exv4w1



 





Exhibit 4.1




BIOGEN IDEC INC.,




as Issuer




and




The Bank of New York Trust Company, N.A.,




as Trustee




First Supplemental Indenture




Dated as of March 4, 2008




 









 





TABLE OF CONTENTS




	 	 	 	 	 
	 	 	Page	 
	 
	 	 	 	 
	ARTICLE I. DEFINITIONS
	 	 	1	 
	 
	SECTION 1.1. Certain Terms Defined in the Indenture
	 	 	1	 
	 
	SECTION 1.2. Definitions
	 	 	2	 
	 
	 	 	 	 
	ARTICLE II. FORM AND TERMS OF THE NOTES
	 	 	5	 
	 
	SECTION 2.1. Form and Dating
	 	 	5	 
	 
	SECTION 2.2. Terms of the Notes
	 	 	7	 
	 
	SECTION 2.3. Optional Redemption
	 	 	10	 
	 
	SECTION 2.4. Repurchase of Notes Upon a Change of Control
	 	 	10	 
	 
	SECTION 2.5. Limitation on Liens
	 	 	11	 
	 
	SECTION 2.6. Limitation on Sale and Leaseback Transactions
	 	 	12	 
	 
	SECTION 2.7. Exempted Liens and Sale and Leaseback Transactions
	 	 	13	 
	 
	SECTION 2.8. SEC Reports
	 	 	13	 
	 
	 	 	 	 
	 
	ARTICLE III. MISCELLANEOUS
	 	 	13	 
	 
	SECTION 3.1. Trust Indenture Act Controls
	 	 	13	 
	 
	SECTION 3.2. Governing Law
	 	 	13	 
	 
	SECTION 3.3. Multiple Counterparts
	 	 	14	 
	 
	SECTION 3.4. Severability
	 	 	14	 
	 
	SECTION 3.5. Ratification
	 	 	14	 
	 
	SECTION 3.6. Effectiveness
	 	 	14	 
	 
	 	 	 	 
	EXHIBIT A— Form of 6.000% Senior Note due 2013
	 	 	A-1	 
	EXHIBIT B— Form of 6.875% Senior Note due 2018
	 	 	B-1	 







i









 








FIRST SUPPLEMENTAL INDENTURE




     SUPPLEMENTAL INDENTURE (this “First Supplemental Indenture”), dated as of March 4, 2008,
between BIOGEN IDEC INC., a Delaware corporation (the “Company”), and The Bank of New York Trust
Company, a national association, as Trustee (the “Trustee”).



RECITALS OF THE COMPANY




     WHEREAS, the Company and the Trustee executed and delivered an Indenture, dated as of February
26, 2008 (the “Indenture”), to provide for the issuance by the Company from time to time of
Securities to be issued in one or mores series as provided in the Indenture;



     WHEREAS, the issuance and sale of $450,000,000 aggregate principal amount of a new series of
the Securities of the Company designated as its 6.000% Senior Notes due March 1, 2013 (the “Notes
due 2013”) and $550,000,000 aggregate principal amount of a new series of the Securities of the
Company designated as its 6.875% Senior Notes due March 1, 2018 (the “Notes due 2018”, and together
with the Notes due 2013, the “Notes”) have been authorized by resolutions adopted by the Board of
Directors of the Company;



     WHEREAS, the Company desires to issue and sell $1,000,000,000 aggregate principal amount of
the Notes on the date hereof;



     WHEREAS, Sections 2.2 and 8.1 of the Indenture provide that the Company, when authorized by a
Board Resolution, and the Trustee may amend or supplement the Indenture to provide for the issuance
of and to establish the form or terms and conditions of Securities of any Series as permitted by
the Indenture;



     WHEREAS, the Company desires to establish the form, terms and conditions of the Notes; and



     WHEREAS, all things necessary to make this First Supplemental Indenture a valid supplement to
the Indenture according to its terms and the terms of the Indenture have been done;



     NOW, THEREFORE, for and in consideration of the premises stated herein and the purchase of the
Notes by the Holders thereof, the parties hereto hereby enter into this First Supplemental
Indenture, for the equal and proportionate benefit of all Holders of the Notes, as follows:



ARTICLE I.




DEFINITIONS




     SECTION 1.1. Certain Terms Defined in the Indenture.



     For purposes of this Supplemental Indenture, all capitalized terms used but not defined herein
shall have the meanings ascribed to such terms in the Indenture, as amended hereby.



 









 





     SECTION 1.2. Definitions.



     For the benefit of the Holders of the Notes, Section 1.1 of the Indenture shall be amended by
adding the following new definitions:



     “Attributable Debt” means, with respect to a Sale and Leaseback Transaction, an amount equal
to the lesser of: (1) the fair market value of the property (as determined in good faith by the
Company’s board of directors); and (2) the present value of the total net amount of rent payments
to be made under the lease during its remaining term, discounted at the rate of interest set forth
or implicit in the terms of the lease, compounded semi-annually. The calculation of the present
value of the total net amount of rent payments is subject to adjustments specified in the
indenture.



