1
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Nguyen GN, Lindgren JR, Seleme MC, Kafle S, Zander CB, Zheng XL, Sabatino DE. Altered cleavage of human factor VIII at the B-domain and acidic region 3 interface enhances expression after gene therapy in hemophilia A mice. J Thromb Haemost 2023; 21:2101-2113. [PMID: 37080538 PMCID: PMC11157168 DOI: 10.1016/j.jtha.2023.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/17/2023] [Accepted: 04/04/2023] [Indexed: 04/22/2023]
Abstract
BACKGROUND Variants of human factor VIII (hFVIII) have been developed to further understand the structure and function of hFVIII and improve gene-based therapeutics. We have previously characterized several hFVIII variants of the furin cleavage site (1645-1648) with improved secretion. We have also identified a second cleavage site in the acidic region 3 (a3) (1657-1658) that becomes the primary hFVIII intracellular cleavage position in the absence of the furin site. We tested a hypothesis that modification of this site may confer additional functional advantages to hFVIII. OBJECTIVES The aim of this study was to conduct the biochemical and functional characterization of hFVIII variants of the furin cleavage site, the a3 cleavage site, or in combination, both in vitro and in vivo after AAV mediated gene therapy. METHODS Recombinant hFVIII variants of the furin cleavage site (hFVIII-Δ3), the a3 cleavage site (hFVIII-S1657P/D1658E [SP/DE]), or in combination (hFVIII-Δ3-SP/DE) were purified and characterized in vitro and in vivo. RESULTS Recombinant hFVIII-Δ3, hFVIII-SP/DE, and hFVIII-Δ3-SP/DE variants all had comparable specific activity to B-domain deleted (BDD) hFVIII. Hemophilia A mice tolerant to hFVIII did not develop immune responses to hFVIII after protein challenge with these variants or after adeno-associated virus (AAV) delivery. Following AAV delivery, hFVIII-Δ3-SP/DE resulted in expression levels that were 2- to 5-fold higher than those with hFVIII-BDD in hemophilia A mice. CONCLUSION The novel hFVIII-Δ3-SP/DE variant of the furin and a3 cleavage sites significantly improved secretion compared with hFVIII-BDD. This key feature of the Δ3-SP/DE variant provides a unique strategy that can be combined with other approaches to further improve factor VIII expression to achieve superior efficacy in AAV-based gene therapy for hemophilia A.
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Affiliation(s)
- Giang N Nguyen
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Jonathan R Lindgren
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Maria C Seleme
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Samita Kafle
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Catherine B Zander
- Department of Pathology, University of Alabama at Birmingham School of Medicine, University of Alabama, Birmingham, Alabama, USA
| | - X Long Zheng
- Department of Pathology and Laboratory Medicine, The University of Kansas Medical Center, Kansas City, Kansas, USA; Institute of Reproductive Medicine and Developmental Science, The University of Kansas Medical Center, Kansas City, Kansas, USA
| | - Denise E Sabatino
- The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Pediatrics, Division of Hematology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Ivanciu L, Arruda VR, Camire RM. Factor IXa variants resistant to plasma inhibitors enhance clot formation in vivo. Blood 2023; 141:2022-2032. [PMID: 36724452 PMCID: PMC10163311 DOI: 10.1182/blood.2022018083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 12/28/2022] [Accepted: 01/13/2023] [Indexed: 02/03/2023] Open
Abstract
Factor IXa (FIXa) plays a pivotal role in coagulation by contributing to FX activation via the intrinsic pathway. Although antithrombin (AT) and other plasma inhibitors are thought to regulate FIXa procoagulant function, the impact of FIXa inhibition on thrombin generation and clot formation in vivo remains unclear. Here, we generated FIXa variants with altered reactivity to plasma inhibitors that target the FIXa active site but maintain procoagulant function when bound to its cofactor, FVIIIa. We found that selected FIXa variants (eg, FIXa-V16L) have a prolonged activity half-life in the plasma due, in part, to AT resistance. Studies using hemophilia B mice have shown that delayed FIXa inhibition has a major impact on reducing the bleeding phenotype and promoting thrombus formation following administration of FIX protein. Overall, these results demonstrate that the regulation of FIXa inhibition contributes in a major way to the spatial and temporal control of coagulation at the site of vascular injury. Our findings provide novel insights into the physiological regulation of FIXa, enhance our understanding of thrombus formation in vivo via the intrinsic pathway, and suggest that altering FIXa inhibition could have therapeutic benefits.
