Biogen Idec Commences Mailing of Proxy Materials to Shareholders



    Biogen Idec (Nasdaq: BIIB) today commenced the mailing of proxy

    materials encouraging shareholders to vote at the company´s

    June 19, 2008 Annual Meeting for four highly regarded and accomplished

    individuals nominated for election by the Board of Directors. In the

    proxy materials, shareholders are advised by the Board to reject the

    three director nominees proposed by Carl Icahn.
    In a letter to shareholders accompanying the proxy materials, Chairman

    Bruce R. Ross and Chief Executive Officer James C. Mullen note that

    three of the Board´s nominees, Cecil B.

    Pickett, Ph.D., Lynn Schenk and Phillip A. Sharp, Ph.D., have

    contributed as directors to the growth and success of the company, and

    Stelios Papadopoulos, Ph.D., a new nominee, is an investment banker with

    a distinguished career in biotechnology.
    The letter emphasizes three critical points for shareholders to consider

    in determining their vote:
    1. The Biogen Idec Board, including the three directors up for

    re-election, has a track record of delivering value, as evidenced by the

    company´s consistently strong financial

    results and stock performance exceeding the Amex Biotechnology Index

    (BTK) by 26% in the four-plus years since the Biogen Idec merger (as of

    May 2, 2008).
    2. Each of the Board´s four nominees is

    committed to creating significant value for all shareholders and will

    continue to pursue all options to do so.
    3. Mr. Icahn has consistently promoted a single-minded agenda to sell

    the company. The company believes that electing his slate will impair

    the company´s efforts to deliver and drive

    shareholder value.
    The letter cautions shareholders not to "jeopardize

    your company´s continued growth by electing to

    your Board an Icahn faction committed only to a sale of the company

    regardless of whether that is in your best interests as a shareholder." Shareholders are asked to "elect your Board´s

    nominees who are committed to creating value for all owners and who are

    open to all options to create shareholder value."
    The full letter to shareholders follows:
    May 8, 2008
    Dear Fellow Shareholder:
    Your vote at the June 19, 2008 Annual Meeting is critically important to

    the future of your investment in Biogen Idec.
    As you may know, Carl Icahn has launched a proxy contest to get his

    hand-picked representatives elected to the Biogen Idec Board of

    Directors.
    We strongly urge you to vote for the four highly regarded and

    accomplished individuals nominated by your Board. Please use the WHITE proxy card to vote today "“ by telephone, by

    Internet or by signing, dating and returning the enclosed WHITE proxy card.
    It is important that you carefully consider these three critical points:
    1. Your Board, including the three directors up for re-election, has a

    track record of delivering value, as evidenced by your company´s

    consistently strong financial results and stock performance exceeding

    the Amex Biotechnology Index (BTK) by 26% in the four-plus years since

    the Biogen Idec merger.1
    2. Each of your Board´s four nominees is

    committed to creating significant value for all shareholders and will

    continue to pursue all options to do so.
    3. Mr. Icahn has consistently promoted a single-minded agenda to sell

    the company. Electing his slate will impair our efforts to deliver and

    drive shareholder value.
    A PROVEN TRACK RECORD OF DELIVERING VALUE
    Your Board has an exceptional record of creating value for all

    shareholders. The proof is in the results (see chart 1 in accompanying

    multimedia).
    Your Board´s superior leadership has

    benefited all shareholders:

    Your Board has delivered on the revenue and earnings goals set at the

    time of the 2003 merger of Biogen, Inc. and IDEC Pharmaceuticals

    Corp., generating 14% compound annual revenue growth and 22% compound

    annual non-GAAP earnings growth.

    In 2007, Biogen Idec generated nearly $3.2 billion in revenues.

    In the first quarter of 2008, we reported revenues of $942 million, up

    32% from the same period last year, and non-GAAP diluted earnings per

    share (EPS) of $0.83, up 41%.

