STALLERGENES : Sales Guidance Exceeded : €193 Million, up 13%

Strong Sales Growth in Q4: Up 15%

ANTONY, France, January 14 -

    Million EUR              2008           08/07    2009              09/08
                             MEUR   %Sales  Var.%    MEUR     %Sales   Var.%
    Southern Europe (1)        36.4     73      14      42.4        74    16
    Other EU countries (2)     11.3     23      17      13.1        23    16
    Other markets               2.0      4      45       1.5         3   (25)

    SLIT                       40.4     81      17      48.5        85    20
    SCIT                        7.5     15       6       6.8        12   (10)
    Other products              1.8      4      32       1.7         3    (5)

    Total Q4 sales             49.7    100      15      57.0       100    15

    Million EUR              2008           08/07    2009              09/08
                             MEUR   %Sales  Var.%    MEUR     %Sales   Var.%
    Southern Europe (1)       124.9     73      14     138.6        72    11
    Other EU countries (2)     38.5     23      18      47.6        25    24
    Other markets               7.5      4      38       6.7         3   (11)

    SLIT                      137.9     81      18     160.0        83    16
    SCIT                       26.3     15       6      25.9        13    (2)
    Other products              6.7      4      16       6.9         4     4

    Cumulated sales           170.9    100      16     192.8       100    13
    (1) Portugal, Spain, France, Italy, Greece; (2) Switzerland
    included

Sales growth and financial position

Sales growth sped up over the fourth quarter to 15%, 3
percentage points higher than that of third quarter 2009. The markets of
Northern Europe ("Other EU") and the sublingual route drove this progression
but the markets of Southern Europe had an encouraging recovery in growth over
the last quarter. Other markets were affected by a negative basis effect due
to the strong growth achieved in 2008.

Organic growth, after restatement for foreign exchange effects
stood at 13% over the quarter and 12% over the full year.

As a consequence, results for the year will markedly improve:
operating profit and net profit as a percentage of sales should remain close
to the levels achieved in 2008 (16% and 11%, respectively). The Company had a
positive net cash position at the end of the financial year.

The comprehensive 2009 results will be published on 16 March
2010 after close of trading.

As for 2010, the Group is currently expecting significant
growth and a further improvement in its results due to the limitation put on
R&D expenses.

Significant 4th quarter transactions and events

Following the mutual recognition procedure, Oralair(R)
(immunotherapy tablet for grass pollen) was granted a marketing authorisation
in 22 European countries in its adult and paediatric indications on 27
November 2009.

The outstanding results of the study devoted to showing the
long-term sustained effect of Oralair(R) were announced on 7 December 2009.
They significantly confirmed the clinical relevance of Oralair(R). This study
is being continued with a view to demonstrating the persistence of the effect
after completion of the treatment (carry-over effect), which should be the
subject of an announcement at the end of 2010.

The Oralair(R) phase III clinical study in the US was
completed in good conditions. Talks are ongoing with the FDA on statistical
analysis matters. These exchanges have no impact on the results of the study
but must be concluded before the database is opened for analysis.
Consequently, the delivery of the preliminary results will take place in a
few weeks.

The authorisation to carry out a Phase III clinical study on
children for Actair(R) (immunotherapy tablet for dust mites) on 450 patients
has been granted in Europe and patients are being recruited. The preliminary
results should be published in mid-2011.

The presentation of the clinical results obtained in 2009 and
at the start of 2010 will be the subject of a specific meeting, to be
organised shortly.

About Stallergenes

Stallergenes is a European biopharmaceutical laboratory
specialising in treatments by immunotherapy for the prevention and treatment
of allergy-related respiratory conditions, such as rhino conjunctivitis,
rhinitis and allergic asthma. Stallergenes is ranked seventh among French
pharmaceutical laboratories. A pioneer and a leader in immunotherapy
treatments by sublingual administration, Stallergenes dedicates 21% (gross)
of its sales to its Research and Development activities, which are primarily
directed at developing a new therapeutic range enabling the provision of
immunotherapy treatments by sublingual tablets.

Stallergenes realised 2009 sales of EUR 193 million, with over
500,000 patients treated with Stallergenes desensitisation products.

Euronext Paris (Compartment B).

SBF 120 index.

ISIN code: FR0000065674

Reuters code: GEN.PA

Bloomberg code: GEN.FP

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

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