1
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Zeng M, Jia K, Liu M, Wang M, Yang L, Xie H. A novel mutation p.Met1Val in SERPINC1 gene causes hereditary antithrombin deficiency in a Chinese family with thrombotic disease. Thromb Res 2023; 232:104-107. [PMID: 37976729 DOI: 10.1016/j.thromres.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 10/10/2023] [Accepted: 11/02/2023] [Indexed: 11/19/2023]
Affiliation(s)
- Manlin Zeng
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China
| | - Kaiqi Jia
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China
| | - Meina Liu
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China
| | - Mingshan Wang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China
| | - Lihong Yang
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China
| | - Haixiao Xie
- Department of Clinical Laboratory, Key Laboratory of Clinical Laboratory Diagnosis and Translational Research of Zhejiang Province, The First Affiliated Hospital of Wenzhou Medical University, Shangcai Village, Ouhai District, Wenzhou 325000, China.
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2
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Das K, Pendurthi UR, Manco-Johnson M, Martin EJ, Brophy DF, Rao LVM. Factor VIIa treatment increases circulating extracellular vesicles in hemophilia patients: Implications for the therapeutic hemostatic effect of FVIIa. J Thromb Haemost 2022; 20:1928-1933. [PMID: 35608928 PMCID: PMC9846311 DOI: 10.1111/jth.15768] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 03/22/2022] [Indexed: 01/21/2023]
Affiliation(s)
- Kaushik Das
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, USA
| | - Usha R. Pendurthi
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, USA
| | | | - Erika J. Martin
- Department of Pharmacotherapy & Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia, USA
| | - Donald F. Brophy
- Department of Pharmacotherapy & Outcomes Science, Virginia Commonwealth University School of Pharmacy, Richmond, Virginia, USA
| | - L. Vijaya Mohan Rao
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, USA
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3
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Yeom RS, Wang XA, Elia E, Yoon U. Severe Congenital Factor VII Deficiency with Normal Perioperative Coagulation Profile Based on ROTEM Analysis in a Hepatectomy. AMERICAN JOURNAL OF CASE REPORTS 2021; 22:e930245. [PMID: 34375324 PMCID: PMC8366573 DOI: 10.12659/ajcr.930245] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 06/29/2021] [Accepted: 06/15/2021] [Indexed: 11/09/2022]
Abstract
BACKGROUND Factor VII (FVII) deficiency is the most common autosomal-recessive bleeding disorder. FVII activity level (FVII: C) of 10-20% is often used as the threshold for administering activated recombinant FVII (rFVIIa) for patients undergoing major surgery. However, rFVIIa is expensive and carries the risk of a thromboembolic event, and thus should only be administered when truly indicated. CASE REPORT A 22-year-old woman with 8% FVII: C underwent a hepatectomy. Although there were no clinical signs of bleeding, peri-operative administration of rFVIIa was recommended by the hematologist (first dose at surgical incision, then 4 h later, then every 12 h until 48 h postoperatively). Intraoperatively, serials of ROTEM analysis were performed to evaluate the effect of rFVIIa administration. No significant effect of rFVIIa was seen on NATEM. Surgery was unremarkable, without any significant blood loss. The patient developed radial artery thrombosis 24 h postoperatively, the arterial line was removed, and rFVIIa was discontinued (PT: 14.6, FVII: C 36%). On POD 3, INR was elevated (3.15, FVII: C 3%). To correct INR, the patient was transfused 8 units of FFP, despite any signs of clinical bleeding. However, INR and FVII: C did not correct and the patient was discharged on POD 7 in a stable condition. CONCLUSIONS Even with FVII: C of 8%, the ROTEM analysis revealed a normal coagulation status. The administration of rFVIIa did not improve the already normal baseline coagulation profile, but rather potentially led to an accelerated coagulation or hypercoagulable state and may have led to the radial artery thrombosis. We endorse the use of viscoelastic testing for hemostasis assessment and factor replacement in congenital FVII deficiency.
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Affiliation(s)
- Richard S. Yeom
- Department of Anesthesiology, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Xuejun A. Wang
- Department of Internal Medicine, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Elia Elia
- Department of Anesthesiology, Thomas Jefferson University Hospital, Philadelphia, PA, USA
| | - Uzung Yoon
- Department of Anesthesiology, Thomas Jefferson University Hospital, Philadelphia, PA, USA
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4
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Sim DS, Mallari CR, Teare JM, Feldman RI, Bauzon M, Hermiston TW. In vitro characterization of CT-001-a short-acting factor VIIa with enhanced prohemostatic activity. Res Pract Thromb Haemost 2021; 5:e12530. [PMID: 34263099 PMCID: PMC8265787 DOI: 10.1002/rth2.12530] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Accepted: 04/12/2021] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Traumatic injury and the associated acute bleeding are leading causes of death in people aged 1 to 44 years. Acute bleeding in pathological and surgical settings also represents a significant burden to the society. Yet there are no approved hemostatic drugs currently available. While clinically proven as an effective pro-coagulant, activated factor VII (FVIIa) use in acute bleeding has been hampered by unwanted thromboembolic events. Enhancing the ability of FVIIa to quickly stop a bleed and clear rapidly from circulation may yield an ideal molecule suitable for use in patients with acute bleeding. OBJECTIVES To address this need and the current liability of FVIIa, we produced a novel FVIIa molecule (CT-001) with enhanced potency and shortened plasma residence time by cell line engineering and FVIIa protein engineering for superior efficacy for acute bleeding and safety. METHODS To address safety, CT-001, a FVIIa protein with 4 desialylated N-glycans was generated to promote active recognition and clearance via the asialoglycoprotein receptor. To enhance potency, the gamma-carboxylated domain was modified with P10Q and K32E, which enhanced membrane binding. RESULTS Together, these changes significantly enhanced potency and clearance while retaining the ability to interact with the key hemostatic checkpoint proteins antithrombin and tissue factor pathway inhibitor. CONCLUSIONS These results demonstrate that a FVIIa molecule engineered to combine supra-physiological activity and shorter duration of action has the potential to overcome the current limitations of recombinant FVIIa to be a safe and effective approach to the treatment of acute bleeding.
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Affiliation(s)
| | | | | | | | - Maxine Bauzon
- Were employed at Bayer HealthCare when part of this study was performed
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5
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Kjalke M, Kjelgaard‐Hansen M, Andersen S, Hilden I. Thrombin generation potential in the presence of concizumab and rFVIIa, APCC, rFVIII, or rFIX: In vitro and ex vivo analyses. J Thromb Haemost 2021; 19:1687-1696. [PMID: 33819375 PMCID: PMC8360123 DOI: 10.1111/jth.15323] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/03/2021] [Accepted: 03/25/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND The anti-tissue factor plasma inhibitor monoclonal antibody concizumab is under clinical investigation for subcutaneous prophylaxis of hemophilia A/B (HA/HB) with or without inhibitors. Breakthrough bleeds while on concizumab prophylaxis may be treated with bypassing agents (recombinant activated factor VIIa [rFVIIa] and activated prothrombin complex concentrate [APCC]), or with factor VIII (FVIII) or factor IX (FIX). OBJECTIVES To evaluate the effect of combining concizumab with rFVIIa, APCC, rFVIII, and rFIX on thrombin generation (TG) potential. METHODS Pooled HA plasma was spiked in vitro with concizumab alone or together with rFVIIa, APCC, or rFVIII. rFVIIa, APCC, and rFVIII were added ex vivo to plasma from HA patients receiving concizumab prophylaxis. Pooled HB plasma was spiked with concizumab alone or together with rFIX. TG potential was measured after initiation with tissue factor. RESULTS Concizumab increased thrombin peak in a concentration-dependent manner. Adding rFVIIa, APCC, rFVIII, or rFIX caused a further increase in thrombin peak. The effects of concizumab and rFVIIa, APCC, rFVIII, or rFIX were mainly additive, with no or up to maximally ~25% extra effect caused by drug--drug interaction. No strong synergistic effects were observed upon combining concizumab with rFVIIa, APCC, rFVIII, or rFIX. The thrombin peak obtained with 0.5 IU/ml rFVIII or rFIX in the presence of concizumab was on occasion slightly higher, but mostly comparable to the thrombin peak with 1 IU/ml rFVIII or rFIX in the absence of concizumab. CONCLUSION rFVIIa, APCC, rFVIII, and rFIX enhanced plasma TG potential in the presence of concizumab. Dose levels of concomitant use should be adjusted accordingly to balance potential safety concerns while maintaining the necessary hemostatic effect. Please see the video in the Supplementary Material for an animated summary of the data presented.
