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Abstract
This article represents a republication of an article originally published in STH in 2005. This republication is to help celebrate 50 years of publishing for STH. The original abstract follows.Platelets are specialized blood cells that play central roles in physiologic and pathologic processes of hemostasis, inflammation, tumor metastasis, wound healing, and host defense. Activation of platelets is crucial for platelet function that includes a complex interplay of adhesion and signaling molecules. This article gives an overview of the activation processes involved in primary and secondary hemostasis, for example, platelet adhesion, platelet secretion, platelet aggregation, microvesicle formation, and clot retraction/stabilization. In addition, activated platelets are predominantly involved in cross-talk to other blood and vascular cells. Stimulated "sticky" platelets enable recruitment of leukocytes at sites of vascular injury under high shear conditions. Platelet-derived microparticles as well as soluble adhesion molecules, sP-selectin and sCD40L, shed from the surface of activated platelets, are capable of activating, in turn, leukocytes and endothelial cells. This article focuses further on the new view of receptor-mediated thrombin generation of human platelets, necessary for the formation of a stable platelet-fibrin clot during secondary hemostasis. Finally, special emphasis is placed on important stimulatory and inhibitory signaling pathways that modulate platelet function.
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Affiliation(s)
- Kerstin Jurk
- Department of Anaesthesiology and Intensive Care, Experimental and Clinical Haemostasis, University-Hospital Munster, Munster, Germany
| | - Beate E Kehrel
- Department of Anaesthesiology and Intensive Care, Experimental and Clinical Haemostasis, University-Hospital Munster, Munster, Germany
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Sim DS, Mallari CR, Hermiston TW, Bae D, Lee S, Allen T, Gilner J, Kim SC, James AH. CT-001, a novel fast-clearing factor VIIa, enhanced the hemostatic activity in postpartum samples. Blood Adv 2024; 8:287-295. [PMID: 38039512 PMCID: PMC10824690 DOI: 10.1182/bloodadvances.2023011398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 12/03/2023] Open
Abstract
ABSTRACT The hemostatic system is upregulated to protect pregnant mothers from hemorrhage during childbirth. Studies of the details just before and after delivery, however, are lacking. Recombinant factor VIIa (rFVIIa) has recently been granted approval by the European Medicines Agency for the treatment of postpartum hemorrhage (PPH). A next-generation molecule, CT-001, is being developed as a potentially safer and more efficacious rFVIIa-based therapy. We sought to evaluate the peripartum hemostatic status of pregnant women and assess the ex vivo hemostatic activity of rFVIIa and CT-001 in peripartum blood samples. Pregnant women from 2 study sites were enrolled in this prospective observational study. Baseline blood samples were collected up to 3 days before delivery. Postdelivery samples were collected 45 (±15) minutes after delivery. Between the 2 time points, soluble fibrin monomer and D-dimer increased whereas tissue factor, FVIII, FV, and fibrinogen decreased. Interestingly, the postdelivery lag time and time to peak in the thrombin generation assay were shortened, and the peak thrombin generation capacity was maintained despite the reduced levels of coagulation proteins after delivery. Furthermore, both rFVIIa and CT-001 were effective in enhancing clotting activity of postdelivery samples in activated partial thromboplastin time, prothrombin time, thrombin generation, and viscoelastic hemostatic assays, with CT-001 demonstrating greater activity. In conclusion, despite apparent ongoing consumption of coagulation factors at the time of delivery, thrombin output was maintained. Both rFVIIa and CT-001 enhanced the upregulated hemostatic activity in postdelivery samples, and consistent with previous studies comparing CT-001 and rFVIIa in vitro and in in vivo, CT-001 demonstrated greater activity than rFVIIa.
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Affiliation(s)
| | | | | | | | - Sul Lee
- Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea
| | - Terrence Allen
- Department of Anesthesiology, Duke University, Durham, NC
| | - Jennifer Gilner
- Department of Obstetrics and Gynecology, Duke University, Durham, NC
| | - Seung-Chul Kim
- Department of Obstetrics and Gynecology, Pusan National University School of Medicine, Busan, Republic of Korea
| | - Andra H. James
- Department of Obstetrics and Gynecology, Duke University, Durham, NC
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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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Pipe SW, Dunn AL, Young G. Efficacy and safety evaluation of eptacog beta (coagulation factor VIIa [recombinant]-jncw) for the treatment of hemophilia A and B with inhibitors. Expert Rev Hematol 2023; 16:715-729. [PMID: 37602448 DOI: 10.1080/17474086.2023.2248385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/26/2023] [Accepted: 08/11/2023] [Indexed: 08/22/2023]
Abstract
INTRODUCTION Bypassing agents (BPAs) are used to treat acute bleeding episodes, manage bleeding during perioperative care, and prophylactically minimize bleed occurrence in persons with hemophilia A or B with inhibitors (PwHABI). However, the effectiveness of BPAs that have been prescribed for the last several decades can be variable, motivating the development of a new recombinant activated factor VII, eptacog beta. AREAS COVERED This review covers key eptacog beta findings from phase 1b and phase 3 (PERSEPT) clinical trials, which formed the basis for its regulatory approval to treat PwHABI ages 12 and older. Descriptions of eptacog beta structure and glycosylation profile, mechanism of action, preclinical study results, and cost analyses are also presented. EXPERT OPINION PwHABI have had only two options for bleed treatment for the past several decades. With its distinct glycosylation profile, eptacog beta offers a novel therapy aiming to improve upon BPAs currently in use, providing an option with more than one dosing regimen and a rapid response that allows most bleeds to be treated with just one dose. This has become particularly important given the use of subcutaneous medications (e.g., emicizumab) for prophylaxis of bleeding. Clinicians should consider eptacog beta as a BPA for all PwHABI.
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Affiliation(s)
- Steven W Pipe
- Departments of Pediatrics and Pathology, University of Michigan, Ann Arbor, MI, USA
| | - Amy L Dunn
- Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Guy Young
- Department of Pediatrics, Children's Hospital Los Angeles, Los Angeles, CA, USA
- Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Peyvandi F, Kavakli K, El‐Beshlawy A, Rangarajan S. Management of haemophilia A with inhibitors: A regional cross-talk. Haemophilia 2022; 28:950-961. [PMID: 35868021 PMCID: PMC9796719 DOI: 10.1111/hae.14638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 07/04/2022] [Accepted: 07/09/2022] [Indexed: 01/07/2023]
Abstract
INTRODUCTION The development of inhibitors with factor VIII (FVIII) replacement therapy is one of the most common and challenging complications of haemophilia A (HA) treatment, jeopardising treatment efficacy and predisposing patients to high risks of morbidity and mortality. The management of patients with inhibitors is particularly challenging in countries where resources are limited. AIM To provide a comprehensive summary of the management of HA with inhibitors while focusing on differences in practice between Western and non-Western countries and how resource scarcity can impact HA management, leading to suboptimal outcomes in patients with inhibitors. METHODS Summary of key evidence and regional expert opinion. RESULTS We address, particularly, the diagnosis of and testing for inhibitors, as well as the epidemiology of inhibitors, including incidence, prevalence and disease burden. Secondly, we provide an overview of the current treatment landscape in HA with inhibitors regarding the eradication of inhibitors with immune tolerance induction and the treatment and prevention of bleeding with bypassing agents, non-factor replacement agents and other experimental therapies. This is complemented with insights from the authors around the applicability of, and challenges associated with, such therapies in their settings of practice. CONCLUSIONS We conclude by proposing some key steps towards bridging the gaps in the management of HA with inhibitors in resource-limited countries, including: (1) the collection of quality data that can inform healthcare reforms and policies; (2) improving disease knowledge among healthcare practitioners and patients with the aim of standardising disease management across centres and (3) working towards promoting equal access to HA care and therapies for everyone.
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Affiliation(s)
- Flora Peyvandi
- Angelo Bianchi Bonomi Hemophilia and Thrombosis CenterFondazione IRCCS Ca’ Granda Ospedale Maggiore PoliclinicoMilanItaly,Department of Pathophysiology and TransplantationUniversità degli Studi di MilanooMilanItaly
| | - Kaan Kavakli
- Department of Pediatric HematologyEge University Children's HospitalIzmirTurkey
| | - Amal El‐Beshlawy
- Department of Pediatric Hematology, Faculty of MedicineCairo UniversityCairoEgypt
| | - Savita Rangarajan
- Department of HaematologyUniversity Hospital Southampton NHS Foundation TrustSouthamptonUK,Clinical Trials and Research UnitKJ Somaiya Super Specialty Hospital and Research CentreMumbaiIndia
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Rehni AK, Cho S, Quero HN, Shukla V, Zhang Z, Dong C, Zhao W, Perez-Pinzon MA, Koch S, Jy W, Dave KR. Red Blood Cell Microparticles Limit Hematoma Growth in Intracerebral Hemorrhage. Stroke 2022; 53:3182-3191. [PMID: 36069183 PMCID: PMC9529820 DOI: 10.1161/strokeaha.122.039641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 07/06/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Spontaneous intracerebral hemorrhage (sICH) is the deadliest stroke subtype with no effective therapies. Limiting hematoma expansion is a promising therapeutic approach. Red blood cell-derived microparticles (RMPs) are novel hemostatic agents. Therefore, we studied the potential of RMPs in limiting hematoma growth and improving outcomes post-sICH. METHODS sICH was induced in rats by intrastriatal injection of collagenase. RMPs were prepared from human RBCs by high-pressure extrusion. Behavioral and hematoma/lesion volume assessment were done post-sICH. The optimal dose, dosing regimen, and therapeutic time window of RMP therapy required to limit hematoma growth post-sICH were determined. We also evaluated the effect of RMPs on long-term behavioral and histopathologic outcomes post-sICH. RESULTS RMP treatment limited hematoma growth following sICH. Hematoma volume (mm3) for vehicle- and RMP- (2.66×1010 particles/kg) treated group was 143±8 and 86±4, respectively. The optimal RMP dosing regimen that limits hematoma expansion was identified. RMPs limit hematoma volume when administered up to 4.5-hour post-sICH. Hematoma volume in the 4.5-hour post-sICH RMP treatment group was lower by 24% when compared with the control group. RMP treatment also improved long-term histopathologic and behavioral outcomes post-sICH. CONCLUSIONS Our results demonstrate that RMP therapy limits hematoma growth and improves outcomes post-sICH in a rodent model. Therefore, RMPs have the potential to limit hematoma growth in sICH patients.
