Astellas Enters into Partnership With Optimer on Life-Saving Antibiotic Fidaxomicin

Staines, England (ots/PRNewswire) - Astellas Pharma
Europe Ltd. announced today that it has entered into an exclusive
collaboration and license agreement with Optimer Pharmaceuticals
Inc., San Diego for the development and commercialisation of
fidaxomicin, an investigational antibiotic for Clostridium difficile
infection (CDI) in Europe and certain other countries in the Middle
East, Africa and the Commonwealth of Independent States (CIS).

Fidaxomicin is an orally administered, macrocyclic antibiotic
with a new mechanism and narrow spectrum of action. This novel
medicine is currently being reviewed for market authorisation in both
the US and Europe for the treatment of CDI and reduction in the risk
of recurrence when used for treatment of initial CDI. Optimer filed
the marketing authorisation application (MAA) for fidaxomicin with
the European Medicines Agency (EMA) on 2 August 2010, and the EMA
accepted it for review as treatment for patients with Clostridium
difficile infection (CDI) and for the recurrences of CDI in the EU.
Additionally, although Astellas will not have marketing rights to
fidaxomicin in the United States, Optimer filed a New Drug
Application (NDA) for the product with the Food and Drug
Administration (FDA) late last year, and the FDA has accepted that
application and has granted the company's request for a six-month
Priority Review, assigning a Prescription Drug User Fee Act goal date
of 30 May 2011.

To date, two phase III clinical studies have been completed
showing that fidaxomicin successfully met the primary endpoint of
non-inferiority when comparing the treatment to oral vancomycin in
achieving clinical cure - defined as patients requiring no further
CDI therapy two days after completion of study medication, as
determined by the investigator. Furthermore in both trials,
fidaxomicin was statistically superior to vancomycin in global cure
and in reducing recurrences of CDI by up to 47%. This evidence is of
great significance given that the medical community has yet to find a
successful and reliable treatment for recurrent CDI.

"We believe the strengths of Astellas' world-class anti-infective
business capabilities including established relationships with payers
and hospitals in Europe and other markets, combined with Optimer's
novel therapeutic for CDI, represents the most effective way to
address a serious, unmet health need," said Mr. Masao Yoshida,
President and CEO of Astellas Pharma Europe Ltd. "We look forward to
bringing fidaxomicin to these markets to help patients and providers
address this serious life threatening disease."

Under the terms of the agreement, Astellas is granted exclusive
rights to develop and commercialise fidaxomicin in Europe and certain
other countries in the Middle East, Africa and the Commonwealth of
Independent States (CIS). Astellas will pay EUR50 million up front
and approximately EUR115 million in milestone payments on achievement
of pre-specified development and sales milestones.

"We expect the Astellas collaboration will help Optimer realize
the full potential of fidaxomicin and will help position this
medication in these countries as the first line of treatment, both
for treating CDI and reducing recurrences," said Pedro Lichtinger,
Optimer's President and CEO. "CDI poses a significant cost burden on
the healthcare system, and we believe, if approved, fidaxomicin will
provide a cost-savings opportunity for hospitals and payers,
especially when used in populations at risk of recurrence such as the
elderly, patients with a prior episode, those taking concomitant
antibiotics, immuno compromised patients or those with renal
impairment."

Clostridium difficile, commonly referred to as "C.difficile" or
"C.diff" is a bacteria that causes serious illness- through infecting
the inner lining of the colon and producing toxins that cause
inflammation of the colon, severe diarrhoea and in the most serious
cases, death. Patients typically develop CDI following the use of
broad-spectrum antibiotics that disrupt the normal gastrointestinal
(gut) flora, thus allowing Clostridium difficile bacteria to flourish
and produce harmful side effects.

Clostridium difficile in Europe is associated with significant
health and economic burden, and incidence of this serious disease has
been increasing across Europe over the last 10 years. Treatments that
provide both a high success rate and low infection recurrence rate
are, therefore, welcomed in order to combat this illness.

Astellas already has an ongoing commitment to combating
infectious disease through the worldwide launch of its injectable
antifungal, the echinocandin Mycamine(R) (micafungin), and in
September 2009, the launch in the United States of Vibativ(R)
(telavancin) an injectable antibacterial for the treatment of adults
with infections caused by gram-positive pathogens including MRSA.
Astellas is currently liaising with the European regulatory
authorities to license Vibativ for the treatment of adults with
Nosocomial Pneumonia and complicated Skin and Soft Tissue Infections
(cSSTIs). In addition, Astellas is continuing to develop its
franchise in infectious disease with the development of
isavuconazole, an antifungal for the treatment of invasive fungal
infections, including Aspergillosis. The compound is currently in
Phase III trials. This new partnership is an important step to
further expand our business and to reinforce our franchise in
infectious diseases.

About Astellas Pharma Europe Ltd:

Astellas Pharma Europe Ltd., located in the UK, is a European
subsidiary of Tokyo-based Astellas Pharma Inc. Astellas is a
pharmaceutical company dedicated to improving the health of people
around the world through the provision of innovative and reliable
pharmaceuticals. The organisation is committed to becoming a global
company by combining outstanding R&D and marketing capabilities and
continuing to grow in the world pharmaceutical market. Astellas
Pharma Europe Ltd. is responsible for 21 affiliate offices located
across Europe, the Middle East and Africa, an R&D site and three
manufacturing plants. The company employs approximately 3,900 staff
across these regions. For more information about Astellas Pharma
Europe, please visit http://www.astellas.eu.

About Optimer Pharmaceuticals:

Optimer Pharmaceuticals, Inc. is a biopharmaceutical company
focused on discovering, developing and commercializing hospital
specialty products to treat serious infections and address unmet
medical needs. Optimer has two anti-infective product candidates in
development, fidaxomicin and Pruvel(TM) (prulifloxacin). Fidaxomicin
is a narrow spectrum antibiotic being developed for the treatment of
Clostridium difficile infection. The FDA granted Optimer's request
for a six-month Priority Review of fidaxomicin, and has assigned a
Prescription Drug User Fee Act (PDUFA) goal date of May 30, 2011.
Optimer has also filed a MAA with the European Medicines Agency (EMA)
for fidaxomicin. Pruvel(TM) is a prodrug in the fluoroquinolone class
of antibiotics being developed as a treatment for infectious
diarrhea. Additional information can be found at
http://www.optimerpharma.com.

Contacts for inquiries or additional information
Astellas Pharma Europe Ltd
Corporate Communications
Mindy Dooa
Tel: +44(0)1784-419408
http://www.astellas.eu

ots Originaltext: Astellas Pharma Europe Limited
Im Internet recherchierbar: http://www.presseportal.de

Contact:
CONTACT: Contacts for inquiries or additional information: Astellas
PharmaEurope Ltd, Corporate Communications, Mindy Dooa, Tel:
+44(0)1784-419408