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PubMed | French Atomic Energy Commission, University of Paris Descartes, University Paris - Sud and Endotis Pharma
Type: Journal Article | Journal: Organic & biomolecular chemistry | Year: 2016

Heparan Sulfate (HS) mimetics are able to block crucial interactions of the components of the extracellular matrix in angiogenic processes and as such, represent a valuable class of original candidates for cancer therapy. Here we first report the synthesis and in vitro angiogenic inhibition properties of a conjugated, novel and rationally-designed octasaccharide-based HS mimetic. We also herein report its labeling with fluorine-18 and present the preliminary in vivo Positron Emission Tomography imaging data in rats. This constitutes one of the rare examples of labeling and in vivo evaluation of a synthetic, polysaccharide-based, macromolecule.

Hechler B.,University of Strasbourg | Freund M.,University of Strasbourg | Alame G.,University of Strasbourg | Leguay C.,University of Strasbourg | And 4 more authors.
Journal of Pharmacology and Experimental Therapeutics | Year: 2011

EP224283 combines in a single molecule idraparinux and tirofiban, which allows obtaining a predictable and sustained antiplatelet effect through the transfer of the pharmacokinetics properties of idraparinux to the anti-αIIbβ3 antagonist. The activity can be instantaneously neutralized by injection of avidin, a specific antidote. We have tested the effects of this new profile anticoagulant in various thrombosis models. The antithrombotic effect of EP224283 was compared with those of the parent compounds used alone or in association at doses achieving low to moderate inhibition of platelet aggregation ex vivo. In a model of systemic thromboembolism independent of thrombin generation, tirofiban and EP224283 had similar effects at equimolar doses. On the other hand, EP224283 was more potent than tirofiban or idraparinux under thrombin-dependent conditions. In a ferric chloride-induced thrombosis model, EP224283 was more potent than either parent compound or their combination. Similar results were obtained after atherosclerotic plaque rupture in ApoE(-/-) mice. Thus, the dual action of EP224283 exceeds that of the parent compounds used in combination. A possible explanation is that EP224283 could concentrate antithrombin inside the thrombus by binding to αIIbβ3 through the tirofiban moiety, as shown by immunolabeling of the occluded vessel. No prolongation of the bleeding time was observed at doses achieving strong antithrombotic effects, suggesting that low to moderate αIIbβ3 inhibition combined with factor Xa inhibition minimizes the bleeding risk. The favorable antithrombotic profile of EP224283 together with its possible neutralization by avidin makes it an interesting drug candidate for the treatment and prevention of acute ischemic events. Copyright © 2011 by The American Society for Pharmacology and Experimental Therapeutics.

Alame G.,University of Strasbourg | Mangin P.H.,University of Strasbourg | Freund M.,University of Strasbourg | Riehl N.,University of Strasbourg | And 4 more authors.
Thrombosis and Haemostasis | Year: 2015

EP217609 is a new synthetic parenteral dual-action anticoagulant combining a direct thrombin inhibitor (α-NAPAP analog), an indirect factor Xa inhibitor (fondaparinux analog) and a biotin moiety allowing its neutralisation. EP217609 exhibited similar in vitro anticoagulant properties as its parent compounds. On the basis of dose-response curves, we identified low and moderate doses of EP217609 resulting in similar ex vivo prolongation of the APTT as α-NAPAP analog and comparable ex vivo anti-FXa activity as fondaparinux. The effects of EP217609 were compared to those of its parent compounds used alone or in combination in two models of experimental thrombosis induced by FeCl3 injury of the carotid artery or mechanical injury of atherosclerotic plaques in ApoE-deficient mice. When administered at low doses increasing the APTT by only 1.1 fold, EP217609 significantly reduced the thrombus area in both models as compared to α-NAPAP analog or fondaparinux alone, but not to the combination of these drugs. In contrast, at higher doses increasing the APTT 1.5 times, EP217609 was not superior to either parent compound. Low doses of EP217609 did not prolong the tail bleeding time or increase the volume of blood loss, although a tendency towards an increased blood loss was observed in five out of 12 mice. Finally, the effects of EP217609 could be neutralised in vivo by injection of avidin. The pharmacological profile of EP217609, its performance in arterial thrombosis models and its possible neutralisation make it an interesting molecule and a potential candidate as an antithrombotic drug. © Schattauer 2015.

Sapay N.,French National Center for Scientific Research | Cabannes E.,Endotis Pharma | Petitou M.,Endotis Pharma | Imberty A.,French National Center for Scientific Research
Biopolymers | Year: 2012

Heparan sulfate is abundantly present in the extracellular matrix. As other glycosaminoglycans, it is synthesized in the Golgi apparatus and then exposed on the cell surface. The glucuronidase activity of human heparanase plays a major role in the structural remodeling of the extracellular matrix, which underlies cell migration, hence tumor invasion. Heparanase is therefore a major target for anti-cancer treatment. Several inhibitors of its enzymatic activity have been synthesized. However, their design is limited by the absence of experimental structure of the protein. Homology modeling is proposed based on the structure of the endoxylanase from Penicillium simplicissimum co-crystallized with a series of xylan oligosaccharide. The new heparanase model is consistent with the few experimental data suited for the validation of such work. Furthermore, the presence of natural substrates in the template structure allowed us to propose a binding model for a hydrolyzed heparin sulfate pentasaccharide. Several lysine residues have been identified to play a key role in binding to the anionic polysaccharide substrate. In addition, two phenylalanine residues are also potentially important for the interaction with the substrate. The enzymatic mechanism investigated in the light of this new model allows for the proposal of several amino acids that can influence the protonation state of the nucleophile and the proton donor. Copyright © 2011 Wiley Periodicals, Inc.