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Affiliation(s)
- Ashish K. Rehni
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Sunjoo Cho
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Hever Navarro Quero
- The Wallace H Coulter Platelet Laboratory, Division of Hematology/Oncology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Vibha Shukla
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Zhexuan Zhang
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146
| | - Chuanhui Dong
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Weizhao Zhao
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL 33146
| | - Miguel A. Perez-Pinzon
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Sebastian Koch
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Wenche Jy
- The Wallace H Coulter Platelet Laboratory, Division of Hematology/Oncology, Department of Medicine, University of Miami Miller School of Medicine, Miami, Florida 33136
| | - Kunjan R. Dave
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Miller School of Medicine, Miami, Florida 33136
- Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida 33136
- Neuroscience Program, University of Miami Miller School of Medicine, Miami, Florida 33136
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Local pulmonary administration of factor VIIa (rFVIIa) in massive pulmonary haemorrhage in post-operative cardiac infant. Cardiol Young 2022; 33:835-837. [PMID: 36156187 DOI: 10.1017/s1047951122003006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Diffuse pulmonary haemorrhage is an ominous condition that has a high paediatric mortality rate. Recombinant activated factor VIIa (rFVIIa) is a powerful haemostatic agent which has been used intravenously in life-threatening haemorrhage in variety of conditions in which conventional medical or surgical therapy are unsuccessful. We report off-label successful use of endotracheal rFVIIa for massive life-threatening respiratory haemorrhage following aspiration and cardiopulmonary resuscitation in a 3-month-old infant who was anticoagulated with enoxaparin following corrective cardiac surgery with other comorbidities. Off-label administration of endotracheal rFVIIa permitted rapid safe control of massive pulmonary haemorrhage and prevented further detrimental decline in respiratory function with satisfactory outcome.
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CT-001 is a rapid clearing factor VIIa with enhanced clearance and hemostatic activity for the treatment of acute bleeding in non-hemophilia settings. Thromb Res 2022; 215:58-66. [DOI: 10.1016/j.thromres.2022.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/16/2022] [Indexed: 11/21/2022]
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Østerud B, Latysheva N, Schoergenhofer C, Jilma B, Hansen JB, Snir O. A rapid, sensitive, and specific assay to measure TF activity based on chromogenic determination of thrombin generation. J Thromb Haemost 2022; 20:866-876. [PMID: 34822223 DOI: 10.1111/jth.15606] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Accepted: 11/22/2021] [Indexed: 12/27/2022]
Abstract
BACKGROUND Most tissue factor (TF) activity assays are based on measurement of factor X (FX) activation by TF in the presence of factor VII (FVII)/FVIIa. This requires long incubation, which may result in TF-independent activity of FX and inaccurate measurement of TF activity. AIM To develop a sensitive and specific TF activity assay, which does not register a non-specific TF activity, using commercial coagulation factors. METHODS Tissue factor activity was measured based on the ability of TF to accelerate the activation of FX by FVIIa in the presence of factor V (FV)/Va, prothrombin, and phospholipids. Following 4 min incubation at 37°C, TF activity was quantified in test samples of different nature by thrombin generation using a chromogenic substrate. RESULTS The TF activity assay proved high sensitivity (low fM range) and specificity, assessed by neutralization of TF activity by anti-TF antibody and the use of FVIIai. TF activity was detected in extracellular vesicles (EVs) derived from HAP1-TF+cells, while no activity was measured in EVs from HAP1-TF/KO cells. The assay was applicable for measurement of TF activity on the surface of live endothelial cells and monocytes activated in vitro, and cell lysates. Infusion of low dose lipopolysaccharide (2 ng/kg bodyweight endotoxin) caused a transient 8-fold increase (peaked at 4 h) in TF activity in EVs isolated from plasma of healthy volunteers. CONCLUSION Our assay provides a fast, sensitive, and specific measurement of TF activity. It reliably quantifies TF activity on cell surface, cell lysate, and isolated EVs. The assay can be used for laboratory and clinical research.
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Affiliation(s)
- Bjarne Østerud
- Thrombosis Research Center (TREC), Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - Nadezhda Latysheva
- Thrombosis Research Center (TREC), Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | | | - Bernd Jilma
- Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria
| | - John-Bjarne Hansen
- Thrombosis Research Center (TREC), Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
- Division of Internal Medicine, University Hospital of North Norway, Tromsø, Norway
| | - Omri Snir
- Thrombosis Research Center (TREC), Department of Clinical Medicine, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
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Escobar M, Castaman G, Boix SB, Callaghan M, de Moerloose P, Ducore J, Hermans C, Journeycake J, Leissinger C, Luck J, Mahlangu J, Miesbach W, Mitha IH, Négrier C, Quon D, Recht M, Schved JF, Shapiro AD, Sidonio R, Srivastava A, Stasyshyn O, Vilchevska KV, Wang M, Young G, Alexander WA, Al-Sabbagh A, Bonzo D, Macie C, Wilkinson TA, Kessler C. The safety of activated eptacog beta in the management of bleeding episodes and perioperative haemostasis in adult and paediatric haemophilia patients with inhibitors. Haemophilia 2021; 27:921-931. [PMID: 34636112 PMCID: PMC9292935 DOI: 10.1111/hae.14419] [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: 04/13/2021] [Revised: 08/31/2021] [Accepted: 09/06/2021] [Indexed: 01/19/2023]
Abstract
Introduction Haemophilia patients with inhibitors often require a bypassing agent (BPA) for bleeding episode management. Eptacog beta (EB) is a new FDA‐approved recombinant activated human factor VII BPA for the treatment and control of bleeding in haemophilia A or B patients with inhibitors (≥12 years of age). We describe here the EB safety profile from the three prospective Phase 3 clinical trials performed to date. Aim To assess EB safety, immunogenicity and thrombotic potential in children and adults who received EB for treatment of bleeding and perioperative care. Methods Using a randomized crossover design, 27 subjects in PERSEPT 1 (12‐54 years) and 25 subjects in PERSEPT 2 (1‐11 years) treated bleeding episodes with 75 or 225 μg/kg EB initially followed by 75 μg/kg dosing at predefined intervals as determined by clinical response. Twelve PERSEPT 3 subjects (2‐56 years) received an initial preoperative infusion of 75 μg/kg (minor procedures) or 200 μg/kg EB (major surgeries) with subsequent 75 μg/kg doses administered intraoperatively and post‐operatively as indicated. Descriptive statistics were used for data analyses. Results Sixty subjects who received 3388 EB doses in three trials were evaluated. EB was well tolerated, with no allergic, hypersensitivity, anaphylactic or thrombotic events reported and no neutralizing anti‐EB antibodies detected. A death occurred during PERSEPT 3 and was determined to be unlikely related to EB treatment by the data monitoring committee. Conclusion Results from all three Phase 3 trials establish an excellent safety profile of EB in haemophilia A or B patients with inhibitors for treatment of bleeding and perioperative use.
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Affiliation(s)
- Miguel Escobar
- Gulf States Hemophilia and Thrombophilia Center, Houston, Texas, USA
| | - Giancarlo Castaman
- Center for Bleeding Disorders and Coagulation, Careggi University Hospital, Florence, Italy
| | | | | | | | - Jonathan Ducore
- Hematology/Oncology Clinic, University of California at Davis, Sacramento, California, USA
| | - Cédric Hermans
- Cliniques Saint-Luc, Université Catholique de Louvain, Brussels, Belgium
| | - Janna Journeycake
- Oklahoma Bleeding and Clotting Disorders Center at OU Health, Oklahoma City, Oklahoma, USA
| | - Cindy Leissinger
- Section of Hematology/Oncology, Tulane University School of Medicine, New Orleans, Louisiana, USA
| | - James Luck
- Orthopaedic Hemophilia Treatment Center, Los Angeles, California, USA
| | - Johnny Mahlangu
- Hemophilia Comprehensive Care Center, University of the Witwatersrand and National Health Laboratory Service, Johannesburg, South Africa
| | | | | | | | - Doris Quon
- Orthopaedic Hemophilia Treatment Center, Los Angeles, California, USA
| | - Michael Recht
- American Thrombosis and Hemostasis Network, Rochester, New York, USA.,Oregon Health & Science University, Portland, Oregon, USA
| | - Jean François Schved
- Haemophilia Treatment Centre, University Hospital Montpellier, Montpellier, France
| | - Amy D Shapiro
- Indiana Hemophilia and Thrombosis Center, Indianapolis, Indiana, USA
| | - Robert Sidonio
- Aflac Cancer and Blood Disorders Center, Emory University, Atlanta, Georgia, USA
| | | | | | | | - Michael Wang
- Hemophilia and Thrombosis Center, University of Colorado, Aurora, Colorado, USA
| | - Guy Young
- Children's Hospital Los Angeles, Los Angeles, California, USA.,Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | | | | | | | | | | | - Craig Kessler
- Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, District of Columbia, USA
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Tanaka K, Toyoda K. Clinical Strategies Against Early Hematoma Expansion Following Intracerebral Hemorrhage. Front Neurosci 2021; 15:677744. [PMID: 34526875 PMCID: PMC8435629 DOI: 10.3389/fnins.2021.677744] [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: 03/08/2021] [Accepted: 08/05/2021] [Indexed: 02/01/2023] Open
Abstract
Hematoma volume is the strongest predictor of morbidity and mortality after intracerebral hemorrhage. Protection against early hematoma growth is therefore the mainstay of therapeutic intervention for acute intracerebral hemorrhage, but the current armamentarium is restricted to early blood pressure lowering and emergent reversal for anticoagulant agents. Although intensive lowering of systolic blood pressure to <140 mmHg appears likely to prevent hematoma growth, two recent randomized trials, INTERACT-2 and ATACH-2, demonstrated non-significant trends of reduced hematoma enlargement by intensive blood pressure control, with only a small magnitude of benefit or no benefit for clinical outcomes. While oral anticoagulants can be immediately reversed by prothrombin complex concentrate, or the newly developed idarucizumab for direct thrombin inhibitor or andexanet for factor Xa inhibitors, the situation regarding reversal of antiplatelet agents is not yet quite as advanced. However, considering at most the approximately 10% rate of anticoagulant use among patients with intracerebral hemorrhage, what is most essential for patients with intracerebral hemorrhage in general is early hemostatic therapy. Tranexamic acid may safely reduce hematoma expansion, but its hemostatic effect was insufficient to be translated into improved functional outcomes in the TICH-2 randomized trial with 2,325 participants. In this context, recombinant activated factor VII (rFVIIa) is a candidate to be added to the armory against hematoma enlargement. The FAST, a phase 3 trial that compared doses of 80 and 20 μg/kg rFVIIa with placebo in 841 patients within 4 h after the stroke onset, showed a significant reduction in hematoma growth with rFVIIa treatment, but demonstrated no significant difference in the proportion of patients with severe disability or death. However, a post hoc analysis of the FAST trial suggested a benefit of rFVIIa in a target subgroup of younger patients without extensive bleeding at baseline when treated earlier after stroke onset. The FASTEST trial is now being prepared to determine this potential benefit of rFVIIa, reflecting the pressing need to develop therapeutic strategies against hematoma enlargement, a powerful but modifiable prognostic factor in patients with intracerebral hemorrhage.