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Affiliation(s)
| | | | | | - Ida Hilden
- Global Drug DiscoveryNovo Nordisk A/SMåløvDenmark
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6
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Grandoni J, Duretz V, Bonzo D, Evans S, Plantier JL. Exploratory in vitro evaluation of thrombin generation of eptacog beta (recombinant human fviia) and emicizumab in congenital haemophilia A plasma. Haemophilia 2021; 27:321-328. [PMID: 33550714 PMCID: PMC8048629 DOI: 10.1111/hae.14253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/22/2020] [Accepted: 12/24/2020] [Indexed: 01/11/2023]
Abstract
Introduction/Aim Eptacog beta is a recombinant activated human factor VII approved to treat and control bleeding in haemophilia A and B patients with inhibitors. Emicizumab is a factor VIIIa mimetic antibody approved for prophylactic treatment of haemophilia A with and without inhibitors (HAI and HA, respectively). Inhibitor patients treated with emicizumab should expect breakthrough bleeding that requires bypassing agent treatment to restore haemostasis. The aim of this study is to quantify the in vitro thrombin generation induced by the addition of eptacog beta to HAI and HA plasma containing emicizumab. Methods Thrombin generation assays were performed using HAI and HA plasma. Thrombin generation parameters were examined using a fixed effects model with inhibitor titre, eptacog beta concentration and emicizumab concentration as main effects, and eptacog beta concentration with inhibitor and emicizumab concentration with inhibitor as interaction effects. Results A significant increase in peak thrombin, ETP and velocity was observed when combinations of eptacog beta (0, 1, 2 or 5 µg/ml) and emicizumab (0, 50 or 100 µg/ml) were evaluated in HA and HAI plasma; the effect remained below that observed in Normal Plasma (NP). A small shortening of lag time below that of NP was observed. Conclusions Eptacog beta and emicizumab induced thrombin generation in haemophilia A plasma (with and without inhibitors) with the thrombin generation parameters remaining below those of normal plasma. These data provide in vitro proof of concept supporting the concept of use of eptacog beta for the treatment and control of breakthrough bleeding in patients on emicizumab prophylaxis.
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Affiliation(s)
- Jerry Grandoni
- LFB USA, Framingham, MA, USA.,Allena Pharmaceuticals, Sudbury, MA, USA
| | - Véronique Duretz
- LFB Biotechnologies, Les Ulis, France.,LFB Biomédicaments, Lille, France
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7
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Bernardi F, Mariani G. Biochemical, molecular and clinical aspects of coagulation factor VII and its role in hemostasis and thrombosis. Haematologica 2021; 106:351-362. [PMID: 33406812 PMCID: PMC7849579 DOI: 10.3324/haematol.2020.248542] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 10/29/2020] [Indexed: 12/21/2022] Open
Abstract
Activated factor VII (FVIIa), the first protease of clotting, expresses its physiological procoagulant potential only after complexing with tissue factor (TF) exposed to blood. Deep knowledge of the FVIIa-TF complex and F7 gene helps to understand the Janus-faced clinical findings associated to low or elevated FVII activity (FVIIc). Congenital FVII deficiency, the most frequent among the recessively inherited bleeding disorders, is caused by heterogeneous mutations in the F7 gene. Complete FVII deficiency causes perinatal lethality. A wide range of bleeding symptoms, from life-threatening intracranial hemorrhage to mild mucosal bleeding, is observed in patients with apparently modest differences in FVIIc levels. Though clinically relevant FVIIc threshold levels are still uncertain, effective management, including prophylaxis, has been devised, substantially improving the quality of life of patients. The exposure of TF in diseased arteries fostered investigation on the role of FVII in cardiovascular disease. FVIIc levels were found to be predictors of cardiovascular death and to be markedly associated to F7 gene variation. These genotype-phenotype relationships are among the most extensively investigated in humans. Genome-wide analyses extended association to numerous loci that, together with F7, explain >50% of FVII level plasma variance. However, the ability of F7 variation to predict thrombosis was not consistently evidenced in the numerous population studies. Main aims of this review are to highlight i) the biological and clinical information that distinguishes FVII deficiency from the other clotting disorders and ii) the impact exerted by genetically predicted FVII level variation on bleeding as well as on the thrombotic states.
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Affiliation(s)
- Francesco Bernardi
- Department of Life Science and Biotechnology, University of Ferrara, Ferrara.
| | - Guglielmo Mariani
- Department of Science and Technology, University of Westminster, London
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8
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Linari S, Castaman G. Concomitant Use of rFVIIa and Emicizumab in People with Hemophilia A with Inhibitors: Current Perspectives and Emerging Clinical Evidence. Ther Clin Risk Manag 2020; 16:461-469. [PMID: 32547043 PMCID: PMC7251291 DOI: 10.2147/tcrm.s205310] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 04/23/2020] [Indexed: 01/19/2023] Open
Abstract
Emicizumab, a humanized, bi-specific, monoclonal antibody subcutaneously administered, mimicking the function of FVIIIa, represents a milestone in treatment of patients affected by hemophilia A complicated with inhibitors. The HAVEN 1 and 2 studies have clearly established its superiority compared to bypassing agents for routine prophylaxis in preventing or reducing bleeding episodes in adult and pediatric patients with inhibitors. However, its protection against bleeding is only partial, and concomitant use of a bypassing agent may be required with potential prothrombotic risk. The emicizumab Phase III trials (HAVEN 1, 2 and 4) have shown that the traditional bypassing agents, activated prothrombin complex concentrates or recombinant activated factor VII (rFVIIa), may be necessary for the treatment of breakthrough bleeds or surgery management. A post hoc analysis in particular has shown that the concomitant use of emicizumab and rFVIIa is safe and no thrombotic events have been described. The review describes the state of the art of the concomitant use of emicizumab and rFVIIa for treating acute bleeding and surgeries, its efficacy and safety and the lack of thrombotic events associated with this treatment modality. Data still derive mainly from HAVEN trials; however, the availability of emicizumab in clinical practice is progressively increasing the number of patients treated and no adverse events directly attributed to this agent have occurred. The availability of guidelines for the use and dosing of rFVIIa during emicizumab prophylaxis is useful in clinical practice for managing suspected or ongoing bleeding, emergency situations and elective invasive procedures. In the next years, careful prospective post-licensure surveillance to monitor safety of rFVIIa use during prophylaxis with emicizumab is highly recommended.
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Affiliation(s)
- Silvia Linari
- Department of Oncology, Center for Bleeding Disorders and Coagulation, Careggi University Hospital, Florence, Italy
| | - Giancarlo Castaman
- Department of Oncology, Center for Bleeding Disorders and Coagulation, Careggi University Hospital, Florence, Italy
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9
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Larsen MS, Vestergaard Juul R, Zintner SM, T Kristensen A, Margaritis P, Kjelgaard-Hansen M, Wiinberg B, Simonsson USH, Kreilgaard M. Rotational thromboelastometry can predict the probability of bleeding events in a translational rat model of haemophilia A following gene-based FVIIa prophylaxis. Haemophilia 2019; 26:164-172. [PMID: 31797491 DOI: 10.1111/hae.13899] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 11/15/2019] [Accepted: 11/15/2019] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Monitoring of clinical effectiveness of bypassing agents in haemophilia patients is hampered by the lack of validated laboratory assays. Thromboelastography (TEG) and rotational thromboelastometry (ROTEM) have been evaluated for predicting clinical effectiveness of bypassing agents, however, with limited success. AIM Application of a longitudinal model-based approach may allow for a quantitative characterization of the link between ROTEM parameters and the probability of bleeding events. METHODS We analyse longitudinal data from haemophilia A rats receiving gene-based FVIIa prophylaxis in terms of total circulatory levels of FVII/FVIIa, clotting time (CT) measured using ROTEM and the probability of bleeding events. RESULTS Using population pharmacokinetic-pharmacodynamic (PKPD) modelling, a PK-CT-repeated time-to-event (RTTE) model was developed composed of three submodels (a) a FVII/FVIIa PK model, (b) a PK-CT model describing the relationship between predicted FVIIa expression and CT and (c) a RTTE model describing the probability of bleeding events as a function of CT. The developed PK-CT-RTTE model accurately described the vector dose-dependent plasma concentration-time profile of total FVII/FVIIa and the exposure-response relationship between AAV-derived FVIIa expression and CT. Importantly, the developed model accurately described the occurrence of bleeding events over time in a quantitative manner, revealing a linear relationship between predicted change from baseline CT and the probability of bleeding events. CONCLUSION Using PK-CT-RTTE modelling, we demonstrated that ROTEM parameters can accurately predict the probability of bleeding events in a translational animal model of haemophilia A.