     “Bankruptcy Law” means title 11, U.S. Code or any similar foreign, Federal or State law for
the relief of debtors.



     “Capitalized Lease” means any obligation of a Person to pay rent or other amounts incurred
with respect to real property or equipment acquired or leased by such Person and used in its
business that is required to be recorded as a capital lease in accordance with generally accepted
accounting principles.



     “Change of Control” means the occurrence of any of the following: (1) the consummation of any
transaction (including, without limitation, any merger or consolidation) the result of which is
that any “person” (as such term is used in Section 13(d) of the Exchange Act) (other than the
Company or one of its Subsidiaries) becomes the beneficial owner (as defined in Rules 13d-3 and
13d-5 under the Exchange Act), directly or indirectly, of more than 50% of the Voting Stock of the
Company or other Voting Stock into which the Voting Stock of the Company is reclassified,
consolidated, exchanged or changed, measured by voting power rather than number of shares; (2) the
direct or indirect sale, transfer, conveyance or other disposition (other than by way of merger or
consolidation), in one or more series of related transactions, of all or substantially all of the
assets of the Company and the assets of its Subsidiaries, taken as a whole, to one or more
“persons” (as such term is used in Section 13(d) of the Exchange Act) (other than to the Company or
one of its Subsidiaries); (3) the Company consolidates with, or merges with or into, any “person”
(as such term is used in Section 13(d) of the Exchange Act), or any such person consolidates with,
or merges with or into, the Company, in either case, pursuant to a transaction in which any of the
Company’s outstanding Voting Stock or the Voting Stock of such other person is converted into or
exchanged for cash, securities or other property, other than pursuant to a transaction in which
shares of the Company’s Voting Stock outstanding immediately prior to the transaction constitute,
or are converted into or exchanged for, a majority of the Voting Stock of the surviving person
immediately after giving effect to such transaction; (4) the adoption of a plan relating to the
Company’s liquidation or dissolution; or (5) the first day on which a majority of the members of
the Board of Directors of the Company are not Continuing Directors.



     “Change of Control Triggering Event” means the occurrence of both a Change of Control and a
Rating Event.



2









 





     “Comparable Treasury Issue” means the United States Treasury security or securities selected
by an Independent Investment Banker as having an actual or interpolated maturity comparable to the
remaining term of the Notes to be redeemed that would be utilized, at the time of selection and in
accordance with customary financial practice, in pricing new issues of corporate debt securities of
a comparable maturity to the remaining term of such Notes.



     “Comparable Treasury Price” means, with respect to any Redemption Date, (A) the average of the
Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and
lowest such Reference Treasury Dealer Quotations, or (B) if the Trustee obtains fewer than four
such Reference Treasury Dealer Quotations, the average of all quotations.



     “Continuing Director” means, as of any date of determination, any member of the Company’s
board of directors who (1) was a member of such board of directors on the date the Notes were
issued, (2) was nominated for election to such board of directors with the approval of a committee
of the board of directors consisting of a majority of independent Continuing Directors or (3) was
nominated for election, elected or appointed to such board of directors with the approval of a
majority of the Continuing Directors who were members of such board of directors at the time of
such nomination, election or appointment (either by a specific vote or by approval of the Company’s
proxy statement in which such member was named as a nominee for election as a director, without
objection to such nomination).



     “Consolidated Total Assets” means, with respect to any Person as of any date, the amount of
total assets as shown on the consolidated balance sheet of such Person for the most recent fiscal
quarter for which financial statements have been filed with the Securities and Exchange Commission,
prepared in accordance with accounting principles generally accepted in the United States.



     “Exchange Act” means the Securities Exchange Act of 1934, as amended.



     “Global Notes” means, individually and collectively, each of the Notes in the form of Global
Securities issued to the Depositary or its nominee, substantially in the form of Exhibits A and B.



     “Indebtedness” of any Person means, without duplication (1) any obligation of such Person for
money borrowed, (2) any obligation of such Person evidenced by bonds, debentures, notes or other
similar instruments, (3) any reimbursement obligation of such Person in respect of letters of
credit or other similar instruments which support financial obligations which would otherwise
become Indebtedness, and (4) any obligation of such Person under Capitalized Leases; provided,
however, that “Indebtedness” of such Person shall not include any obligation of such Person to any
Subsidiary of such Person or to any Person with respect to which such Person is a Subsidiary.



     “Independent Investment Banker” means one of the Reference Treasury Dealers appointed by the
Trustee after consultation with the Company.