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Affiliation(s)
- Lacramioara Ivanciu
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Valder R. Arruda
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Rodney M. Camire
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, Children’s Hospital of Philadelphia, Philadelphia, PA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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3
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Liu W, Xue F, Fu R, Ding B, Li M, Sun T, Chen Y, Liu X, Ju M, Dai X, Wu Q, Zhou Z, Yu J, Wang X, Zhu Q, Zhou H, Yang R, Zhang L. Preclinical studies of a factor X activator and a phase 1 trial for hemophilia patients with inhibitors. J Thromb Haemost 2023; 21:1453-1465. [PMID: 36796484 DOI: 10.1016/j.jtha.2023.01.040] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 01/10/2023] [Accepted: 01/30/2023] [Indexed: 02/16/2023]
Abstract
BACKGROUND Bleeding episodes in hemophiliacs with inhibitors are difficult to control. Staidson protein-0601 (STSP-0601), a specific factor (F)X activator purified from the venom of Daboia russelii siamensis, has been developed. OBJECTIVES We aimed to investigate the efficacy and safety of STSP-0601 in preclinical and clinical studies. METHODS In vitro and in vivo preclinical studies were performed. A phase 1, first-in-human, multicenter, and open-label trial was conducted. The clinical study was divided into parts A and B. Hemophiliacs with inhibitors were eligible for this study. Patients received a single intravenous injection of STSP-0601 (0.01 U/kg, 0.04 U/kg, 0.08 U/kg, 0.16 U/kg, 0.32 U/kg, or 0.48 U/kg) in part A or a maximum of 6 4-hourly injections (0.16 U/kg) in part B. The primary endpoint for each part was the number of adverse events (AEs) from baseline to 168 hours after administration. This study was registered at clinicaltrials.gov (NCT-04747964 and NCT-05027230). RESULTS Preclinical studies showed that STSP-0601 could specifically activate FX in a dose-dependent manner. In the clinical study, 16 patients in part A and 7 patients in part B were enrolled. Eight (22.2%) AEs in part A and 18 (75.0%) AEs in part B were reported to be related to STSP-0601. Neither severe AEs nor dose-limiting toxicity events were reported. There were no thromboembolic event. The antidrug antibody of STSP-0601 was not detected. CONCLUSION Preclinical and clinical studies showed that STSP-0601 had a good ability to activate FX and had a good safety profile. STSP-0601 could be used as a hemostatic treatment in hemophiliacs with inhibitors.
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Affiliation(s)
- Wei Liu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Feng Xue
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Rongfeng Fu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Bingjie Ding
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Hemostasis and Thrombosis Diagnostic Engineering Research Center of Henan Province, Zhengzhou, China
| | - Mengjuan Li
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Hemostasis and Thrombosis Diagnostic Engineering Research Center of Henan Province, Zhengzhou, China
| | - Ting Sun
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Yunfei Chen
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Xiaofan Liu
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Mankai Ju
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Xinyue Dai
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China
| | - Quanrui Wu
- Staidson (Beijing) Biopharmaceuticals Co, Ltd, Beijing, China
| | - Zan Zhou
- Staidson (Beijing) Biopharmaceuticals Co, Ltd, Beijing, China
| | - Jiaojiao Yu
- Staidson (Beijing) Biopharmaceuticals Co, Ltd, Beijing, China
| | - Xiaomin Wang
- Staidson (Beijing) Biopharmaceuticals Co, Ltd, Beijing, China
| | - Qing Zhu
- Staidson (Beijing) Biopharmaceuticals Co, Ltd, Beijing, China
| | - Hu Zhou
- Department of Hematology, The Affiliated Cancer Hospital of Zhengzhou University & Henan Cancer Hospital, Hemostasis and Thrombosis Diagnostic Engineering Research Center of Henan Province, Zhengzhou, China.
| | - Renchi Yang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China.
| | - Lei Zhang
- State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Tianjin Key Laboratory of Gene Therapy for Blood Diseases, Chinese Academy of Medical Sciences Key Laboratory of Gene Therapy for Blood Diseases, Tianjin, China.
