scholarly journals New anticoagulants in the prevention and treatment of venous thromboembolism

2011 ◽  
Vol 152 (25) ◽  
pp. 983-992 ◽  
Author(s):  
Mátyás Keltai ◽  
Katalin Keltai

Clinical data on the risk factors, incidence, consequences and current treatment options of venous thromboembolism are reviewed. Current guidelines advise anticoagulant treatment for a few weeks or months in immobilized patients treated in hospital, and after major surgery. The initial treatment is based on heparin, followed by vitamin K antagonist treatment. Recently a number of new, partially orally administered medications have undergone clinical investigations and based on the results three of them were also registered for the prevention and treatment of venous thromboembolism. Direct thrombin inhibitors, direct and indirect Factor Xa inhibitors exhibited proven non-inferiority or superiority compared with traditional treatment options. The superior efficacy or non-inferiority was not accompanied with an increase in the bleeding risk. Results of the most important clinical trials are reviewed. Based on these results, prevention and treatment of venous thromboembolism will change substantially in the next future. Orv. Hetil., 2011, 152, 983–992.

2016 ◽  
Vol 42 (2) ◽  
pp. 146-154 ◽  
Author(s):  
Caio Julio Cesar dos Santos Fernandes ◽  
José Leonidas Alves Júnior ◽  
Francisca Gavilanes ◽  
Luis Felipe Prada ◽  
Luciana Kato Morinaga ◽  
...  

Worldwide, venous thromboembolism (VTE) is among the leading causes of death from cardiovascular disease, surpassed only by acute myocardial infarction and stroke. The spectrum of VTE presentations ranges, by degree of severity, from deep vein thrombosis to acute pulmonary thromboembolism. Treatment is based on full anticoagulation of the patients. For many decades, it has been known that anticoagulation directly affects the mortality associated with VTE. Until the beginning of this century, anticoagulant therapy was based on the use of unfractionated or low-molecular-weight heparin and vitamin K antagonists, warfarin in particular. Over the past decades, new classes of anticoagulants have been developed, such as factor Xa inhibitors and direct thrombin inhibitors, which significantly changed the therapeutic arsenal against VTE, due to their efficacy and safety when compared with the conventional treatment. The focus of this review was on evaluating the role of these new anticoagulants in this clinical context.


Hematology ◽  
2006 ◽  
Vol 2006 (1) ◽  
pp. 450-456 ◽  
Author(s):  
Kenneth A. Bauer

Abstract Traditional anticoagulant drugs, including unfractionated heparin and warfarin, have several limitations. New anticoagulants have been developed that target a single coagulation factor and have predictable dose-response relationships. These include direct thrombin inhibitors and factor Xa inhibitors. Two parenteral direct thrombin inhibitors, lepirudin and argatroban, have FDA approval for the management of heparin-induced thrombocytopenia (HIT). Bivalirudin is a parenteral direct thrombin inhibitor that is licensed for patients undergoing percutaneous coronary interventions and for those with HIT who require percutaneous coronary interventions. Ximelagatran, an oral prodrug of the direct thrombin inhibitor melagatran, showed efficacy in the prevention and treatment of venous thromboembolism as well as stroke prevention in patients with atrial fibrillation. However, due to nonhematologic safety concerns, it did not receive FDA approval in the US. Fondaparinux is a synthetic pentasaccharide, which binds to antithrombin, thereby indirectly selectively inhibiting factor Xa. Fondaparinux demonstrated efficacy compared to low-molecular-weight heparin in randomized clinical trials and is FDA approved for the prevention and treatment of venous thromboembolism. The OASIS 5 trial in non-ST-segment elevation acute coronary syndromes recently demonstrated that the fondaparinux dose approved for prophylaxis of deep venous thrombosis is as efficacious with respect to ischemic outcomes as therapeutic doses of enoxaparin; fondaparinux, however, was associated with a substantial reduction in major bleeding at 9 days and mortality at 1 and 6 months. A number of oral direct factor Xa inhibitors as well as other oral direct thrombin inhibitors are in clinical development for the prevention and treatment of thrombosis; the current status of these anticoagulants is reviewed along with the challenges faced in designing pivotal clinical trials of these agents in comparison to existing anticoagulants.