     “Investment Grade Rating” means a rating equal to or higher than Baa3 (or the equivalent) by
Moody’s and BBB- (or the equivalent) by S&P, and the equivalent investment



3









 







grade credit rating from any additional rating agency or Rating Agencies selected by the
Company.



     “Lien” means any pledge, mortgage, lien, encumbrance or other security interest.



     “Moody’s” means Moody’s Investors Service, Inc. or any successor thereto.



     “Person” means any individual, corporation, limited liability company, partnership, joint
venture, association, joint stock company, trust, unincorporated organization or government or any
agency or political subdivision thereof or other similar entity.



     “Property” means any property or asset, whether real, personal or mixed, or tangible or
intangible.



     “Rating Agencies” means (1) each of Moody’s and S&P, and (2) if any of Moody’s and S&P ceases
to rate the Notes or fails to make a rating of the Notes publicly available for reasons outside of
the control of the Company, a “nationally recognized statistical rating organization” within the
meaning of Rule 15c3-1(c)(2)(vi)(F) under the Exchange Act selected by the Company (as certified by
a resolution of the Board of Directors of the Company) and which is reasonably acceptable to the
Trustee as a replacement agency for Moody’s or S&P or both of them, as the case may be.



     “Rating Event” means (A) with respect to the Notes due 2013, the rating on the Notes due 2013
is lowered by each of the Rating Agencies and the Notes due 2013 are rated below an Investment
Grade Rating by each of the Rating Agencies, and (B) with respect to the Notes due 2018, the rating
on the Notes due 2018 is lowered by each of the Rating Agencies and the Notes due 2018 are rated
below an Investment Grade Rating by each of the Rating Agencies, in either case, on any day during
the period commencing on the earlier of the date of the first public notice of the occurrence of a
Change of Control or the Company’s intention to effect a Change of Control and ending 60 days
following consummation of such Change of Control (which period will be extended so long as the
rating of the applicable series of Notes is under publicly announced consideration for a possible
downgrade by any of the Rating Agencies).



     “Reference Treasury Dealer” means each of Merrill Lynch, Pierce, Fenner & Smith Incorporated
and Goldman, Sachs & Co. or their respective affiliates, which are primary U.S. Government
securities dealers in The City of New York, and their respective successors plus three other
primary U.S. Government securities dealers in The City of New York selected by the Company;
provided, however, that if any of the foregoing or their affiliates shall cease to be a primary
U.S. Government securities dealer in The City of New York (a “Primary Treasury Dealer”), the
Company will substitute therefor another Primary Treasury Dealer.



     “Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer
and any Redemption Date, the average, as determined by the Trustee, of the bid and asked prices for
the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount)
quoted in writing to the Trustee by the Reference Treasury Dealers at 3:30 p.m. New York time on
the third Business Day preceding such Redemption Date.



4









 





     “Sale and Leaseback Transaction” means any arrangement with any Person providing for the
leasing by the Company or any Subsidiary of the Company of any Property that has been or is to be
sold or transferred by the Company or such Subsidiary, as the case may be, to such Person.



     “Subsidiary” of any Person means (1) a corporation, a majority of the outstanding voting stock
of which is, at the time, directly or indirectly, owned by such Person by one or more Subsidiaries
of such Person, or by such Person and one or more Subsidiaries thereof or (2) any other Person
(other than a corporation), including, without limitation, a partnership or joint venture, in which
such Person, one or more Subsidiaries thereof or such Person and one or more Subsidiaries thereof,
directly or indirectly, at the date of determination thereof, has at least majority ownership
interest entitled to vote in the election of directors, managers or trustees thereof (or other
Person performing similar functions).



     “S&P” means Standard & Poor’s Ratings Services, a division of The McGraw-Hill Companies, Inc.,
or any successor thereto.



     “Treasury Rate” means, with respect to any Redemption Date, the rate per annum equal to the
semiannual equivalent yield to maturity or interpolated (on a day count basis) of the Comparable
Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of
its principal amount) equal to the Comparable Treasury Price for such Redemption Date.



     “Voting Stock” means, with respect to any specified “person” (as that term is used in Section
13(d) of the Exchange Act) as of any date, the capital stock of such person that is at the time
entitled to vote generally in the election of the board of directors of such person.



ARTICLE II.




FORM AND TERMS OF THE NOTES




     SECTION 2.1. Form and Dating.



     The Notes due 2013 and the Trustee’s certificate of authentication shall be substantially in
the form of Exhibit A attached hereto. The Notes due 2018 and the Trustee’s certificate of
authentication shall be substantially in the form of Exhibit B attached hereto. The Notes
shall be executed on behalf of the Company by two Officers of the Company or an Officer and an
Assistant Secretary of the Company. The Company’s seal shall be impressed, affixed, imprinted or
reproduced thereon. The Notes may have notations, legends or endorsements required by law, stock
exchange rules or usage. Each Note shall be dated the date of its authentication. The Notes and
any beneficial interest in the Notes shall be in minimum denominations of $2,000 and integral
multiples of $1,000 in excess thereof.