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4
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Camire RM. Blood coagulation factor X: molecular biology, inherited disease, and engineered therapeutics. J Thromb Thrombolysis 2021; 52:383-390. [PMID: 33886037 DOI: 10.1007/s11239-021-02456-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/13/2021] [Indexed: 12/19/2022]
Abstract
Blood coagulation factor X/Xa sits at a pivotal point in the coagulation cascade and has a role in each of the three major pathways (intrinsic, extrinsic and the common pathway). Due to this central position, it is an attractive therapeutic target to either enhance or dampen thrombin generation. In this brief review, I will summarize key developments in the molecular understanding of this critical clotting factor and discuss the molecular basis of FX deficiency, highlight difficulties in expressing recombinant factor X, and detail two factor X variants evaluated clinically.
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Affiliation(s)
- Rodney M Camire
- Division of Hematology and the Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA. .,Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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5
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Wang D, Shao X, Wang Q, Pan X, Dai Y, Yao S, Yin T, Wang Z, Zhu J, Xi X, Chen Z, Chen S, Zhang G. Activated factor X targeted stored in platelets as an effective gene therapy strategy for both hemophilia A and B. Clin Transl Med 2021; 11:e375. [PMID: 33783994 PMCID: PMC7989710 DOI: 10.1002/ctm2.375] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 03/08/2021] [Accepted: 03/15/2021] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND Treatment of hemophiliacs with inhibitors remains challenging, and new treatments are in urgent need. Coagulation factor X plays a critical role in the downstream of blood coagulation cascade, which could serve as a bypassing agent for hemophilia therapy. Base on platelet-targeted gene therapy for hemophilia by our and other groups, we hypothesized that activated factor X (FXa) targeted stored in platelets might be effective in treating hemophilia A (HA) and B (HB) with or without inhibitors. METHODS To achieve the storage of FXa in platelets, we constructed a FXa precursor and used the integrin αIIb promoter to control the targeted expression of FXa precursor in platelets. The expression cassette (2bFXa) was carried by lentivirus and introduced into mouse hematopoietic stem and progenitor cells (HSPCs), which were then transplanted into HA and HB mice. FXa expression and storage in platelets was examined in vitro and in vivo. We evaluated the therapeutic efficacy of platelet-stored FXa by tail bleeding assays and the thrombelastography. In addition, thrombotic risk was assessed in the recipient mice and the lipopolysaccharide induced inflammation mice. RESULTS By transplanting 2bFXa lentivirus-transduced HSPCs into HA and HB mice, FXa was observed stably stored in platelet α-granules, the stored FXa is releasable and functional upon platelet activation. The platelet-stored FXa can significantly ameliorate bleeding phenotype in HA and HB mice as well as the mice with inhibitors. Meanwhile, no FXa leakage in plasma and no signs of increased risk of hypercoagulability were found in transplantation recipients and lipopolysaccharide induced septicemia recipients. CONCLUSIONS Our proof-of-principle data indicated that target expression of the FXa precursor to platelets can generate a storage pool of FXa in platelet α-granules, the platelet-stored FXa is effective in treating HA and HB with inhibitors, suggesting that this could be a novel choice for hemophilia patients with inhibitors.
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Affiliation(s)
- Dawei Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
- National Research Center for Translational MedicineRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Xiaohu Shao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Qiang Wang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Xiaohong Pan
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Yujun Dai
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Shuxian Yao
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Tong Yin
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
- National Research Center for Translational MedicineRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Zhugang Wang
- Shanghai Research Center for Model OrganismsShanghaiChina
| | - Jiang Zhu
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Xiaodong Xi
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
| | - Zhu Chen
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
- National Research Center for Translational MedicineRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Saijuan Chen
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
- National Research Center for Translational MedicineRuijin Hospital Affiliated to Shanghai Jiao Tong University School of MedicineShanghaiChina
| | - Guowei Zhang
- State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated to Shanghai Jiao Tong University (SJTU) School of MedicineKey Laboratory of Systems Biomedicine of Ministry of Education, Shanghai Center for Systems BiomedicineSJTUShanghaiChina
- Key Laboratory of Aging and Cancer Biology of Zhejiang ProvinceDepartment of Basic Medical SciencesHangzhou Normal University School of MedicineHangzhouZhejiang ProvinceChina
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6
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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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7
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8
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Brake MA, Ivanciu L, Maroney SA, Martinez ND, Mast AE, Westrick RJ. Assessing Blood Clotting and Coagulation Factors in Mice. ACTA ACUST UNITED AC 2019; 9:e61. [PMID: 30875463 DOI: 10.1002/cpmo.61] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The mammalian blood coagulation system was designed to restrict blood loss due to injury as well as keep the blood fluid within the blood vessels of the organism. Blood coagulation activity in inbred mouse strains varies widely among strains, suggesting that many genomic variants affect hemostasis. Some of these molecules have been discovered and characterized; however, many are still unknown. Genetically modified mouse technologies are providing a plethora of new mouse models for investigating the regulation of blood coagulation. Here we provide a protocol for the tail bleeding time as a primary assessment of in vivo blood coagulation, as well as in vitro methods such as the prothrombin time, activated partial thromboplastin time, and thrombin generation assay. We also provide protocols for the assessment of the activities of specific known factors involved in blood coagulation. © 2019 by John Wiley & Sons, Inc.
