Sanofi-Aventis (France) Release: The Lancet Publishes PREVAIL Study Results Showing Lovenox(R) Superiority Over Unfractionated Heparin for Reducing the Risk of Venous ThromboEmbolism in Patients With Acute Ischemic Stroke

BRIDGEWATER, N.J., April 20 /PRNewswire-FirstCall/ -- Sanofi-aventis announced the publication of the PREVAIL (Prevention of VTE after Acute Ischemic Stroke with LMWH Enoxaparin) trial in the April 21st issue of The Lancet. The results of the trial showed that once daily administration of Clexane(R) / Lovenox(R) (enoxaparin sodium injection) 40 mg was more effective than UnFractionated Heparin (UFH) 5000 IU twice a day for the prevention of VTE in patients who suffered an acute ischemic stroke, a group of medically- ill patients at an increased risk for developing VTE.

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).

PREVAIL study showed a significant 43% relative risk reduction in VTE events was observed with Clexane(R) / Lovenox(R) vs. UFH for the primary efficacy endpoint, the composite of symptomatic or asymptomatic DVT, symptomatic and/or fatal PE during the treatment period (10.2 % vs. 18.1%; p= 0.0001).

Importantly, the reduction in VTE risk was also observed in patients presenting with different levels of ischemic stroke severity, without significant difference in clinically important bleedings as well.

The significant reduction of VTE risk with Clexane(R) / Lovenox(R) versus UFH was maintained when therapy was initiated within 24 hours or 24 hours-48 hours after stroke onset.

The incidence of the composite of symptomatic intracranial and major extracranial haemorrhage was small with no difference between groups (enoxaparin 1.3%, UFH 0.7%; p=0.2275). No difference was observed for symptomatic intracranial haemorrhage between groups (0.5% vs 0.7%, respectively; p=0.5466). The rate of major extracranial bleeding, mainly gastrointestinal bleeding, was higher with enoxaparin (0.8% vs. %, p=0.0154) but did not lead to increased mortality. There was no difference in all-cause mortality between groups.

In conclusion the authors said that “enoxaparin is preferable to unfractionated heparin for venous thromboembolism prophylaxis in this high- risk medically ill patient in view of its better clinical benefits to risk ratio and convenience of once daily administration.”

About PREVAIL

The PREVAIL trial is the first large-scale, multinational, prospective, randomized, open-label study, which enrolled 1,762 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 40 mg SC or UFH 5000 IU SC Q 12 treatment for 10 days +/- 4 days with a follow up period of 90 days and stratified by NIH Stroke Scale Score (severe being greater than or equal to 14 and less severe less than 14).

The primary efficacy endpoint was the composite of symptomatic or asymptomatic DVT, symptomatic or fatal PE during the treatment period. The primary safety endpoints included symptomatic intracranial bleeding, major extracranial bleeding and all-cause mortality.

About Venous Thromboembolism (VTE)

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 individuals who have experienced an acute ischemic stroke (AIS), a population of medically-ill patients at particularly high-risk for VTE.

About Enoxaparin

Enoxaparin is an anticoagulant of the low molecular weight heparin (LMWH) class. Its clinical applications are linked to its antithrombotic properties. It is used to inhibit clot formation in venous or arterial vessels to avoid potential acute or chronic complications of venous or arterial thrombosis such as pulmonary embolism, myocardial infarction or death of cardiovascular origin. As with all anticoagulants, the most frequently reported side effect for enoxaparin is bleeding. Clinical indications for enoxaparin may vary from one country to another.

Important Safety Information

LOVENOX(R) (enoxaparin sodium injection) cannot be used interchangeably with other low-molecular-weight heparins or unfractionated heparin, as they differ in their manufacturing process, molecular weight distribution, anti-Xa and anti-IIa activities, units, and dosage.

When epidural/spinal anesthesia or spinal puncture is employed, patients anticoagulated or scheduled to be anticoagulated with low-molecular-weight heparins or heparinoids are at risk of developing an epidural or spinal hematoma, which can result in long-term or permanent paralysis.

The risk of these events is increased by the use of postoperative indwelling epidural catheters or by the concomitant use of drugs affecting hemostasis. Patients should be frequently monitored for signs and symptoms of neurological impairment. (See boxed WARNING).

As with other anticoagulants, use with extreme caution in patients with conditions that increase the risk of hemorrhage. Dosage adjustment is recommended in patients with severe renal impairment. Unless otherwise indicated, agents that may affect hemostasis should be discontinued prior to LOVENOX(R) therapy. Bleeding can occur at any site during LOVENOX(R) therapy. An unexplained fall in hematocrit or blood pressure should lead to a search for a bleeding site. (See WARNINGS and PRECAUTIONS).

Thrombocytopenia can occur with LOVENOX(R). In patients with a history of heparin-induced thrombocytopenia, LOVENOX(R) should be used with extreme caution. Thrombocytopenia of any degree should be monitored closely. If the platelet count falls below 100,000/mm3, LOVENOX(R) should be discontinued. Cases of heparin-induced thrombocytopenia have been observed in clinical practice. (See WARNINGS).

The use of LOVENOX(R) has not been adequately studied for thromboprophylaxis in pregnant women with mechanical prosthetic heart valves. (See WARNINGS).

LOVENOX(R) is contraindicated in patients with hypersensitivity to enoxaparin sodium, heparin, or pork products, and in patients with active major bleeding.

Please see accompanying full prescribing information including boxed WARNING.

Please visit http://www.lovenox.com for complete prescribing information, including boxed WARNING, and additional important information.

About sanofi-aventis

Sanofi-aventis is one of the world’s leading pharmaceutical companies. Backed by a world-class R&D organization, sanofi-aventis is developing leading positions in seven major therapeutic areas: cardiovascular, thrombosis, oncology, metabolic diseases, central nervous system, internal medicine and vaccines. Sanofi-aventis is listed in Paris and in New York .

Forward Looking Statements

This press release contains forward-looking statements as defined in the Private Securities Litigation Reform Act of 1995, as amended. Forward-looking statements are statements that are not historical facts. These statements include financial projections and estimates and their underlying assumptions, statements regarding plans, objectives, intentions and expectations with respect to future events, operations, products and services, and statements regarding future performance. Forward-looking statements are generally identified by the words “expects,” “anticipates,” “believes,” “intends,” “estimates,” “plans” and similar expressions. Although sanofi-aventis’ management believes that the expectations reflected in such forward-looking statements are reasonable, investors are cautioned that forward-looking information and statements are subject to various risks and uncertainties, many of which are difficult to predict and generally beyond the control of sanofi-aventis, that could cause actual results and developments to differ materially from those expressed in, or implied or projected by, the forward- looking information and statements. These risks and uncertainties include those discussed or identified in the public filings with the SEC and the AMF made by sanofi-aventis, including those listed under “Risk Factors” and “Cautionary Statement Regarding Forward-Looking Statements” in sanofi-aventis’ annual report on Form 20-F for the year ended December 31, 2006. Other than as required by applicable law, sanofi-aventis does not undertake any obligation to update or revise any forward-looking information or statements.

U.S. Contacts: Marisol Peron, 1-908-981-6565, Marisol.Peron@sanofi-aventis.com Amy Ba, 1-908-981-6563, Amy.Ba@sanofi-aventis.com

sanofi-aventis

CONTACT: Marisol Peron, +1-908-981-6565, Marisol.Peron@sanofi-aventis.com,or Amy Ba, +1-908-981-6563, Amy.Ba@sanofi-aventis.com, both ofsanofi-aventis

MORE ON THIS TOPIC