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Affiliation(s)
- Kanta Tanaka
- Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Kazunori Toyoda
- Department of Cerebrovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Japan
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Factor VIIa is not just a factor X activator. Blood 2021; 137:3324-3325. [PMID: 34137849 DOI: 10.1182/blood.2021010839] [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] Open
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Abstract
Intracerebral hemorrhage is a stroke subtype with high mortality and poor functional outcome in survivors. Its main causes are hypertension, cerebral amyloid angiopathy, and anticoagulant treatment. Hematomas have a high frequency of expansion in the first hours after symptom onset, a process associated with neurologic deterioration and poor outcome. Control of severe hypertension, reversal of anticoagulant effect, and management of increased intracranial pressure are the mainstays of management of intracerebral hemorrhage in the acute phase. Surgical evacuation of the hematoma by conventional craniotomy does not improve outcomes, but minimally invasive techniques may be a valuable approach that deserves further evaluation.
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Affiliation(s)
- Carlos S Kase
- Department of Neurology, Emory University School of Medicine, Atlanta, GA, USA.
| | - Daniel F Hanley
- Division of Brain Injury Outcomes, Johns Hopkins University, Baltimore, MD, USA
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Abstract
STUDY DESIGN Case report. OBJECTIVE To summarize the clinical manifestations and treatment of Factor XI deficiency in a patient with cervical spondylotic myelopathy. SUMMARY OF BACKGROUND DATA Factor XI deficiency is a rare genetic bleeding disorder caused by reduced levels and insufficient activity of a coagulation factor XI. It is claimed to be associated with prominent bleeding in case of trauma and surgery irrelevant to the FXI level. This is the first ever case of a patient with factor XI deficiency with cervical spondylotic myelopathy. METHODS A case was investigated retrospectively and the relevant literature was reviewed. RESULTS A 66-year-old man with a 2-months history of lack of finger dexterity and gait disturbance was referred to our department. He did not have a history of bleeding or coagulation disorder nor did his family. Magnetic resonance imaging (MRI) of the cervical spine revealed spinal canal stenosis at C3/4 to C5/6 and intramedullary hyperintensity at C3/4 on the :T2 weighted image (T2WI). Preoperative examination revealed no abnormal findings but a severe prolonged activated partial-thromboplastin time (APTT) of 139.8 seconds. Coagulation factor activity assay revealed severe deficiency of factor XI (<0.1%). In accordance with hematologist's recommendation, four units of fresh frozen plasma (FFP) were transfused on the day before surgery and APTT assayed early morning on the day of surgery was 70.5 seconds. An additional four units of FFP were transfused during the surgery and APTT was 60 seconds. The postoperative course was uneventful and the patient was discharged on the postoperative day 14. CONCLUSION Factor XI deficiency patients may develop excessive bleeding after trauma or surgery. Preoperative examination with prolonged APTT should be pursued until a diagnosis of is made. Under diagnosis of Factor XI deficiency, meticulous attentions are required for perioperative bleeding management including postoperative hematoma in spinal surgery.Level of Evidence: 5.
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He S, Cao H, Thålin C, Svensson J, Blombäck M, Wallén H. The Clotting Trigger Is an Important Determinant for the Coagulation Pathway In Vivo or In Vitro-Inference from Data Review. Semin Thromb Hemost 2020; 47:63-73. [PMID: 33348413 DOI: 10.1055/s-0040-1718888] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
Blood coagulation comprises a series of enzymatic reactions leading to thrombin generation and fibrin formation. This process is commonly illustrated in a waterfall-like manner, referred to as the coagulation cascade. In vivo, this "cascade" is initiated through the tissue factor (TF) pathway, once subendothelial TF is exposed and bound to coagulation factor VII (FVII) in blood. In vitro, a diminutive concentration of recombinant TF (rTF) is used as a clotting trigger in various global hemostasis assays such as the calibrated automated thrombogram, methods that assess fibrin turbidity and fibrin viscoelasticity tests such as rotational thromboelastometry. These assays aim to mimic in vivo global coagulation, and are useful in assessing hyper-/hypocoagulable disorders or monitoring therapies with hemostatic agents. An excess of rTF, a sufficient amount of negatively charged surfaces, various concentrations of exogenous thrombin, recombinant activated FVII, or recombinant activated FIXa are also used to initiate activation of specific sub-processes of the coagulation cascade in vitro. These approaches offer important information on certain specific coagulation pathways, while alterations in pro-/anticoagulants not participating in these pathways remain undetectable by these methods. Reviewing available data, we sought to enhance our knowledge of how choice of clotting trigger affects the outcome of hemostasis assays, and address the call for further investigations on this topic.
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Affiliation(s)
- Shu He
- Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.,Division of Coagulation Research, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Honglie Cao
- Division of Coagulation Research, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Charlotte Thålin
- Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden
| | - Jan Svensson
- Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden
| | - Margareta Blombäck
- Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden.,Division of Coagulation Research, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - Håkan Wallén
- Department of Clinical Sciences, Karolinska Institutet, Danderyd Hospital, Stockholm, Sweden
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16
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Chang Z, Chu X, Liu Y, Liu D, Feng Z. Use of recombinant activated factor VII for the treatment of perioperative bleeding in noncardiac surgery patients without hemophilia: A systematic review and meta-analysis of randomized controlled trials. J Crit Care 2020; 62:164-171. [PMID: 33385773 DOI: 10.1016/j.jcrc.2020.12.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 12/06/2020] [Accepted: 12/12/2020] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the efficacy and safety of perioperative use of recombinant activated factor VII (rFVIIa) in noncardiac patients. MATERIALS AND METHODS We searched electronic databases for randomized controlled trials (RCTs) that involved the use of rFVIIa through December 13, 2019 in noncardiac patients without hemophilia. Two investigators extracted the related data and assessed the quality of the included trials. RESULTS Eleven RCTs examining 993 perioperative patients were ultimately included. The use of rFVIIa did not decrease all-cause mortality (RR:0.90; 95% CI:0.50,1.64; I2 = 0.0%; P = 0.738), shorten the length of ICU (SMD:-0.15; 95% CI:-0.47,0.17; I2 = 0.0%; P = 0.346) or hospital (SMD:0.42; 95% CI:-0.05,0.89; I2 = 0.0%; P = 0.078) stay, or increase incidence of the thromboembolic events (RR:1.30; 95% CI:0.70,2.41; I2 = 0.0%; P = 0.403) among perioperative patients. However, individual RCT analyses showed that the use of rFVIIa could reduce the volume of blood loss (including prostatic cancer, severe acute pancreatitis (SAP), and spinal disease) and the transfusion of RBCs (including prostatic cancer, SAP, and spinal disease) and FFP (SAP) in a subset of perioperative patients. Publication bias was not present. CONCLUSIONS For perioperative hemorrhagic patients, rFVIIa-based hemostatic therapy showed no effect on mortality, ICU or hospital LOS, or the rate of thromboembolic events, although it appears to decrease blood loss and reduce the need for blood product transfusion in a subset of patients.
