STALLERGENES : Patrick Langlois Appointed Non Executive Chairman of the Board of Directors of Stallergenes

Regulatory News:

Stallergenes (Paris:GENP)(Euronext Paris CAC small) announces the appointment of Patrick Langlois as non executive Chairman of the Board of Directors, with effect from 1^st July 2012.

Patrick Langlois has more than 30 years of experience at a global level for companies and markets in the healthcare sector. Having notably served as Group Executive Vice President, Chief Financial Officer and Vice-Chairman of the Management Board of Aventis S.A, he has developed significant expertise both in enterprise development and strategy and merger and acquisition transactions in the pharmaceutical industry.

"We are delighted to have Patrick Langlois as Chairman; his experience in the international development and in mergers and acquisitions of healthcare companies will be an undeniable strength in turning Stallergenes into a global pharmaceutical laboratory", stated Roberto Gradnik, Chief Executive Officer of Stallergenes.

In accordance with his wishes, Albert Saporta, whose term of office as Chairman expires on 30 June 2012, will remain as a member of the Board of Directors to continue to support Stallergenes' development.

Furthermore, Jean-Michel Lévy, an Independent Director, has tended his resignation on 27^th May 2012 to the Chairman of the Board of Directors, who duly took note of this. The Board has decided to co-opt a new Director to replace Jean-Michel Lévy. The co-option will take place over forthcoming meetings of the Board of Directors.

ABOUT STALLERGENES

Stallergenes is a European biopharmaceutical company specialised in the treatment by allergen immunotherapy of allergy related respiratory diseases, such as severe rhinoconjunctivitis and rhinitis, as well as allergic asthma. The seventh largest pharmaceutical company in France and the leader in sublingual immunotherapy treatment, Stallergenes devotes almost 20% of its gross turnover to Research & Development and is actively involved in the development of a new therapeutic class, sublingual immunotherapy tablets.
In 2011, the company had sales of ? 235 million and more than 500,000 patients were treated with Stallergenes products

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

For further information, please visit our website: www.stallergenes.com

Forward-looking statements related to Stallergenes
This press release may contain forward-looking statements, including forecasts of future revenue and operating profit as well as expected business-related events. Such statements are based upon the current beliefs and expectations of Stallergenes' management and are subject to risks and uncertainties. Actual results may differ from those set forth in the forward-looking statements, due to various factors. Without being exhaustive, such factors include economic situations and business conditions, including legal and product evaluation issues, fluctuations in currencies and demand, changes in competitive factors and reliance on suppliers. The Company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information or future events and except as required by law.

Roberto Gradnik, Chief Executive Officer
Tel: [phone]
or
Investor and Analyst Relations
Christian Thiry, Chief Financial Officer
Tel: [phone]
e-mail: [e-mail]
Pavie Finance: Lucile de Fraguier
Tel: [phone]
e-mail: [e-mail]
or
Press relations
Lise Lemonnier, Communication Manager
Tel: + 33 1 55 59 20 96
e-mail: [e-mail]
Chandler Chicco Agency: Bahar Turkoglu
Tel: + 33 1 41 43 02 27
e-mail: [e-mail]