Biogen Idec and mondoBIOTECH Sign Collaboration and Licensing Agreement to Develop and Commercialize Aviptadil for Pulmonary Arterial Hypertension

Biogen Idec (NASDAQ: BIIB) and mondoBIOTECH AG, a
private Swiss biotechnology company, today announced the signing of an
exclusive collaboration and license agreement for Biogen Idec to
develop, manufacture and commercialize Aviptadil, a clinical compound
for the treatment of Pulmonary Arterial Hypertension (PAH).
Under terms of the agreement, mondoBIOTECH will receive a $7.5
million upfront payment and up to $30 million in milestones payments
for successful development and commercialization of Aviptadil in PAH
in the United States (US) and Europe, as well as royalty payments on
commercial sales. Separately, Biogen Idec intends to make a minority
equity investment of $5 million in mondoBIOTECH during an envisaged
initial public offering.
"This in-licensing opportunity supports our strategic initiative
to expand into new therapeutic areas where we can leverage our global
capabilities in serving specialized medical markets with high unmet
need," said James C. Mullen, Biogen Idec's President and Chief
Executive Officer (CEO). "Aviptadil has the potential to be an
important therapy in treating pulmonary arterial hypertension, an
often deadly disease with few effective treatment options for
patients. We look forward to developing Aviptadil for these patients
and building on the strong work initiated by mondoBIOTECH."
"Biogen Idec is a premier biotechnology partner with a global
structure, excellent clinical development and commercialization
capabilities, and a strong record of accomplishments. We are excited
to enter this collaboration which is a validation for our business
model addressing fatal and rare lung diseases," said Fabio Cavalli,
CEO of mondoBIOTECH.
"Biogen Idec's support will strongly advance the development of
Aviptadil in PAH and our scientific efforts in identifying novel
therapies for rare diseases," stated Dorian Bevec, Ph.D., Chief
Science Officer of mondoBIOTECH.
In accordance with the agreement, Biogen Idec will be responsible
for the global manufacturing, clinical development, regulatory
approval and commercialization of Aviptadil. Biogen Idec intends to
finalize the development plan for Aviptadil and initiate additional
clinical work in 2007.

About Aviptadil

Aviptadil is a synthetically produced human peptide (Vasoactive
Intestinal Peptide) with Orphan Drug Designation status for PAH in the
European Community and in the US. In addition, Aviptadil is the first
drug to receive combined, parallel scientific advice for clinical
development in PAH from the US Food and Drug Administration and the
European Medicines Agency.
An open-label Phase II study, designed to evaluate the efficacy
and safety of inhaled Aviptadil in patients with PAH, achieved its
primary efficacy endpoint, showing an improvement in physical exercise
as measured by an increase in walking distance with three or six
months of treatment. No significant adverse events were observed in
the eight PAH patients treated in this trial. Larger studies will be
necessary to fully define the safety profile of Aviptadil.

About Pulmonary Arterial Hypertension (PAH)

PAH is a debilitating and life-threatening disorder characterized
by increased pressure in the pulmonary arteries. Patients suffer from
shortness of breath, fatigue, chest pain, and ultimately heart failure
and premature death. PAH can occur with no clear cause (idiopathic
PAH) or can be inherited (familial PAH), and is frequently secondary
to other conditions such as scleroderma, congenital heart disease,
HIV/AIDS or other disorders. PAH patients are typically classified by
functional ability on the World Health Organization (WHO) criteria,
increasing in severity from Class I to Class IV.
The disease affects approximately 100,000 to 200,000 people
worldwide. Despite increasing awareness of the disease among
clinicians, PAH is frequently undiagnosed and the unmet medical need
of patients continues to be high.

About mondoBIOTECH

mondoBIOTECH AG, a private Swiss breathing swiss air(TM) biotech
company headquartered in Basel is focused on development of treatment
options for fatal and rare lung diseases. In addition to PAH, the
company has a variety of clinical Phase II studies in pulmonary
diseases ongoing. For more information, please visit
www.mondoBIOTECH.com.

About Biogen Idec

Biogen Idec creates new standards of care in oncology, neurology
and immunology. As a global leader in the development, manufacturing,
and commercialization of novel therapies, Biogen Idec transforms
scientific discoveries into advances in human healthcare. For press
releases and additional information about the company, please visit
www.biogenidec.com.

Biogen Idec Safe Harbor

This press release contains forward-looking statements regarding
the agreement with mondoBIOTECH and the development of Aviptadil. Drug
development involves a high degree of risk. Only a small number of
research and development programs result in commercialization of a
product. Factors which could cause actual results to differ materially
from Biogen Idec's current expectations include the risk that the
company may not be able to demonstrate the safety and efficacy of
Aviptadil at each stage of the clinical trial process; technical
hurdles relating to the manufacture of Aviptadil may be encountered;
the company may not be able to meet applicable regulatory standards or
regulatory authorities may fail to approve Aviptadil; and the company
may encounter other unexpected hurdles. For more detailed information
on the risks and uncertainties associated with Biogen Idec's drug
development activities, see the section entitled "Risk Factors" in
Biogen Idec's quarterly report on Form 10-Q for the fiscal quarter
ended June 30, 2006 that was filed with the Securities and Exchange
Commission, as well as other periodic and current reports of Biogen
Idec filed with the Securities and Exchange Commission. Biogen Idec
assumes no obligation to update any forward-looking statements,
whether as a result of new information, future events or otherwise.