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Ipsen Announces Discontinuation of the Development of Irosustat in Monotherapy


Opportunities for Irosustat in combination  with other hormonal therapies will be further evaluated  
Paris  (France),  6  June  2011  –  Ipsen  (Euronext:  IPN  -  ADR:  IPSEY)  today  announced  its decision to assess the alternative development of Irosustat (BN 83495) in combination with other  hormonal  therapies.  This  decision  is  based  on  the  futility  analysis  from  the  proof-of-concept  trial  phase  II  clinical  study  carried  out  in  Europe  in  monotherapy  in  endometrial cancer, and on the phase I/II clinical study results obtained in metastatic prostate and breast cancers.
The  futility  analysis  of  the  European  study  in  patients  suffering  from  endometrial  cancer demonstrates that the primary endpoint will not be reached (patients on treatment for more than  6  months  without  progression)  and  that  the  superiority  will  not  be  demonstrated  with Irosustat versus megestrol acetate in terms of progression free survival (PFS). Thus, Ipsen has  decided  to  discontinue  the  development  of  Irosustat  in  monotherapy.  Of  note,  the treatment was well tolerated and has shown an inhibition of the steroid sulfatase associated with  a  significant  reduction  in  the  levels  of  some  circulating  steroid  hormones  and  with  insome  patients,  prolonged  clinical  partial  responses,  demonstrating  the  clinical  interest  of sulfatase inhibition.
On  the  basis  of  this  clinical  safety  profile  associated  with  the  reduction  of  hormonal parameters  and  with  this  potentially  encouraging  clinical  efficacy  signal  in  monotherapy, Ipsen will explore options to develop Irosustat in combination with other hormonal therapies in hormone-dependent cancers. This perspective comes in line with the recommendation of clinical expert committees.
About Irosustat
Irosustat  is a  first-in-class  orally  available  irreversible  steroid  sulfatase  (STS)  inhibitor.  The steroid sulfatase pathway gives rise to oestrone and dehydroepiandrosterone (DHEA) that in turn  produce  oestradiol  and  androstenediol  (Adiol)  that  can  both  stimulate  the  growth  of hormone-dependent tumors. This compound has been tested for postmenopausal metastatic breast cancer as well as in PI/II clinical development for castrate resistant prostate cancer.

There  are  three  Ipsen  sponsored  ongoing  clinical  studies  for  which  Ipsen  is  discontinuing
patient recruitment.

About this phase II European trial in endometrial cancer
The  European  clinical  trial  compares  single-agent  Irosustat  to  megestrol  acetate  (MA)  in post-menopausal women with histologically confirmed hormone receptor positive endometrial cancer, presenting with recurrent or advanced disease not eligible for treatment with surgery  The  primary  endpoint  for  the  study  was  the  proportion  of  patients  who  have  neither progressed  nor  died  after  6  months  of  treatment  with  Irosustat.  Progression  free  survival (PFS), clinical benefits and overall survival were evaluated as secondary endpoints. 

About Endometrial Cancer
Endometrial cancer, which develops from the inner lining of the uterus, is the most common cancer found in the female reproductive system. According to the American Cancer Society, about 40,100 new cases of endometrial cancer were diagnosed in the United States and approximately 7,470 women died from this disease
in 2008. There is a strong medical need for new products to be available in this indication. 
About Ipsen
Ipsen  is  a  global  biopharmaceutical  group,  with  sales  exceeding  €1.1  billion  in  2010.  The  Group  has  total
worldwide  staff  of  more  than  4,400  employees,  of  which  more  than  900  contribute  to  the  discovery  and
development of innovative drugs for patient care. Ipsen’s development strategy is based on fast growing specialty
care  drugs  in  oncology,  endocrinology,  neurology  and  hematology  and  on  primary  care  drugs.  This  strategy  is supported by an active policy of partnerships. Ipsen’s research & development (R&D) centers and its peptide & protein engineering platform give the Group a strong competitive edge. In 2010, R&D expenditure totaled more than €220 million, above 20% of Group sales. Ipsen’s shares are traded on segment A of Euronext Paris (stock code: IPN, ISIN code: FR0010259150) and eligible to the “Service de Règlement Différé” (“SRD”). The Group is part  of  the  SBF  120  index.  Ipsen  has  implemented  a  Sponsored  Level  I  American  Depositary  Receipt  (ADR) program,  which  trade  on  the  over-the-counter  market  in  the  United  States  under  the  symbol  IPSEY.  For  moreinformation on Ipsen, visit
Ipsen’s forward Looking Statement
The  forward-looking  statements,  objectives  and  targets  contained  herein  are  based  on  the  Group’s management strategy, 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  targets  described  in  this  document  were  prepared  without taking  into  account  external  growth  assumptions  and  potential  future  acquisitions,  which  may  alter these parameters. These objectives are based on data and assumptions regarded as reasonable by the  Group.  These  targets  depend  on  conditions  or  facts  likely  to  happen  in  the  future,  and  not exclusively  on  historical  data.  Notably,  future  currency  fluctuations  may  negatively  impact  the profitability of the Group and its ability to reach its objectives. Actual results may depart significantly from these targets given the occurrence of certain risks and uncertainties. The Group does not commit nor gives any guarantee that it will meet the targets mentioned above. Furthermore, the Research and Development process involves several stages each of which involve the substantial risk that the Group may  fail  to  achieve  its  objectives  and  be  forced  to  abandon  its  efforts  with  regards  to  a  product  in
which it has invested significant sums. Therefore, the Group cannot be certain that favorable 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. The  Group  also  depends  on  third  parties  to  develop  and  market  some  of  its  products  which  could potentially  generate  substantial  royalties;  these  partners  could  behave  in  such  ways  which  could cause  damage  to  the  Group’s  activities  and  financial  results.  The  Group  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. The Group’s  business  is  subject  to  the  risk  factors  outlined  in  its  registration  documents  filed  with  the French Autorité des Marchés Financiers. 
For further information
Didier Véron
Director, Public Affairs and Corporate Communications
Tel.: +33 (0)1 58 33 51 16 
Fax: +33 (0)1 58 33 50 58
Financial Community
Pierre Kemula
Stéphane Durant des Aulnois
Investor Relations Officer
Tel.: +33 (0)1 58 33 60 08 
Fax: +33 (0)1 58 33 50 63
Investor Relations Manager
Tel.: +33 (0)1 58 33 60 09 
Fax: +33 (0)1 58 33 50 63

Posted: June 2011

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