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Affiliation(s)
- Zhigang Chang
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, 1(st) Dahua Rd, Dongcheng District, Beijing 100730, PR China.
| | - Xin Chu
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, 1(st) Dahua Rd, Dongcheng District, Beijing 100730, PR China
| | - Yalin Liu
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, 1(st) Dahua Rd, Dongcheng District, Beijing 100730, PR China
| | - Dadong Liu
- Department of Critical Care Medicine, Affiliated Hospital of Jiangsu University, 438 Jiefang Road, Zhenjiang, Jiangsu 212001, PR China
| | - Zhe Feng
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, 1(st) Dahua Rd, Dongcheng District, Beijing 100730, PR China
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17
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Chang ZG, Chu X, Chen W, Hu JH, Gong JW, Liu DD, He Q, Feng Z, Xiao SR, Liu YL. Use of Low-Dose Recombinant Factor Ⅶa for Uncontrolled Perioperative Bleeding. Dose Response 2020; 18:1559325820969569. [PMID: 33281510 PMCID: PMC7686627 DOI: 10.1177/1559325820969569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 09/25/2020] [Accepted: 10/07/2020] [Indexed: 11/16/2022] Open
Abstract
Background Recombinant activated factor VIIa (rFVIIa) is a prohemostatic agent initially approved for use in hemophilia patients and has also been used for a diverse range of off-label indications in the context of massive uncontrolled blood loss; however, no convincing evidence exists regarding the optimal dose of rFVIIa to treat uncontrolled bleeding in surgical patients. Aim To evaluate the effects and safety of a very low dose of rFⅦa in patients with uncontrolled perioperative bleeding in the surgical intensive care unit (ICU). Methods 55 patients from Beijing Hospital, who received rFⅦa between July 2004 and November 2018 for uncontrolled perioperative bleeding were included. The controls were matched for age, sex, severity, and operation type. The baseline demographics, survival, changes in bleeding and transfusion, coagulation parameters and complications were analyzed. Results A low dose of rFⅦa (2.0∼3.6 mg, with a median dose of 39.02 μg/kg) appears to be effective in controlling massive hemorrhage (with an effective rate of 74.55%), and can reduce volume of red blood cell transfusion, improve coagulation status, while has a relatively low risk of thromboembolic complications (3.6%). Conclusion In patients with uncontrolled perioperative bleeding, a low dose of rFⅦa could be used when traditional methods are ineffective.
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Affiliation(s)
- Zhi-Gang Chang
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Xin Chu
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Wen Chen
- School of Clinical Medicine, Tianjing Medical University, Tianjin, People's Republic of China
| | - Jun-Hua Hu
- Department of Transfusion, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Ji-Wu Gong
- Department of Transfusion, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Da-Dong Liu
- Department of Critical Care Medicine, Affiliated Hospital of Jiangsu University, Jiangsu, People's Republic of China
| | - Qing He
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Zhe Feng
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Shi-Rou Xiao
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
| | - Ya-Lin Liu
- Department of Surgical Intensive Care Medicine, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China
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18
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Østerud B. Commentary on "Therapeutic doses of recombinant factor VIIa in hemophilia generates thrombin in platelet-dependent and -independent mechanisms". J Thromb Haemost 2020; 18:1853-1854. [PMID: 32749057 DOI: 10.1111/jth.14877] [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: 04/21/2020] [Revised: 04/23/2020] [Accepted: 04/27/2020] [Indexed: 11/30/2022]
Affiliation(s)
- Bjarne Østerud
- K.G. Jebsen Thrombosis Research and Expertise Center (TREC), UiT The Arctic University of Norway, Tromsø, Norway
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19
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Keshava S, Pendurthi UR, Esmon CT, Rao LVM. Therapeutic doses of recombinant factor VIIa in hemophilia generates thrombin in platelet-dependent and -independent mechanisms. J Thromb Haemost 2020; 18:1911-1921. [PMID: 32359012 PMCID: PMC7415704 DOI: 10.1111/jth.14881] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 04/09/2020] [Accepted: 04/14/2020] [Indexed: 11/28/2022]
Abstract
BACKGROUND In hemophilia bypass therapy, a platelet-dependent mechanism is believed to be primarily responsible for recombinant factor VIIa (rFVIIa)'s hemostatic effect. rFVIIa may also possibly interact with other cells through its binding to endothelial cell protein C receptor (EPCR) or cell surface phospholipids. OBJECTIVES We aim to investigate the relative contribution of platelet-dependent and platelet-independent mechanisms in rFVIIa-mediated thrombin generation in hemophilic conditions at the injury site. METHODS Platelets were depleted in acquired and genetic hemophilia mice using anti-platelet antibodies. The mice were subjected to the saphenous vein injury, and the hemostatic effect of pharmacological concentrations of rFVIIa was evaluated by measuring thrombin generation at the injury site. RESULTS Administration of anti-mouse CD42 antibodies to mice depleted platelets by more than 95%. As expected, hemophilia mice, compared with wild-type mice, generated only a small fraction of thrombin at the injury site. The depletion of platelets in hemophilia mice further reduced thrombin generation. However, when pharmacological doses of rFVIIa were administered to hemophilia mice, substantial amounts of thrombin were generated even in the platelet-depleted hemophilia mice. No differences in thrombin generation were detected among FVIII-/- , EPCR-deficient FVIII-/- , and EPCR-overexpressing FVIII-/- mice depleted of platelets or not. Evaluation of platelets by flow cytometry as well as immunoblot analysis showed no detectable expression of EPCR. CONCLUSIONS Our data suggest that pharmacological concentrations of rFVIIa generate thrombin in hemophilia in both platelet-dependent and platelet-independent mechanisms.
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Affiliation(s)
- Shiva Keshava
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Texas, USA
| | - Usha R Pendurthi
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Texas, USA
| | - Charles T. Esmon
- Coagulation Biology Laboratory, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, USA
| | - L. Vijaya Mohan Rao
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Texas, USA
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20
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Schreuder M, Reitsma PH, Bos MHA. Reversal Agents for the Direct Factor Xa Inhibitors: Biochemical Mechanisms of Current and Newly Emerging Therapies. Semin Thromb Hemost 2020; 46:986-998. [DOI: 10.1055/s-0040-1709134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
AbstractThe direct oral anticoagulants targeting coagulation factor Xa or thrombin are widely used as alternatives to vitamin K antagonists in the management of venous thromboembolism and nonvalvular atrial fibrillation. In case of bleeding or emergency surgery, reversal agents are helpful to counteract the anticoagulant therapy and restore hemostasis. While idarucizumab has been established as an antidote for the direct thrombin inhibitor dabigatran, reversal strategies for the direct factor Xa inhibitors have been a focal point in clinical care over the past years. In the absence of specific reversal agents, the off-label use of (activated) prothrombin complex concentrate and recombinant factor VIIa have been suggested as effective treatment options during inhibitor-induced bleeding complications. Meanwhile, several specific reversal agents have been developed. In this review, an overview of the current state of nonspecific and specific reversal agents for the direct factor Xa inhibitors is provided, focusing on the biochemistry and mechanism of action and the preclinical assessment of newly emerging therapies.
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Affiliation(s)
- Mark Schreuder
- Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Pieter H. Reitsma
- Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
| | - Mettine H. A. Bos
- Division of Thrombosis and Hemostasis, Einthoven Laboratory for Vascular and Regenerative Medicine, Leiden University Medical Center, Leiden, The Netherlands
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21
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Sang Y, Roest M, de Laat B, de Groot PG, Huskens D. Interplay between platelets and coagulation. Blood Rev 2020; 46:100733. [PMID: 32682574 PMCID: PMC7354275 DOI: 10.1016/j.blre.2020.100733] [Citation(s) in RCA: 133] [Impact Index Per Article: 33.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 06/12/2020] [Accepted: 07/06/2020] [Indexed: 12/15/2022]
Abstract
Haemostasis stops bleeding at the site of vascular injury and maintains the integrity of blood vessels through clot formation. This regulated physiological process consists of complex interactions between endothelial cells, platelets, von Willebrand factor and coagulation factors. Haemostasis is initiated by a damaged vessel wall, followed with a rapid adhesion, activation and aggregation of platelets to the exposed subendothelial extracellular matrix. At the same time, coagulation factors aggregate on the procoagulant surface of activated platelets to consolidate the platelet plug by forming a mesh of cross-linked fibrin. Platelets and coagulation mutually influence each other and there are strong indications that, thanks to the interplay between platelets and coagulation, haemostasis is far more effective than the two processes separately. Clinically this is relevant because impaired interaction between platelets and coagulation may result in bleeding complications, while excessive platelet-coagulation interaction induces a high thrombotic risk. In this review, platelets, coagulation factors and the complex interaction between them will be discussed in detail.
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Affiliation(s)
- Yaqiu Sang
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands; Synapse Research Institute, Maastricht, the Netherlands
| | - Mark Roest
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands; Synapse Research Institute, Maastricht, the Netherlands
| | - Bas de Laat
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands; Synapse Research Institute, Maastricht, the Netherlands
| | | | - Dana Huskens
- Department of Biochemistry, Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Maastricht, the Netherlands; Synapse Research Institute, Maastricht, the Netherlands.
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22
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Zhao W, Wu C, Stone C, Ding Y, Ji X. Treatment of intracerebral hemorrhage: Current approaches and future directions. J Neurol Sci 2020; 416:117020. [PMID: 32711191 DOI: 10.1016/j.jns.2020.117020] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/25/2020] [Accepted: 07/07/2020] [Indexed: 12/20/2022]
Abstract
Intracerebral hemorrhage (ICH) stands out among strokes, both for the severely morbid outcomes it routinely produces, and for the striking deficiency of defenses possessed against the same. The brain damage caused by ICH proceeds through multiple pathophysiological mechanisms, broadly differentiated into those considered primary, arising from the hematoma itself, and the secondary consequences of hematoma presence and expansion thereof. A number of interventions against ICH and its sequelae have been investigated (e.g., hemostatic therapies, blood pressure control, hematoma evacuation, and a variety of neuroprotective strategies), but conclusive demonstrations of clinical benefit have remained largely elusive. In this review, we begin with a description of these interventions and the trials in which they have been implemented, coupled with an attempt to account for their failure. Possible causes discussed include iatrogenic injury during hematoma evacuation, secondary injury initiated by hematoma persistence after evacuation, and inadequate therapeutic power arising from an excessively narrow focus on a single component of the complex pathophysiology of ICH injury. To conclude, we propose several strategies, such as enhancing endogenous hematoma resolution, hematoma evacuation-based neuroprotection, and multi-targeted therapy, that hold promise as prospects for the extension of anti-ICH therapy into the domain of clinical significance.