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Affiliation(s)
- Marisa A Brake
- Department of Biological Sciences, Oakland University, Rochester, Michigan
| | - Lacramioara Ivanciu
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Divison of Hematology, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Susan A Maroney
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin
| | - Nicolas D Martinez
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin
| | - Alan E Mast
- Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin.,Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Randal J Westrick
- Department of Biological Sciences, Oakland University, Rochester, Michigan.,Center for Data Science and Big Data Analysis, Center for Biomedical Research, Oakland University, Rochester, Michigan
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9
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Novel therapeutics for hemophilia and other bleeding disorders. Blood 2018; 132:23-30. [DOI: 10.1182/blood-2017-09-743385] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Accepted: 04/17/2018] [Indexed: 11/20/2022] Open
Abstract
Abstract
Hemophilia and von Willebrand disease are the most common congenital bleeding disorders. Treatment of these disorders has focused on replacement of the missing coagulation factor to prevent or treat bleeding. New technologies and insights into hemostasis have driven the development of many promising new therapies for hemophilia and von Willebrand disease. Emerging bypass agents including zymogen-like factor IXa and Xa molecules are in development and a bispecific antibody, emicizumab, demonstrated efficacy in a phase 3 trial in people with hemophilia A and inhibitors. Tissue factor pathway inhibitor, the protein C/S system, and antithrombin are targets of novel compounds in development to alter the hemostatic balance and new approaches using modified factor VIII molecules are being tested for prevention and eradication of inhibitor antibodies in hemophilia A. The first recombinant von Willebrand factor (VWF) product has been approved and has unique VWF multimer content and does not contain factor VIII. These new approaches may offer better routes of administration, improved dosing regimens, and better efficacy for prevention and treatment of bleeding in congenital bleeding disorders.
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10
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Ragni MV. Novel alternate hemostatic agents for patients with inhibitors: beyond bypass therapy. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2017; 2017:605-609. [PMID: 29222310 PMCID: PMC6142579 DOI: 10.1182/asheducation-2017.1.605] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Inhibitor formation is among the most severe complications of hemophilia treatment. With a cumulative incidence of ∼30% in those with severe hemophilia A and ∼3% in those with severe hemophilia B, inhibitors are caused by a T-cell response directed against infused coagulation factor; these inhibitors neutralize factor VIII or IX activity and disrupt normal hemostasis. Inhibitor patients become unresponsive to standard factor treatment and, as an alternative, use bypass treatment (eg, recombinant factor VIIa or factor VIII inhibitor bypass activity). However, response to bypass agents is poorer and the burden of disease is higher, with greater morbidity, hospitalization, cost, and mortality, than in noninhibitor patients. Furthermore, inhibitor formation interferes with prophylaxis to prevent bleeding episodes and is a contraindication to gene therapy. Thus, more effective therapies for inhibitor patients are greatly needed. In the last several years, there has been an explosion of novel alternative hemostatic agents for hemophilia patients with and without inhibitors. These agents take advantage of technologic manipulation of coagulation factors and natural anticoagulants to promote hemostasis. The approaches include the following: (1) mutants or mimics of coagulation factors, rendering them resistant to natural anticoagulants; or (2) knock-down or disruption of natural anticoagulants, preventing degradation of coagulation factors. The purpose of this article was to review these novel alternative hemostatic agents and their mechanisms of action, as well as the preliminary pharmacokinetic, safety, and efficacy data available from early-phase clinical trials.