    Your company has grown into a true industry leader. Since the merger

    its value has grown by more than $7 billion to $18.3 billion as of May

    2, 2008. The stock price outperformed the industry over this four-year

    period, rising 86% compared to 68% for the BTK, the industry benchmark

    index. In the past year, the business gained even greater momentum with

    the stock price increasing an impressive 30%, while the BTK fell 9% (see

    chart 2 in accompanying multimedia).
    COMMITTED TO CREATING VALUE FOR ALL SHAREHOLDERS
    Your Board has nominated four highly regarded and accomplished

    individuals. Cecil B. Pickett, Ph.D., Lynn Schenk and Phillip A. Sharp

    Ph.D., have contributed as directors to the growth and success of your

    company. Stelios Papadopoulos, Ph.D., a new nominee, is an investment

    banker with a distinguished career in the biotechnology sector.
    Each of these individuals is committed to building on the strong growth

    momentum already underway at Biogen Idec. They, like the rest of your

    Board, are open to all opportunities for continuing to build value and

    will objectively evaluate all options for maximizing your investment in

    Biogen Idec. That commitment includes considering a potential sale as

    circumstances evolve.
    Your Board conducted a thorough sale process last fall that resulted in

    no offers to buy the company. This Board is focused on executing a

    comprehensive strategic growth plan that does not rely on any single

    event or single approach; rather its components include:

    Growing the sales and markets for our approved products;

    Advancing our robust product pipeline;

    Continuing disciplined business-development efforts to enrich our

    pipeline and product portfolio; and

    Attracting and retaining top professionals, including medical and

    scientific talent.

    By focusing on executing our strategic plan and driving the business

    forward, we intend to continue to grow revenues at a 15% compound annual

    growth rate (CAGR) and non-GAAP diluted EPS at a 20% CAGR through 2010.
    Our goals for 2010 are supported by our 2008 financial guidance, which

    we raised on April 23 when we reported our outstanding first-quarter

    results:

    Total revenue growth of 20% over 2007;

    Non-GAAP diluted EPS in the range of $3.25-$3.45, representing growth

    consistent with our stated goal of achieving 20% non-GAAP EPS compound

    growth through 2010.

    WE BELIEVE ELECTING THE ICAHN FACTION WILL HARM SHAREHOLDER VALUE
    After the receipt last fall of an offer for the company from Mr. Icahn

    as well as other expressions of interest, the Board of Directors

    determined it was appropriate to explore whether the sale of the company

    could generate greater value for shareholders than continuing to execute

    upon our business strategy as an independent company. Mr. Icahn chose

    not to participate in the process.
    Your Board, in consultation with management and independent advisors

    developed and executed a sale process that was professional, objective

    and thorough. In the end, market conditions were not right, and

    definitive bids for the company were not made.
    Despite those facts, Mr. Icahn and his nominees insist on advancing a

    single-minded agenda of forcing a sale of the company. In light of the

    results of the recent sale process, your Board has concerns about the

    consequences of restarting a sale process at this time.
    Pursuing such a single-minded strategy, especially within the six-month

    timeframe that Mr. Icahn has publicly specified, poses a very real risk

    to shareholder value and the strong growth momentum currently underway

    at your company. The ongoing uncertainty of putting a perpetual "for

    sale" sign on the company would harm our

    efforts to attract and retain top professionals "“ including top medical and scientific talent "“ and our ability to execute strategic partnerships and licensing

    agreements.
    Over more than two decades, Mr. Icahn has waged a long string of proxy

    fights, largely against underperforming companies. In stark contrast

    Biogen Idec has been delivering strong performance and your company´s

    prospects for growth have never been better. Even Mr. Icahn has said

    that Biogen Idec is a "great company," and we agree.
    Do not jeopardize your company´s continued

    growth by electing to your Board an Icahn faction committed only to a

    sale of the company regardless of whether that is in your best interests

    as a shareholder.
    We urge you to elect your Board´s nominees

    who are committed to creating value for all owners and who are open to

    all options to create shareholder value.
    Please vote today to re-elect Cecil B. Pickett, Ph.D., Lynn Schenk and

