Biogen Idec Issues Statement.

CAMBRIDGE, Mass. -- 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.