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Affiliation(s)
- Malte Selch Larsen
- Haemophilia Research, Global Research, Novo Nordisk A/S, Maaloev, Denmark.,Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | | | - Shannon M Zintner
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Annemarie T Kristensen
- Department of Veterinary Clinical Sciences, University of Copenhagen, Frederiksberg, Denmark
| | - Paris Margaritis
- Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, USA.,The University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA
| | | | - Bo Wiinberg
- Haemophilia Research, Global Research, Novo Nordisk A/S, Maaloev, Denmark
| | | | - Mads Kreilgaard
- Haemophilia Research, Global Research, Novo Nordisk A/S, Maaloev, Denmark
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10
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Factor VIIa. Platelets 2019. [DOI: 10.1016/b978-0-12-813456-6.00063-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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11
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Shapiro AD, Mitchell IS, Nasr S. The future of bypassing agents for hemophilia with inhibitors in the era of novel agents. J Thromb Haemost 2018; 16:2362-2374. [PMID: 30264916 DOI: 10.1111/jth.14296] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Indexed: 01/19/2023]
Abstract
Bypassing agents are presently the standard of care for the treatment of bleeding episodes in patients with hemophilia and high-titer inhibitors and are also used for bleed prevention. Only two bypassing agents are available to patients, and these products trace their lineage to the 1970s (activated prothrombin complex concentrates) and the 1980s (recombinant factor VIIa). Given the limited repertoire of available products, clinicians have relied on experience, empirical observation, registry data and individualized care to improve clinical outcomes on a case-by-case basis. Research over the past two decades has culminated in a greatly improved understanding of human coagulation; resulting from this, new products have been developed that offer treatment options and mechanisms of actions that differ from current bypassing agents. The most advanced in clinical development is emicizumab, a bispecific antibody that mimics the function of FVIIIa in the intrinsic Xase complex and is indicated for once-weekly or every-other-week prophylactic dosing in inhibitor patients. Other non-traditional products in clinical development include fitusiran and antibodies directed against tissue factor pathway inhibitor. As non-factor-based therapies become more widely utilized over time, the use of bypassing agents may be expected to decrease; however, bypassing agents will remain essential for the foreseeable future. As such, clinical development of bypassing agents continues, with some products (e.g. eptacog beta) under regulatory review. In this review we examine the optimal use of bypassing agents and their mechanism of action. We also discuss newer products and how these might theoretically be administered in conjunction with traditional bypassing agents.
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Affiliation(s)
- A D Shapiro
- Indiana Hemophilia and Thrombosis Center, Inc., Indianapolis, IN, USA
| | | | - S Nasr
- GLOVAL, LLC, Broomfield, CO, USA
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12
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Gruppo RA, Malan D, Kapocsi J, Nemes L, Hay CRM, Boggio L, Chowdary P, Tagariello G, von Drygalski A, Hua F, Scaramozza M, Arkin S. Phase 1, single-dose escalating study of marzeptacog alfa (activated), a recombinant factor VIIa variant, in patients with severe hemophilia. J Thromb Haemost 2018; 16:1984-1993. [PMID: 30151972 DOI: 10.1111/jth.14247] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Indexed: 11/29/2022]
Abstract
Essentials Marzeptacog alfa (activated) [MarzAA] is a novel variant of activated human factor VII. A phase 1 dose escalation trial of MarzAA was conducted in subjects with severe hemophilia. MarzAA was safe and tolerated at intravenous doses up to 30 μg kg-1 Data observed support further trials for hemophilia patients with inhibitors to factors VIII/IX. SUMMARY Background Marzeptacog alfa (activated) (MarzAA), a new recombinant activated human factor VII (rFVIIa) variant with four amino acid substitutions, was developed to provide increased procoagulant activity and a longer duration of action in people with hemophilia. Objectives To investigate the safety, tolerability, immunogenicity, pharmacokinetics (PK) and pharmacodynamics (PD) of single ascending intravenous bolus doses of MarzAA in non-bleeding patients with congenital hemophilia A or B with or without inhibitors. Methods This international, phase 1, open-label study (NCT01439971) enrolled males aged 18-64 years with severe hemophilia A or B, with or without FVIII or FIX inhibitors. Subjects were assigned to single-dose MarzAA cohorts (0.5, 4.5, 9, 18 or 30 μg kg-1 ). Blood sampling was performed predose and postdose, and subjects were monitored for 60 days postdose. Safety endpoints included adverse events, vital sign changes, electrocardiograms, laboratory abnormalities, and immunogenicity; secondary endpoints included evaluation of PK and PD. Results Overall, in 25 patients, MarzAA was well tolerated at all dose levels tested, and was not associated with dose-limiting toxicity. No treatment-emergent severe or serious adverse events occurred. MarzAA showed linear dose-response PK across the 4.5-30 μg kg-1 dose range, with a terminal half-life of ⁓ 3.5 h. Dose-dependent shortening of the activated partial thromboplastin time and prothrombin time, and evidence of an increase in peak thrombin as determined with a thrombin generation assay, were observed at all doses. Conclusions MarzAA was tolerated at doses up to 30 μg kg-1 . The safety profile and pharmacological effects observed support further clinical trials for the treatment of hemophilic patients with inhibitors.
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Affiliation(s)
- R A Gruppo
- Comprehensive Hemophilia and Thrombosis Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - D Malan
- Phoenix Pharma Pty Ltd, Mount Croix, Port Elizabeth, South Africa
| | - J Kapocsi
- Semmelweis University 1st Department of Medicine, Budapest, Hungary
| | - L Nemes
- National Hemophilia Center and Hemostasis Department, Medical Center of the Hungarian Defense Forces, Budapest, Hungary
| | - C R M Hay
- University Department of Haematology, Manchester Royal Infirmary, Manchester, UK
| | - L Boggio
- Hemophilia and Thrombophilia Center, Rush University Medical Center, Chicago, IL, USA
| | - P Chowdary
- KD Haemophilia and Thrombosis Centre, Royal Free Hospital, London, UK
| | - G Tagariello
- Department of Medicine, Hemophilia Center, Castelfranco Veneto Hospital, Castelfranco, Italy
| | | | - F Hua
- Applied BioMath, Concord, MA, USA
| | - M Scaramozza
- Early Clinical Development, Pfizer Worldwide R&D, Pfizer Inc., Cambridge, MA, USA
| | - S Arkin
- Rare Disease Research Unit, Pfizer Inc., Cambridge, MA, USA
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Abstract
Haemophilia is a rare disease for which the approved therapeutic options have remained virtually unchanged for 50 years. In the past decade, however, there has been an explosion of innovation in the treatment options that are either in development or have been approved for haemophilia, including engineered clotting factors and an extensive pipeline of new approaches and modalities. Several of these new modalities, especially gene therapy, demonstrate proof of principle in haemophilia but could have broader applications. These advances, in combination with better diagnostics, are now enabling clinicians to improve the standard of care for people with haemophilia. The different mechanisms of action and modifications used in these therapies have implications for their safe and efficacious use, which must be balanced with their therapeutic utility. This Review focuses on the biological aspects of the most advanced and innovative approaches for haemophilia treatment and considers their future use.