Blood ◽  
2005 ◽  
Vol 105 (2) ◽  
pp. 453-463 ◽  
Author(s):  
Jack Hirsh ◽  
Martin O'Donnell ◽  
Jeffrey I. Weitz

AbstractAnticoagulants are pivotal agents for prevention and treatment of thromboembolic disorders. Limitations of existing anticoagulants, vitamin K antagonist and heparins, have led to the development of newer anticoagulant therapies. These anticoagulants have been designed to target specific coagulation enzymes or steps in the coagulation pathway. New anticoagulants that are under evaluation in clinical trials include: (1) inhibitors of the factor VIIa/tissue factor pathway; (2) factor Xa inhibitors, both indirect and direct; (3) activated protein C and soluble thrombomodulin; and (4) direct thrombin inhibitors. Although most of these are parenteral agents, several of the direct inhibitors of factor Xa and thrombin are orally active. Clinical development of these therapies often starts with studies in the prevention of venous thrombosis before evaluation for other indications, such as prevention of cardioembolism in patients with atrial fibrillation or prosthetic heart valves. At present, the greatest clinical need is for an oral anticoagulant to replace warfarin for long-term prevention and treatment of patients with venous and arterial thrombosis. Ximelagatran, an oral direct thrombin inhibitor, is the first of a series of promising new agents that might fulfill this need. Large phase 3 trials evaluating ximelagatran for the secondary prevention of venous thromboembolism and prevention of cardioembolic events in patients with atrial fibrillation have been completed.


2011 ◽  
Vol 31 (01) ◽  
pp. 21-27 ◽  
Author(s):  
U. Harbrecht

SummaryVitamin-K-antagonists (VKA) and heparins have been complementary anticoagulants for prevention and treatment of thrombosis for almost 70 years. In contrast to heparins, VKA have not been modified pharmacologically, however treatment surveillance has improved by introducing INR and self-monitoring/management. Disclosure of the molecular basis of interaction with VKORC1, the target enzyme of VKA, has helped to better understand coumarin sensitivity and resistance. New oral anticoagulants have now been approved and stimulated expectations in patients and physicians to get rid of the burdening frequent controls of VKA without loss of efficacy and safety.This review will summarize the development and profile of the new substances. Main difference compared to VKA is their direct mode of action against one clotting factor which is factor IIa in dabigatran and factor Xa in rivaroxaban and other “xabanes” currently under intensive investigation. Half lifes of the new anticoagulants are much shorter than that of the mainly used coumarins (phenprocoumon, warfarin), making “anticoagulation bridging” unnecessary before surgery. Therapeutic width of direct thrombin inhibitors and factor Xa inhibitors is broader and they are given at fixed doses. Clinical studies in thromboprophylaxis, thromboembolism and atrial fibrillation indicate at least non-inferiority or even superior efficacy compared with enoxaparin and VKA at comparable safety outcomes. Limitations of the new substances may arise from gastrointestinal side effects, mode of metabolism and route of elimination. Specific antidots are not available for none of them.Undoubtedly, the new oral anticoagulants are very promising. But, although thousands of study patients already have been treated, there are questions to be answered such as treatment adherence in absence of monitoring, safety and efficacy in risk patients, dosage adjustment and interactions with other drugs, before conclusions can be drawn towards their potential to replace VKA.