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Affiliation(s)
- Margaret V Ragni
- Department of Medicine, Division Hematology/Oncology, University of Pittsburgh, and Hemophilia Center of Western Pennsylvania, Pittsburgh, PA
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11
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Engineered factor Xa variants retain procoagulant activity independent of direct factor Xa inhibitors. Nat Commun 2017; 8:528. [PMID: 28904343 PMCID: PMC5597622 DOI: 10.1038/s41467-017-00647-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 07/17/2017] [Indexed: 01/02/2023] Open
Abstract
The absence of an adequate reversal strategy to prevent and stop potential life-threatening bleeding complications is a major drawback to the clinical use of the direct oral inhibitors of blood coagulation factor Xa. Here we show that specific modifications of the substrate-binding aromatic S4 subpocket within the factor Xa active site disrupt high-affinity engagement of the direct factor Xa inhibitors. These modifications either entail amino-acid substitution of S4 subsite residues Tyr99 and/or Phe174 (chymotrypsinogen numbering), or extension of the 99-loop that borders the S4 subsite. The latter modifications led to the engineering of a factor Xa variant that is able to support coagulation in human plasma spiked with (supra-)physiological concentrations of direct factor Xa inhibitors. As such, this factor Xa variant has the potential to be employed to bypass the direct factor Xa inhibitor-mediated anticoagulation in patients that require restoration of blood coagulation. A major drawback in the clinical use of the oral anticoagulants that directly inhibit factor Xa in order to prevent blood clot formation is the potential for life threatening bleeding events. Here the authors describe factor Xa variants that are refractory to inhibition by these anticoagulants and could serve as rescue agents in treated patients.
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12
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Abstract
PURPOSE OF REVIEW New therapies are needed to control bleeding in a range of clinical conditions. This review will discuss the biochemical properties of zymogen-like factor Xa, its preclinical assessment in different model systems, and future development prospects. RECENT FINDINGS Underlying many procoagulant therapeutic approaches is the rapid generation of thrombin to promote robust clot formation. Clinically tested prohemostatic agents (e.g., factor VIIa) can provide effective hemostasis to mitigate bleeding in hemophilia and other clinical situations. Over the past decade, we explored the possibility of using zymogen-like factor Xa variants to rapidly improve clot formation for the treatment of bleeding conditions. Compared to the wild-type enzyme, these variants adopt an altered, low activity, conformation which enables them to resist plasma protease inhibitors. However, zymogen-like factor Xa variants are conformationally dynamic and ligands such as its cofactor, factor Va, stabilize the molecule rescuing procoagulant activity. At the site of vascular injury, the variants in the presence of factor Va serve as effective prohemostatic agents. Preclinical data support their use to stop bleeding in a variety of clinical settings. Phase 1 studies suggest that zymogen-like factor Xa is safe and well tolerated, and a phase 1b is ongoing to assess safety in patients with intracerebral hemorrhage. SUMMARY Zymogen-like factor Xa is a unique prohemostatic agent for the treatment of a range of bleeding conditions.
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Affiliation(s)
- Nabil K Thalji
- Division of Hematology, Department of Pediatrics, The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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Parsons-Rich D, Hua F, Li G, Kantaridis C, Pittman DD, Arkin S. Phase 1 dose-escalating study to evaluate the safety, pharmacokinetics, and pharmacodynamics of a recombinant factor Xa variant (FXa I16L ). J Thromb Haemost 2017; 15:931-937. [PMID: 28294526 DOI: 10.1111/jth.13673] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Indexed: 11/28/2022]
Abstract
Essentials FXaI16L is a recombinant zymogen-like variant of activated coagulation factor X (FXa). A phase 1 dose escalation clinical trial of FXaI16L was conducted in healthy adults. FXaI16L was safe and tolerated at doses up to 5 μg/kg; no dose-limiting toxicity was observed. Data support further development of FXaI16L for patients with acute hemorrhagic conditions. SUMMARY Background FXaI16L (PF-05230907) is a zymogen-like variant of activated factor X (FXa). It shows enhanced resistance to inactivation by endogenous inhibitors as compared with wild-type FXa, and restores hemostatic activity in non-clinical models of various bleeding conditions. Objectives To evaluate the safety, pharmacokinetics and pharmacodynamics of FXaI16L by performing a phase 1, first-in-human, dose-escalation clinical trial in healthy adult volunteers. Methods Participants were assigned to one of six ascending single-dose cohorts (0.1, 0.3, 1, 2, 3 or 5 μg kg-1 ), each planned to comprise six volunteers treated with FXaI16L and two treated with placebo. Assessments included safety monitoring, pharmacokinetic and pharmacodynamic (PD) analyses, and immunogenicity testing. Results The trial enrolled 49 male volunteers. Administration of a single intravenous bolus dose of FXaI16L was safe and tolerated at all dose levels tested, with no dose-limiting toxicity or serious adverse events. FXaI16L plasma levels appeared to increase dose-proportionally, with a half-life of ~ 4 min. Treatment-related PD changes were observed for activated partial thromboplastin time, thrombin generation assay, thrombin-antithrombin complexes, prothrombin fragment 1 + 2, and D-dimer. One volunteer had a weak and transient non-neutralizing antidrug antibody response, which did not cross-react with native FX or native FXa. Conclusions FXaI16L was safe and tolerated, and showed a pharmacologic effect in healthy adults when administered at doses up to 5 μg kg-1 . The safety profile, pharmacokinetics and pharmacodynamics observed in this clinical trial support the further development of FXaI16L for hemostatic treatment in individuals with acute hemorrhagic conditions.