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14
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Larsen MS, Juul RV, Groth AV, Simonsson US, Kristensen AT, Knudsen T, Agersø H, Kreilgaard M. Prediction of human pharmacokinetics of activated recombinant factor VII and B-domain truncated factor VIII from animal population pharmacokinetic models of haemophilia. Eur J Pharm Sci 2018; 115:196-203. [DOI: 10.1016/j.ejps.2018.01.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/15/2018] [Accepted: 01/19/2018] [Indexed: 12/01/2022]
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15
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Abstract
Coagulation factor VIIa (FVIIa) is an intrinsically poor serine protease that requires assistance from its cofactor tissue factor (TF) to trigger the extrinsic pathway of blood coagulation. TF stimulates FVIIa through allosteric maturation of its active site and by facilitating substrate recognition. The surface dependence of the latter property allowed us to design a potent membrane-triggered activity switch in FVIIa by engineering a disulfide cross-link between an allosterically silent FVIIa variant and soluble TF. These results show that optimization of substrate recognition remote from the active site represents a promising new route to simultaneously enhance and localize the procoagulant activity of FVIIa for therapeutic purposes. Recombinant factor VIIa (FVIIa) variants with increased activity offer the promise to improve the treatment of bleeding episodes in patients with inhibitor-complicated hemophilia. Here, an approach was adopted to enhance the activity of FVIIa by selectively optimizing substrate turnover at the membrane surface. Under physiological conditions, endogenous FVIIa engages its cell-localized cofactor tissue factor (TF), which stimulates activity through membrane-dependent substrate recognition and allosteric effects. To exploit these properties of TF, a covalent complex between FVIIa and the soluble ectodomain of TF (sTF) was engineered by introduction of a nonperturbing cystine bridge (FVIIa Q64C-sTF G109C) in the interface. Upon coexpression, FVIIa Q64C and sTF G109C spontaneously assembled into a covalent complex with functional properties similar to the noncovalent wild-type complex. Additional introduction of a FVIIa-M306D mutation to uncouple the sTF-mediated allosteric stimulation of FVIIa provided a final complex with FVIIa-like activity in solution, while exhibiting a two to three orders-of-magnitude increase in activity relative to FVIIa upon exposure to a procoagulant membrane. In a mouse model of hemophilia A, the complex normalized hemostasis upon vascular injury at a dose of 0.3 nmol/kg compared with 300 nmol/kg for FVIIa.
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Fernández-Bello I, Stenmo C, Butta N, Lind V, Ezban M, Jiménez-Yuste V. The pharmacokinetics and pharmacodynamics of single-dose and multiple-dose recombinant activated factor VII in patients with haemophilia A or B. Haemophilia 2017; 23:868-876. [DOI: 10.1111/hae.13312] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/20/2017] [Indexed: 11/29/2022]
Affiliation(s)
| | | | - N. Butta
- University Hospital La Paz-IdiPaz; Madrid Spain
| | - V. Lind
- Novo Nordisk A/S; Måløv Denmark
| | | | - V. Jiménez-Yuste
- University Hospital La Paz-IdiPaz; Madrid Spain
- Autonoma University; Madrid Spain
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Spiezia L, Campello E, Valle FD, Woodhams B, Simioni P. Factor VIIa-antithrombin complex: a possible new biomarker for activated coagulation. ACTA ACUST UNITED AC 2017; 55:484-488. [DOI: 10.1515/cclm-2016-0399] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 07/12/2016] [Indexed: 11/15/2022]
Abstract
AbstractThe activation of the extrinsic coagulation pathway occurs after endothelial injury when the tissue factor (TF), a transmembrane protein located outside the vasculature, binds factor VII (FVII) or activated FVII (FVIIa). Once formed, the TF-VIIa complex activates both factor IX and X and initiates the coagulation process. The TF-VIIa complex is inhibited by both TF pathway inhibitor (TFPI) and antithrombin (AT). The interaction between TF-VIIa and AT induces FVIIa-AT complex formation, which is released into the plasma. Because AT reacts with FVIIa only when it is bound to TF, the circulating levels of FVIIa-AT reflect the degree of exposure of TF to blood. Preliminary clinical studies have shown higher plasma levels of FVIIa-AT complex both in patients with a prior arterial or venous thrombotic event. Increased plasma levels of FVIIa-AT have also been reported in a number of other prothrombotic conditions – antiphospholipid antibodies, solid and hematological malignancies, pre-eclampsia (PE), obesity and cardiac surgery. However, most of the studies published so far are retrospective and with a limited sample size. Larger prospective clinical studies are needed to confirm these findings and to assess the prognostic role of this possible new biomarker for activated coagulation.
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Grandoni J, Perret G, Forier C. Kinetic analysis and binding studies of a new recombinant human factor VIIa for treatment of haemophilia. Haemophilia 2016; 23:300-308. [PMID: 27995727 DOI: 10.1111/hae.13110] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION/AIM LR769 is a new second-generation recombinant human Factor VIIa (rhFVIIa) developed for haemophilia treatment. We determined enzymatic properties of LR769 and its interaction with antithrombin, tissue factor, platelets and endothelial protein C receptor (EPCR), compared with NovoSevenRT. METHODS Kinetic enzyme assays and active site titration were used for enzymatic studies. Surface Plasmon Resonance (SPR) was used for determination of binding constants. Cellular binding was determined for platelets and cultured human umbilical vein endothelial cells (HUVEC). RESULTS The dissociation constant (Kd ) for activated platelet binding was in the 1 μm range for both products. At saturation, more LR769 than NovoSevenRT was bound to the platelets. Binding to HUVEC was 25-50% higher for LR769 than for NovoSevenRT. Protein C, soluble EPCR, and anti-EPCR antibody all reduced the binding, indicating specificity for EPCR. LR769 was similar to NovoSevenRT in all kinetic assays. Active site titration demonstrated 0.7 mole of active site/mole of protein. The kcat /Km values for activation of FX and FIX with purified recombinant tissue factor and phospholipids were 10.5 s-1 /0.32 μm and 3.3 s-1 /0.44 μm respectively. The apparent second-order rate constant for inactivation by human plasma AT was 5.9 ± 0.4 × 103 m-1 s-1 . The Kd values for binding of LR769 to soluble tissue factor and full-length tissue factor were 8.1 nm and 0.9 nm, respectively, and the Kd for binding to soluble EPCR was 41 nm. CONCLUSION Overall, LR769 exhibited characteristics similar to NovoSevenRT, but bound EPCR on HUVEC with somewhat higher affinity than NovoSevenRT.
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Lee D, Nayak S, Martin SW, Heatherington AC, Vicini P, Hua F. A quantitative systems pharmacology model of blood coagulation network describes in vivo biomarker changes in non-bleeding subjects. J Thromb Haemost 2016; 14:2430-2445. [PMID: 27666750 DOI: 10.1111/jth.13515] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 09/01/2016] [Indexed: 01/03/2023]
Abstract
Essentials Baseline coagulation activity can be detected in non-bleeding state by in vivo biomarker levels. A detailed mathematical model of coagulation was developed to describe the non-bleeding state. Optimized model described in vivo biomarkers with recombinant activated factor VII treatment. Sensitivity analysis predicted prothrombin fragment 1 + 2 and D-dimer are regulated differently. SUMMARY Background Prothrombin fragment 1 + 2 (F1 + 2 ), thrombin-antithrombin III complex (TAT) and D-dimer can be detected in plasma from non-bleeding hemostatically normal subjects or hemophilic patients. They are often used as safety or pharmacodynamic biomarkers for hemostatis-modulating therapies in the clinic, and provide insights into in vivo coagulation activity. Objectives To develop a quantitative systems pharmacology (QSP) model of the blood coagulation network to describe in vivo biomarkers, including F1 + 2 , TAT, and D-dimer, under non-bleeding conditions. Methods The QSP model included intrinsic and extrinsic coagulation pathways, platelet activation state-dependent kinetics, and a two-compartment pharmacokinetics model for recombinant activated factor VII (rFVIIa). Literature data on F1 + 2 and D-dimer at baseline and changes with rFVIIa treatment were used for parameter optimization. Multiparametric sensitivity analysis (MPSA) was used to understand key proteins that regulate F1 + 2 , TAT and D-dimer levels. Results The model was able to describe tissue factor (TF)-dependent baseline levels of F1 + 2 , TAT and D-dimer in a non-bleeding state, and their increases in hemostatically normal subjects and hemophilic patients treated with different doses of rFVIIa. The amount of TF required is predicted to be very low in a non-bleeding state. The model also predicts that these biomarker levels will be similar in hemostatically normal subjects and hemophilic patients. MPSA revealed that F1 + 2 and TAT levels are highly correlated, and that D-dimer is more sensitive to the perturbation of coagulation protein concentrations. Conclusions A QSP model for non-bleeding baseline coagulation activity was established with data from clinically relevant in vivo biomarkers at baseline and changes in response to rFVIIa treatment. This model will provide future mechanistic insights into this system.