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Affiliation(s)
- Wenbo Zhao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Key Laboratory of Hypoxic Conditioning Translational Medicine, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Chuanjie Wu
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Christopher Stone
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Yuchuan Ding
- Department of Neurosurgery, Wayne State University School of Medicine, Detroit, MI, USA
| | - Xunming Ji
- Department of Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China; Beijing Municipal Geriatric Medical Research Center, Beijing, China.
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23
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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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24
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Dejhansathit S, Suvannasankha A. Acquired Factor X Deficiency in Patients With Primary Light Chain Amyloidosis. J Investig Med High Impact Case Rep 2020; 7:2324709619832332. [PMID: 30947547 PMCID: PMC6452584 DOI: 10.1177/2324709619832332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Acquired factor X (FX) deficiency is a rare but serious complication of primary amyloidosis, presumably caused by the binding of amyloid proteins to the clotting factors. The prolonged prothrombin time, partial thromboplastin time, and low FX level, which are correctable by mixing study, are the disease hallmarks. An immediate goal of care is to stop bleeding. Clotting factor replacement requires close monitoring of coagulogram and FX levels due to varying FX clearance among patients. High-purity FX is currently approved for hereditary FX deficiency and has been successfully used in some acquired FX deficiency cases. Ongoing bleeding risk complicates the treatment decision. Novel therapies yielding rapid and deep response reduce amyloid protein production and improve long-term outcome.
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25
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Enoksson M, Martin EJ, Holmberg H, Jensen MS, Kjelgaard-Hansen M, Egebjerg T, Buchardt J, Krogh TN, Demuth H, Sanfridson A, Hilden I, Kjalke M, Brophy DF. Enhanced potency of recombinant factor VIIa with increased affinity to activated platelets. J Thromb Haemost 2020; 18:104-113. [PMID: 31549480 DOI: 10.1111/jth.14644] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 09/09/2019] [Accepted: 09/19/2019] [Indexed: 12/13/2022]
Abstract
BACKGROUND Recombinant factor VIIa (rFVIIa) enhances thrombin generation in a platelet-dependent manner; however, rFVIIa binds activated platelets with relatively low affinity. Triggering receptor expressed on myeloid cells (TREM)-like transcript (TLT)-1 is expressed exclusively on activated platelets. OBJECTIVE To enhance the potency of rFVIIa via binding TLT-1. METHODS Recombinant FVIIa was conjugated to a TLT-1 binding Fab. In vitro potency of this platelet-targeted rFVIIa (PT-rFVIIa) was evaluated using factor X activation assays and by measuring viscoelastic changes in whole blood. In vivo potency was evaluated using a tail vein transection model in F8-/- mice expressing human TLT-1. RESULTS PT-rFVIIa and rFVIIa had similar dissociation constant values for tissue factor binding and similar tissue factor-dependent factor X activation. However, PT-rFVIIa had increased catalytic efficiency on TLT-1-loaded vesicles and activated platelets. The in vitro potency in normal human blood with antibody-induced hemophilia A was dependent on assay conditions used; with maximally activated platelets, the half maximal effective concentration for clot time for PT-rFVIIa was 49-fold lower compared with rFVIIa. In the murine bleeding model, a 53-fold lower half maximal effective concentration was observed for blood loss for PT-rFVIIa, supporting the relevance of the assay conditions with maximally activated platelets. In vitro analysis of blood from subjects with hemophilia A confirmed the data obtained with normal blood. CONCLUSIONS Increasing the affinity of rFVIIa to activated platelets resulted in approximately 50-fold increased potency both in vitro and in the mouse model. The correlation of in vivo with in vitro data using maximally activated platelets supports that these assay conditions are relevant when evaluating platelet-targeted hemostatic concepts.
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Affiliation(s)
| | - Erika J Martin
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, USA
| | | | | | | | | | | | | | | | | | | | | | - Donald F Brophy
- Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University, Richmond, VA, USA
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26
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Ferrière S, Kawecki C, Ottavi JF, Denis CV, Kauskot A, Christophe OD, Lenting PJ. A single-domain antibody that blocks factor VIIa activity in the absence but not presence of tissue factor. J Thromb Haemost 2019; 17:2035-2046. [PMID: 31423724 DOI: 10.1111/jth.14615] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Accepted: 08/12/2019] [Indexed: 11/30/2022]
Abstract
BACKGROUND Activated factor VII (FVIIa) is pertinent to the initiation of blood coagulation. Proteolytic and amidolytic activity of FVIIa are greatly enhanced by its cofactor, tissue factor (TF). OBJECTIVE We aimed to generate a single-domain antibody (sdAb) that recognizes free FVIIa rather than TF-bound FVIIa. METHODS A llama-derived phage library was used to screen for anti-FVIIa sdAbs. RESULTS One sdAb, KB-FVIIa-004, bound to FVIIa, but not to its precursor FVII or to homologous proteins (prothrombin, factor X, or their activated derivatives). FVIIa amidolytic activity was inhibited by KB-FVIIa-004 (Ki = 28-45 nM) in a competitive manner. KB-FVIIa-004 also inhibited FVIIa-mediated FX activation (Ki = 26 nM). In contrast, KB-FVIIa-004 was inefficient in prolonging the clotting time of the prothrombin time-test, which was prolonged by a maximum of 10 s at high sdAb concentrations (10 μM). Furthermore, FVIIa/TF amidolytic activity or FVIIa/TF-mediated FX activation remained unaffected up to a 50-fold to 1000-fold molar excess of KB-FVIIa-004. These data suggest that KB-FVIIa-004 loses its inhibitory activity in the presence of TF. A KB-FVIIa-004/albumin fusion-protein (004-HSA) was generated for in vivo testing. By using 004-HSA, we observed that this sdAb blocked the therapeutic capacity of FVIIa to correct bleeding in FVIII-deficient mice. DISCUSSION This observation is compatible with the view that FVIIa functions independently of TF under these conditions. In conclusion, we have generated a sdAb that specifically blocks TF-independent activity of FVIIa. This antibody can be used to gain insight into the roles of TF-bound and TF-free FVIIa.
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Affiliation(s)
- Stephen Ferrière
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Charlotte Kawecki
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | | | - Cécile V Denis
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Alexandre Kauskot
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Olivier D Christophe
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - Peter J Lenting
- Laboratory of Hemostasis-Inflammation-Thrombosis, Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Univ. Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
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Meeks SL, Leissinger CA. The evolution of factor VIIa in the treatment of bleeding in haemophilia with inhibitors. Haemophilia 2019; 25:911-918. [PMID: 31489759 PMCID: PMC6899648 DOI: 10.1111/hae.13845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2019] [Revised: 08/07/2019] [Accepted: 08/19/2019] [Indexed: 01/19/2023]
Abstract
The use of activated factor VII (FVIIa) for the treatment of bleeding events in haemophilia patients with inhibitors was first reported over 30 years ago. Since then clinical trials, registries, case series, real‐world experience and an understanding of its mechanism of action have transformed what was originally a scientific curiosity into one of the major treatments for inhibitor patients, with innovative therapeutic regimens, dose optimization and individualized care now widely practiced. Given current understanding and use, it might be easy to forget the years of clinical research that led up to this point; in this review, we lay out changes based on broad eras of rFVIIa use. These eras cover the original uncertainty associated with dosing, efficacy and safety; the transformation of care ushered in with its widespread use; and the optimization and individualization of patient care and the importance of specialized support provided by haemophilia treatment centres. Today with the introduction of novel prophylactic agents such as emicizumab, we once again find ourselves dealing with the uncertainties of how best to utilize rFVIIa and newer investigational variants such as marzeptacog alfa and eptacog beta; we hope that the experiences of the past three decades will serve as a guide for this new era of care.
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Affiliation(s)
- Shannon L Meeks
- Department of Pediatrics, Aflac Cancer and Blood Disorders Center at Children's Healthcare of Atlanta, Emory University School of Medicine, Atlanta, GA, USA
| | - Cindy A Leissinger
- Section of Hematology/Oncology, Tulane University School of Medicine, New Orleans, LA, USA
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Nieuwland R, Gardiner C, Dignat‐George F, Mullier F, Mackman N, Woodhams B, Thaler J. Toward standardization of assays measuring extracellular vesicle-associated tissue factor activity. J Thromb Haemost 2019; 17:1261-1264. [PMID: 31231949 PMCID: PMC6851965 DOI: 10.1111/jth.14481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/06/2019] [Accepted: 05/02/2019] [Indexed: 11/30/2022]
Affiliation(s)
- Rienk Nieuwland
- Laboratory of Experimental Clinical Chemistry, and Vesicle Observation CentreAmsterdam UMCAcademic Medical CentreAmsterdamthe Netherlands
| | - Chris Gardiner
- Research Department of HaematologyHaemostasis ResearchUniversity College LondonLondonUK
| | | | - François Mullier
- Namur Thrombosis and Hemostasis CenterUniversité catholique de LouvainCHU UCL NamurYvoirBelgium
| | - Nigel Mackman
- University of North CarolinaChapel HillNorth Carolina
| | | | - Johannes Thaler
- Clinical Division of Haematology and HaemostaseologyDepartment of Medicine IMedical University of ViennaViennaAustria
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Efficacy and Safety of Recombinant Activated Factor VII Off-label Use in a Pediatric Hematology/Oncology Cohort. J Pediatr Hematol Oncol 2019; 41:e72-e78. [PMID: 30608491 DOI: 10.1097/mph.0000000000001379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
BACKGROUND Recombinant activated factor VII (rFVIIa) has been used off-label to treat or prevent severe bleeding in patients for whom conventional treatments are unsuccessful. However, studies in children remain limited. PROCEDURE To examine the efficacy and safety of rFVIIa, we performed a retrospective analysis of rFVIIa off-label use in a pediatric hematology/oncology cohort at a single center from 2006 to 2014. RESULTS Of 58 patients identified, 46 (79.3%) received rFVIIa to treat bleeding and 12 (20.7%) to prevent bleeding. Thirty-three (71.7%) patients had life-threatening bleeding. In the treatment group, 63.0% patients were responders (ie, bleeding decreased or stopped) and 37.0% were nonresponders (ie, bleeding did not change). Blood products usage was similar between responders and nonresponders. After rFVIIa administration, prothrombin time, partial thromboplastin time and lactate were significantly lower, but fibrinogen was significantly higher in responders than nonresponders. Venous thromboembolism developed in 5.2% (3/58) patients, but its relation to rFVIIa remains unclear. Responders had significantly lower mortality than nonresponders (17.2% vs. 82.4%, P<0.0001). CONCLUSIONS rFVIIa controlled most bleeding events in this cohort, despite predominance of life-threatening bleeding, suggesting good efficacy. Venous thromboembolism rate was low. Further studies are warranted to identify predictors of favorable response to rFVIIa in similar patients.