2016 ◽  
Vol 116 (S 02) ◽  
pp. S41-S49 ◽  
Author(s):  
Alexander Turpie ◽  
Walter Ageno

SummaryVenous thromboembolism (VTE), comprising both deep-vein thrombosis (DVT) and pulmonary embolism (PE), is a serious and common cardiovascular disease associated with the risk of chronic complications, recurrent VTE events and even death. The treatment landscape has, in recent years, seen a paradigm shift from the use of traditional anticoagulants (low-molecular-weight heparin [LMWH] overlapping with and followed by a vitamin K antagonist [VKA]) to non-VKA oral anticoagulants (NOACs). This class of agents, encompassing direct factor Xa inhibitors and direct thrombin inhibitors have shown non-inferior efficacy and better safety to standard of care in randomised controlled trials (RCTs). The direct, oral factor Xa inhibitor rivaroxaban was the first to be approved for treatment of acute DVT and PE and secondary prevention of recurrent VTE events based on data from EINSTEIN DVT and EINSTEIN PE, respectively. Real-world evidence now helps to further support data from RCTs, and also bridges the gap for physicians regarding any areas of clinical uncertainty that may not be addressed by RCTs. XA inhibition with rivaroxaban for Long-term and Initial Anticoagulation in venous thromboembolism (XALIA) was the first large, prospective, observational, real-world study that has investigated the safety and effectiveness profile of rivaroxaban in patients with DVT and PE associated with DVT in routine clinical practice. This article will present the key clinical outcomes from this important global non-interventional study, and will discuss remaining questions to be addressed in Phase IV studies.


2005 ◽  
Vol 21 (4) ◽  
pp. 480-486
Author(s):  
Lisa Kwok ◽  
Dana Molckovsky ◽  
Michel Boucher

Objectives: This assessment sought to evaluate the comparative benefit and adverse effect profile of ximelagatran, as well as the clinical issues surrounding its potential use.Methods: We performed a Dialog OneSearch across BIOSIS Previews, EMBASE, MEDLINE, PASCAL, and ToxFile to identify published literature. PubMed and The Cochrane Library were also searched. Gray literature was identified by searching a variety of Web sites of health technology assessment and related agencies and their associated databases. The manufacturer's Canadian office, AstraZeneca, was invited to submit information.Results: Ximelagatran is the first oral agent from a new class of anticoagulants called direct thrombin inhibitors. Other oral anticoagulants require routine blood monitoring; ximelagatran does not. Ximelagatran has been evaluated in the areas of venous thromboembolism management, particularly after orthopedic surgery, and stroke prevention in patients with atrial fibrillation. Overall, ximelagatran's efficacy appears comparable to other anticoagulants in these clinical settings. Also, bleeding rates were generally similar between ximelagatran and comparators but, as for warfarin, bleeding risk increases with higher ximelagatran doses. In addition, there is no specific antidote to help manage ximelagatran-induced bleeding. Finally, significantly more patients exposed to long-term ximelagatran developed elevated liver enzymes more than three times the upper normal limit, compared with patients on comparator anticoagulants.Conclusions: Given its apparent simplicity of use, ximelagatran carries the potential to replace, at least in part, anticoagulants currently used in the management of venous thromboembolism or for preventing stroke in atrial fibrillation patients. However, the safety of ximelagatran will not be fully known without further evaluation and surveillance for potential liver toxicity. There is also a need to evaluate its use in special populations such as patients with renal failure and patients using several concurrent medications.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1883-1883 ◽  
Author(s):  
Jeanine M. Walenga ◽  
Debra Hoppensteadt ◽  
Omer Iqbal ◽  
Brian Neville ◽  
Walter P. Jeske ◽  
...  

