sanorg-34006 and Thromboembolism

This study was designed to compare efficacy and safety among novel oral anticoagulants (NOACs), which have not been directly compared in randomized control trials to date.. We performed network meta-analyses of randomized control trials in preventing thromboembolic events and major bleeding in patients with atrial fibrillation. PubMed, Embase, and the Cochrane Database of Systematic Reviews for published studies and various registries of clinical trials for unpublished studies were searched for 2002-2013. All phase III randomized controlled trials (RCTs) of NOACs (apixaban, edoxaban, dabigatran, rivaroxaban), idraparinux, and ximelagatran were reviewed.. A systematic literature search identified nine phase III RCTs for primary analyses. The efficacy of each NOAC was similar with respect to our primary composite endpoint following adjustment for open label designs [odds ratios (ORs) versus vitamin K antagonists: apixaban 0.79; dabigatran 150mg 0.77; edoxaban 60mg 0.87; rivaroxaban 0.86] except for dabigatran 110mg and edoxaban 30mg. Apixaban and edoxaban 30mg and 60mg had significantly fewer major bleeding events than dabigatran 150mg, ricvaroxaban, and vitamin K antagonists. All NOACs were similar in reducing secondary endpoints with the exception of dabigatran 110mg and 150mg which were associated with a significantly greater incidence of myocardial infarction compared to apixaban, edoxaban 60mg, and rivaroxaban.. Our indirect comparison with adjustment for study design suggests that the efficacy of the examined NOACs is similar across drugs, but that some differences in safety and risk of myocardial infarction exist, and that open label study designs appear to overestimate safety and treatment efficacy. Differences in study design should be taken into account in the interpretation of results from RCTs of NOACs.

Topics: Administration, Oral; Aged; Aged, 80 and over; Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Dabigatran; Hemorrhage; Humans; Myocardial Infarction; Odds Ratio; Oligosaccharides; Pyrazoles; Pyridines; Pyridones; Randomized Controlled Trials as Topic; Rivaroxaban; Stroke; Thiazoles; Thromboembolism; Treatment Outcome; Vitamin K

As the population ages, the burden of thromboembolic disease increases. The development of new anticoagulants that overcome the shortcomings of the vitamin K antagonists represents an important advance.Clinical evaluation of new anticoagulants typically begins in short-term indications, such as prophylaxis against venous thromboembolism in patients undergoing orthopaedic surgery, followed by investigation in chronic conditions, such as stroke prevention in patients with atrial fibrillation. Factors for consideration in clinical trials include methodological issues (blinded versus open-label; active-control statistical designs; patient selection, etc.). Despite its subsequent withdrawal, clinical trials of ximelagatran demonstrated the efficacy of fixed doses of an oral, direct thrombin inhibitor for prevention of thromboembolism. Direct and indirect inhibition of activated Factor X is another target for new anticoagulants. Evidence-based data from trials such as these will pave the way for new anticoagulants, with the goal of bringing optimum prophylactic therapy to those requiring anticoagulation.

Topics: Anticoagulants; Azetidines; Benzimidazoles; Benzylamines; Clinical Trials as Topic; Dabigatran; Drugs, Investigational; Humans; Oligosaccharides; Pyridines; Thromboembolism; United States

Idraparinux is a synthetic pentasaccharide that binds to antithrombin with high affinity. In view of its long half-life, it is suitable for once-a-week administration.. To review the evidence favoring the use of idraparinux for the acute and long-term treatment of patients with venous thromboembolism (VTE) and for the prevention of thromboembolic events in patients with atrial fibrillation (AF).. All preclinical and clinical studies carried out with the use of idraparinux were sought through electronic searches of MEDLINE from January 1, 1999 up to December 31, 2007.. The administration of idraparinux in subcutaneous fixed doses of 2.5 mg once weekly was found to be as effective and safe as conventional antithrombotic therapy in the initial treatment of patients with deep vein thrombosis, but less effective than standard therapy in the initial treatment of patients with primary pulmonary embolism. During a 6-month extension of thromboprophylaxis, idraparinux was effective in preventing recurrent VTE but was associated with an increased risk of bleeding versus placebo. Finally, in patients with AF the long-term treatment with idraparinux was as effective as vitamin K antagonists, but caused more bleeding.. In its current formulation, idraparinux can be recommended only for the initial treatment of patients with deep vein thrombosis. The bioequipotency of a biotinylated version of idraparinux (idrabiotaparinux), whose effects can be reversed by a neutralizing agent (avidin), is under investigation in the treatment of VTE at present, as is the use of lower doses in patients with AF.

