STALLERGENES: Strong Sales Growth in 1st Half-Year: up 12% Full-Year Guidance Maintained

ANTONY, France -

Million EUR 2008 08/07 2009 09/08 MEUR %Sales Var.% MEUR %Sales Var.% Southern Europe (1) 26.7 71 15 28.5 68 7 Other EU countries (2) 9.3 24 20 11.4 28 23 Other markets 2.0 5 47 1.5 4 (23) SLIT 30.3 80 21 33.8 82 12 SCIT 6.1 16 7 5.9 14 (3) Other products 1.6 4 4 1.7 4 9 Q2 sales 38.0 100 18 41.4 100 9 Southern Europe (1) 64.7 75 15 70.3 72 9 Other EU countries (2) 18.6 21 18 24.1 25 30 Other markets 3.7 4 46 3.2 3 (12) SLIT 71.3 82 19 81.0 83 14 SCIT 12.3 14 4 12.8 13 4 Other products 3.4 4 6 3.8 4 10 H1 sales 87.0 100 16 97.6 100 12 (1) Portugal, Spain, France, Italy, Greece; (2) Switzerland included

HY1 sales

2nd quarter growth remained high at 9% (organic* 8%), but slowed down compared with the very strong start of the year. Sales growth over the first half-year remained strong at 12% (organic 11%), reflecting the continuing breakthrough of the sublingual route (+14%), which represented 83% of total sales.

The analysis by geographic region highlights the sharp increase of “Other EU countries” to 30% of sales, primarily due to the successful launch of Oralair(R) and the price increases introduced in Germany, as well as the transfer of the operations to a subsidiary in Switzerland.

Growth was more moderate in Southern Europe (up 9%). In addition to the consequences of weak pollen seasons in 2008, these markets appeared more affected by the economic crisis in a context of partial reimbursement (Italy and Spain).

The decline in “Other markets”, a very diverse group whose performance is volatile, was mostly due to exceptional 2008 sales and foreign exchange effects.

HY1 highlights

5 years of research were rewarded in the 1st half-year 2009 with the positive results of the phase III clinical study carried out on the house dust mite desensitization tablet.

Moreover, the mutual recognition procedure for Oralair(R) (grass pollen desensitization tablet) started at an operational level and should lead to registration in most European countries by the end of 2009.

Outlook

The 1st half-year 2009 financial results, to be published on 26 August next after close of trading, should report a slight improvement over the 1st half-year 2008.

We confirm our previously issued full-year guidance of sales growth of about 10% and an operating profit maintained at the same high level as 2008, against a background of strong accompanying R&D investments.

Lastly, the second half-year will be marked by a particularly busy news flow: 3 Oralair(R) phase III studies (US, 3rd year of long-term study, protocol optimization), 1 phase IIb/III study on the birch pollen desensitization tablet, which for the first time includes a recombinant allergen, and 1 phase III Staloral(R) study on asthma, carried out in China.

Shareholders’ agenda

The 2009 first half-year results will be presented on 27 August 2009 at 11.30am CET at Le Bristol hotel, 112, rue du Faubourg Saint-Honore, 75008 Paris, France.

A webcast of the meeting will be available both in French and English from 3pm.

ABOUT STALLERGENES

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

In 2008, Stallergenes had sales of EUR 171 million and provided desensitization treatments to more than 500,000 patients.

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

Additional financial information is available at: www.stallergenes.com

* Excluding foreign exchange effects

Source: Stallergenes

Contacts: Albert Saporta, Chairman and CEO, Tel: +33-1-55-59-20-04, Christian Thiry, Chief Financial Officer, Tel: +33-1-55-59-20-95, e-mail: investorrelations 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; Stallergenes Press Relations, Lise Lemonnier, Communication Officer, Tel: + 33-1-55-59-20-96, e-mail: llemonnier at stallergenes.fr