STALLERGENES is Granted a Marketing Authorization for Oralair(R) in Europe

PARIS, November 27 - Stallergenes has been granted European approval to market
Oralair(R) in both adults and children through a Mutual Recognition
Procedure. Germany, the first country where Oralair(R) has been marketed,
was the reference Member state.

Oralair(R) is now registered in Austria, Belgium, Bulgaria,
Cyprus, the Czech Republic, Estonia, France, Germany, Greece, Hungary,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands,
Poland, Portugal, Romania, Slovakia, Slovenia, and Spain. All the countries
in which Stallergenes filed its application have approved it.

Oralair(R) is an immunotherapy tablet aimed at patients
suffering from severe rhinoconjunctivitis caused by grass pollens,
inadequately controlled using symptomatic treatments (antihistamines,
corticosteroids).

"The European registration of Oralair(R) is a major milestone
for Stallergenes. It confirms the evolution of immunotherapy towards
EBM-documented, well-tolerated treatments, effective from the very first
season. Immunotherapy tablets now share the same level of recognition as
conventional pharmaceuticals and form a new therapeutic class: allergens. The
next step is to implement the price and reimbursement assessment procedures
prior to the launch country by country," says Albert Saporta, Chairman and
CEO of Stallergenes.

About Oralair(R)

The Oralair(R) active substance consists of a set of pollens
corresponding to the epidemiological characteristics of patient exposure in
Europe: perennial rye grass (Lolium perenne), meadow grass (Poa pratensis),
timothy grass (Phleum pratense), cocksfoot (Dactylis glomerata) and sweet
vernal grass (Anthoxanthum odoratum).

From the outset, its clinical development has taken into
account the benefit to patients: proven efficacy, safety, ease of use,
compliance, and cost-containment through a pre- and coseasonal protocol (the
treatment is taken for four months prior to the pollen season and then
throughout it, for three consecutive seasons) rather than a perennial
protocol (when the treatment is taken all year round). A pharmacodynamic
study has demonstrated that Oralair(R) is effective from the first month of
treatment.

The clinical development program for Oralair(R) is continuing.
The results of three phase III clinical studies are expected by the end the
year: the US study in adults, the third year of a long-term study, and the
protocol optimization study. The long-term results will be available in a
year.

About The Stalair(R) Program

Stalair(R) is the pharmaceutical and clinical development
program for immunotherapy tablets being implemented by Stallergenes with a
view to obtaining marketing registrations for pharmaceutical products in
Europe and in other strategic markets.

Oralair(R) is the first project resulting from this program. A
Mutual Recognition Procedure has been completed.

A positive phase IIb/III study was completed for the dust mite
immunotherapy tablet, Actair(R) in allergic rhinitis in adults during the
first half of 2009. A pediatric phase III study has been launched.

The Bet v 1 tablet (birch pollen recombinant) has been the
subject of a positive phase IIb/III clinical trial conducted in allergic
rhinitis caused by birch pollen. A confirmatory phase III study is currently
being prepared with a view to EMEA registration.

The other allergens concerned by the program are ragweed for
the North American market and Japanese cedar pollen for the Japanese market.
Altogether, the program covers 80% of the epidemiology for all markets.

About Stallergenes

Stallergenes is a European biopharmaceutical company dedicated
to immunotherapy treatments for the prevention and treatment of
allergy-related respiratory diseases, such as allergic rhinoconjunctivitis,
rhinitis and asthma. As of today, Stallergenes is the seventh-ranked French
pharmaceutical company. A pioneer and leader in sublingual immunotherapy
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 immunotherapy tablets.

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

    Euronext Paris (Compartment B)
    SBF 120.
    ISIN code: FR0000065674
    Reuters code: GEN.PA
    Bloomberg code: GEN.FP

    Additional information is available at www.stallergenes.com

Contacts: Albert Saporta - Chairman and CEO, Tel: +33-1-55-59-20-04; 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