain necessary for maintaining FV in an inactive conformation via interaction with an acidic region of the B domain. We demonstrate rapid inhibition of prothrombinase by TFPIα mediated through a high-affinity exosite interaction between the basic region of TFPIα and the FV acidic region, which is retained in FXa-activated FVa and platelet FVa. This inhibitory activity is not mediated by TFPIβ and is lost upon removal of the acidic region of FVa by thrombin. The data identify a previously undescribed, isoform-specific anticoagulant function for TFPIα and are a unique description of physiologically relevant inhibition of prothrombinase. These findings, combined with previous descriptions of differential expression patterns of TFPIα and TFPIβ in platelets and endothelial cells, suggest that the TFPI isoforms may act through distinct mechanisms to inhibit the initial stages of intravascular coagulation, with TFPIβ acting to dampen TF expressed on the surface of vascular cells, whereas TFPIα dampens the initial prothrombinase formed on the activated platelet surface.
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40
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Abstract
Hemophilia is caused by a functional deficiency of one of the coagulation proteins. Therapy for no other group of genetic diseases has seen the progress that has been made for hemophilia over the past 40 years, from a life expectancy in 1970 of ∼20 years for a boy born with severe hemophilia to essentially a normal life expectancy in 2013 with current prophylaxis therapy. However, these therapies are expensive and require IV infusions 3 to 4 times each week. These are exciting times for hemophilia because several new technologies that promise extended half-lives for factor products, with potential for improvements in quality of life for persons with hemophilia, are in late-phase clinical development.
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41
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Broze GJ, Girard TJ. Factor V, tissue factor pathway inhibitor, and east Texas bleeding disorder. J Clin Invest 2013; 123:3710-2. [PMID: 23979154 DOI: 10.1172/jci71220] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
In a report reading like a fascinating detective story, Vincent and colleagues crack the mysterious case of east Texas bleeding disorder. They show that affected individuals have a mutation in exon 13 of the coagulation F5 gene that causes increased expression of an alternatively spliced transcript, which encodes a previously unrecognized factor V (FV) isoform they call FV-short. This FV isoform lacks a large portion of the B domain of FV, which is normally released upon the proteolytic activation of FV by thrombin and binds tightly to the coagulation regulator tissue factor pathway inhibitor-α (TFPIα). This interaction leads to an approximately 10-fold increase in the level of TFPIα circulating in plasma and a resultant anticoagulant effect that produces a hemorrhagic diathesis.
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Affiliation(s)
- George J Broze
- Division of Hematology, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
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42
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Waters EK, Genga RM, Thomson HA, Kurz JC, Schaub RG, Scheiflinger F, McGinness KE. Aptamer BAX 499 mediates inhibition of tissue factor pathway inhibitor via interaction with multiple domains of the protein. J Thromb Haemost 2013; 11:1137-45. [PMID: 23528042 DOI: 10.1111/jth.12201] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 03/13/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND Tissue factor pathway inhibitor (TFPI) is a multidomain protein that negatively regulates the coagulation cascade. TFPI inhibits the tissue factor (TF)-activated factor VII-activated FX (FXa) complex during TF-mediated coagulation initiation. The aptamer BAX 499 binds specifically to TFPI and inhibits its function, mediating a procoagulant effect in both in vitro and in vivo models of hemophilia. OBJECTIVES This study sought to identify the regions of TFPI that are critical for BAX 499 binding, and to determine how binding mediates aptamer inhibition of TFPI. METHODS AND RESULTS In vitro biochemical methods were used to evaluate the BAX 499 interaction with and inhibition of TFPI. Binding experiments indicated that the full-length TFPI protein is required for tight aptamer binding. Binding-competition experiments implicated the Kunitz 1, Kunitz 3 and C-terminal domains of TFPI in aptamer binding, a finding that is supported by hydrogen-deuterium exchange experiments, and indicated that aptamer and FXa can bind simultaneously to TFPI. In enzymatic assays, BAX 499 inhibited TFPI in a manner that is distinct from domain-specific antibodies, and aptamer inhibitory activity is reduced in the presence of the TFPI cofactor protein S. CONCLUSIONS These studies demonstrate that BAX 499 binds to TFPI via multiple domains of the protein in a manner that is distinct from other TFPI inhibitors, mediating a mechanism of inhibition that does not involve direct competition with FXa. With this unique inhibitory mechanism, BAX 499 provides a useful tool for studying TFPI biology in health and disease.