     The terms and notations contained in the Notes shall constitute, and are hereby expressly
made, a part of the Indenture as supplemented by this First Supplemental Indenture and the Company
and the Trustee, by their execution and delivery of this First Supplemental Indenture, expressly
agree to such terms and provisions and to be bound thereby.



5









 





     (a) Global Notes. The Notes of each series designated herein shall be issued
initially in the form of one or more fully registered Global Securities, which shall be
deposited on behalf of the purchasers of the Notes represented thereby with The Depository
Trust Company, New York, New York (the “Depositary”) and registered in the name of Cede &
Co., the Depositary’s nominee, duly executed by the Company, authenticated by the Trustee
and with guarantees endorsed thereon as hereinafter provided. The aggregate principal
amount of outstanding Notes may from time to time be increased or decreased by adjustments
made on the records of the Trustee and the Depositary or its nominee as hereinafter
provided.



     The Global Notes may not be transferred except by the Depositary, in whole and not in
part, to another nominee of the Depositary or to a successor of the Depositary or its
nominee. If at any time the Depositary for the Notes notifies the Company that the
Depositary is unwilling to continue as Depositary for the Global Notes or ceases to be a
clearing agency, or if the Company so elects or if there is an Event of Default under the
Notes, then the Company shall execute, and the Trustee shall, upon receipt of a Company
Order for authentication, authenticate and deliver, Definitive Notes in an aggregate
principal amount equal to the principal amount of the Global Notes in exchange for such
Global Note, which the Depositary will distribute to its participants.



     (b) Book-Entry Provisions. This Section 2.1(b) shall apply only to the Global
Notes deposited with or on behalf of the Depositary.



     The Company shall execute and the Trustee shall, in accordance with this Section
2.1(b), authenticate and deliver the Global Notes that shall be registered in the name of
the Depositary or the nominee of the Depositary and shall be delivered by the Trustee to the
Depositary or pursuant to the Depositary’s instructions.



     Depositary Participants shall have no rights either under the Indenture or with respect
to any Global Notes held on their behalf by the Depositary or under such Global Notes. The
Depositary shall be treated by the Company, the Trustee and any agent of the Company or the
Trustee as the absolute owner of such Global Note for all purposes under the Indenture.
Notwithstanding the foregoing, nothing herein shall prevent the Company or the Trustee from
giving effect to any written certification, proxy or other authorization furnished by the
Depositary or impair, as between the Depositary and the Depository Participants, the
operation of customary practices of such Depositary governing the exercise of the rights of
an owner of a beneficial interest in the Global Notes.



     (c) Definitive Notes. Notes issued in certificated form shall be substantially
in the form of Exhibit A or Exhibit B, as applicable, attached hereto, but without including
the text referred to therein as applying only to Global Notes. Except as provided above in
subsection (a), owners of beneficial interests in the Global Notes will not be entitled to
receive physical delivery of certificated Notes.



     (d) Transfer and Exchange of the Notes. The transfer and exchange of
beneficial interests in the Global Notes shall be effected through the Depositary, in
accordance with the Indenture and the procedures of the Depositary therefor. Beneficial



6









 







interests in the Global Notes may be transferred to Persons who take delivery thereof
in the form of a beneficial interest in the Global Notes.



     (e) Paying Agent. The Company appoints the Trustee as the initial agent of the
Company for the payment of the principal of (and premium, if any) and interest on the Notes
and the Corporate Trust Office of the Trustee in the Borough of Manhattan, the City of New
York, be and hereby is, designated as the office or agency where the Notes may be presented
for payment and where notices to or demands upon the Company in respect of the Notes and the
Indenture pursuant to which the Notes are to be issued may be served.



     SECTION 2.2. Terms of the Notes.



     The following terms relating to the Notes are hereby established:



     (a) Title. The Notes due 2013 shall constitute a series of Securities having
the title “6.000% Senior Notes due 2013” and the Notes due 2018 shall constitute a separate
series of Securities having the title “6.875% Senior Notes due 2018.”



     (b) Principal Amount. The aggregate principal amount of the Notes due 2013
that may be initially authenticated and delivered under the Indenture (except for Notes due
2013 authenticated and delivered upon registration of, transfer of, or in exchange for, or
in lieu of, other Notes due 2013 pursuant to Sections 2.7, 2.8, 2.11, 3.6 or 8.5 of the
Indenture) shall be $450,000,000. The aggregate principal amount of the Notes due 2018 that
may be initially authenticated and delivered under the Indenture (except for Notes due 2018
authenticated and delivered upon registration of, transfer of, or in exchange for, or in
lieu of, other Notes due 2018 pursuant to Sections 2.7, 2.8, 2.11, 3.6 or 8.5 of the
Indenture) shall be $550,000,000. The Company may from time to time, without the consent of
the Holders of Notes of either series, issue additional Notes (in any such case “Additional
Notes”) of either series having the same ranking and the same interest rate, maturity and
other terms as the Notes of that series. Any additional Notes of a series and the existing
Notes of that series will constitute a single series under the Indenture and all references
to the relevant Notes shall include the Additional Notes unless the context otherwise
requires.