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Affiliation(s)
- D Lee
- PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA
| | - S Nayak
- Pharmacometrics, Global Innovative Pharma Business, Pfizer Inc., Cambridge, MA, USA
| | - S W Martin
- Pharmacometrics, Global Innovative Pharma Business, Pfizer Inc., Cambridge, MA, USA
| | - A C Heatherington
- PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA
| | - P Vicini
- Pharmacokinetics, Dynamics and Metabolism - New Biological Entities, Pfizer Inc., San Diego, CA, USA
| | - F Hua
- PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA
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Fazavana JG, Muczynski V, Proulle V, Wohner N, Christophe OD, Lenting PJ, Denis CV. LDL receptor-related protein 1 contributes to the clearance of the activated factor VII-antithrombin complex. J Thromb Haemost 2016; 14:2458-2470. [PMID: 27614059 DOI: 10.1111/jth.13502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/30/2016] [Indexed: 11/30/2022]
Abstract
Essentials Factor VIIa is cleared principally as a complex with antithrombin. Enzyme/serpin complexes are preferred ligands for the scavenger-receptor LRP1. Factor VIIa/antithrombin but not factor VIIa alone is a ligand for LRP1. Macrophage-expressed LRP1 contributes to the clearance of factor VIIa/antithrombin. SUMMARY Background Recent findings point to activated factor VII (FVIIa) being cleared predominantly (± 65% of the injected protein) as part of a complex with the serpin antithrombin. FVIIa-antithrombin complexes are targeted to hepatocytes and liver macrophages. Both cells lines abundantly express LDL receptor-related protein 1 (LRP1), a scavenger receptor mediating the clearance of protease-serpin complexes. Objectives To investigate whether FVIIa-antithrombin is a ligand for LRP1. Methods Binding of FVIIa and pre-formed FVIIa-antithrombin to purified LRP1 Fc-tagged cluster IV (rLRP1-cIV/Fc) and to human and murine macrophages was analyzed. FVIIa clearance was determined in macrophage LRP1 (macLRP1)-deficient mice. Results Solid-phase binding assays showed that FVIIa-antithrombin bound in a specific, dose-dependent and saturable manner to rLRP1-cIV/Fc. Competition experiments with human THP1 macrophages indicated that binding of FVIIa but not of FVIIa-antithrombin was reduced in the presence of annexin-V or anti-tissue factor antibodies, whereas binding of FVIIa-antithrombin but not FVIIa was inhibited by the LRP1-antagonist GST-RAP. Additional experiments revealed binding of both FVIIa and FVIIa-antithrombin to murine control macrophages. In contrast, no binding of FVIIa-antithrombin to macrophages derived from macLRP1-deficient mice could be detected. Clearance of FVIIa-antithrombin but not of active site-blocked FVIIa was delayed 1.5-fold (mean residence time of 3.3 ± 0.1 h versus 2.4 ± 0.2 h) in macLRP1-deficient mice. The circulatory presence of FVIIa was prolonged to a similar extent in macLRP1-deficient mice and in control mice. Conclusions Our data show that FVIIa-antithrombin but not FVIIa is a ligand for LRP1, and that LRP1 contributes to the clearance of FVIIa-antithrombin in vivo.
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Affiliation(s)
- J G Fazavana
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - V Muczynski
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - V Proulle
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- Department of Biological Hematology, CHU Bicetre, Hôpitaux Universitaires Paris Sud, AP-HP, Paris, France
| | - N Wohner
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - O D Christophe
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - P J Lenting
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - C V Denis
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
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Bauer KA, Nguyen-Cao TM, Spears JB. Issues in the Diagnosis and Management of Hereditary Antithrombin Deficiency. Ann Pharmacother 2016; 50:758-67. [DOI: 10.1177/1060028016651276] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Objective: To review insights gained in the past several years about hereditary antithrombin (AT) deficiency and to outline approaches to the management of patients with AT deficiency in the acute and chronic settings. Data Sources: An extensive literature search of Scopus (January 2008-April 2016) was performed for the terms congenital antithrombin deficiency, inherited antithrombin deficiency, or hereditary antithrombin deficiency. Additional references were identified by reviewing literature citations. Study Selection: All relevant English-language case reports, reviews, clinical studies, meeting abstracts, and book chapters assessing hereditary AT deficiency were included. Data Synthesis: AT deficiency significantly increases the risk of venous thromboembolism (VTE). The risk of VTE is particularly high during pregnancy, the postpartum period, and following major surgery. Effective clinical management includes determination of the appropriate type and duration of antithrombotic therapy (ie, AT replacement for acute situations) while minimizing the risk of bleeding. For persons newly diagnosed with AT deficiency, age, lifestyle, concurrent medical conditions, family history, and personal treatment preferences can be used to individualize patient management. Patients should be informed of the risks associated with hormonal therapy, pregnancy, surgical procedures, and immobility, which further increase the risk of VTE in patients with AT deficiency. Conclusion: AT deficiency poses the highest risk for VTE among the hereditary thrombophilias, often requiring long-term anticoagulation. Undertaking an evaluation for hereditary thrombophilia is controversial; however, a diagnosis of VTE in association with AT deficiency can have management implications. An important treatment option for patients with this disorder in high-risk situations is AT concentrate.
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In vitro reversal of supratherapeutic rivaroxaban levels with coagulation factor concentrates. BLOOD TRANSFUSION = TRASFUSIONE DEL SANGUE 2016; 14:481-6. [PMID: 27177413 DOI: 10.2450/2016.0205-15] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 02/09/2016] [Indexed: 11/21/2022]
Abstract
BACKGROUND A bleeding patient undergoing therapy with new oral anticoagulants is every clinician's nightmare as no specific reversal agent is available yet. This in vitro study investigated the effect of prothrombin complex concentrate (PCC), recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (aPCC) on supratherapeutic rivaroxaban concentrations using standard laboratory parameters (prothrombin time [PT], activated partial thromboplastin time [aPTT] and PT ratio) and thromboelastometry (clotting time [CT]). MATERIALS AND METHODS Blood samples from 10 healthy volunteers were collected and spiked with a supratherapeutic dose of rivaroxaban. Afterwards PCC, rFVIIa and aPCC were added in two doses. The laboratory parameters were measured and thromboelastometry was performed. RESULTS The addition of the reversal agents had the following statistically significant effects (all p<0.01): +25 IU/kg PCC: CT -15 s, aPTT +5 s; +50 IU/kg PCC: aPTT +11 s; +90 μg rFVIIa: CT -141 s; +25 IU/kg aPCC: CT -142 s, aPTT -9 s, PT ratio +14%, PT -10.5 s; +50 IU/kg aPCC: CT -118 s, aPTT -7 s, PT ratio +17%, PT -12.2 s. DISCUSSION rFVIIa and aPCC, but not PCC, appear to shorten coagulation times significantly in standard laboratory and thromboelastometry assays. These results need confirmation through evaluation of these agents in the clinical setting.