Topics: Animals; Antithrombins; Atrial Fibrillation; Clinical Trials as Topic; Drug Administration Schedule; Drug Evaluation; Fibrinolytic Agents; Half-Life; Humans; Oligosaccharides; Protein Binding; Thromboembolism

Atrial fibrillation is the most common sustained arrhythmia in clinical practice and is associated to thromboembolic complications. Anticoagulation with vitamin K antagonists is clearly useful to reduce the incidence of emboli, but associated with important limitations. Therefore, there is an active search for medications that are more effective and simpler to prescribe and manage. Synthetic pentasaccharides of heparin such as idraparinux for parenteral use, showed promising results. Direct inhibitors of thrombin were also useful for the prevention of thromboembolism. However, they were withdrawn from the market due to potentially fatal adverse reactions. Other area of investigation has been the effectiveness of the combination of antiplatelet agents such as aspirin and clopidrogel. Although this combination is attractive, results of clinical trials must be awaited to have an opinion about its real usefulness. Finally, left atrial appendage transcatheter occlusion (PLAATO) is an effective and reasonably safe method for patients with contraindications for anticoagulation or those that continue to embolize despite well prescribed anticoagulation. The long term results of this intervention must also be awaited.

Topics: Anticoagulants; Atrial Fibrillation; Controlled Clinical Trials as Topic; Heparin; Humans; Multicenter Studies as Topic; Oligosaccharides; Platelet Aggregation Inhibitors; Thrombin; Thromboembolism

Shortcomings of the existing anticoagulants, vitamin K antagonists and heparins, have led to the development of newer anticoagulant therapies. In particular, Vitamin K antagonists' slow onset of action, numerous drug interactions, narrow therapeutic window and need for frequent monitoring make it the most obvious target for replacement. Targeting specific coagulation enzymes or steps in the coagulation pathway, new anticoagulants have been or are under evaluation in clinical trials for a number of clinical indications, namely the prevention and treatment of venous thromboembolism, the prevention of ischemic stroke in patients with atrial fibrillation, and in acute coronary syndromes. Following a brief review of pharmacological aspects, this article will summarize the results of Phase III clinical trials evaluating the novel anticoagulants fondaparinux, ximelagatran and idraparinux. At present, most attention is directed at developing an oral anticoagulant to replace vitamin K antagonists for prevention of systemic thromboembolism. A number of newer agents are in both early and advanced stages of investigation.

Topics: Anticoagulants; Atrial Fibrillation; Azetidines; Benzylamines; Clinical Trials, Phase III as Topic; Fondaparinux; Humans; Oligosaccharides; Polysaccharides; Thromboembolism; Thrombosis; Venous Thrombosis

Novel anticoagulants to replace unfractionated heparins, low molecular weight heparins and vitamin K antagonists, are needed urgently. Coagulation factor Xa is an attractive target for drug development because of its position at the convergence of the intrinsic and extrinsic clotting pathways. There are two differing strategies of inhibiting factor Xa that are being pursued: indirect inhibition by compounds such as fondaparinux and idraparinux, requiring antithrombin as a cofactor; and direct inhibition by compounds such as rivaroxaban (BAY 597939), DX-9065a, otamixaban, LY517717 and YM150. Of these compounds, fondaparinux is approved for the prevention and treatment of venous thromboembolism, and idraparinux is in Phase III for venous thromboembolism treatment and stroke prevention in patients with atrial fibrillation. Rivaroxaban has undergone extensive Phase II studies for venous thromboembolism prevention after orthopaedic surgery, and Phase III studies have begun. In this review, we will discuss the pharmacological effects of factor Xa inhibitors and the latest clinical developments.