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Affiliation(s)
- D Parsons-Rich
- PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA
| | - F Hua
- PharmaTherapeutics Clinical Research, Pfizer Inc., Cambridge, MA, USA
| | - G Li
- PharmaTherapeutics Clinical Research, Pfizer Inc., Collegeville, PA, USA
| | - C Kantaridis
- Pfizer Clinical Research Unit, Pfizer Inc., Brussels, Belgium
| | - D D Pittman
- Rare Disease Research, Pfizer Inc., Cambridge, MA, USA
| | - S Arkin
- Rare Disease Research, Pfizer Inc., Cambridge, MA, USA
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Abstract
There is a clinical need to develop safe and rapid therapeutic strategies to control bleeding arising from a host of emergent situations. Over the past several years our laboratory has developed novel zymogen-like FXa variants and tested their safety and efficacy using hemophilia as a model system. The variants have a spectrum of properties resulting from an amino acid change at the N-terminus of the heavy chain that alters a critical conformational change. These properties, which include resistance to plasma protease inhibitors, low activity in the absence of FVa, and rescue of low activity upon incorporation in prothrombinase, yield remarkably effective pro-hemostatic agents. The FVa-dependent restoration of activity is a key aspect to their efficacy and also contributes to localizing the variants to the site of vascular injury. While pre-clinical data support their use in the setting of hemophilia, they have the potential to act as rapid pro-hemostatic agents for the treatment of a range of bleeding conditions. This review will discuss the biochemical properties of these FXa zymogen-like variants and their in vivo characterization.
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Affiliation(s)
- Rodney M Camire
- The Children's Hospital of Philadelphia, The Raymond G. Perelman Center for Cellular and Molecular Therapeutics, and Division of Hematology, Department of Pediatrics, The University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104.
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Ragni MV. New and Emerging Agents for the Treatment of Hemophilia: Focus on Extended Half-Life Recombinant Clotting Proteins. Drugs 2016; 75:1587-600. [PMID: 26310188 DOI: 10.1007/s40265-015-0451-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Hemophilia A and B are X-linked disorders caused by deficient or defective clotting factor VIII (FVIII) or IX factor (FIX) proteins, and characterized by spontaneous or traumatic bleeding into joints and muscles. Previous use of plasma and plasma-derived clotting factors that lacked appropriate viral inactivation steps in manufacturing led to significant morbidity associated with transfusion-transmitted HIV and hepatitis C virus (HCV). The development of recombinant proteins revolutionized their treatment, and, with no new HIV or HCV infection via clotting proteins for nearly 30 years, greatly improved their lifespan, which now approaches that of the general population, and with the same risks for aging complications. Novel long-acting factor proteins are being licensed to extend FVIII and FIX half-life, thereby reducing infusion frequency and potentially bleed frequency and associated morbidity. Further, novel therapeutics which take advantage of new technologies, including siRNA, monoclonal antibody, and small peptide inhibition technologies, have the potential to simplify treatment and improve outcomes for those with inhibitors.
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Affiliation(s)
- Margaret V Ragni
- Division Hematology/Oncology, Department of Medicine, Hemophilia Center of Western Pennsylvania, University of Pittsburgh, 3636 Boulevard of the Allies, Pittsburgh, PA, 15213-4306, USA.
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