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Słomka A, Świtońska M, Sinkiewicz W, Żekanowska E. Assessing Circulating Factor VIIa-Antithrombin Complexes in Acute Ischemic Stroke: A Pilot Study. Clin Appl Thromb Hemost 2016; 23:351-359. [PMID: 26873107 DOI: 10.1177/1076029616631424] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
AIM The goal of this study was to determine the levels of factor VII (FVII), factor VIIa-antithrombin complexes (FVIIa-AT), total tissue factor (TF), and tissue factor-bearing microparticles (MPs-TF) in patients with acute ischemic stroke. Further, we sought evidence of an association between hemostatic markers, time of blood sampling, type of treatment, and patient outcomes. METHODS Venous blood samples were collected from 33 patients on the first day and on the seventh day after stroke diagnosis. Age-matched controls were also included (n = 20). Plasma levels of FVII, FVIIa-AT, total TF, and MPs-TF were measured by enzyme-linked immunosorbent assay. We divided patients into 2 groups: thrombolysis group (n = 13) and nonthrombolysis group (n = 20). Furthermore, evaluation of the National Institutes of Health Stroke Scale and the Barthel Index was performed on the first day and the seventh day. RESULTS Patients with ischemic stroke showed significantly lower plasma FVII, FVIIa-AT, and total TF levels than controls (median, 112.25% vs 132.05%, P = .004; 107.97 pmol/L vs 154.94 pmol/L, P < .001; 81.74 pg/mL vs 105.71 pg/mL, P < .001, respectively). In contrast, levels of plasma MPs-TF were significantly higher in patients with stroke compared to healthy controls (1.60 pg/mL vs 0.74 pg/mL, P < .001). Additionally, the thrombolysis group had lower FVII levels on the seventh day compared to the first day (median, 109.80% vs 115.74%, P = .04). CONCLUSION Factor VII, FVIIa-AT, and total TF are decreased, while MPs-TF are elevated in patients with ischemic stroke. We observed a slight but significant effect of alteplase on FVII plasma levels.
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Affiliation(s)
- Artur Słomka
- 1 Department of Pathophysiology, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland
| | - Milena Świtońska
- 2 Neurology and Stroke Care Unit, Jan Biziel University Hospital № 2, Bydgoszcz, Poland
| | - Władysław Sinkiewicz
- 3 Second Chair of Cardiology, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland
| | - Ewa Żekanowska
- 1 Department of Pathophysiology, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland
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New Insights Into the Treatment of Glanzmann Thrombasthenia. Transfus Med Rev 2016; 30:92-9. [PMID: 26968829 DOI: 10.1016/j.tmrv.2016.01.001] [Citation(s) in RCA: 66] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Revised: 01/12/2016] [Accepted: 01/12/2016] [Indexed: 11/21/2022]
Abstract
Glanzmann thrombasthenia (GT) is a rare inherited autosomal recessive bleeding disorder of platelet function caused by a quantitative or qualitative defect of platelet membrane glycoprotein IIb/IIIa (integrin αIIbβ3), a fibrinogen receptor required for platelet aggregation. Bleeds in GT are variable and may be severe and unpredictable. Bleeding not responsive to local and adjunctive measures, as well as surgical procedures, is treated with platelets, recombinant activated factor VII (rFVIIa), or antifibrinolytics, alone or in combination. Although platelets are the standard treatment for GT, their use is associated with the risk of blood-borne infection transmission and may also cause the development of platelet antibodies (to human leukocyte antigens and/or αIIbβ3), potentially resulting in platelet refractoriness. Currently, where rFVIIa is approved for use in GT, this is mostly for patients with platelet antibodies and/or a history of platelet refractoriness. However, data from the prospective Glanzmann's Thrombasthenia Registry (829 bleeds and 206 procedures in 218 GT patients) show that rFVIIa was frequently used in nonsurgical and surgical bleeds, with high efficacy rates, irrespective of platelet antibodies/refractoriness status. The mechanisms underpinning rFVIIa effectiveness in GT have been studied. At therapeutic concentrations, rFVIIa binds to activated platelets and directly activates FX to FXa, resulting in a burst of thrombin generation. Thrombin converts fibrinogen to fibrin and also enhances GT platelet adhesion and aggregation mediated by the newly converted (polymeric) fibrin, leading to primary hemostasis at the wound site. In addition, thrombin improves the final clot structure and activates thrombin-activatable fibrinolysis inhibitor to decrease clot lysis.
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Böhm E, Seyfried BK, Dockal M, Graninger M, Hasslacher M, Neurath M, Konetschny C, Matthiessen P, Mitterer A, Scheiflinger F. Differences in N-glycosylation of recombinant human coagulation factor VII derived from BHK, CHO, and HEK293 cells. BMC Biotechnol 2015; 15:87. [PMID: 26382581 PMCID: PMC4574471 DOI: 10.1186/s12896-015-0205-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2015] [Accepted: 09/09/2015] [Indexed: 04/16/2023] Open
Abstract
UNLABELLED BACKGROUND & METHODS Recombinant factor VII (rFVII), the precursor molecule for recombinant activated FVII (rFVIIa), is, due to its need for complex post translational modifications, produced in mammalian cells. To evaluate the suitability of a human cell line in order to produce rFVII with post-translational modifications as close as possible to pdFVII, we compared the biochemical properties of rFVII synthesized in human embryonic kidney-derived (HEK)293 cells (HEK293rFVII) with those of rFVII expressed in Chinese hamster ovary (CHO, CHOrFVII) and baby hamster kidney (BHK, BHKrFVII) cells, and also with those of plasma derived FVII (pdFVII), using various analytical methods. rFVII was purified from selected production clones derived from BHK, CHO, and HEK293 cells after stable transfection, and rFVII isolates were analyzed for protein activity, impurities and post-translational modifications. RESULTS & DISCUSSION The analytical results showed no apparent gross differences between the various FVII proteins, except in their N-linked glycosylation pattern. Most N-glycans found on rFVII produced in HEK293 cells were not detected on rFVII from CHO and BHK cells, or, somewhat unexpectedly, on pdFVII; all other protein features were similar. HEK293rFVII glycans were mainly characterized by a higher structural variety and a lower degree of terminal sialylation, and a high amount of terminal N-acetyl galactosamines (GalNAc). All HEK293rFVII oligosaccharides contained one or more fucoses (Fuc), as well as hybrid and high mannose (Man) structures. CONCLUSIONS From all rFVII isolates investigated, CHOrFVII contained the highest degree of sialylation and no terminal GalNAc, and CHO cells were therefore assumed to be the best option for the production of rFVII.
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Affiliation(s)
- Ernst Böhm
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
| | - Birgit K Seyfried
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
| | - Michael Dockal
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
| | - Michael Graninger
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
| | | | - Marianne Neurath
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
| | | | - Peter Matthiessen
- BaxaltaInnovations GmbH, Industriestraße 72, A-1220, Vienna, Austria.
| | - Artur Mitterer
- Baxalta Innovations GmbH, Uferstraße 15, A-2304, Orth/Donau, Austria.
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Vatsyayan R, Kothari H, Mackman N, Pendurthi UR, Rao LVM. Inactivation of factor VIIa by antithrombin in vitro, ex vivo and in vivo: role of tissue factor and endothelial cell protein C receptor. PLoS One 2014; 9:e103505. [PMID: 25102166 PMCID: PMC4125150 DOI: 10.1371/journal.pone.0103505] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/30/2014] [Indexed: 11/19/2022] Open
Abstract
Recent studies have suggested that antithrombin (AT) could act as a significant physiologic regulator of FVIIa. However, in vitro studies showed that AT could inhibit FVIIa effectively only when it was bound to tissue factor (TF). Circulating blood is known to contain only traces of TF, at best. FVIIa also binds endothelial cell protein C receptor (EPCR), but the role of EPCR on FVIIa inactivation by AT is unknown. The present study was designed to investigate the role of TF and EPCR in inactivation of FVIIa by AT in vivo. Low human TF mice (low TF, ∼1% expression of the mouse TF level) and high human TF mice (HTF, ∼100% of the mouse TF level) were injected with human rFVIIa (120 µg kg−1 body weight) via the tail vein. At varying time intervals following rFVIIa administration, blood was collected to measure FVIIa-AT complex and rFVIIa antigen levels in the plasma. Despite the large difference in TF expression in the mice, HTF mice generated only 40–50% more of FVIIa-AT complex as compared to low TF mice. Increasing the concentration of TF in vivo in HTF mice by LPS injection increased the levels of FVIIa-AT complexes by about 25%. No significant differences were found in FVIIa-AT levels among wild-type, EPCR-deficient, and EPCR-overexpressing mice. The levels of FVIIa-AT complex formed in vitro and ex vivo were much lower than that was found in vivo. In summary, our results suggest that traces of TF that may be present in circulating blood or extravascular TF that is transiently exposed during normal vessel damage contributes to inactivation of FVIIa by AT in circulation. However, TF’s role in AT inactivation of FVIIa appears to be minor and other factor(s) present in plasma, on blood cells or vascular endothelium may play a predominant role in this process.
