ORLANDO, Fla.--13 Dec--PRNewswire-AsiaNet/InfoQuest - The PREVAIL Study Showed That in Acute Ischemic Stroke Patients Treated With Clexane(R) / Lovenox(R), the Risk of Having a VTE was Lowered by a Significant 43% With no Significant Increase in Clinically Important Bleedings When Compared to UFH Sanofi-aventis announced today that the results of the PREVAIL (Prevention of VTE after Acute Ischemic Stroke with LMWH Enoxaparin) study presented at the 48th American Society of Hematology (ASH) annual meeting in Orlando emonstrated a significant 43% reduction in venous thromboembolism (VTE) events with enoxaparin vs. unfractionated heparin (UFH) in medically-ill patients who suffered an acute ischemic stroke. Among medically-ill patients, stroke patients are at an increased risk for developing VTE. Without VTE prophylaxis, up to 75% of patients with hemiplegia following stroke develop deep-vein thrombosis (DVT) and 20% develop pulmonary embolism (PE)[1,2]. The primary efficacy endpoint of the study was the composite of symptomatic or asymptomatic DVT, and/or symptomatic or fatal PE during the treatment period. The significant 43% relative risk reduction in VTE events observed with enoxaparin vs. UFH for the primary efficacy endpoint (10.2 % vs. 18.1%; p=0.0001) was associated with a consistent reduction in proximal DVT by 53% (4.5% vs. 9.6%; p=0.0003). There was no significant difference in clinically important bleedings (1.3% vs. 0.7%, p=0.20), corresponding to the combination of both symptomatic intracranial bleeding, the most serious complication, and major extracranial bleeding. The reduction in VTE risk was also observed in patients presenting with different levels of stroke severity, with no significant difference in clinically important bleedings. "Balancing the benefits of lowering the risk of VTE while minimizing the risk of bleeding is a very important element in choosing prophylactic regimens for this particularly fragile patient population, as it combines the usual factors of VTE in addition to the stroke context," said Dr. David Sherman, Professor in the Division of Neurology in the Department of Medicine at the University of Texas Health Science Center (UTHSC) in San Antonio, and principal investigator of the study. "PREVAIL showed that enoxaparin, when compared to UFH, had a superior efficacy with no significant increase in clinically important bleedings. These data provide new evidence that suggests enoxaparin can be used as VTE prophylaxis in this high risk population". About Venous Thromboembolism (VTE) Venous thromboembolism is a general term used to describe the formation of a blood clot (thrombus) that blocks a vessel. 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 individuals who have experienced an acute ischemic stroke (AIS). About PREVAIL PREVAIL trial is the first large-scale, multinational, prospective, randomized study which enrolled 1,762 ischemic stroke patients (stratified by NIH Stroke Scale Score) in over 15 countries. Patients confirmed with an acute ischemic stroke, were randomized within 48 hours of stroke symptoms to receive enoxaparin daily 40 mg SC or UFH 5000 IU SC Q 12 treatment for 10 days +/- 4 days with a follow up period of 90 days andstratified by NIH Stroke Scale Score (severe greater than or equal to 14 and less severe