Topics: Administration, Oral; Animals; Anticoagulants; Blood Coagulation; Blood Coagulation Tests; Factor Xa; Factor Xa Inhibitors; Fondaparinux; Humans; Injections, Intravenous; Injections, Subcutaneous; Morpholines; Naphthalenes; Oligosaccharides; Polysaccharides; Propionates; Randomized Controlled Trials as Topic; Rivaroxaban; Thiophenes; Thromboembolism

Anticoagulant therapy is the cornerstone of treatment of venous thromboembolism (VTE). Such treatment is divided into two stages. Rapid initial anticoagulation is given to minimize the risk of thrombus extension and fatal pulmonary embolism, whereas extended anticoagulation is aimed at preventing recurrent VTE, thereby reducing the risk of postphlebitic syndrome. With currently available drugs, immediate anticoagulation can only be achieved with parenteral agents, such as heparin, low-molecular-weight heparin, or fondaparinux. Extended treatment usually involves the administration of vitamin K antagonists, such as warfarin. Emerging anticoagulants have the potential to streamline VTE treatment. These agents include idraparinux, a long-acting synthetic pentasaccharide that is given subcutaneously on a once-weekly basis, and new oral anticoagulants that target thrombin or factor Xa. This paper i) reviews the pharmacology of these agents, ii) outlines their potential strengths and weaknesses, iii) describes the results of clinical trials with these new drugs, and iv) identifies the evolving role of new anticoagulants in the management of VTE.

Topics: Anticoagulants; Fondaparinux; Glycosaminoglycans; Heparin, Low-Molecular-Weight; Humans; Models, Chemical; Oligosaccharides; Polysaccharides; Postphlebitic Syndrome; Pulmonary Embolism; Thromboembolism; Venous Thrombosis; Vitamin K; Warfarin

Venous thromboembolic disease (VTE) is a major cause of morbidity and mortality. Unfractioned heparin, low-molecular weight heparins and vitamin K antagonists, currently used in the prophylaxis and treatment of VTE, are effective and relatively safe. Otherwise, they have some important limitations (narrow therapeutic window, highly variable dose-response relationship; limitation by the need of parenteral administration for heparins and the risk of heparin-induced thrombocytopenia) which provide opportunities for new antithrombotic drugs. These drugs include: inhibitors of factors IXa and factor VIIa/tissue factor complex, agents that enhance the protein C anticoagulant pathway, direct and antithrombin-dependent Xa inhibitors, direct and indirect thrombin inhibitors. Fondaparinux and idraparinux, two new indirect parenteral factor Xa inhibitors, have been studied in well conducted trials, showing interesting results both in the prevention and in the treatment of VTE. Ximelagatran, the first orally available thrombin inhibitor, represents a promising new anticoagulant drug for the prophylaxis of VTE after major orthopedic surgery and for the treatment of deep vein thrombosis.

Topics: Anticoagulants; Azetidines; Benzylamines; Fibrinolytic Agents; Fondaparinux; Humans; Oligosaccharides; Polysaccharides; Thromboembolism

Modern approaches to prevention of venous thromboembolic complications in patients with chronic heart failure are analyzed in this review which contains results of large studies of low molecular weight heparins. In MEDENOX trial the use of enoxaparin in medical patients was associated with 63% reduction of risk of thrombosis. The authors own experience showed that 2 weeks of therapy with enoxaparin in patients with chronic stage IIB-III heart failure caused significant lowering of soluble fibrin-monomer complexes, fibrinogen, and index of turbo-dynamic potential. These changes evidenced for decreased intravascular blood coagulation. Thus enoxaparin can be effectively used for prevention of thrombosis and thromboembolism in patients with chronic heart failure. Novel antithrombotic agents fondaparinux, idraparinux, ximelagatran, recombinant thrombomodulin are perspective medications for prevention of venous thromboses and embolism in medical patients.

Topics: Anticoagulants; Azetidines; Benzylamines; Dalteparin; Double-Blind Method; Enoxaparin; Fibrinolytic Agents; Fondaparinux; Heart Failure; Humans; Multicenter Studies as Topic; Oligosaccharides; Placebos; Polysaccharides; Randomized Controlled Trials as Topic; Risk Factors; Thromboembolism; Thrombomodulin; Thrombosis; Time Factors; Venous Thrombosis

Anticoagulant therapy is effective at preventing the development of venous thromboembolism in high-risk patients, and reduces morbidity and mortality in individuals with established thromboembolic disease. Vitamin K antagonists and heparins are currently the most commonly used anticoagulant drugs, but they have practical limitations. Therefore, new antithrombotic agents with predictable dose-responses (thereby decreasing the need for monitoring without compromising efficacy or safety), ideally available in an oral formulation and with a rapidly reversible anticoagulant effect, are needed. New drugs fulfilling some of the above criteria have been developed and have proven to be effective agents for the treatment and prevention of venous thromboembolism.

