1
|
Larsen MS, Juul RV, Groth AV, Simonsson US, Kristensen AT, Knudsen T, Agersø H, Kreilgaard M. Prediction of human pharmacokinetics of activated recombinant factor VII and B-domain truncated factor VIII from animal population pharmacokinetic models of haemophilia. Eur J Pharm Sci 2018; 115:196-203. [DOI: 10.1016/j.ejps.2018.01.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 01/15/2018] [Accepted: 01/19/2018] [Indexed: 12/01/2022]
|
2
|
Fazavana JG, Muczynski V, Proulle V, Wohner N, Christophe OD, Lenting PJ, Denis CV. LDL receptor-related protein 1 contributes to the clearance of the activated factor VII-antithrombin complex. J Thromb Haemost 2016; 14:2458-2470. [PMID: 27614059 DOI: 10.1111/jth.13502] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/30/2016] [Indexed: 11/30/2022]
Abstract
Essentials Factor VIIa is cleared principally as a complex with antithrombin. Enzyme/serpin complexes are preferred ligands for the scavenger-receptor LRP1. Factor VIIa/antithrombin but not factor VIIa alone is a ligand for LRP1. Macrophage-expressed LRP1 contributes to the clearance of factor VIIa/antithrombin. SUMMARY Background Recent findings point to activated factor VII (FVIIa) being cleared predominantly (± 65% of the injected protein) as part of a complex with the serpin antithrombin. FVIIa-antithrombin complexes are targeted to hepatocytes and liver macrophages. Both cells lines abundantly express LDL receptor-related protein 1 (LRP1), a scavenger receptor mediating the clearance of protease-serpin complexes. Objectives To investigate whether FVIIa-antithrombin is a ligand for LRP1. Methods Binding of FVIIa and pre-formed FVIIa-antithrombin to purified LRP1 Fc-tagged cluster IV (rLRP1-cIV/Fc) and to human and murine macrophages was analyzed. FVIIa clearance was determined in macrophage LRP1 (macLRP1)-deficient mice. Results Solid-phase binding assays showed that FVIIa-antithrombin bound in a specific, dose-dependent and saturable manner to rLRP1-cIV/Fc. Competition experiments with human THP1 macrophages indicated that binding of FVIIa but not of FVIIa-antithrombin was reduced in the presence of annexin-V or anti-tissue factor antibodies, whereas binding of FVIIa-antithrombin but not FVIIa was inhibited by the LRP1-antagonist GST-RAP. Additional experiments revealed binding of both FVIIa and FVIIa-antithrombin to murine control macrophages. In contrast, no binding of FVIIa-antithrombin to macrophages derived from macLRP1-deficient mice could be detected. Clearance of FVIIa-antithrombin but not of active site-blocked FVIIa was delayed 1.5-fold (mean residence time of 3.3 ± 0.1 h versus 2.4 ± 0.2 h) in macLRP1-deficient mice. The circulatory presence of FVIIa was prolonged to a similar extent in macLRP1-deficient mice and in control mice. Conclusions Our data show that FVIIa-antithrombin but not FVIIa is a ligand for LRP1, and that LRP1 contributes to the clearance of FVIIa-antithrombin in vivo.
