Phase III Clinical Trial with 4-Month Long-Acting Formulation of Triptorelin: Ipsen Decides Not to Perform Further Administration

Regulatory News:

Ipsen (Paris:IPN) announced today that the preliminary data from
the ongoing phase III study for its investigational 4-month
formulation of triptorelin do not support the expected sustainable
blood levels of triptorelin for a duration of 4 months in all
patients. Therefore, Ipsen has decided not to perform the second
administration as planned in the protocol. No safety concerns have
been observed throughout the trial. At the end of their respective
monitoring period, patients will be switched to appropriate approved
treatment.

The 4-month investigational product, one of Ipsen's new sustained
release formulation candidates of triptorelin using one amongst
several Ipsen proprietary technologies, has shown an adequate efficacy
and safety profile in phase II allowing a move to phase III. Ipsen's
goal remains to have a new formulation of triptorelin available when
the current patents of the 3-month formulation of Decapeptyl(R)
expire.

Jacques-Pierre Moreau, Executive Vice-President, Chief Scientific
Officer of Ipsen said: "We are taking all appropriate actions to solve
the scale-up issues seen during this phase III, which are inherent to
advanced formulations based on cutting edge technologies. From the
onset, the introduction of an innovative subcutaneous presentation
using a new retro-injection device was well received by patients and
investigators. Thus, the teams are now focusing their energy and
expertise in order to resume phase III as soon as possible. Our
advanced drug delivery platform has already been validated through the
success of Somatuline(R) Autogel(R), and we are confident in Ipsen's
ability to have a differentiated formulation of triptorelin."

About triptorelin

Triptorelin is a metabolically stabilized analogue of LHRH
(Luteinizing Hormone Releasing Hormone) an hypothalamic hormone
secreted in a pulsatile fashion. Upon binding to its pituitary
receptor LHRH triggers the release of luteinizing hormone, a key
factor for the regulation of reproductive function. Continuous
administration of exogenous LHRH or its agonists such as triptorelin
leads to a rapid desensitization of its pituitary receptor resulting
in a paradoxical effect that translates into the suppression of
gonadal steroids such as testosterone and estradiol. This chemically
induced and reversible castration is of therapeutic benefit in the
treatment of hormone sensitive tumours such as breast and prostate.
Triptorelin is the active ingredient of Decapeptyl(R) and
Diphereline(R) available as 1- and 3-month sustained release
formulations registered for the treatment of advanced metastatic
hormone-dependent prostate cancer.

About Ipsen

Ipsen is an innovation driven international specialty
pharmaceutical group with over 20 products on the market and a total
worldwide staff of nearly 4,000. The company's development strategy is
based on a combination of products in targeted therapeutic areas
(oncology, endocrinology and neuromuscular disorders) which are growth
drivers, and primary care products which contribute significantly to
its research financing. This strategy is also supported by an active
policy of partnerships. The location of its four Research and
Development centres (Paris, Boston, Barcelona, London) gives the Group
a competitive edge in gaining access to leading university research
teams and highly qualified personnel. In 2006, R&D expenditure was EUR
178.3 million, i.e. 20.7% of consolidated sales, which amounted to EUR
861.7 million while total revenues amounted to EUR 945.3 million (in
IFRS). 700 people in R&D are dedicated to the discovery and
development of innovative drugs for patient care. Ipsen's shares are
traded on Segment A of Eurolist by Euronext(TM) (stock code: IPN, ISIN
code: FR0010259150). Ipsen's shares are eligible to the "Systeme a
Reglement Differe" ("SRD") and the Group is part of the SBF 250 index.
For more information on Ipsen, visit our website at www.ipsen.com.

Forward-looking statements

The forward-looking statements and targets contained herein are
based on Ipsen's management's current views and assumptions. Such
statements involve known and unknown risks and uncertainties that may
cause actual results, performance or events to differ materially from
those anticipated herein. Moreover, the Research and Development
process involves several stages at each of which there is a
substantial risk that the Group will fail to achieve its objectives
and be forced to abandon its efforts in respect of a product in which
it has invested significant sums. Therefore, the Group cannot be
certain that favourable results obtained during pre-clinical trials
will be confirmed subsequently during clinical trials, or that the
results of clinical trials will be sufficient to demonstrate the safe
and effective nature of the product concerned. Ipsen expressly
disclaims any obligation or undertaking to update or revise any
forward-looking statements, targets or estimates contained in this
press release to reflect any change in events, conditions, assumptions
or circumstances on which any such statements are based, unless so
required by applicable law. Ipsen's business is subject to the risk
factors outlined in its information documents filed with the French
Autorite des Marches Financiers.