New Study Shows That Extending Prophylaxis With Clexane(R) / Lovenox(R) (enoxaparin Sodium Injection) to 5 Weeks is More Effective Than 10 Days for Reducing the Risk of Venous Thromboembolism (VTE) in

Paris, France (ots/PRNewswire) -

- EXCLAIM is the First International Study to Show That Extended
Thromboprophylaxis Reduces VTE Risk in Acutely-ill Medical Patients
With a Statistically Significant 44%

Sanofi-aventis announced today 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(R)/Lovenox(R) 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 plus or minus 4 days) has
already been demonstrated in this patient population and is
considered as the standard regimen(1). Nonetheless clinical practice
suggests that the risk of VTE may continue beyond 10 days(1)
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(2,3) and therefore recommended by
international guidelines(4).

The objective of EXCLAIM study was to assess the superiority of
enoxaparin prophylaxis given for 28 plus or minus 4 days versus
placebo, both following an initial treatment with enoxaparin for 10
plus or minus 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(R) 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".

About EXCLAIM

The EXCLAIM trial is the first international, multicenter,
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 plus or minus 4 days)
venous thromboembolism (VTE) prophylaxis with enoxaparin, a
low-molecular-weight heparin (LMWH) with the standard regimen of
enoxaparin (10 plus or minus 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 plus or minus 4 days and were then randomized to receive the same
enoxaparin regimen or placebo for an additional 28 plus or minus 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 2 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 plus or minus 4 days versus
placebo, both following an initial treatment with enoxaparin for 10
plus or minus 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.

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 acutely-ill medical
patients who have recently been immobilized, a population of
medically-ill patients at particularly high-risk for VTE.

About Clexane(R) / Lovenox(R) (enoxaparin)

Lovenox(R) is a unique chemical entity in a class of
antithrombotic agents known as low-molecular weight heparin (LMWH).
The no. 1 selling low-molecular weight heparin in the world,
Lovenox(R) is obtained by alkaline degradation of heparin benzyl
ester and is about one-third the molecular size of unfractionated
heparin. Lovenox(R) 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(R) is bleeding.
Clinical indications for Lovenox(R) may vary from one country to
another.

About sanofi-aventis

Sanofi-aventis is one of the world's leading pharmaceutical
companies, ranking number one in Europe. Backed by a world-class R&D
organisation, 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 (EURONEXT: SAN) and in
New York (NYSE: SNY).

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.

1. Samama.New England Journal of Medicine.Sept.1999.

2. Bergqvist New England Journal of Medicine March 2002/ Vol
346, No.13.

3. Hull, Ann Intern Med.2001; 135:858-869.

4. Geerts.Chest.2004.

ots Originaltext: sanofi-aventis Group
Im Internet recherchierbar: http://www.presseportal.de

Contact:
Contact: Philippe BARQUET +33-6-70-48-61-28