     (c) Maturity Date. The entire outstanding principal of the Notes due 2013
shall be payable on March 1, 2013, and the entire outstanding principal of the Notes due
2018 shall be payable on March 1, 2018.



     (d) Interest Rate. (i) The rate at which the Notes due 2013 shall bear
interest shall be 6.000% per annum and the rate at which the Notes due 2018 shall bear
interest shall be 6.875% per annum, in each case, subject to Section 2.2(d)(ii); the date
from which interest shall accrue on the Notes shall be March 4, 2008, or the most recent
Interest Payment Date to which interest has been paid or provided for; the Interest Payment
Dates for the Notes shall be March 1 and September 1 of each year, beginning September 1,
2008; the interest so payable, and punctually paid or duly provided for, on any Interest
Payment Date, will be paid, in immediately available funds, to the Persons in



7









 







whose names the Notes (or one or more predecessor Securities) is registered at the
close of business on the Regular Record Date for such interest, which shall be February 15
or August 15, as the case may be, next preceding such Interest Payment Date. Any such
interest not punctually paid or duly provided for shall forthwith cease to be payable to the
respective Holders on such Regular Record Date, and such defaulted interest, may be paid to
the Persons in whose names the Notes (or one or more predecessor Securities) is registered
at the close of business on a special record date for the payment of such defaulted interest
to be fixed by the Trustee, notice whereof shall be given to Holders of Notes not less than
15 days prior to such special record date, or may be paid at any time in any other lawful
manner not inconsistent with requirements of any securities exchange on which the Notes may
be listed, and upon such notice as may be required by such exchange, all as more fully
provided in said Indenture. Payment of principal and interest on this Note will be made at
the Corporate Trust Office of the Trustee or such other office or agency of the Company as
may be designated for such purpose, in such coin or currency of the United States of America
as at the time of payment is legal tender for payment of public and private debts;
provided, however, that each installment of interest and principal on this
Notes may at the Company’s option be paid in immediately available funds by transfer to an
account maintained by the payee located in the United States.



     (ii) The interest rate payable on the Notes of each series shall be subject to
adjustment from time to time if either Moody’s or S&P downgrades (or subsequently upgrades)
the debt rating assigned to the Notes in the manner described below.



     If the rating from Moody’s of the Notes of a series is decreased to a rating set forth
in the immediately following table, the interest rate payable on the Notes of such series
will increase from the interest rate payable on the Notes of such series on the date of
their issuance by the percentage set forth opposite that rating:



	 	 	 	 	 
	Rating	 	Percentage
	Ba1
	 	 	0.25	%
	Ba2
	 	 	0.50	%
	Ba3
	 	 	0.75	%
	B1 or below
	 	 	1.00	%






     If the rating from S&P of the Notes of a series is decreased to a rating set forth in
the immediately following table, the interest rate payable on the Notes of such series will
increase from the interest rate payable on the Notes of such series on the date of their
issuance by the percentage set forth opposite that rating:



	 	 	 	 	 
	Rating	 	Percentage
	BB+
	 	 	0.25	%
	BB
	 	 	0.50	%
	BB-
	 	 	0.75	%
	B+ or below
	 	 	1.00	%






8









 






     If at any time the interest rate payable on the Notes of a series has been adjusted
upward and either Moody’s or S&P, as the case may be, subsequently increases its rating of
the Notes of that series to any of the threshold ratings set forth above, the interest rate
payable on the Notes of such series will be decreased such that the interest rate payable on
the Notes of such series equals the interest rate payable on the Notes of such series on the
date of their issuance plus the percentages set forth opposite the ratings from the tables
above in effect immediately following the increase. If Moody’s subsequently increases its
rating of the Notes of a series to Baa3 or higher and S&P increases its rating to BBB- or
higher the interest rate payable on the Notes of such series will be decreased to the
interest rate payable on the Notes of such series on the date of their issuance. In
addition, the interest rates on the Notes of each series shall permanently cease to be
subject to any adjustment described above (notwithstanding any subsequent decrease in the
ratings by either or both rating agencies) if the Notes of such series become rated Baa1 and
A- or higher by Moody’s and S&P, respectively (or one of these ratings if only rated by one
rating agency).




