Extended use of enoxaparin could cut vein clot risk: sanofi-aventis
Sanofi-aventis announced the results of the Exclaim (EXtended CLinical prophylaxis in Acutely Ill Medical patients) study, which showed the benefit of extended prophylaxis in acutely ill medical patients with reduced mobility by demonstrating the superiority of 5 weeks course of prophylaxis with Clexane/Lovenox compared to 10 days regimen with a statistically significant 44% reduction in venous thromboembolism (VTE) events (Deep Vein Thrombosis and/or Pulmonary Embolism). The findings were presented at the XXIst ISTH Congress (International Society on Thrombosis and Haemostasis) in Geneva, Switzerland.
Acutely ill medical patients are at high risk of VTE. The benefit of thromboprophylaxis with enoxaparin (10+/- 4 days) has already been demonstrated in this patient population and is considered as the standard regimen. Nonetheless clinical practice suggests that the risk of VTE may continue beyond 10 days particularly in patients with reduced mobility. The efficacy and safety of extended prophylaxis in this medical population had never been assessed although it has been demonstrated for several high-risk surgical patient populations and therefore recommended by international guidelines.
The objective of Exclaim study was to assess the superiority of enoxaparin prophylaxis given for 28+/- 4 days versus placebo, both following an initial treatment with enoxaparin for 10+/- 4 days, to reduce VTE events rate. The primary efficacy endpoint was the incidence of asymptomatic deep-vein thrombosis (DVT), symptomatic DVT, symptomatic pulmonary embolism (PE), or fatal PE during the double-blind period.
The statistically significant 44% relative risk reduction in VTE events observed for extended duration prophylaxis with enoxaparin vs. placebo for the primary endpoint (2.8% vs. 4.9%; p=0.0011) was associated with a reduction in symptomatic VTE by 73% (0.3% vs. 1.1%; p=0.0044) and asymptomatic proximal DVT by 34% (2.5% vs. 3.7%; p=0.0319). No statistically significant differences were observed for symptomatic pulmonary embolism (PE) or fatal PE. The statistically significant relative risk reduction of VTE observed with enoxaparin at 38 days was maintained at 90 days (3.0% vs. 5.2%; p=0.0015).
Victor F. Tapson, MD, Professor of Medicine, Director, Center for Pulmonary Vascular Disease, Division of Pulmonary and Critical Care, Duke University Medical Center, Durham, NC, and a lead investigator of the EXCLAIM study said :"What the trial results showed is that patients do not leave their risk for VTE at the door when they leave the hospital. With continued prophylaxis, Lovenox statistically significantly reduced the risk by 44% in acutely ill medical patients with prolonged immobility."
In comparison with placebo, the rate of major bleeding was statistically significantly higher in the extended enoxaparin arm (0.6% vs. 0.15%, p=0.019), but the overall event rate was low. There was no difference in all-cause mortality between extended enoxaparin vs. placebo at 6 months (10.1% vs. 8.9%; p=0.18).
"Exclaim is the first study to assess the benefit of extended thromboprophylaxis in acutely ill medical patients with reduced mobility and to demonstrate the clinical benefit of 5 weeks enoxaparin treatment versus 10 days in this patient population" said Professor Russell Hull from the University of Calgary, Canada and Chair of the Steering Committee for the Exclaim study
"Similarly to the initial demonstration of the benefit of thromboprophylaxis for acutely ill medical patients, first established by the Medenox trial, the Exclaim study should be a landmark trial in advancing the standard of care of patients at high risk for VTE and it further establishes enoxaparin as a reference treatment for VTE prophylaxis in acutely ill medical patients".
The Exclaim trial is the first international, multicentre prospective, randomized, double-blind, placebo-controlled study. It enrolled 5,105 acutely-ill patients with recent reduced mobility in 20 countries, comparing extended-duration (28±4 days) venous thromboembolism (VTE) prophylaxis with enoxaparin, a low-molecular-weight heparin (LMWH) with the standard regimen of enoxaparin (10±4 days) for the prophylaxis of VTE. Patients recently immobilized for up to 3 days with level 1 mobility (total bed rest or sedentary patients) or with level 2 mobility (with bathroom privileges) with age > 75 years or history of VTE or diagnosis of cancer and predefined acute medical illness were randomized to received enoxaparin 40 mg subcutaneously once daily for 10±4 days and were then randomized to receive the same enoxaparin regimen or placebo for an additional 28±4 days. The steering committee followed the Data Safety Monitoring Board (DSMB) suggestion that in addition to level 1 mobility patients to re-define the inclusion criteria by adding on level mobility patients inclusion criteria : Age >75 years, or prior VTE or diagnosed cancer.
The objective of the Exclaim study was to assess the superiority of enoxaparin prophylaxis given for 28+/- 4 days versus placebo, both following an initial treatment with enoxaparin for 10+/- 4 days, to reduce VTE events
The primary efficacy endpoint was the incidence of asymptomatic deep-vein thrombosis (DVT) detected by routine standardized ultrasonography, symptomatic DVT, symptomatic pulmonary embolism (PE), or fatal PE during the double-blind period. Secondary efficacy endpoints include the incidence of VTE at 3 months and the incidence of mortality up to 6 months after enrolment. The primary safety endpoint was major hemorrhagic complications during the same period.
Venous thromboembolism is a general term used to describe the formation of a blood clot (thrombus) that blocks a vein. This may occur in any part of the venous system, but the most common manifestations are deep-vein thrombosis (DVT), usually in the leg, and pulmonary embolism (PE). VTE is also a common complication among acutely-ill medical patients who have recently been immobilized, a population of medically-ill patients at particularly high-risk for VTE.
Lovenox is a unique chemical entity in a class of antithrombotic agents known as lowmolecular weight heparin (LMWH). The no. 1 selling low-molecular weight heparin in the world, Lovenox is obtained by alkaline degradation of heparin benzyl ester and is about one-third the molecular size of unfractionated heparin. Lovenox is the most widely studied LMWH, with 20 years of use in the treatment of 185 million patients in 96 countries. Its clinical applications are linked to its antithrombotic properties. It is used to inhibit clot formation in venous and arterial vessels to prevent potential acute or chronic complications of venous or arterial thrombosis. As with all anticoagulants, the most frequently reported side effect with Lovenox® is bleeding. Clinical indications for Lovenox may vary from one country to another.