    Phillip A. Sharp, Ph.D., and elect Stelios Papadopoulos, Ph.D., to your

    Board of Directors "“ by telephone, by

    Internet or by signing, dating and returning the enclosed WHITE proxy card.
    Sincerely

    Bruce Ross, Chairman James Mullen, Chief Executive Officer
    Your Vote Is Important, No Matter How Many Or How Few Shares You Own.
    If you have questions about how to vote your shares, or need additional

    assistance, please contact the firm assisting us in the solicitation of

    proxies:
    INNISFREE M&A INCORPORATED|Stockholders Call

    Toll-Free: (877) 750-5836Banks and Brokers Call Collect:

    (212) 750-5833
    IMPORTANT
    We urge you NOT to sign any Gold proxy card sent to you by The Icahn

    Parties. If you have already done so, you have every legal right to

    change your vote by using the enclosed WHITE proxy card to vote TODAY"” by telephone, by Internet, or by signing, dating and returning the WHITE proxy card in the postage-paid envelope provided.
    Safe Harbor
    This letter to shareholders contains forward-looking statements, which

    appear under the heading "Committed to

    Creating Value for All Shareholders" above.

    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

    and RITUXAN, the uncertainty of success in commercializing other

    products including TYSABRI, the occurrence of adverse safety events with

    our products, the consequences of the nomination of directors for

    election to our Board by an activist shareholder, 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 1.A. Risk Factors in our reports on Form 10-K

    and Form 10-Q and in other periodic and current reports we file with the

    SEC. These forward-looking statements speak only as of the date of this

    letter, 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.
    Important Information
    On May 8, 2008, Biogen Idec filed a definitive proxy statement with the

    Securities and Exchange Commission (the "SEC")

    in connection with the Company´s 2008 Annual

    Meeting. Biogen Idec´s stockholders are

    strongly advised to read the definitive proxy statement carefully before

    making any voting or investment decision because the definitive proxy

    statement contains important information. The Company´s

    proxy statement and any other materials filed by the Company with the

    SEC can be obtained free of charge at the SEC´s

    web site at www.sec.gov or from Biogen Idec at http://investor.biogenidec.com.

    The Company´s definitive proxy statement and

    other materials will also be available for free by writing to Biogen

    Idec Inc., 14 Cambridge Center, Cambridge, MA 02142 or by contacting our

    proxy solicitor, Innisfree M&A Incorporated, by toll-free telephone at

    (877) 750-5836.
    Non-GAAP Information
    GAAP financial presentations include significant purchase accounting

    charges in 2003 and subsequent periods. Accordingly, we provide a "Ëœnon-GAAP´ perspective that removes these merger-related accounting impacts as well

    as other charges. Our non-GAAP financial measures are defined as

    reported, or GAAP, excluding (1) purchase accounting and merger-related

    adjustments, (2) stock option expense and the cumulative effect of an

    accounting change relating to the initial adoption of SFAS No. 123R and

    (3) other items. We believe it is important to share these non-GAAP

    financial measures with shareholders as they: better represent the

    ongoing economics of the business, reflect how we manage the business

    internally and set operational goals, and form the basis of our

    management incentive programs. Accordingly, we believe investors´ understanding of the Company´s financial

    performance is enhanced as a result of our disclosing these non-GAAP

    financial measures. Non-GAAP net income and diluted EPS should not be

    viewed in isolation or as a substitute for reported, or GAAP, net income

    and diluted EPS.
    GAAP EPS Reconciliation for 2010 Goals On a reported basis

    calculated in accordance with accounting principles generally accepted

    in the U.S. (GAAP), the Company aims to grow GAAP EPS from 2007 through

    2010 at a 25% CAGR. The long-term non-GAAP EPS goal excludes the impact

    of purchase accounting, merger-related adjustments, stock option

    expense, and their related tax effects. In order to reconcile long-term

    GAAP and non-GAAP EPS figures, the Company has excluded the following

    items for 2008 through 2010 from our non-GAAP EPS goal provided above:

    Purchase accounting charges, including amortization of acquired

    intangible assets and IPR&D, is estimated to be $760-$800 million for

    already completed transactions;

    Stock option expense due to FAS 123R is estimated to be in the range

    of $80-$90 million;

    Tax benefit of $220-$240 million related to the pre-tax reconciling

    items.