     Each adjustment required by any decrease or increase in a rating set forth above,
whether occasioned by the action of Moody’s or S&P, shall be made independent of any and all
other adjustments. In no event shall (1) the interest rate payable on the Notes of a series
be reduced to below the interest rate payable on the Notes of such series on the date of
their issuance or (2) the total increase in the interest rate payable on the Notes of a
series exceed 2.00% above the interest rate payable on the Notes of such series on the date
of their issuance.




     If either Moody’s or S&P ceases to provide a rating of the Notes of a series, any
subsequent increase or decrease in the interest rate payable on the Notes of such series
necessitated by a reduction or increase in the rating by the agency continuing to provide
the rating shall be twice the percentage set forth in the applicable table above. No
adjustments in the interest rate payable on the Notes of either series shall be made solely
as a result of either Moody’s or S&P ceasing to provide a rating. If both Moody’s and S&P
cease to provide a rating of the Notes of a series, the interest rate payable on the Notes
of such series will increase to, or remain at, as the case may be, 2.00% above the interest
rate payable on the Notes of such series on the date of their issuance.




     Any interest rate increase or decrease described above will take effect from the first
day of the interest period during which a rating change requires an adjustment in the
interest rate.




     If the interest rate payable on the Notes of a series is increased as described in this
Section 2.2(d)(ii), then the term “interest,” as used in this First Supplemental Indenture,
the Indenture and the Notes of the applicable series, will be deemed to include any such
additional interest unless the context otherwise requires.



          (e) Currency. The currency of denomination of the Notes is United States Dollars.
Payment of principal of and interest and premium, if any, on the Notes will be made in United
States Dollars.




9









 








     SECTION 2.3. Optional Redemption.



     (a) The provisions of Article 3 of the Indenture shall apply to the Notes.



     (b) At any time and from time to time, the Notes of each series will be redeemable, as
a whole or in part, at the Company’s option, on at least 30 days, but not more than 60 days,
prior notice mailed to the registered address of each holder of the Notes of the applicable
series, at a redemption price equal to the greater of (i) 100% of principal amount of the
Notes to be redeemed, or (ii) the sum of the present values of the remaining scheduled
payments of interest and principal thereon (exclusive of interest accrued and unpaid to, but
not including, the date of redemption) discounted to the date of redemption on a semiannual
basis, assuming a 360-day year consisting of twelve 30-day months, at the Treasury Rate plus
50 basis points, plus, in either case, accrued and unpaid interest to, but not including,
the date of redemption.



     (c) On and after the Redemption Date for the Notes of either series, interest will
cease to accrue on the Notes of such series or any portion thereof called for redemption,
unless the Company defaults in the payment of the redemption price. On or before the
Redemption Date for the Notes of such series, the Company will deposit with a Paying Agent,
or the Trustee, funds sufficient to pay the redemption price of the Notes to be redeemed on
such date. If less than all of the Notes of a series are to be redeemed, the Notes of that
series to be redeemed will be selected by the Trustee by such method as the Trustee deems
fair and appropriate.



     SECTION 2.4. Repurchase of Notes Upon a Change of Control.



     (a) If a Change of Control Triggering Event occurs with respect to the Notes of a
series, unless the Company shall have exercised its option to redeem the Notes of such
series as described in Section 2.3 of this First Supplemental Indenture, the Company shall
be required to make an offer (the “Change of Control Offer”) to each holder of the Notes of
such series to repurchase all or any part (equal to $2,000 or an integral multiple of $1,000
in excess thereof) of such Holder’s Notes of such series on the terms set forth in this
Section 2.4 and in the Notes. In the Change of Control Offer, the Company shall offer
payment in cash equal to 101% of the aggregate principal amount of Notes repurchased, plus
accrued and unpaid interest, if any, on the Notes repurchased to but not including the date
of repurchase (the “Change of Control Payment”). With respect to the Notes of each series,
within 30 days following any Change of Control Triggering Event or, at the option of the
Company, prior to any Change of Control, but after the public announcement of the
transaction that constitutes or may constitute the Change of Control, the Company shall mail
a notice to Holders of Notes of the applicable series describing the transaction that
constitutes or may constitute the Change of Control Triggering Event and offering to
repurchase the Notes of such series on the date specified in the notice, which date shall be
no earlier than 30 days and no later than 60 days from the date such notice is mailed or, if
the notice is mailed prior to the Change of Control, no earlier than 30 days and no later
than 60 days from the date on which the Change of Control Triggering Event occurs (the
“Change of Control Payment Date”). The notice shall, if mailed prior to the date of
consummation of the Change of Control, state that the offer to



10









 







purchase is conditioned on the Change of Control Triggering Event occurring on or prior
to the Change of Control Payment Date.