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Lauritzen B, Olling J, Abel KL, Augustsson C, Balling K, Bjelke M, Hegelund AC, Hilden I. Administration of recombinant FVIIa (rFVIIa) to concizumab-dosed monkeys is safe, and concizumab does not affect the potency of rFVIIa in hemophilic rabbits. J Thromb Haemost 2019; 17:460-469. [PMID: 30614620 DOI: 10.1111/jth.14380] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 01/19/2023]
Abstract
Essentials Hemophilia patients on concizumab prophylaxis may need rFVIIa to treat breakthrough bleeds. Effect and safety of concizumab + rFVIIa were tested in vitro and in vivo. Concizumab + rFVIIa had no additive effects on bleeding in hemophilic rabbits. High steady-state levels of concizumab did not affect the safety of rFVIIa in cynomolgus monkeys. SUMMARY: Background Concizumab is a monoclonal antibody (mAb) against tissue factor pathway inhibitor (TFPI), currently in clinical development as a subcutaneous prophylactic therapy for hemophilia A/B with and without inhibitors. In patients with inhibitors, the treatment choice for breakthrough bleeding will comprise bypassing agents, e.g. activated recombinant FVIIa (rFVIIa) or activated prothrombin complex concentrates. Objectives To explore the effect and safety of concizumab and rFVIIa when they are simultaneously present. Methods Human blood made hemophilic with a FVIII antibody was spiked with increasing concentrations of concizumab, rFVIIa, or concizumab and rFVIIa in combination, and this was followed by thrombin generation test or thromboelastography. Blood loss in hemophilic rabbits was measured when concizumab, rFVIIa or concizumab + rFVIIa was administered either before or during cuticle bleeding. In a safety study, cynomolgus monkeys were exposed to high steady-state concizumab concentrations and given three doses of rFVIIa, and then subjected to full necropsy and histopathological examination. Results In human blood, concizumab + rFVIIa had more pronounced procoagulant effects under hemophilic conditions than the sum of individual responses. In contrast, concizumab + rFVIIa had no additional effects on blood loss in hemophilic rabbits as compared with rFVIIa or concizumab alone. In cynomolgus monkeys, the macroscopic and microscopic pathological examinations revealed no thrombi or other signs of excessive coagulation activation. Both rFVIIa and concizumab caused increases in thrombin-antithrombin and D-dimer concentrations; this effect tended to be additive with concomitant administration. Conclusions Concizumab did not affect the potency or safety of rFVIIa in vivo. These results support a clinical evaluation of rFVIIa at standard dose (90 μg kg-1 ) to treat breakthrough bleeds in concizumab clinical trials.
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Affiliation(s)
| | - Janne Olling
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | | | | | - Mads Bjelke
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
| | | | - Ida Hilden
- Global Drug Discovery, Novo Nordisk A/S, Måløv, Denmark
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Faraoni D, DiNardo JA. Recombinant Activated Factor VII in Children Undergoing Cardiac Surgery: Remember How and Why to Use It. J Cardiothorac Vasc Anesth 2019; 33:1276-1278. [PMID: 30770180 DOI: 10.1053/j.jvca.2019.01.052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2019] [Indexed: 11/11/2022]
Affiliation(s)
- David Faraoni
- Division of Cardiac Anesthesia, Department of Anesthesia and Pain Medicine, The Hospital for Sick Children, University of Toronto, Toronto, Canada
| | - James A DiNardo
- Division of Cardiac Anesthesia, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA
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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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Rajpurkar M, Cooper DL. Continuous infusion of recombinant activated factor VII: a review of data in congenital hemophilia with inhibitors and congenital factor VII deficiency. J Blood Med 2018; 9:227-239. [PMID: 30568523 PMCID: PMC6276614 DOI: 10.2147/jbm.s184040] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Introduction Continuous infusion (CI) of clotting factors as a replacement therapy for perioperative hemostatic protection has been performed for many years, including with factors VIII and IX and recombinant activated factor VII (rFVIIa). This approach provides steady factor levels without requiring frequent administration of bolus doses. Aim To review safety, efficacy, and dosing data regarding CI of rFVIIa for hemostatic management of patients with congenital hemophilia with inhibitors (CHwI) or congenital factor VII deficiency (C7D). Materials and methods A literature review identified instances of CI of rFVIIa in patients with CHwI or C7D undergoing surgery or experiencing bleeding episodes. Data regarding safety, efficacy, and dosing were extracted. Results The safety and efficacy of 50 mcg/kg/h CI of rFVIIa following a 90 mcg/kg bolus injection, vs a standard bolus injection regimen, was reported for 24 patients with CHwI undergoing elective surgery in an open-label, randomized, Phase III trial. Efficacy was similar between CI and bolus injection groups at all postoperative time points assessed. Additionally, a postmarketing surveillance study reported effective (80%) and partially effective (20%) CI of rFVIIa in a Japanese cohort of ten patients with CHwI who underwent 15 surgical procedures. Finally, the safety and dosing of rFVIIa CI in 193 and 26 patients with CHwI and C7D, respectively, were reported in 11 prospective studies, 10 retrospective studies, and 30 case reports. No unexpected safety findings were reported. Conclusion rFVIIa CI has been performed safely and effectively in patients with CHwI and C7D undergoing surgery and during bleeding episodes in patients with CHwI.
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Affiliation(s)
- Madhvi Rajpurkar
- Division of Hematology/Oncology, Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, MI, USA,
| | - David L Cooper
- Clinical, Medical and Regulatory Affairs, Novo Nordisk Inc., Plainsboro, NJ, USA
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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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Affiliation(s)
- M Hoffman
- Duke University Medical Center, Durham Veterans Affairs Medical Center, Durham, NC, USA
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Fager AM, Machlus KR, Ezban M, Hoffman M. Human platelets express endothelial protein C receptor, which can be utilized to enhance localization of factor VIIa activity. J Thromb Haemost 2018; 16:1817-1829. [PMID: 29879294 PMCID: PMC6166658 DOI: 10.1111/jth.14165] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Indexed: 12/01/2022]
Abstract
Essentials Factor VIIa binds activated platelets to promote hemostasis in hemophilia patients with inhibitors. The interactions and sites responsible for platelet-FVIIa binding are not fully understood. Endothelial cell protein C receptor (EPCR) is expressed on activated human platelets. EPCR binding enhances the efficacy of a FVIIa variant and could impact design of new therapeutics. SUMMARY Background High-dose factor VIIa (FVIIa) is routinely used as an effective bypassing agent to treat hemophilia patients with inhibitory antibodies that compromise factor replacement. However, the mechanism by which FVIIa binds activated platelets to promote hemostasis is not fully understood. FVIIa-DVQ is an analog of FVIIa with enhanced tissue factor (TF)-independent activity and hemostatic efficacy relative to FVIIa. Our previous studies have shown that FVIIa-DVQ exhibits greater platelet binding, thereby suggesting that features in addition to lipid composition contribute to platelet-FVIIa interactions. Objectives Endothelial cell protein C receptor (EPCR) also functions as a receptor for FVIIa on endothelial cells. We therefore hypothesized that an interaction with EPCR might play a role in platelet-FVIIa binding. Methods/results In the present study, we used flow cytometric analyses to show that platelet binding of both FVIIa and FVIIa-DVQ is partially inhibited in the presence of excess protein C or an anti-EPCR antibody. This decreased binding results in a corresponding decrease in the activity of both molecules in FXa and thrombin generation assays. Enhanced binding to EPCR was sufficient to account for the increased platelet binding of FVIIa-DVQ compared with wild-type FVIIa. As EPCR protein expression has not previously been shown in platelets, we confirmed the presence of EPCR in platelets using immunofluorescence, flow cytometry, immunoprecipitation, and mass spectrometry. Conclusions This work represents the first demonstration that human platelets express EPCR and suggests that modulation of EPCR binding could be utilized to enhance the hemostatic efficacy of rationally designed FVIIa analogs.