Sapay N.,French National Center for Scientific Research | Cabannes E.,Endotis Pharma | Petitou M.,Endotis Pharma | Imberty A.,French National Center for Scientific Research
Glycobiology | Year: 2011

Heparan sulfate is a polysaccharide belonging to the glycaminoglycan family. It interacts with numerous proteins of the extracellular matrix, in particular cellular growth factors. The number of experimental protein-heparin sulfate complexes obtained by crystallography or nuclear magnetic resonance is limited. Alternatively, computational approaches can be employed. Generally, they restrain the conformation of the glycosidic rings and linkages in order to reduce the complexity of the problem. Modeling the interaction between protein and heparan sulfate is indeed challenging because of the large size of the fragment needed for a strong binding, the flexibility brought by the glycosidic rings and linkages and the high density of negative charges. We propose a two-step method based on molecular docking and molecular dynamics simulation. Molecular docking allows exploring the positioning of a rigid heparin sulfate fragment on the protein surface. Molecular dynamics refine selected docking models by explicitly representing solvent molecules and not restraining the polysaccharide backbone. The interaction of a hexamer of heparin sulfate was studied in interaction with fibroblast growth factor 2 and stromal cell-derived factor 1. This approach shed light on the plasticity of the growth factors interacting with heparan sulfate. This approach can be extended to the study of other protein/glycosaminoglycan complexes. © 2011 The Author.

Gueret P.,University Hospital Pontchaillou | Krezel C.,Endotis Pharma | Fuseau E.,EMF Consulting | van Giersbergen P.L.M.,Van Giersbergen Consulting | And 2 more authors.
Journal of Thrombosis and Haemostasis | Year: 2014

Background: EP42675 is a first-in-class, synthetic, parenteral, anticoagulant combining in a single molecule a direct thrombin inhibitor and an indirect factor Xa(FXa) inhibitor. Objectives: To investigate the safety, pharmacokinetics, and pharmacodynamics of EP42675 and its interaction with aspirin, clopidogrel, and unfractionated heparin (UFH). Subjects and Methods: In study 1, healthy male subjects were administered intravenously single-ascending doses (1-10 mg) of EP42675 or placebo. In study 2, healthy male subjects were administered intravenously a single dose of 5 mg EP42675 on day 1 followed by oral administration of aspirin (100 mg) and clopidogrel (75 mg) once daily from day 8 to 21. On day 15, a second dose of 5 mg EP42675 was administered, and subjects were then randomized to receive a single dose of UFH (30 or 60 IU kg-1) or placebo. Results and Conclusions: Mild bleedings were the only drug-related adverse events. EP42675 pharmacokinetics were dose-proportional and characterized by a low clearance, a small volume of distribution, a long terminal half-life. EP42675 pharmacodynamics were characterized by a long-lasting, dose-dependent increase in activated clotting time, ecarin clotting time, thrombin time, anti-FXa activity, activated partial thromboplastin time, prothrombin time, and a decrease in endogenous thrombin potential, measured by a thrombin generation test. Dose-dependent additive effects were seen with UFH on coagulation tests. EP42675 had no additive effect on the inhibition of platelet aggregation induced by aspirin and clopidogrel. These results warrant further clinical development of this new class of anticoagulant. © 2013 International Society on Thrombosis and Haemostasis.

El Hadri A.,Endotis Pharma | Petitou M.,Endotis Pharma
Chimia | Year: 2011

For a long time, heparin and low molecular weight heparins have been the drugs of choice for the management of thrombosis. Discovery of the antithrombin binding domain in heparin, a critical element in the anticoagulant activity of this polysaccharide, allowed a rational approach based on medicinal carbohydrate chemistry in the design of new anticoagulants. The fully synthetic pentasaccharide fondaparinux that selectively targets blood coagulation factor Xa was first to be developed as a drug. Fondaparinux was followed by various heparin mimicking oligosaccharides prepared with a view to replace polydisperse heparin and low molecular weight heparins by structurally-defined anticoagulants with no unwanted side-effects. © Schweizerische Chemische Gesellschaft.