     (b) On the Change of Control Payment Date, the Company shall, to the extent lawful:




     (1) accept for payment all Notes or portions of Notes properly tendered
pursuant to the Change of Control Offer;




     (2) deposit with the Paying Agent an amount equal to the Change of Control
Payment in respect of all Notes or portions of Notes properly tendered; and




     (3) deliver or cause to be delivered to the Trustee the Notes properly accepted
together with an Officers’ Certificate stating the aggregate principal amount of
Notes or portions of Notes being repurchased.



     (c) The Company shall not be required to make a Change of Control Offer upon the
occurrence of a Change of Control Triggering Event if a third party makes such an offer in
the manner, at the times and otherwise in compliance with the requirements for an offer made
by the Company and the third party repurchases all Notes properly tendered and not withdrawn
under its offer. In addition, the Company shall not repurchase any Notes if there has
occurred and is continuing on the Change of Control Payment Date an Event of Default under
the Indenture, other than an Event of Default arising as a result of a default in the
payment of the Change of Control Payment upon a Change of Control Triggering Event.



     (d) The Company shall comply in all material respects with the requirements of Rule
14e-1 under the Exchange Act and any other securities laws and regulations thereunder to the
extent such laws and regulations are applicable in connection with the repurchase of the
Notes as a result of a Change of Control Triggering Event. To the extent that the
provisions of any such securities laws or regulations conflict with the Change of Control
Offer provisions of the Notes, the Company shall comply with the applicable securities laws
and regulations and shall not be deemed to have breached its obligations under the Change of
Control Offer provisions of the Notes by virtue of any such conflict.



     SECTION 2.5. Limitation on Liens.



     For the benefit of the Holders of the Notes, a new Section 4.7 shall be added to the Indenture
as follows:



     “Other than as provided in Section 4.9, the Company shall not, and shall not permit any
Subsidiaries of the Company to, create or assume any Indebtedness secured by any Lien on any of the
Company’s or such Subsidiary’s respective Properties unless the Notes are secured by such Lien
equally and ratably with, or prior to, the Indebtedness secured by such Lien. This restriction
does not apply to Indebtedness that is secured by (i) Liens existing on the date of the issuance of
the Notes; (ii) Liens securing only the Notes; (iii) Liens on Property or shares of



11









 







stock in respect of Indebtedness of a Person existing at the time such Person becomes a
Subsidiary of the Company or is merged into or consolidated with, or its assets are acquired by,
the Company or any Subsidiary of the Company (provided that such Lien was not incurred in
anticipation of such transaction and was in existence prior to such transaction) so long as such
Lien does not extend to any other Property and the Indebtedness so secured is not increased; (iv)
Liens to secure Indebtedness incurred for the purpose of all or any part of a Property’s purchase
price or cost of construction or additions, repairs, alterations, or other improvements; provided
that (1) the principal amount of any Indebtedness secured by such Lien does not exceed 100% of such
Property’s purchase price or cost, (2) such Lien does not extend to or cover any other Property
other than the Property so purchased, constructed or on which such additions, repairs, alterations
or other improvements were so made, and (3) such Lien is incurred prior to or within 270 days after
the acquisition of such Property or the completion of construction or such additions, repairs,
alterations or other improvements and the full operation of such Property thereafter; (v) Liens in
favor of the United States or any state thereof, or any instrumentality of either, to secure
certain payments pursuant to any contract or statute; (vi) Liens for taxes or assessments or other
governmental charges or levies which are not overdue for a period exceeding 60 days unless such
Liens are being contested in good faith and for which adequate reserves are being maintained, to
the extent required by generally accepted accounting principles; (vii) title exceptions, easements,
licenses, leases and other similar Liens that are not consensual and that do not materially impair
the use of the Property subject thereto; (viii) Liens to secure obligations under worker’s
compensation laws, unemployment compensation, old-age pensions and other social security benefits
or similar legislation; (ix) Liens arising out of legal proceedings, including Liens arising out of
judgments or awards; (x) warehousemen’s, materialmen’s, carrier’s, landlord’s and other similar
Liens for sums not overdue for a period exceeding 60 days unless such Liens are being contested in
good faith and for which adequate reserves are being maintained, to the extent required by
generally accepted accounting principles; (xi) Liens incurred to secure the performance of
statutory obligations, surety or appeal bonds, performance or return-of-money bonds, insurance,
self-insurance or other obligations of a like nature incurred in the ordinary course of business;
(xii) Liens that are rights of set-off relating to the establishment of depository relations with
banks not given in connection with the issuance of Indebtedness; (xiii) Liens on the assets of a
special purpose Subsidiary resulting from securitization transactions with respect to accounts
receivable, royalties and similar assets included in such securitization transactions; or (xiv)
Liens to secure any extension, renewal, refinancing or refunding (or successive extensions,
renewals, refinancings or refundings), in whole or in part, of any Indebtedness secured by Liens
referred to in clauses (i) to (xiii) or Liens created in connection with any amendment, consent or
waiver relating to such Indebtedness, so long as such Lien does not extend to any other Property
and the Indebtedness so secured does not exceed the fair market value (as determined by the
Company’s board of directors) of the assets subject to such Liens at the time of such extension,
renewal, refinancing or refunding, or such amendment, consent or waiver, as the case may be.”



