STALLERGENES and ActoGeniX to Develop Together an Innovative New Class of Oral Treatments for Allergy

-- STALLERGENES to develop and commercialize novel oral allergy drugs based
      on ActoGeniX's proprietary local mucosal delivery technology 

   -- ActoGeniX eligible for milestone payments up to EUR 75 million per
      allergen and for royalties on STALLERGENES' net sales

ANTONY, France & GHENT, Belgium--STALLERGENES S.A. (Paris:GENP) (Euronext Paris: GENP), worldwide leader in allergen immunotherapy, and ActoGeniX NV, creator of ActoBiotics(TM) , announced today that they have entered into an agreement for the development of innovative first-in-class treatments of allergic diseases.

ActoBiotics(TM) , which are genetically engineered lactic acid bacteria, is a breakthrough mucosal delivery technology based on the oral administration and local mucosal delivery of recombinant allergens, expressed and secreted at the mucosa. This first-in-class technology modulates the immune response to allergens and could significantly increase the efficacy of allergen immunotherapy treatments, with a reduced dose of allergens.

Under the terms of this agreement, ActoGeniX will be responsible for the creation of ActoBiotics(TM) expressing and secreting a range of allergens. ActoGeniX will deliver to STALLERGENES clinical product candidates that express a set of predefined allergens. Upon exercise of its option, STALLERGENES will have full development and exclusive worldwide commercialization rights on the product candidates, and ActoGeniX will be eligible to receive upfront, preclinical, clinical, regulatory and commercial milestone payments totaling up to EUR 75 million per allergen, as well as tiered royalties on the future product's net sales.

STALLERGENES currently holds an option to different groups of allergens amongst the most prevalent and with the highest unmet medical needs. Further details are not disclosed.

Dr. Bernard Coulie, CEO of Actogenix, said:

To have our delivery platform recognized in an entirely new therapeutic domain by a global leader is clear proof that we have created scientific value over the past 6 years. We can continue our focus on our existing pipeline, while teaming up with STALLERGENES in allergic diseases."

Dr. Roberto Gradnik, Chief Executive Officer of STALLERGENES, said: "This collaboration with ActogeniX on their very promising new delivery platform is another illustration of STALLERGENES' commitment to innovation. The ActoBiotics(TM) technology could provide even greater efficacy and a targeted delivery of allergen-based treatments, for the benefit of allergic patients."

About ActoGeniX

ActoGeniX is a biopharmaceutical company focused on the development and commercialization of ActoBiotics(TM), a novel class of orally available biopharmaceuticals for the targeted treatment of severe diseases with a high medical need. ActoBiotics(TM) represent a novel concept for oral administration of therapeutic proteins, and are designed to be safer and more effective than injectable biopharmaceuticals. ActoBiotics(TM) can deliver a wide range of therapeutic peptides and proteins, including cytokines, enzymes, hormones and monoclonal antibodies.

ActoGeniX has confirmed the broad applicability of ActoBiotics(TM) and its proprietary technology platform for a wide range of diseases, including oral, gastrointestinal, metabolic, immune, and allergic diseases.

ActoGeniX was founded in 2006 as a spin-off from VIB and Ghent University. The Company is headquartered in Ghent (Belgium) and employs 22 staff. ActoGeniX raised 46 million Euro (approximately 60 million US$) in 3 equity financing rounds from a consortium of leading life sciences investors such as Gimv, Biotech Fund Flanders, Baekeland Fund, Biovest, Saffelberg Investments (Belgium), Life Sciences Partners, Aescap Venture (The Netherlands) and Ventech (France).

ActoGeniX has a strong and broad intellectual property position with a patent estate encompassing more than 20 distinct patent families. With broad patent claims already granted in major territories like the US, Europe, Japan, and China ActoGeniX is uniquely positioned to successfully exploit the commercial potential of its promising ActoBiotics(TM).

www.actogenix.com

About STALLERGENES

STALLERGENES is an international biopharmaceutical company dedicated to the treatment of allergy-related respiratory diseases, such as severe rhinoconjunctivitis and rhinitis, as well as allergic asthma, using allergen immunotherapy. The leader in sublingual immunotherapy treatments, STALLERGENES devotes around 20% of its annual gross revenues to Research & Development and is actively involved in the development of a new therapeutic class: sublingual immunotherapy tablets.

In 2012, the Company generated revenues of EUR 240 million, and more than 500,000 patients were treated with STALLERGENES products.

Euronext Paris (Compartment B)

CAC small

ISIN: FR0000065674

Reuters: GEN.PA

Bloomberg: GEN.FP

Additional information is available at http://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.