Stallergenes Signs an Exclusive Partnership Agreement With Solvay Pharmaceuticals for the Promotion and Distribution of its Products in Russia and the CIS*

ANTONY, France - Stallergenes S.A. and Solvay Pharmaceuticals Marketing and
Licensing AG (subsidiary of Solvay Group) announce the signing of an
exclusive partnership agreement for the promotion and distribution of
Stallergenes diagnostic and treatment products in Russia and the Commonwealth
of Independent States (CIS).

With an estimated 20 million allergy sufferers and a strong
demand on the part of the medical community for quality products, the Russian
market represents a real opportunity for Stallergenes.

The main products in Stallergenes’ injectable and sublingual
ranges will soon be the subject of registration applications. This
partnership will enable Stallergenes to meet more than 80% of the needs of
allergy sufferers in Russia and the CIS by 2011.

“We’re delighted to be teaming up with Solvay Pharmaceuticals
to target the potential growth this new market represents. Thanks to its
franchise and its considerable expertise recognized by allergy specialists,
Solvay Pharmaceuticals will enable us to promote the desensitization
standardized products, and notably the sublingual route, and their benefits
for patients,” declared Albert Saporta, Stallergenes’ Chairman and CEO.

“We’re tremendously enthusiastic about the prospect of
collaborating with the world leader in sublingual desensitization therapy and
making its innovative standardized products available to practitioners,”
emphasizes Mr. Jens Neuschaefer, Vice President, Regional Director, Solvay
Pharmaceuticals.

*countries concerned: Russia, Georgia, CIS (Commonwealth of Independent
States: Armenia, Azerbaijan, Belarus, Kazakhstan, Kyrgyzstan, Moldavia,
Uzbekistan, Russia, Tajikistan, Turkmenistan, and Ukraine).

ABOUT stallergenes’ INTERNATIONAL DEVELOPMENT

Today, Stallergenes markets its products in more than 50
different countries, via 11 subsidiaries throughout Europe and numerous
distribution and partnership agreements around the globe.

To help it pursue its development in new markets, Stallergenes
is supported by unique expertise and the responsiveness of its structure. In
high-potential emerging markets such as Russia, Stallergenes adopts a
tailored product offer strategy, working with partners closely involved in
the field of respiratory allergy treatment.

In the last five years, five new subsidiaries have been opened
in Europe and several partnership agreements have been signed.

ABOUT STALLERGENES

Stallergenes is a European biopharmaceutical company dedicated
to desensitization therapies for the prevention and treatment of
allergy-related respiratory diseases, such as rhinoconjunctivitis and
allergic asthma. A pioneer and leader in sublingual desensitization
treatments, Stallergenes devotes 21% of its turnover, in gross terms, to
Research and Development and is actively involved in the development of a new
therapeutic class: sublingual desensitization tablets.

In 2008, Stallergenes had a turnover of 171 million euros and
more than 500,000 patients were treated with Stallergenes desensitization
products.

Stallergenes is listed on Euronext Paris (Compartment B and is
part of the sample composing the SBF 120 index.

ISIN code: FR0000065674
Reuters code: GEN.PA
Bloomberg code: GEN.FP

Additional information is available at www.stallergenes.com

ABOUT SOLVAY PHARMACEUTICALS

Solvay Pharmaceuticals is a research driven group of companies
that constitutes the global pharmaceutical business of the Solvay Group.
These companies seek to fulfill carefully selected, unmet medical needs in
the therapeutic areas of neuroscience, cardiometabolic, influenza vaccines,
gastroenterology and men’s and women’s health. Its 2008 sales were EUR 2.7
billion, and it employs more than 9,000 people worldwide. For more
information, visit www.solvaypharmaceuticals.com.

SOLVAY GROUP is an international chemical and pharmaceutical
Group with headquarters in Brussels. It employs more than 29,000 people in 50
countries. In 2008, its consolidated sales amounted to EUR 9.5 billion,
generated by its three sectors of activity: Chemicals, Plastics and
Pharmaceuticals. Solvay is listed on the NYSE Euronext stock exchange in
Brussels (NYSE Euronext: SOLB.BE - Bloomberg: SOLB.BB - Reuters: SOLBt.BR).
Details are available at www.solvay.com.

Source: Stallergenes

Stallergenes: Contacts: Christian Thiry - Financial Director, Tel.: +33-1-55-59-20-95, e-mail: investorrelations at stallergenes.fr; Press relations, Lise Lemonnier - Communication Manager, Tel.: +33-1-55-59-20-96, e-mail: llemonnier at stallergenes.fr; Investor and Analyst Relations, Lucile de Fraguier - Pavie Finance, Tel.: +33-1-42-15-04-39, e-mail: contact at pavie-finance.com; Solvay Pharmaceuticals: Contacts: Solvay Pharma Russia, Leonid Parshenkov - General Director, Sergey Klipunovskiy - New Business Development Manager, Ekaterina Kryukova - Communication Manager, Tel.: +7-495-411-69-11, e-mail: info at solvay-pharma.ru