Topics: Animals; Anticoagulants; Azetidines; Benzylamines; Blood Coagulation; Factor VII; Factor Xa Inhibitors; Fondaparinux; Helminth Proteins; Humans; Oligosaccharides; Polysaccharides; Recombinant Proteins; Thrombin; Thromboembolism; Thrombomodulin; Thromboplastin; Treatment Outcome; Venous Thrombosis

The aim of this review is to perform a critical analysis of all completed studies evaluating pentasaccharides-synthetically derived, selective inhibitors of activated factor X-in prophylaxis in major orthopedic surgery and the treatment of venous thromboembolism.. Venous thromboembolism is a disorder with considerable morbidity when left untreated. New antithrombotic agents have been developed that selectively inhibit components of the coagulation system, thereby avoiding the difficulties associated with current anticoagulants. The pentasaccharides fondaparinux and idraparinux are the first of a new class of synthetic selective inhibitors of activated factor X. Fondaparinux has been extensively investigated in two areas: orthopedic surgery and venous thromboembolism. It is clear from four thromboprophylaxis studies in major orthopedic surgery that fondaparinux is 50% more effective in reducing venous thromboembolism than enoxaparin. This superior efficacy led to an overall increase in major bleeding, which was however primarily due to more fondaparinux-treated patients with bleeding indexes of 2 or greater. The incidence of fatal bleeding, critical organ bleeding, or bleeding leading to reoperation did not differ significantly between the two groups. In the initial treatment of patients with proximal vein thrombosis and pulmonary embolism, fondaparinux was equally effective as low molecular weight heparins and unfractionated heparin, respectively, without a different incidence in major bleeding in fondaparinux and comparator heparin groups.. Fondaparinux, one of the first of a new class of synthetic selective factor Xa inhibitors, is overall 50% more effective in reducing venous thromboembolism than enoxaparin in major orthopedic surgery, with an overall 1% increased rate of major bleeding, when compared with enoxaparin. The incidence of fatal bleeding, critical organ bleeding, or bleeding leading to reoperation did not differ significantly between the two treatment groups. Fondaparinux is equally effective as low molecular weight heparins and unfractionated heparin in the initial treatment of patients with proximal vein thrombosis and pulmonary embolism, respectively. Finally, as with any new drug, fondaparinux should be used cautiously and only in patients who reflect the population of the clinical trials in which the drug was evaluated.

Topics: Clinical Trials as Topic; Factor Xa Inhibitors; Fondaparinux; Humans; Oligosaccharides; Orthopedic Procedures; Polysaccharides; Thromboembolism; Venous Thrombosis

Treatment of venous thromboembolism (VTE) usually starts with concomitant administration of heparin or low-molecular-weight heparin (LMWH) and a vitamin K antagonist. The parenteral anticoagulant, which is given for at least 5 days, is stopped once the vitamin K antagonist produces a therapeutic level of anticoagulation. Although the introduction of LMWH has simplified the initial treatment of VTE, problems remain. LMWH must be given by daily subcutaneous (SC) injection and vitamin K antagonists require routine coagulation monitoring, which is inconvenient for patients and physicians. Recently, 3 new anticoagulants have been introduced in an attempt to overcome these limitations. These include fondaparinux and idraparinux, synthetic analogs of the pentasaccharide sequence that mediates the interaction of heparin and LMWH with antithrombin, and ximelagatran, an orally active inhibitor of thrombin. These agents produce a predictable anticoagulant response; thus, routine coagulation monitoring is unnecessary. Because they do not bind to platelets or platelet factor 4, fondaparinux and idraparinux do not cause heparin-induced thrombocytopenia (HIT). Unlike vitamin K antagonists, ximelagatran has a rapid onset of action, thereby obviating the need for concomitant administration of a parenteral anticoagulant when starting treatment. The lack of an antidote for these new agents is a drawback, particularly for idraparinux, which has a long half-life.