    Because the Company cannot predict with certainty the nature or the

    amount of non-operating or unusual charges through 2010, it has made no

    assumption regarding new purchase accounting charges in this GAAP EPS

    goal. The Company may incur charges or realize income through 2010 which

    could cause actual results to vary from the goal.
    GAAP EPS Reconciliation for 2008 Guidance

    Non-GAAP diluted EPS in the range of $3.25-$3.45 representing growth

    consistent with the Company´s stated goal of achieving 20% non-GAAP

    EPS compound annual growth through 2010.

    GAAP diluted EPS in the range of $2.28-$2.48.

    In order to reconcile the 2008 GAAP and non-GAAP EPS guidance, we have

    excluded the following items from non-GAAP diluted EPS guidance

    provided above:

    - Purchase accounting charges, including amortization of acquired

    intangible assets and IPR&D, are estimated to be $340 million pre-tax

    or approximately $0.92 per diluted share after-tax, for already

    completed transactions;

    - Stock option expense due to SFAS 123R in 2008 is estimated to be

    approximately $20 million pre-tax (including approximately $4 million

    in R&D and approximately $16 million in SG&A), or approximately $0.05

    per diluted share after-tax.

    Since the Company cannot predict with certainty the nature or the amount

    of non-operating or unusual charges for 2008, we have made no

    assumptions regarding other such charges in this GAAP guidance. The

    Company may incur charges or realize gains in 2008 that could cause

    actual results to vary from this guidance.
    GAAP Net Income and EPS Reconciliation for 2003-2007 The

    reconciliation between GAAP and non-GAAP net income and diluted EPS for

    the years 2003 through 2007 can be found in the table below and is taken

    from Annual Reports, 10-K filings and earnings press releases (FY

    2003-2007).

    = = = = = = = = = = =

    Three Months Ended March 31, 2008
    - - - - - -

    EARNINGS PER SHARE

    2008

    2007
    - - - - - -

    - - - - - -

    GAAP earnings per share - Diluted

    $
    0.54

    $
    0.38

    - - - - - -

    Adjustment to net income (as detailed below)

    0.29

    0.21

    - - - - - -

    Non-GAAP earnings per share - Diluted

    $
    0.83

    $
    0.59

    - - - - - -

    - - - - - -

    - - - - - -

    An itemized reconciliation between net income on a GAAP basis and

    net income on a non-GAAP basis is as follows (in millions):
    - - - - - -

    - - - - - -

    GAAP net income

    $
    163.1

    $
    131.5

    - - - - - -

    Adjustments:

    - - - - - -

    R&D: Stock option expense

    2.7

    3.0

    - - - - - -

    R&D: FIN 46 consolidations of Cardiokine and Neurimmune

    0.8

    -

    - - - - - -

    SG&A: Restructuring

    -

    0.1

    - - - - - -

    SG&A: Stock option expense

    3.1

    6.1

    - - - - - -

    Amortization of acquired intangible assets

    74.8

    59.9

    - - - - - -

    In-process research and development related to the contingent

    consideration payment in 2008 associated with Conforma acquisition

    and the acquisition of Syntonix in 2007

    25.0

    18.4

    - - - - - -

    Other income, net: FIN 46 consolidations of Cardiokine and Neurimmune

    (0.8
    )

    -

    - - - - - -

    Income taxes: Income tax effect of reconciling items

    (18.4
    )

    (16.6
    )
    - - - - - -

    - - - - - -

    Non-GAAP net income

    $
    250.3

    $
    202.4

    - - - - - -

    *The GAAP figures reflect: 2004-2007 "“ the

    combined Biogen Idec; 2003 "“ a full year of

    IDEC Pharmaceuticals and 7 weeks of the former Biogen, Inc. (for the

    period 11/13/03 through 12/31/03). Numbers may not foot due to rounding.
    GAAP Net Income EPS Reconciliation for Q1 2008 The reconciliation

    between GAAP and non-GAAP net income and diluted EPS for the first

    quarter of 2008 can be found in the table below and is taken from Annual

    Reports, 10-K filings and earnings press releases.