Abstract BAY 59-7939 is an orally bioavailable, small-molecule, direct Factor Xa (FXa) inhibitor in advanced clinical trials for the prevention and treatment of thromboembolic disorders. Unfractionated heparin and the low molecular weight heparins (LMWHs) are the current standards of care for patients requiring anticoagulation. However, their use can be restricted by heparin-induced thrombocytopenia (HIT), which may be associated with severe thrombotic complications. It has been reported previously that fondaparinux, a heparin-derived pentasaccharide that indirectly inhibits FXa, does not cross-react with anti-heparin/PF4 (HIT) antibodies. However, we have shown that increased sulfation of fondaparinux does result in strong cross-reactivity with HIT antibodies, leading to platelet activation/aggregation. Previous studies have shown that direct thrombin inhibitors (DTIs), such as argatroban and lepirudin, do not cross-react with HIT antibodies. Current guidelines for patients who have HIT recommend use of a DTI to prevent or treat associated thrombosis. This study was performed to evaluate whether BAY 59-7939 cross-reacts with HIT antibodies, in order to examine its potential as an alternative anticoagulant for the management of patients with HIT. The effect of BAY 59-7939 on platelet activation mediated by HIT antibodies was examined in sera collected from 63 patients diagnosed with HIT (HIT sera), using platelet aggregation assays, the [14C]serotonin release assay, and flow cytometry for the detection of platelet P-selectin expression and platelet microparticle formation. Heparin, the LMWH enoxaparin, fondaparinux, and the DTI melagatran were included for comparison. BAY 59-7939 did not activate platelets or cause aggregation with any of the HIT sera tested, establishing that there is no interaction between BAY 59-7939 and HIT antibodies. As expected, heparin strongly activated platelets and caused their aggregation, and gave a positive response with 100% of the HIT sera tested. Enoxaparin showed positive responses with 73% of the sera. Of all the HIT sera tested, one exhibited a weak positive response with fondaparinux. As has been observed with other DTIs, melagatran did not cause any platelet activation or aggregation responses with the HIT sera. This study clearly demonstrates that BAY 59-7939, a novel, orally active, direct FXa inhibitor, does not interact with preformed HIT antibodies. Therefore, BAY 59-7939 has potential as a new option for the prevention and treatment of thrombosis in patients with HIT.


Hematology ◽  
2004 ◽  
Vol 2004 (1) ◽  
pp. 424-438 ◽  
Author(s):  
Jeffrey I. Weitz ◽  
Saskia Middeldorp ◽  
William Geerts ◽  
John A. Heit

Abstract Venous thromboembolism, which includes deep vein thrombosis and pulmonary embolism, is the result of an imbalance among procoagulant, anticoagulant and profibrinolytic processes. This imbalance reflects a complex interplay between genetic and environmental or acquired risk factors. Genetic thrombophilic defects influence the risk of a first episode of thrombosis. How these defects influence the risk of recurrence in patients whose first episode of venous thromboembolism was unprovoked is less certain. Thus, when anticoagulants are stopped, patients with unprovoked venous thromboembolism have a risk of recurrence of at least 7% to 10% per year, even in the absence of an underlying thrombophilic defect. Consequently, there is a trend toward longer durations of anticoagulation therapy for these patients, which is problematic given the limitation of existing anticoagulants. This chapter provides an overview of the thrombophilic defects and how they influence the risk of venous thromboembolism. The chapter also details advances in anticoagulant therapy, focusing on new inhibitors of factor Xa and thrombin. In Section I, Dr. Saskia Middeldorp describes the various thrombophilic defects and reviews their relative importance in the pathogenesis of a first episode of venous thromboembolism. She then discusses the influence of these defects on the risk of recurrent thrombotic events in patients with unprovoked venous thromboembolism and in those whose thrombosis occurred in association with a known risk factor, such as surgery. In Section II, Dr. William Geerts reviews the pharmacology of new parenteral and oral factor Xa inhibitors and describes the results of the Phase II and III clinical trials with these agents. He then provides perspective on the potential advantages and drawbacks of these drugs for the prevention and treatment of venous thromboembolism. In Section III, Dr. John Heit focuses on direct thrombin inhibitors. He discusses their mechanism of action and compares and contrasts their pharmacological profiles prior to describing the results of Phase II and III clinical trials. Dr. Heit then provides perspective on the potential advantages and limitations of these drugs relative to existing anticoagulants.


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