Collapse
Affiliation(s)
- J G Fazavana
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - V Muczynski
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - V Proulle
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
- Department of Biological Hematology, CHU Bicetre, Hôpitaux Universitaires Paris Sud, AP-HP, Paris, France
| | - N Wohner
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - O D Christophe
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - P J Lenting
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| | - C V Denis
- Institut National de la Santé et de la Recherche Médicale, UMR_S 1176, Universitaires Paris-Sud, Université Paris-Saclay, Le Kremlin-Bicêtre, France
| |
Collapse
|
3
|
Vatsyayan R, Kothari H, Mackman N, Pendurthi UR, Rao LVM. Inactivation of factor VIIa by antithrombin in vitro, ex vivo and in vivo: role of tissue factor and endothelial cell protein C receptor. PLoS One 2014; 9:e103505. [PMID: 25102166 PMCID: PMC4125150 DOI: 10.1371/journal.pone.0103505] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 06/30/2014] [Indexed: 11/19/2022] Open
Abstract
Recent studies have suggested that antithrombin (AT) could act as a significant physiologic regulator of FVIIa. However, in vitro studies showed that AT could inhibit FVIIa effectively only when it was bound to tissue factor (TF). Circulating blood is known to contain only traces of TF, at best. FVIIa also binds endothelial cell protein C receptor (EPCR), but the role of EPCR on FVIIa inactivation by AT is unknown. The present study was designed to investigate the role of TF and EPCR in inactivation of FVIIa by AT in vivo. Low human TF mice (low TF, ∼1% expression of the mouse TF level) and high human TF mice (HTF, ∼100% of the mouse TF level) were injected with human rFVIIa (120 µg kg−1 body weight) via the tail vein. At varying time intervals following rFVIIa administration, blood was collected to measure FVIIa-AT complex and rFVIIa antigen levels in the plasma. Despite the large difference in TF expression in the mice, HTF mice generated only 40–50% more of FVIIa-AT complex as compared to low TF mice. Increasing the concentration of TF in vivo in HTF mice by LPS injection increased the levels of FVIIa-AT complexes by about 25%. No significant differences were found in FVIIa-AT levels among wild-type, EPCR-deficient, and EPCR-overexpressing mice. The levels of FVIIa-AT complex formed in vitro and ex vivo were much lower than that was found in vivo. In summary, our results suggest that traces of TF that may be present in circulating blood or extravascular TF that is transiently exposed during normal vessel damage contributes to inactivation of FVIIa by AT in circulation. However, TF’s role in AT inactivation of FVIIa appears to be minor and other factor(s) present in plasma, on blood cells or vascular endothelium may play a predominant role in this process.
Collapse
Affiliation(s)
- Rit Vatsyayan
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Hema Kothari
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - Nigel Mackman
- Division of Hematology and Oncology, McAllister Heart Institute, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Usha R. Pendurthi
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
| | - L. Vijaya Mohan Rao
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, Texas, United States of America
- * E-mail:
| |
Collapse
|
4
|
Agersø H, Stennicke HR, Pelzer H, Olsen EN, Merricks EP, Defriess NA, Nichols TC, Ezban M. Pharmacokinetics and pharmacodynamics of turoctocog alfa and N8-GP in haemophilia A dogs. Haemophilia 2012; 18:941-7. [PMID: 22812621 PMCID: PMC3928143 DOI: 10.1111/j.1365-2516.2012.02896.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2012] [Indexed: 01/23/2023]
Abstract
The objective of the present study was to evaluate the pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the new recombinant FVIII compound turoctocog alfa and a Glyco-PEGylated FVIII derivative thereof (N8-GP) in Haemophilia A dogs. Six haemophilic dogs divided into two groups were included in the study. Each dog was administered a dose of 125 U kg(-1) , blood samples were collected at predetermined time points for both pharmacokinetic (FVIII measured by one-stage aPTT assay) and pharmacodynamic [whole blood clotting time (WBCT)] evaluations. After intravenous administration to haemophilic dogs, the plasma concentration at the first sampling point was comparable for turoctocog alfa and N8-GP, and the clearance was estimated to be 6.5 and 3.9 mL h(-1) kg(-1) for turoctocog alfa and N8-GP respectively. Both turoctocog alfa and N8-GP were able to reduce the WBCT time to normal levels (<20 min), however, the reduced clearance was reflected in the WBCT, which returned to baseline at a later time point for N8-GP as compared with dogs dosed with turoctocog alfa. The clearance was 40% reduced for N8-GP as compared with turoctocog alfa. Simulations of a multiple dosing regimen in dogs, suggest that to maintain WBCT <20 min N8-GP can be dosed at reduced intervals, e.g. with 4 days between doses, whereas turoctocog alfa will have to be dosed with 2½ day between doses. Data thereby supports N8-GP as an alternative to standard rFVIII replacement therapy, with a more convenient dosing regimen.