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Affiliation(s)
- E K Waters
- Baxter Healthcare Corporation, Cambridge, MA, USA
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43
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Escobar MA. Advances in the treatment of inherited coagulation disorders. Haemophilia 2013; 19:648-59. [DOI: 10.1111/hae.12137] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/03/2013] [Indexed: 01/16/2023]
Affiliation(s)
- M. A. Escobar
- Department of Pediatrics and Internal Medicine; Division of Hematology; University of Texas Medical School at Houston; Houston; Texas
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44
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Knappe S, Gorczyca ME, Jilma B, Derhaschnig U, Hartmann R, Palige M, Scheiflinger F, Dockal M. Plasmatic tissue factor pathway inhibitor is a major determinant of clotting in factor VIII inhibited plasma or blood. Thromb Haemost 2013; 109:450-7. [PMID: 23348798 DOI: 10.1160/th12-07-0529] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 11/29/2012] [Indexed: 11/05/2022]
Abstract
Tissue factor pathway inhibitor (TFPI) is a major inhibitor of coagulation. We therefore hypothesised that high plasmatic TFPI levels are associated with impaired ex vivo clotting in a model of acquired haemophilia. Blood samples were collected in a prospective clinical study from 30 healthy volunteers. Coagulation in normal or factor VIII (FVIII)-inhibited human blood or plasma was measured by the calibrated automated thrombogram (CAT) and rotational thromboelastometry (ROTEM). Both methods are global haemostatic assays that provide insight into the whole coagulation process. Monoclonal mouse antibodies raised against either the C-terminus or the Kunitz domain 2 of TFPI were used to determine full-length (fl-) and total TFPI by an enzyme-immunoassay. Clotting times and parameters of thrombin generation correlated with TFPI levels. Subjects with low fl-TFPI levels had significantly shorter clotting times and a higher endogenous thrombin potential (ETP) compared to those with high fl-TFPI levels (p≤0.005 for all). An even stronger effect was seen in FVIII-inhibited blood/plasma: ROTEM clotting time was 26% shorter (p=0.01) and the ETP assessed by CAT was >2-fold higher in subjects with low fl-TFPI levels (p≤0.0001). Plasmatic TFPI is a major determinant of coagulation in global haemostatic tests particularly when FVIII is missing. Thus, inhibition of TFPI might be a promising novel treatment approach, especially in haemophilia patients with FVIII inhibitors.
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Affiliation(s)
- Sabine Knappe
- Medical University of Vienna, Department of Clinical Pharmacology, Waehringer Guertel 18-20,, 1090 Vienna, Austria
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45
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Kaufman RJ, Powell JS. Molecular approaches for improved clotting factors for hemophilia. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2013; 2013:30-36. [PMID: 24319159 DOI: 10.1182/asheducation-2013.1.30] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Hemophilia is caused by a functional deficiency of one of the coagulation proteins. Therapy for no other group of genetic diseases has seen the progress that has been made for hemophilia over the past 40 years, from a life expectancy in 1970 of ∼20 years for a boy born with severe hemophilia to essentially a normal life expectancy in 2013 with current prophylaxis therapy. However, these therapies are expensive and require IV infusions 3 to 4 times each week. These are exciting times for hemophilia because several new technologies that promise extended half-lives for factor products, with potential for improvements in quality of life for persons with hemophilia, are in late-phase clinical development.