    = = = = = = = = = = =

    Condensed Consolidated Statements of Income "“ Operating Basis

    FY 2003

    FY 2004

    FY 2005

    FY 2006

    FY 2007
    - - - - - -

    GAAP diluted EPS

    (4.92
    )

    0.07

    0.47

    0.63

    1.99

    - - - - - -

    Adjustment to net income (see below)

    6.14

    1.38

    1.10

    1.62

    0.75

    - - - - - -

    Effect of FAS128 and ETIF 0306

    -

    (0.05
    )

    -

    -

    -

    - - - - - -

    Non-GAAP diluted EPS

    1.22

    1.40

    1.57

    2.25

    2.74

    - - - - - -

    GAAP Net Income ($M)

    (875.1
    )

    25.1

    160.7

    217.5

    638.2

    - - - - - -

    Revenue "“ Pre-merger Biogen product

    royalty and corporate partner revenue

    1,173.1

    -

    -

    -

    -

    - - - - - -

    COGS "“ Fair value step up of inventory

    acquired from Biogen and Fumapharm

    231.6

    295.5

    34.2

    7.8

    -

    - - - - - -

    COGS "“ Pre-merger Biogen cost of sales

    (179.2
    )

    -

    -

    -

    -

    - - - - - -

    COGS "“ Royalties related to Corixa

    1.8

    -

    -

    -

    -

    - - - - - -

    COGS "“ Amevive divesture

    -

    -

    36.4

    -

    -

    - - - - - -

    R&D "“ Pre-merger Biogen net R&D

    (301.1
    )

    -

    -

    -

    -

    - - - - - -

    R&D "“ Severance and restructuring

    -

    3.1

    20.3

    0.3

    1.2

    - - - - - -

    R&D "“ Sale of plant

    -

    -

    1.9

    -

    -

    - - - - - -

    SG&A "“ Pre-merger Biogen SG&A

    (346.7
    )

    -

    -

    -

    -

    - - - - - -

    SG&A "“ Merger related and purchase

    accounting costs

    -

    -

    -

    0.1

    -

    - - - - - -

    SG&A "“ Severance and restructuring

    13.2

    9.3

    19.3

    2.0

    0.6

    - - - - - -

    Amortization of intangible assets primarily related to Biogen merger

    33.2

    347.7

    302.3

    267.0

    257.5

    - - - - - -

    In-process R&D related to the Biogen Idec merger, acquisitions of

    Conforma, Syntonix, and Fumapharm, and consolidation of Cardiokine

    Neurimmune and Escoubloc

    823.0

    -

    -

    330.5

    84.2

    - - - - - -

    Loss/(gain) on settlement of license agreements with Fumedica and

    Fumapharm

    -

    -

    -

    (6.1
    )

    -

    - - - - - -

    (Gain)/loss on sale of long lived assets

    -

    -

    111.8

    (16.5
    )

    (0.4
    )
    - - - - - -

    Other income, net: Pre-merger Biogen

    32.9

    -

    -

    -

    -

    - - - - - -

    Other income, net: Consolidation of Cardiokine and Neurimmune and

    gain on sale of long lived assets

    -

    -

    -

    -

    (72.3
    )
    - - - - - -

    Write down of investments

    -

    12.7

    -

    -

    -

    - - - - - -

    Charitable donations and legal settlements

    30.7

    -

    -

    -

    -

    - - - - - -

    Income taxes "“ Effect of reconciling items

    (205.8
    )

    (195.4
    )

    (145.2
    )

    (70.3
    )

    (65.5
    )
    - - - - - -

    Stock option expense

    -

    -

    -

    44.5

    35.6

    - - - - - -

    Non-GAAP Net Income

    431.7

    498.0

    541.7

    776.8

    879.1

    - - - - - -

    About Biogen IdecBiogen 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.1