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Affiliation(s)
- Rit Vatsyayan
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Hema Kothari
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Nigel Mackman
- Division of Hematology and Oncology, McAllister Heart Institute, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Usha R. Pendurthi
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - L. Vijaya Mohan Rao
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- * E-mail:
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Vestergaard B, Appa RS, Lykkesfeldt J, Agersø H. The kidneys play an important role in the clearance of rFVIIa in rats. Thromb Res 2014; 133:1124-9. [PMID: 24731563 DOI: 10.1016/j.thromres.2014.03.034] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Revised: 02/10/2014] [Accepted: 03/11/2014] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Previous distribution and histological studies have indicated that the kidneys and renal proximal tubular cells play a role in clearance of rFVIIa. However, the relative importance of the kidneys in clearance of rFVIIa has not previously been addressed. The objective of the present study was to evaluate the importance of the kidneys in the clearance process of rFVIIa after iv administration to rats using a nephrectomy model. MATERIALS AND METHODS A nephrectomized rat model was established and validated using inulin, a compound primarily cleared by the kidneys, as a test substance and several physiological parameters were monitored to ensure viability and robustness of the model. The model was then used for pharmacokinetic evaluation of renal clearance of rFVIIa. The pharmacokinetic parameters for rFVIIa were evaluated both by use of standard non-compartmental methods and by use of mixed effects methods, where a pharmacokinetic model was used to simultaneously model all data from healthy, sham operated, and nephrectomized rats. RESULTS Nephrectomized animals showed stable rectal temperature, SpO2 and pulse and as expected, clearance of inulin was essentially abolished compared to control animals (p<0.001). For rFVIIa, nephrectomy resulted in a clearance and terminal half-life of 34mL/h/kg and 2.8h compared to 68mL/h/kg and1.9h in rats exposed to sham surgery (p<0.0001 for both parameters). CONCLUSION The present data show that about 50% of the total clearance of rFVIIa from circulation in rats under isoflurane anaesthesia is due to renal clearance.
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Affiliation(s)
- Bill Vestergaard
- Biopharmaceuticals Research Unit, Novo Nordisk A/S, Måløv, Denmark; Faculty of Health and Medical Sciences, University of Copenhagen, Denmark.
| | - Rupa S Appa
- Biopharmaceuticals Research Unit, Novo Nordisk A/S, Måløv, Denmark
| | - Jens Lykkesfeldt
- Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Henrik Agersø
- Biopharmaceuticals Research Unit, Novo Nordisk A/S, Måløv, Denmark
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Zollner S, Schuermann D, Raquet E, Mueller-Cohrs J, Weimer T, Pragst I, Dickneite G, Schulte S. Pharmacological characteristics of a novel, recombinant fusion protein linking coagulation factor VIIa with albumin (rVIIa-FP). J Thromb Haemost 2014; 12:220-8. [PMID: 24641308 PMCID: PMC4166693 DOI: 10.1111/jth.12477] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Indexed: 01/20/2023]
Abstract
BACKGROUND Recombinant factor VIIa (rFVIIa) is approved for use in controlling bleeding episodes in people with hemophilia who have developed inhibitors to replacement therapy. Due to its short half-life (t½), frequent injections are required, limiting its use as a prophylactic treatment. A novel, recombinant fusion protein linking coagulation factor VIIa with albumin (rVIIa-FP) has been developed to extend the t(½) of rFVIIa. OBJECTIVES The aim of our studies was to investigate the pharmacokinetic/pharmacodynamic characteristics of rVIIa-FP in preclinical animal species. METHODS Pharmacokinetic (PK) parameters were derived after single intravenous dosing in hemophilia A mice, rats, rabbits and monkeys. PK analysis was based on human FVII plasma levels determined by measuring FVII antigen levels by ELISA in mice and rats, and FVIIa activity using STACLOT® VIIa-rTF in rabbits and monkeys. Induction of thrombin generation was investigated in mice, while hemostatic activity was assessed by thrombus formation in rabbits. RESULTS Compared with rFVIIa, rVIIa-FP displayed a prolonged t(½), enhanced in vivo recovery and reduced clearance in all species investigated. In mice, 16 h after treatment with rVIIa-FP, thrombin levels were quantifiable, indicating prolonged efficacy, whereas values had approached baseline at this time after treatment with rFVIIa. After 12 h, hemostatic efficacy was negligible in rFVIIa-treated rabbits, but sustained in animals receiving rVIIa-FP. CONCLUSIONS These studies indicate that the longer t(½) of rVIIa-FP compared with rFVIIa translates into extended activity. These findings suggest that rVIIa-FP has the potential to be administered less frequently than rFVIIa-containing concentrates in clinical use.
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Körber MK, Langer E, Ziemer S, Perzborn E, Gericke C, Heymann CV. Measurement and Reversal of Prophylactic and Therapeutic Peak Levels of Rivaroxaban. Clin Appl Thromb Hemost 2013; 20:735-40. [DOI: 10.1177/1076029613494468] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Background: Rivaroxaban (Xarelto, Bayer HealthCare, Leverkusen, Germany) is a new oral anticoagulant drug. Anticoagulants may cause bleeding, thereby requiring reliable monitoring and efficient therapy. We investigated thromboelastometry versus routine coagulation tests to measure prophylactic and therapeutic concentrations of rivaroxaban and their reversal with prothrombin complex concentrate (PCC) and activated recombinant factor VII (rFVIIa) in vitro. Methods: Rivaroxaban was solubilized, and PCC and rFVIIa were added in 2 concentrations to the rivaroxaban-spiked blood samples, and thromboelastometry and measurements were performed. Results: Rivaroxaban increased tissue factor–activated clotting time (CTExTEM) dose dependently. Activated partial prothrombin time (aPTT), prothrombin time ratio (PTR), and prothrombin time (PT) were changed significantly in both concentrations. Reversal with PCC in both dosages caused no significant change in the measured parameters. For prophylactic rivaroxaban dosage, rFVIIa changed the PT significantly but not CTExTEM, aPTT, and PTR. For therapeutic rivaroxaban dosage, the CTExTEM was significantly reduced. The other parameters remained unaffected. Conclusions: Thromboelastometry can detect rivaroxaban effects. In vitro rFVIIa seems highly effective for reversal in contrast to PCC.
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Affiliation(s)
- Mareike Kristina Körber
- Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
| | - Elisabeth Langer
- Labor Berlin—Charite Vivantes, GmbH, Berlin, Germany
- Institute for Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
| | - Sabine Ziemer
- Institute for Laboratory Medicine, Clinical Chemistry and Pathobiochemistry, Charité-Universitätsmedizin Berlin, Campus Charité Mitte, Berlin, Germany
| | | | - Christine Gericke
- Institute of Medical Biometrics and Clinical Epidemiology, Charité–Universitätsmedizin, Berlin, Germany
| | - Christian von Heymann
- Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, Campus Virchow-Klinikum and Campus Charité Mitte, Berlin, Germany
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30
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Factor VIIa. Platelets 2013. [DOI: 10.1016/b978-0-12-387837-3.00061-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Agersø H, Tranholm M. Pharmacokinetics and pharmacodynamics of rFVIIa and new improved bypassing agents for the treatment of haemophilia. Haemophilia 2012; 18 Suppl 5:6-10. [PMID: 22757678 DOI: 10.1111/j.1365-2516.2012.02886.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Animal models have played a critical role in developing our understanding of haemophilia and its treatment. For example, studies in mice and dogs have provided insights into the pharmacokinetics and pharmacodynamics of recombinant activated factor VII (rFVIIa). Such studies have shown that antithrombin has a significant impact on clearance of rFVIIa, which explains discrepancies between the antigen and activity half-lives of rFVIIa. Animal studies have also shown that the major clearance organs for rFVIIa are the liver and the kidneys, whereas distribution studies suggest that FVII and rFVIIa leave the circulation and enter the tissues, before returning to the circulation through the lymph. One agent that has benefited greatly from the use of animal models in its development is vatreptacog alfa, a new analogue of rFVIIa. Promising in vitro results, including increased generation of FXa, shortened clotting times and increased clot stability, were subsequently confirmed in animal models. In a severe tail-bleed model in FVIII knock-out mice, reduction in maximal blood loss was substantially greater with vatreptacog alfa than with rFVIIa, FVIII or plasma-derived activated prothrombin complex concentrate. In a mouse model of joint bleeding, rFVIIa and vatreptacog alfa significantly reduced bleeding compared with vehicle-treated haemophilic controls. More recently, a model of endothelial injury based on mouse cremaster muscle has been developed. Overall, animal models are a valuable tool in elucidating the haemostatic process and the effects of therapeutic agents, although direct extrapolation to the clinical setting should be done with caution.