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Affiliation(s)
- Randal J Kaufman
- 1Degenerative Disease Research, Center for Neuroscience, Aging, and Stem Cell Research, Sanford Burnham Medical Research Institute, La Jolla, CA; and
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46
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Ragni MV. The old and new: PCCs, VIIa, and long-lasting clotting factors for hemophilia and other bleeding disorders. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2013; 2013:44-51. [PMID: 24319161 DOI: 10.1182/asheducation-2013.1.44] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
What is the correct use of established clotting factors, prothrombin complex concentrates (PCCs), and activated factor VII in bleeding complications of trauma, surgery, and old and new oral anticoagulants? How will new clotting factors, specifically the long-acting factors, change the hemostatic management of coagulation deficiency disorders? From bench to bedside, comparative coagulation studies and clinical trials of modified clotting factors are providing insights to help guide hemostatic management of congenital and acquired bleeding disorders. Comparative thrombin-generation studies and preclinical and clinical trials suggest that PCCs and fresh-frozen plasma are effective in reversing the anticoagulant effects of warfarin, yet there are few data to guide reversal of the new oral anticoagulants dabigatran and rivaroxaban. Although coagulation studies support the use of PCCs to reverse new oral anticoagulants, correlation with clinical response is variable and clinical trials in bleeding patients are needed. For congenital bleeding disorders, exciting new technologies are emerging from the bench. Data from clinical trials of molecularly modified coagulation factors with extended half-lives suggest the possibility of fewer infusions, reduced bleeds, and better quality of life in persons with hemophilia. Preclinical studies of other novel prohemostatic approaches for hemophilia and other congenital coagulation disorders include RNA interference silencing of antithrombin, monoclonal anti-tissue factor pathway inhibitor (anti-antibody, anti-tissue factor pathway inhibitor) aptamer, bispecific anti-IXa/X antibody, and fucoidans. Understanding the comparative coagulation studies of established prohemostatic agents, the pharmacokinetics of new long-acting clotting factors, and their correlation with bleeding outcomes will provide opportunities to optimize the hemostatic management of both congenital and acquired hemostatic disorders.
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Affiliation(s)
- Margaret V Ragni
- 1Department of Medicine, Division of Hematology/Oncology, University of Pittsburgh, Pittsburgh, PA
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Gissel M, Orfeo T, Foley JH, Butenas S. Effect of BAX499 aptamer on tissue factor pathway inhibitor function and thrombin generation in models of hemophilia. Thromb Res 2012; 130:948-55. [PMID: 22951415 DOI: 10.1016/j.thromres.2012.08.299] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 08/02/2012] [Accepted: 08/14/2012] [Indexed: 11/26/2022]
Abstract
INTRODUCTION In hemophilia, thrombin generation is significantly suppressed due to decreased factor (F)X activation. Clinical studies and experiments with transgenic mice have suggested that the severity of hemophilia is substantially reduced by tissue factor pathway inhibitor (TFPI) deficiency. METHODS We evaluated the effect of TFPI antagonist aptamer BAX499 (formerly ARC19499) on TFPI function in purified systems and on thrombin generation and clot formation in plasma and blood. RESULTS BAX499 effectively neutralized TFPI inhibition of FXa and FXa dependent inhibition of TF/FVIIa by TFPI. BAX499 did not inhibit FXa or TF/FVIIa when used up to 500 nM. In the synthetic coagulation proteome with TFPI at its mean physiologic concentration, BAX499 at 1 - 10nM increased thrombin generation triggered with 5 pM relipidated TF in a concentration-dependent manner. In severe hemophilia A or B models using the synthetic coagulation proteome, the addition of BAX499 at 5 nM increased thrombin generation to the levels observed in normal control. Thrombin generation measured in induced hemophilia B plasma required ~100nM BAX499 to restore thrombin levels to those seen in untreated plasma. In induced hemophilia B whole blood, BAX499 repaired the clotting time but failed to appreciably impact the propagation phase of thrombin generation. CONCLUSION These data suggest that inhibition of TFPI by BAX499 may have potential for hemophilia treatment but requires further study in blood-based hemophilia systems.
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Affiliation(s)
- Matthew Gissel
- Department of Biochemistry, University of Vermont, Colchester, Vermont 05446, United States
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