Olson S.T.,University of Illinois at Chicago | Swanson R.,University of Illinois at Chicago | Petitou M.,Endotis Pharma
Blood | Year: 2012

EP217609 is a new dual-action parenteral anticoagulant that combines an indirect factor Xa inhibitor (fondaparinux analog) and a direct thrombin inhibitor (α-NAPAP analog) in a single molecule together with a biotin tag to allow avidin neutralization. EP217609 exhibits an unprecedented pharmacologic profile in showing high bioavailability, long plasma half-life, and potent antithrombotic activity in animals without the complications of thrombin rebound. Here we report the exceptional specificity and selectivity profile of EP217609. EP217609 inhibited thrombin with rapid kinetics (k on > 107M-1s-1), a high affinity (KI ∇ 30-40pM), and more than 1000-fold selectivity over other coagulation and fibrinolytic protease targets, comparing favorably with the best direct thrombin inhibitors known. EP217609 bound antithrombin with high affinity (KD ∇ 30nM) and activated the serpin to rapidly (kass ∼ 106M-1s-1) and selectively (> 20-fold) inhibit factor Xa. The dual inhibitor moieties of EP217609 acted largely independently with only modest linkage effects of ligand occupancy of one inhibitor moiety on the potency of the other (∼ 5-fold). In contrast, avidin binding effectively neutralized the potency of both inhibitor moieties (20- to 100-fold). These findings demonstrate the superior anticoagulant efficacy and rapid avidin neutralizability of EP217609 compared with anticoagulants that target thrombin or factor Xa alone. © 2012 by The American Society of Hematology.

PubMed | Van Giersbergen Consulting, University of Rennes 2 – Upper Brittany, EMF Consulting, University Hospital Cochin and Endotis Pharma
Type: Journal Article | Journal: European journal of clinical pharmacology | Year: 2016

EP217609 is a representative of a new class of synthetic parenteral anticoagulants with a dual mechanism of action. It combines in a single molecule a direct thrombin inhibitor and an indirect factor Xa inhibitor. EP217609 can be neutralized by a specific antidote avidin, which binds to the biotin moiety of EP217609.The primary objective was to assess the neutralization of EP217609 by avidin in healthy subjects. Secondary objectives were to define the optimal avidin monomer/EP217609 molar ratio to achieve an adequate neutralization of EP217609 and to assess the safety and tolerability of EP217609 and avidin.Healthy subjects (n=36) were randomized to a 3 by 3 replicated Latin square design between 3 EP217609 doses (4, 8, 12mg) and 3 avidin monomer/EP217609 molar ratios (1:1; 2:1; 3:1). EP217609 was administered as a single intravenous bolus, and avidin as a 30-min intravenous infusion, starting 90min after EP217609 administration.Overall, EP217609 and avidin were well tolerated. One subject experienced a benign and transient typical pseudo-allergic reaction. The administration of EP217609 resulted in dose-dependent increases in pharmacodynamic markers. Avidin triggered a rapid and irreversible neutralization of EP217609 without rebound effect. Adequate neutralization of the anticoagulant activity was achieved with both 2:1 and 3:1 avidin monomer/EP217609 molar ratios. All safety parameters did not show any treatment-emergent clinically relevant changes or abnormalities in any dose group.These results will allow further investigation in patients requiring a neutralizable anticoagulant as those undergoing cardiac surgery.EudraCT number 2010-020216-10.

PubMed | Van Giersbergen Consulting, University of Rennes 2 – Upper Brittany, EMF Consulting, University Hospital Cochin and Endotis Pharma
Type: Journal Article | Journal: European journal of clinical pharmacology | Year: 2016

EP217609 is a parenteral antithrombotic compound combining in one molecule an indirect anti-factor Xa inhibitor, a direct thrombin active site inhibitor and a biotin moiety.The aim of the study is to investigate the safety, pharmacokinetics and pharmacodynamics of single ascending intravenous doses of EP217609.In this randomised double-blind placebo-controlled study, healthy male subjects were administered intravenously single ascending doses (1, 3 or 10mg) of EP217609 or placebo. Each treatment group consisted of 10 subjects of whom 8 received EP217609 and 2 received placebo.All doses of EP217609 were well tolerated. A total of five treatment-emergent adverse events were reported, all considered unrelated, but no bleedings or other significant adverse events occurred during this study. In both plasma and urine, there was a strong correlation between EP217609 concentrations as measured by anti-factor IIa and Xa specific bioassays indicating that the two pharmacological activities of EP217609 did not dissociate in vivo. EP217609 pharmacokinetics were dose proportional and characterised by a low clearance, a small volume of distribution and a terminal half-life of 20.4h. The long half-life was reflected in long-lasting, dose-dependent effects on activated and ecarin clotting time, thrombin and prothrombin time, activated partial thromboplastin time, thrombin generation time and anti-factor Xa activity. Pharmacokinetic/pharmacodynamic modelling indicated that the concentration of EP217609 producing 50% of the pharmacodynamic effect was 3400 and 2210ng/mL for activated clotting time and anti-factor Xa activity, respectively. These results warranted further clinical development of EP217609. There is a limited number of neutralisable anticoagulants, particularly when rapid neutralisation is required. Synthetic anti-Xa compounds have predictable pharmacokinetic profiles. However, problems with thrombin rebound remain because of the inability to inhibit clot-bound thrombin. This manuscript provides a comprehensive investigation of the pharmacokinetics, pharmacodynamics and safety of EP217609, and the results were the basis of future clinical studies in both healthy subjects and patients. The pharmacokinetic/pharmacodynamic modelling provided information for dose selection in such future studies.

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