Collapse
Affiliation(s)
- H Agersø
- Biopharm Research Unit, Novo Nordisk A/S, Maaloev, Denmark.
| | | | | | | | | | | | | | | |
Collapse
|
5
|
Agersø H, Tranholm M. Pharmacokinetics and pharmacodynamics of rFVIIa and new improved bypassing agents for the treatment of haemophilia. Haemophilia 2012; 18 Suppl 5:6-10. [PMID: 22757678 DOI: 10.1111/j.1365-2516.2012.02886.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Animal models have played a critical role in developing our understanding of haemophilia and its treatment. For example, studies in mice and dogs have provided insights into the pharmacokinetics and pharmacodynamics of recombinant activated factor VII (rFVIIa). Such studies have shown that antithrombin has a significant impact on clearance of rFVIIa, which explains discrepancies between the antigen and activity half-lives of rFVIIa. Animal studies have also shown that the major clearance organs for rFVIIa are the liver and the kidneys, whereas distribution studies suggest that FVII and rFVIIa leave the circulation and enter the tissues, before returning to the circulation through the lymph. One agent that has benefited greatly from the use of animal models in its development is vatreptacog alfa, a new analogue of rFVIIa. Promising in vitro results, including increased generation of FXa, shortened clotting times and increased clot stability, were subsequently confirmed in animal models. In a severe tail-bleed model in FVIII knock-out mice, reduction in maximal blood loss was substantially greater with vatreptacog alfa than with rFVIIa, FVIII or plasma-derived activated prothrombin complex concentrate. In a mouse model of joint bleeding, rFVIIa and vatreptacog alfa significantly reduced bleeding compared with vehicle-treated haemophilic controls. More recently, a model of endothelial injury based on mouse cremaster muscle has been developed. Overall, animal models are a valuable tool in elucidating the haemostatic process and the effects of therapeutic agents, although direct extrapolation to the clinical setting should be done with caution.
Collapse
Affiliation(s)
- Henrik Agersø
- Biopharmaceuticals Research Unit, Novo Nordisk A/S, Måløv, Denmark
| | | |
Collapse
|
6
|
Gopalakrishnan R, Pendurthi UR, Hedner U, Agersø H, Esmon CT, Rao LVM. Influence of endothelial cell protein C receptor on plasma clearance of factor VIIa. J Thromb Haemost 2012; 10:971-3. [PMID: 22372829 PMCID: PMC3883585 DOI: 10.1111/j.1538-7836.2012.04670.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
7
|
Hoffman M. Hemostatic properties of the FVIIa analog NN1731. Thromb Res 2012; 129 Suppl 2:S49-50. [PMID: 22446168 DOI: 10.1016/j.thromres.2012.02.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Recombinant activated coagulation factor VII (rFVIIa) has proven to be a useful prohemostatic agent in patients with hemophilia and antibody inhibitors. It has also been used off-label in other settings. A major mechanism of its hemostatic efficacy is its ability to activate factor X on the surface of activated platelets in a tissue factor (TF)-independent manner. Novel analogs of FVIIa have been designed to have greater platelet-surface activity in the hope that these will be more active and reliable hemostatic agents. The analog NN1731 (vatreptacog alfa) was designed to have greater activity in the absence of TF, with the same substrate specificity as FVIIa. Surprisingly, it also binds to a greater number of sites on activated platelets by an, as yet, unknown mechanism. This molecule exhibits greater potency than FVIIa in biochemical assays, in vitro and animal models, and in early phase clinical trials.
Collapse
Affiliation(s)
- Maureane Hoffman
- Duke University and Durham Veterans Affairs Medical Centers, Pathology & Laboratory Medicine Svc, Durham, North Carolina 27705, USA.
| |
Collapse
|