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Affiliation(s)
- A M Fager
- Division of Hematology, Department of Medicine, Duke University School of Medicine, Durham, NC, USA
- Pathology and Laboratory Medicine Service, Durham Veterans Affairs Medical Center, Durham, NC, USA
| | - K R Machlus
- Division of Hematology, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - M Ezban
- Pharmacology, Novo Nordisk A/S, Måløv, Denmark
| | - M Hoffman
- Pathology and Laboratory Medicine Service, Durham Veterans Affairs Medical Center, Durham, NC, USA
- Department of Pathology, Duke University School of Medicine, Durham, NC, USA
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Ogiwara K, Shima M, Nogami K. Factor VIII activation by factor VIIa analog (V158D/E296V/M298Q) in tissue factor-independent mechanisms. Thromb Haemost 2017; 106:665-74. [DOI: 10.1160/th11-04-0264] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 07/18/2011] [Indexed: 11/05/2022]
Abstract
SummaryFactor (F)VIIa with tissue factor (TF) is a primary trigger of blood coagulation. The recombinant (r)FVIIa analog, NN1731 (V158D/E296V/ M298Q) containing a thrombin/FIXa-mimicking catalytic domain, is ~30-fold more effective on activated platelets without TF, but ~1.2-fold with TF, than rFVIIa for FX activation. We have recently demonstrated the FVIIa/TF-dependent FVIII activation in the early coagulation phase. We assessed the action of NN1731 on FVIII activation. NN1731/TF increased FVIII activity ~2.9-fold within 30 seconds, followed by rapid inactivation, and was slightly more active than rFVIIa/TF. NN1731-catalysed activation, however, was enhanced ~6-fold at 5 minutes (min), and its peak level persisted for ~30 min. NN1731/TF proteolysed FVIII at Arg740, Arg372, and Arg336, similar to rFVIIa/TF, but cleavage by NN1731 alone was much slower at Arg336 than at Arg740 and Arg372. The Km and Vmax for NN1731/TF-catalysed activation were ~1.8-fold lower and ~2.3-fold greater than rFVIIa/TF. The Km for NN1731 alone was ~1.3-fold lower than rFVIIa, whilst the Vmax was ~7.9-fold greater, indicating that the efficiency of FVIII activation by NN1731 and NN1731/TF was ~11- and ~4-fold greater, respectively, than equivalent reactions with rFVIIa. In SPR-based assays, NN1731 bound to FVIII and the heavy chain (Kd; 0.62 and 1.9 nM) with ~1.4- and ~3.1-fold higher affinity than rFVIIa, and the A2 domain contributed to this increase. Von Willebrand factor moderated NN1731-catalysed activation more significantly than NN1731/TF. In conclusion, NN1731 was a greater potential than rFVIIa in up-regulating FVIII activity, and the TF-independent FVIII activation might represent a potential extra mode of its enhanced haemostatic effect.
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Giansily-Blaizot M, Schved JF. Recombinant human factor VIIa (rFVIIa) in hemophilia: mode of action and evidence to date. Ther Adv Hematol 2017; 8:345-352. [PMID: 29204261 DOI: 10.1177/2040620717737701] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 09/11/2017] [Indexed: 11/17/2022] Open
Abstract
Recombinant activated factor VII (rFVIIa) is a bypassing agent widely used both in the treatment and prevention of hemorrhagic complications due to hemophilia with inhibitor. In such cases, antihemophilic factors cannot be used. The normal physiology of factor VII/ factor VIIa (FVII/FVIIa) in the hemostatic process requires the presence of tissue factor (TF) that links to FVII leading to a FVIIa-TF complex which activates both factor X and factor IX. The therapeutic use of rFVIIa requires high amount of FVIIa. Some studies demonstrate that FVIIa at high doses still requires tissue factor for function, whereas others suggest that FVIIa activates FX directly on the platelet surface, in a TF-independent manner. In the present article, we discuss the arguments supporting both TF-dependent and TF-independent modes of action. Finally, the coexistence of both TF-dependent and TF-independent mechanisms cannot be excluded.
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Affiliation(s)
| | - Jean-François Schved
- Hemophilia Treatment Centre, Hôpital Saint-Eloi, CHU Montpellier, 80 avenue A Fliche, 34295 Montpellier Cedex 5, France
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Li R, Panckeri KA, Fogarty PF, Cuker A, Diamond SL. Recombinant factor VIIa addition to haemophilic blood perfused over collagen/tissue factor can sufficiently bypass the factor IXa/VIIIa defect to rescue fibrin generation. Haemophilia 2017; 23:759-768. [PMID: 28475272 PMCID: PMC5623167 DOI: 10.1111/hae.13259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/28/2017] [Indexed: 11/30/2022]
Abstract
INTRODUCTION Factor VIII (FVIII) or factor IX (FIX)-deficient haemophilic patients display deficits in platelet and fibrin deposition under flow detectable in microfluidics. Compared to fibrin generation, decreased platelet deposition in haemophilic blood flow is more easily rescued with recombinant factor VIIa (rFVIIa), whereas rFVIIa requires FXIIa participation to generate fibrin when tissue factor (TF) is absent. AIMS Perfusion of haemophilic whole blood (WB) over collagen/TF surfaces was used to determine whether rFVIIa/TF was sufficient to bypass poor FIXa/FVIIIa function in blood from patients with haemophilia A and B. METHODS Whole blood treated with high-dose corn trypsin inhibitor (40 μg mL-1 ) from seven healthy donors and 10 patients was perfused over fibrillar collagen presenting low or high TF (TFlow or TFhigh ) at wall shear rate of 100 s-1 . RESULTS With WB from healthy controls, platelet deposition and fibrin accumulation increased as TF increased. Factor-deficient WB (1-3% of normal) displayed striking deficits in platelet deposition and fibrin formation at either TFlow or TFhigh . In contrast, mildly factor-deficient WB (14-32%) supported fibrin formation under flow on TFhigh /collagen. With either TFlow or TFhigh , exogenously added rFVIIa (20 nm) increased platelet deposition and fibrin accumulation in WB from factor-deficient patients (1-3% of normal) to levels commensurate with untreated healthy WB. CONCLUSION The absence of FIXa/FVIIIa in patients with severe haemophilia results in deficits in fibrin formation that cannot be rescued by wall-derived TF ex vivo. The effects of rFVIIa on platelet adhesion and rFVIIa/TF can act together to reinforce thrombin generation, platelet deposition and fibrin formation under flow.
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Affiliation(s)
- Ruizhi Li
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA. USA
| | - Karen A. Panckeri
- Comprehensive Hemophilia and Thrombosis Program, Hospital of the University of Pennsylvania, Philadelphia, PA. USA
| | - Patrick F. Fogarty
- Comprehensive Hemophilia and Thrombosis Program, Hospital of the University of Pennsylvania, Philadelphia, PA. USA
| | - Adam Cuker
- Comprehensive Hemophilia and Thrombosis Program, Hospital of the University of Pennsylvania, Philadelphia, PA. USA
| | - Scott L. Diamond
- Institute for Medicine and Engineering, Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, PA. USA
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Wang M, Lawrence JB, Quon DV, Ducore J, Simpson ML, Boggio LN, Mitchell IS, Yuan G, Alexander WA, Schved JF. PERSEPT 1: a phase 3 trial of activated eptacog beta for on-demand treatment of haemophilia inhibitor-related bleeding. Haemophilia 2017; 23:832-843. [DOI: 10.1111/hae.13301] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/05/2017] [Indexed: 01/19/2023]
Affiliation(s)
- M. Wang
- Hemophilia and Thrombosis Center; University of Colorado; Aurora CO USA
| | | | - D. V. Quon
- Orthopaedic Hemophilia Treatment Center; Orthopaedic Institute for Children; Los Angeles CA USA
| | - J. Ducore
- University of California, Davis; Comprehensive Cancer Center; Hematology/Oncology Clinic; Sacramento CA USA
| | | | | | | | - G. Yuan
- LFB USA Inc.; Framingham MA USA
| | | | - J.-F. Schved
- Département d'Hématologie Biologique; Hôpital Saint-Eloi; CHU Montpellier; Montpellier France
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Poon MC, Di Minno G, Zotz R, d’Oiron R. Glanzmann’s thrombasthenia: strategies for identification and management. Expert Opin Orphan Drugs 2017. [DOI: 10.1080/21678707.2017.1341306] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Man-Chiu Poon
- Cumming School of Medicine, University of Calgary, Calgary, Canada
- Southern Alberta Rare Blood and Bleeding Disorders Comprehensive Care Program, Foothills Medical Centre, Alberta Health Services, Calgary, Canada
| | - Giovanni Di Minno
- Department of Clinical Medicine and Surgery, Regional Reference Center for Coagulation Disorders, Federico II University, Naples, Italy
| | - Rainer Zotz
- Institute for Laboratory Medicine, Blood Coagulation and Transfusion Medicine (LBT), Düsseldorf, Germany
- Department of Haemostasis, Haemotherapy and Transfusion Medicine, Heinrich Heine University Medical Centre, D-40225 Düsseldorf, Germany
| | - Roseline d’Oiron
- Centre for Haemophilia and Rare Congenital Bleeding Disorders, University Hospitals Paris-Sud, Le Kremlin-Bicêtre, France
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Factor VIIa interaction with EPCR modulates the hemostatic effect of rFVIIa in hemophilia therapy: Mode of its action. Blood Adv 2017; 1:1206-1214. [PMID: 28932824 DOI: 10.1182/bloodadvances.2016004143] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Recent studies established that clotting factor VIIa (FVIIa) binds endothelial cell protein C receptor (EPCR). It has been speculated that FVIIa interaction with EPCR might augment the hemostatic effect of rFVIIa in therapeutic conditions. The present study is carried out to investigate the mechanism by which FVIIa interaction with EPCR contributes to the hemostatic effect of rFVIIa in hemophilia therapy. Active-site inhibited FVIIa, which is capable of binding to EPCR but has no ability to activate factor X, reduced the concentration of rFVIIa required to correct the bleeding following the saphenous vein injury in mouse hemophilia model systems. Higher doses of rFVIIa were required to restore hemostasis in EPCR overexpressing hemophilia mice compared to hemophilia mice expressing normal levels of EPCR. Administration of FVIII antibody induced only mild hemophilic bleeding in EPCR-deficient mice, which was corrected completely with a low dose of rFVIIa. Administration of therapeutic concentrations of rFVIIa increased plasma protein C levels in EPCR overexpressing mice, indicating the displacement of protein C from EPCR by rFVIIa. EPCR levels did not significantly alter the bioavailability of rFVIIa in plasma. Overall, our data indicate that EPCR levels influence the hemostatic effect of rFVIIa in treating hemophilia. Our present findings suggest that FVIIa displacement of anticoagulant protein C from EPCR that results in down-regulation of activated protein C generation and not the direct effect of EPCR-FVIIa on FX activation is the mechanism by which FVIIa interaction with EPCR contributes to the hemostatic effect of rFVIIa in hemophilia therapy.