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Affiliation(s)
- Henrik Agersø
- Biopharmaceuticals Research Unit, Novo Nordisk A/S, Måløv, Denmark
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Simioni P, Spiezia L. Reprint of: Factor VIIa-AT complex plasma levels and arterial thrombosis. Thromb Res 2012; 130:141. [DOI: 10.1016/j.thromres.2012.07.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 09/19/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
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Unifying the mechanism of recombinant FVIIa action: dose dependence is regulated differently by tissue factor and phospholipids. Blood 2012; 120:891-9. [PMID: 22563088 DOI: 10.1182/blood-2011-11-393371] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recombinant factor VIIa (rFVIIa) is used for treatment of hemophilia patients with inhibitors, as well for off-label treatment of severe bleeding in trauma and surgery. Effective bleeding control requires supraphysiological doses of rFVIIa, posing both high expense and uncertain thrombotic risk. Two major competing theories offer different explanations for the supraphysiological rFVIIa dosing requirement: (1) the need to overcome competition between FVIIa and FVII zymogen for tissue factor (TF) binding, and (2) a high-dose-requiring phospholipid-related pathway of FVIIa action. In the present study, we found experimental conditions in which both mechanisms contribute simultaneously and independently to rFVIIa-driven thrombin generation in FVII-deficient human plasma. From mathematical simulations of our model of FX activation, which were confirmed by thrombin-generation experiments, we conclude that the action of rFVIIa at pharmacologic doses is dominated by the TF-dependent pathway with a minor contribution from a phospholipid-dependent mechanism. We established a dose-response curve for rFVIIa that is useful to explain dosing strategies. In the present study, we present a pathway to reconcile the 2 major mechanisms of rFVIIa action, a necessary step to understanding future dose optimization and evaluation of new rFVIIa analogs currently under development.
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Gopalakrishnan R, Pendurthi UR, Hedner U, Agersø H, Esmon CT, Rao LVM. Influence of endothelial cell protein C receptor on plasma clearance of factor VIIa. J Thromb Haemost 2012; 10:971-3. [PMID: 22372829 PMCID: PMC3883585 DOI: 10.1111/j.1538-7836.2012.04670.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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de Paula EV, Kavakli K, Mahlangu J, Ayob Y, Lentz SR, Morfini M, Nemes L, Šalek SZ, Shima M, Windyga J, Ehrenforth S, Chuansumrit A. Recombinant factor VIIa analog (vatreptacog alfa [activated]) for treatment of joint bleeds in hemophilia patients with inhibitors: a randomized controlled trial. J Thromb Haemost 2012; 10:81-9. [PMID: 22470921 DOI: 10.1111/j.1538-7836.2011.04549.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND A recombinant factor VIIa analog (NN1731; vatreptacog alfa [activated]) was developed to provide safe, rapid and sustained resolution of bleeds in patients with hemophilia and inhibitors. PATIENTS/METHODS This global, prospective, randomized, double-blinded, active-controlled, dose-escalation trial evaluated and compared one to three doses of vatreptacog alfa at 5, 10, 20, 40, and 80 lg kg(-1) with one to three doses of recombinant FVIIa (rFVIIa) at 90 lg kg(-1) in the treatment of acute joint bleeds in hemophilia patients with inhibitors. The primary endpoint comprised adverse events; secondary endpoints were evaluations of immunogenicity, pharmacokinetics, and efficacy. RESULTS AND CONCLUSIONS Overall, 96 joint bleeds in 51 patients (> 12 years of age) were dosed. Vatreptacog alfa was well tolerated, with a low frequency of adverse events. No immunogenic or thrombotic events related to vatreptacog alfa were reported. A high efficacy rate of vatreptacog alfa in controlling acute joint bleeds was observed; 98% of bleeds were controlled within 9 h of the initial dose in a combined evaluation of 20–80 lg kg(-1) vatreptacog alfa. The efficacy rate observed for rFVIIa (90%) is consistent with data from published clinical trials. The trial was not powered to compare efficacy, and further trials are needed to investigate the efficacy of vatreptacog alfa as compared with that of rFVIIa. The trial was registered at ClinicalTrials.gov ( REGISTRATION NUMBER NCT00486278).
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Affiliation(s)
- Erich V de Paula
- Hematology and Hemotherapy Center, University of Campinas, São Paulo, Brazil.
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Simioni P, Spiezia L. Factor VIIa-AT complex plasma levels and arterial thrombosis. Thromb Res 2011; 128:507. [PMID: 21995975 DOI: 10.1016/j.thromres.2011.09.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 09/19/2011] [Accepted: 09/19/2011] [Indexed: 11/28/2022]
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Overcoming delayed in-vitro response to rFVIIa: effects of rFVIIa and rFVIIa analogue (vatreptacog alfa) concentration escalation in whole blood assays. Blood Coagul Fibrinolysis 2011; 22:541-6. [PMID: 21681082 DOI: 10.1097/mbc.0b013e328348d9e5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In a previous pharmacokinetic/pharmacodynamic study in nonbleeding hemophilia patients, variability in laboratory response to recombinant factor VIIa (rFVIIa) 90 μg/kg was noted, and the patients were described as delayed or rapid laboratory responders based on time to clot formation. The current study determined whether in-vitro experiments could reproduce previous in-vivo findings; whether the delayed laboratory response to rFVIIa 90 μg/kg is improved by spiking with high-dose rFVIIa or rFVIIa analogue (vatreptacog alfa); whether a dose-response is observed with our method. In-vitro experiments were conducted in our previous patient cohort using rFVIIa 1.28 and 3.84 μg/ml and vatreptacog alfa 0.28 and 0.56 μg/ml. Whole blood studies were conducted using the Hemodyne Hemostasis Analysis System (platelet contractile force, clot elastic modulus, force onset time) and rotational thromboelastometry (clotting time, maximum clot firmness). Spiking with rFVIIa 1.28 μg/ml showed the same distribution of delayed and rapid laboratory response as observed previously. Increasing in-vitro rFVIIa concentrations improved the coagulation parameters; however, there remained delayed and rapid responders. Vatreptacog alfa improved the coagulation parameters at all concentrations tested, and the 0.56 μg/ml concentration normalized the force onset time, platelet contractile force, clot elastic modulus and clotting time parameters. A dose-response was observed with both assays. There was good agreement between the laboratory responses obtained after intravenous administration of rFVIIa 90 μg/kg and in-vitro spiking studies. Escalating rFVIIa and vatreptacog alfa concentrations improved coagulation parameters in all patients compared to rFVIIa 1.28 μg/ml. Vatreptacog alfa produced more pronounced coagulation effects at lower concentrations than rFVIIa; and the 0.56 μg/ml concentration completely normalized responses in all patients.
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Clearance of rFVIIa and NN1731 after intravenous administration to Beagle dogs. Eur J Pharm Sci 2011; 42:578-83. [DOI: 10.1016/j.ejps.2011.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 01/20/2011] [Accepted: 02/24/2011] [Indexed: 11/20/2022]
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