Topics: Anticoagulants; Azetidines; Benzylamines; Clinical Trials as Topic; Fondaparinux; Humans; Oligosaccharides; Polysaccharides; Pulmonary Embolism; Thromboembolism; Venous Thrombosis

Vitamin K antagonists, the current standard treatment for prophylaxis against stroke and systemic embolism in patients with atrial fibrillation, require regular monitoring and dose adjustment; an unmonitored, fixed-dose anticoagulant regimen would be preferable. The aim of this randomised, open-label non-inferiority trial was to compare the efficacy and safety of idraparinux with vitamin K antagonists.. Patients with atrial fibrillation at risk for thromboembolism were randomly assigned to receive either subcutaneous idraparinux (2.5 mg weekly) or adjusted-dose vitamin K antagonists (target of an international normalised ratio of 2-3). Assessment of outcome was done blinded to treatment. The primary efficacy outcome was the cumulative incidence of all stroke and systemic embolism. The principal safety outcome was clinically relevant bleeding. Analyses were done by intention to treat; the non-inferiority hazard ratio was set at 1.5. This trial is registered with ClinicalTrials.gov, number NCT00070655.. The trial was stopped after randomisation of 4576 patients (2283 to receive idraparinux, 2293 to receive vitamin K antagonists) and a mean follow-up period of 10.7 (SD 5.4) months because of excess clinically relevant bleeding with idraparinux (346 cases vs 226 cases; 19.7 vs 11.3 per 100 patient-years; p<0.0001). There were 21 instances of intracranial bleeding with idraparinux and nine with vitamin K antagonists (1.1 vs 0.4 per 100 patient-years; p=0.014); elderly patients and those with renal impairment were at greater risk of such complications. There were 18 cases of thromboembolism with idraparinux and 27 cases with vitamin K antagonists (0.9 vs 1.3 per 100 patient-years; hazard ratio 0.71, 95% CI 0.39-1.30; p=0.007), satisfying the non-inferiority criterion. There were 62 deaths with idraparinux and 61 with vitamin K anatagonists (3.2 vs 2.9 per 100 patient-years; p=0.49).. In patients with atrial fibrillation at risk for thromboembolism, long-term treatment with idraparinux was no worse than vitamin K antagonists in terms of efficacy, but caused significantly more bleeding.

Topics: Acenocoumarol; Aged; Anticoagulants; Atrial Fibrillation; Factor Xa Inhibitors; Female; Hemorrhage; Humans; Kaplan-Meier Estimate; Male; Oligosaccharides; Risk Factors; Single-Blind Method; Stroke; Thromboembolism; Treatment Outcome; Vitamin K; Warfarin

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.

Topics: Animals; Biotin; Disease Models, Animal; Drug Combinations; Factor Xa; Factor Xa Inhibitors; Fibrinolytic Agents; Humans; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Oligosaccharides; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Rats; Thromboembolism; Tirofiban; Tyrosine

Oral anticoagulation, most commonly with warfarin once daily, has long been the main form of long-term treatment and secondary prevention of thromboembolism. The efficacy of warfarin has been established in clinical trials, but problems with unstable anticoagulation with international normalized ratios (INRs) outside the recommended range due to incorrect dosing, drug and food interactions, and with adherence and persistence have been reported in practice. Poor adherence and persistence are serious problems because they result in out-of-range INRs. Many new thromboembolic events, such as strokes, occur when INRs are out-of-range or after warfarin discontinuation. Among the new anticoagulants currently being investigated, some offer the possibility of more stable anticoagulation and weekly administration. Less frequent dosing schedules generally improve adherence. In many cases, such as bisphosphonate treatment for osteoporosis, and the long-term treatment of depressive disorders or multiple sclerosis, adherence to, and persistence with, weekly dosing is improved compared with daily dosing, and most patients prefer weekly dosing. The advent of novel anticoagulants such as idraparinux with its long half-life offers hope for improved adherence with anticoagulation, and ultimately improved outcomes.

Topics: Anticoagulants; Drug Administration Schedule; Drug Interactions; Food-Drug Interactions; Half-Life; Humans; International Normalized Ratio; Medication Adherence; Oligosaccharides; Secondary Prevention; Thromboembolism; Warfarin

Topics: Humans; Oligosaccharides; Randomized Controlled Trials as Topic; Skin Diseases, Vesiculobullous; Thromboembolism

Topics: Anticoagulants; Atrial Fibrillation; Hemorrhage; Humans; Oligosaccharides; Stroke; Thromboembolism; Vitamin K; Warfarin

Topics: Adult; Age Factors; Aged; Anticoagulants; Azetidines; Benzylamines; Dalteparin; Female; Fibrinolytic Agents; Fondaparinux; Humans; Male; Middle Aged; Multicenter Studies as Topic; Oligosaccharides; Placebos; Polysaccharides; Prodrugs; Pulmonary Embolism; Randomized Controlled Trials as Topic; Thromboembolism; Thrombomodulin; Time Factors; Warfarin