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Management of the Jehovah's Witness in Obstetrics and Gynecology: A Comprehensive Medical, Ethical, and Legal Approach. Obstet Gynecol Surv 2017; 71:488-500. [PMID: 27526872 DOI: 10.1097/ogx.0000000000000343] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
IMPORTANCE Obstetricians and gynecologists frequently deal with hemorrhage so they should be familiar with management of patients who refuse blood transfusion. Although there are some reports in the literature about management of Jehovah's Witness patients in obstetrics and gynecology, most of them are case reports, and a comprehensive review about these patients including ethicolegal perspective is lacking. OBJECTIVE This review outlines the medical, ethical, and legal implications of management of Jehovah's Witness patients in obstetrical and gynecological settings. EVIDENCE ACQUISITION A search of published literature using PubMed, Ovid Medline, EMBASE, and Cochrane databases was conducted about physiology of oxygen delivery and response to tissue hypoxia, mortality rates at certain hemoglobin levels, medical management options for anemic patients who refuse blood transfusion, and ethical/legal considerations in Jehovah's Witness patients. RESULTS Early diagnosis of anemia and immediate initiation of therapy are essential in patients who refuse blood transfusion. Medical management options include iron supplementation and erythropoietin. There are also some promising therapies that are in development such as antihepcidin antibodies and hemoglobin-based oxygen carriers. Options to decrease blood loss include antifibrinolytics, desmopressin, recombinant factor VII, and factor concentrates. When surgery is the only option, every effort should be made to pursue minimally invasive approaches. CONCLUSION AND RELEVANCE All obstetricians and gynecologists should be familiar with alternatives and "less invasive" options for patients who refuse blood transfusions.
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Amiral J, Dunois C, Amiral C, Seghatchian J. The various assays for measuring activity states of factor VIIa in plasma and therapeutic products: Diagnostic value and analytical usefulness in various pathophysiological states. Transfus Apher Sci 2016; 56:91-97. [PMID: 28089408 DOI: 10.1016/j.transci.2016.12.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The key coagulation factor FVII, and its activated form FVIIa, present a major interest for their role at the initiation phase of blood coagulation, and because they can activate all blood coagulation cascade, through the extrinsic, but also the intrinsic pathway. Blood activation initiated through FVII is first presented, as it is understood nowadays. Measurement of FVII and FVIIa were of main interest for epidemiological studies, but FVIIa contribution to assay results was only deduced. The introduction of specific FVIIa assays, functional or immunoassays, allowed measuring directly FVIIa without any interference of non-activated FVII, or other coagulation factors or their activated forms. The various methods available, and their characteristics are presented, with a special focus on two assays developed by our group for FVIIa (a clotting one and a chromogenic one). The FVIIa clotting assay shows evident superiority for measuring its activity in plasma, in pathophysiological conditions. The normal range is <2.5ng/ml, which represents less than 0.5% of the FVII protein. FVIIa is elevated in some pathological states. The chromogenic assay is of interest for assigning the potency of FVIIa concentrates, as it has a higher dynamic range. Both assays are fully automatable on laboratory instruments, and standardized in a satisfactory manner thanks to the use of the FVIIa concentrate WHO International Standard (NIBSC). The various applications and usefulness of FVIIa laboratory assays are discussed, for the measurement of therapeutic products, or for following recoveries in treated patients, including hemophiliacs with inhibitors, patients with severe bleeding risk (liver diseases, surgery, trauma, …), and lastly for measurement of its activity in therapeutic products.
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Affiliation(s)
- Jean Amiral
- Hyphen BioMed, Sysmex Group, Neuville sur Oise, France.
| | - Claire Dunois
- Hyphen BioMed, Sysmex Group, Neuville sur Oise, France
| | - Cédric Amiral
- Hyphen BioMed, Sysmex Group, Neuville sur Oise, France
| | - Jerard Seghatchian
- International Consultancy in Blood Components Quality/Safety Improvement, Audit/Inspection and DDR Strategies, London, UK.
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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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Petros S. RETRACTED ARTICLE: Therapie mit Blutprodukten. Notf Rett Med 2016. [DOI: 10.1007/s10049-016-0242-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
It is possible that recombinant activated factor VII (rFVIIa) could revolutionize the medical and surgical management of haemorrhage following trauma due to its ease of administration and mechanism of action. This article reviews the evidence for the use of rFVIIa as a procoagulant, its mechanism of action and its potential role in blunt and penetrating trauma. The role of rFVIIa in the emergency room or operating theatre and in the pre-hospital environment is discussed. Administration of rFVIIa `at the roadside’ may have signifi cant potential implications, especially for the trauma surgeon and even for strategic planners. Finally, the areas where further research is needed to provide objective evidence of its effi cacy are elaborated.
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Affiliation(s)
- W Sapsford
- Biomedical Sciences, Defence Science and Technology Laboratory, Porton, Salisbury, Wiltshire, UK
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Amano K, Seita I, Higasa S, Sawada A, Kuwahara M, Shima M. Treatment of acute bleeding in acquired haemophilia A with recombinant activated factor VII: analysis of 10-year Japanese postmarketing surveillance data. Haemophilia 2016; 23:50-58. [DOI: 10.1111/hae.13033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2016] [Indexed: 01/29/2023]
Affiliation(s)
- K. Amano
- Tokyo Medical University; Tokyo Japan
| | - I. Seita
- Tokyo Medical University; Tokyo Japan
| | - S. Higasa
- Hyogo College of Medicine; Nishinomiya Japan
| | - A. Sawada
- Hyogo College of Medicine; Nishinomiya Japan
| | | | - M. Shima
- Nara Medical University; Kashihara Japan
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Bourti Y, Fazavana J, Armand M, Saller F, Lasne D, Borgel D, Bianchini EP. Inactivated antithrombins as fondaparinux antidotes: a promising alternative to haemostatic agents as assessed in vitro in a thrombin-generation assay. Thromb Haemost 2016; 116:452-60. [PMID: 27412396 DOI: 10.1160/th15-12-0927] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Accepted: 05/14/2016] [Indexed: 01/26/2023]
Abstract
In the absence of specific antidote to fondaparinux, two modified forms of antithrombin (AT), one recombinant inactive (ri-AT) and the other chemically inactivated (chi-AT), were designed to antagonise AT-mediated anticoagulants, e. g. heparins or fondaparinux. These inactive ATs were previously proven to effectively neutralise anticoagulant activity associated with heparin derivatives in vitro and in vivo, as assessed by direct measurement of anti-FXa activity. This study was undertaken to evaluate in vitro the effectivity of inactive ATs to reverse anticoagulation by heparin derivatives and to compare them with non-specific fondaparinux reversal agents, like recombinant-activated factor VII (rFVIIa) or activated prothrombin-complex concentrate (aPCC), in a thrombin-generation assay (TGA). Addition of fondaparinux (3 µg/ml) to normal plasma inhibited thrombin generation by prolonging lag time (LT) as much as 244 % and lowering endogenous thrombin potential (ETP) to 17 % of their control (normal plasma) values. Fondaparinux-anticoagulant activity was reversed by ri-AT and chi-AT, as reflected by the corrections of LT up to 117 % and 114 % of its control value, and ETP recovery to 78 % and 63 %, respectively. Unlike ri-AT that had no effect on thrombin generation in normal plasma, chi-AT retained anticoagulant activity that minimises its reversal capacity. However, both ATs were more effective than rFVIIa or aPCC at neutralising fondaparinux and, unlike non-specific antidotes, inactive ATs specifically reversed AT-mediated anticoagulant activities, as suggested by their absence of procoagulant activity in anticoagulant-free plasma.
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Affiliation(s)
| | | | | | | | | | | | - Elsa P Bianchini
- E. P. Bianchini, UMR-S1176, 80 rue du Général Leclerc, 94276 Le Kremlin-Bicêtre Cedex, France, Tel.: +33 1 49595646, Fax: +33 1 46719472, E-mail:
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Grounds RM, Seebach C, Knothe C, Paluszkiewicz P, Smith TS, Kasal E, Lecumberri R, Urbanec R, Haas T, Wujtewicz M, Rehorkova D, Pelichovska M, Lange M, Uranga M, Bosman R, Rommes JH, Koscielny J. Use of Recombinant Activated Factor VII (Novoseven) in Trauma and Surgery: Analysis of Outcomes Reported to an International Registry. J Intensive Care Med 2016; 21:27-39. [PMID: 16698742 DOI: 10.1177/0885066605285024] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The objective was to evaluate the efficacy and safety of recombinant activated factor VII in patients with massive bleeding. Forty-five patients with severe massive hemorrhage requiring= 14 transfusion units of packed red blood cells received recombinant activated factor VII. Postdrug blood loss and transfusion requirements were assessed, and mortality was compared with predicted outcomes. Blood loss was markedly reduced in 40 of 43 (93.0%) patients, and transfusion requirements decreased after recombinant activated factor VII administration. Mortality rate in trauma patients who had massive hemorrhage was significantly reduced compared with predictions using scoring systems. This may be associated with the use of recombinant activated factor VII. This study failed to demonstrate an improvement in surgical patients. The absence of concurrent controls prevents definitive conclusions regarding actual safety or efficacy of recombinant activated factor VII.
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Affiliation(s)
- R Michael Grounds
- Anaesthesia and Intensive Care Medicine, St George's Hospital, Tooting, London, UK.
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