Biogen Idec Issues Statement

Biogen Idec Inc. (NASDAQ: BIIB) today announced that its Board of
Directors has authorized management to evaluate whether third parties
would have an interest in acquiring the Company at a price and on
terms that would represent a better value for its stockholders than
having the Company continue to execute its strategy on a stand-alone
basis.

The Board emphasized that Biogen Idec's strategy is working and
generating strong operating and financial performance. The Board noted
that it is confident that the Company's business outlook, described in
Biogen Idec's press release on September 6, will result in attractive
value for stockholders. Nevertheless, to determine whether potential
strategic interest on the part of major pharmaceutical companies might
result in superior value in the current environment, the Board has
authorized management to explore interest in a transaction with Biogen
Idec.

In addition, the Company disclosed it has received expressions of
interest, including one from investor Carl Icahn. The Company does not
intend to disclose further information regarding the status of its
evaluation until the process has been completed. Biogen Idec
emphasizes that there can be no assurance that an acquisition of the
Company will occur.

To assist in this process, the Company has retained the services
of Goldman Sachs & Co. and Merrill Lynch & Co. as financial advisors.

In a press release and in a presentation to investors on September
6, 2007, Biogen Idec announced a series of goals that it would seek to
achieve by year-end 2010. These include:

-- 100,000 patients on TYSABRI(R);

-- More than 40% of the Company's revenue coming from its
International business;

-- Four new products and/or existing products launched in new
indications;

-- Six programs in late-stage clinical development; and

-- Generating revenue growth at a 15% compound annual growth rate
(CAGR) and non-GAAP EPS at a 20% CAGR from 2007 through 2010.

About Biogen Idec

Biogen Idec creates new standards of care in therapeutic areas
with high unmet medical needs. Founded in 1978, Biogen Idec is a
global leader in the discovery, development, manufacturing, and
commercialization of innovative therapies. Patients in more than 90
countries benefit from Biogen Idec's significant products that address
diseases such as lymphoma, multiple sclerosis, and rheumatoid
arthritis. For product labeling, press releases and additional
information about the company, please visit www.biogenidec.com.

Safe Harbor

This press release contains forward-looking statements about our
expected revenues, earnings, cash flows, product sales, product
development and other matters. Forward-looking statements are subject
to risks and uncertainties that could cause actual results to differ
materially from that which we expect. Important factors that could
cause our actual results to differ include our continued dependence on
our two principal products, AVONEX(R) and RITUXAN(R), the uncertainty
of success in commercializing other products including TYSABRI(R), the
occurrence of adverse safety events with our products, the failure to
execute our growth strategy successfully or to compete effectively in
our markets, our dependence on collaborations over which we may not
always have full control, possible adverse impact of government
regulation and changes in the availability of reimbursement for our
products, problems with our manufacturing processes and our reliance
on third parties, fluctuations in our operating results, our ability
to protect our intellectual property rights and the cost of doing so,
the risks of doing business internationally and the other risks and
uncertainties that are described in Item 1A "Risk Factors" in our most
recent Form 10-Q filing with the SEC. These forward-looking statements
speak only as of the date of this press release, and we do not
undertake any obligation to publicly update any forward-looking
statements, whether as a result of new information, future events, or
otherwise.