     SECTION 2.6. Limitation on Sale and Leaseback Transactions.



     For the benefit of the Holders of the Notes a new Section 4.8 shall be added to the Indenture
as follows:



12









 





     “Other than as provided under Section 4.9, the Company shall not, and shall not permit any of
its Subsidiaries to, enter into any Sale and Leaseback Transaction with respect to any of the
Company’s or such Subsidiary’s respective Properties, the acquisition or completion of construction
and commencement of full operations of which has occurred more than 270 days prior thereto, unless
(i) the lease is for a period not in excess of five years, including renewal rights; or (ii) the
Company or the Subsidiary, prior to or within 270 days after the sale of such Property in
connection with the Sale and Leaseback Transaction is completed, applies the net cash proceeds of
the sale of the Property leased to (1) the retirement of the Notes or debt of the Company ranking
equally with the Notes or to the retirement of any debt of a Subsidiary of the Company, or (2) the
acquisition of different property, facilities or equipment or the expansion of the Company’s
existing business, including the acquisition of other businesses.”



     SECTION 2.7. Exempted Liens and Sale and Leaseback Transactions.



     For the benefit of the Holders of the Notes a new Section 4.9 shall be added to the Indenture
as follows:



     “Notwithstanding the restrictions described under Sections 4.7 or 4.8, the Company or any
Subsidiary of the Company may create or assume any Liens or enter into any Sale and Leaseback
Transactions not otherwise permitted as described above, if the sum of the following does not
exceed 10% of Consolidated Total Assets (i) the outstanding Indebtedness secured by such Liens (not
including any Liens permitted under Section 4.7 which amount does not include any Liens permitted
under the provisions of this Section 4.9); plus (ii) all Attributable Debt in respect of such Sale
and Leaseback Transaction entered into (not including any Sale and Leaseback Transactions permitted
under Section 4.8 which amount does not include any Sale and Leaseback Transactions permitted under
the provisions of this Section 4.9), measured, in each case, at the time such Lien is incurred or
any such Sale and Leaseback Transaction is entered into by the Company or such Subsidiary of the
Company.”



ARTICLE III.




MISCELLANEOUS




     SECTION 3.1. Trust Indenture Act Controls.



     If any provision of this First Supplemental Indenture limits, qualifies or conflicts with
another provision which is required to be included in this First Supplemental Indenture by the TIA,
the required provision shall control. If any provision of this First Supplemental Indenture
modifies or excludes any provision of the TIA which may be so modified or excluded, the latter
provision shall be deemed to apply to this First Supplemental Indenture as so modified or to be
excluded, as the case may be.



     SECTION 3.2. Governing Law.



     This First Supplemental Indenture and the Notes shall be governed by and construed in
accordance with the laws of the State of New York, as applied to contracts made and performed
within the State of New York without regard to principles of conflicts of law.



13









 





     SECTION 3.3. Multiple Counterparts.



     The parties may sign multiple counterparts of this First Supplemental Indenture. Each signed
counterpart shall be deemed an original, but all of them together represent one and the same First
Supplemental Indenture.



     SECTION 3.4. Severability.



     Each provision of this First Supplemental Indenture shall be considered separable and if for
any reason any provision which is not essential to the effectuation of the basic purpose of this
First Supplemental Indenture or the Notes shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be affected or
impaired thereby and a Holder shall have no claim therefor against any party hereto.



     SECTION 3.5. Ratification.



     The Indenture, as supplemented and amended by this First Supplemental Indenture, is in all
respects ratified and confirmed. The Indenture and this First Supplemental Indenture shall be
read, taken and construed as one and the same instrument. All provisions included in this First
Supplemental Indenture supersede any conflicting provisions included in the Indenture unless not
permitted by law. The Trustee accepts the trusts created by the Indenture, as supplemented by this
First Supplemental Indenture, and agrees to perform the same upon the terms and conditions of the
Indenture, as supplemented by this First Supplemental Indenture.



     SECTION 3.6. Effectiveness.



     The provisions of this First Supplemental Indenture shall become effective as of the date
hereof.



[Remainder of page intentionally left blank.]




14









 








     IN WITNESS WHEREOF, the parties hereto have caused this First Supplemental Indenture to be
duly executed as of the date first above written.



	 	 	 	 	 	 	 
	 	 	BIOGEN IDEC INC.	 	 
	 
	 	 	 	 	 	 
	 

	 	By:	 	 /s/ Michael F. Phelps	 	 
	 

	 	 	 	 

Name: Michael F. Phelps
	 	
	 

	 	 	 	Title:   Vice President and Treasurer	 	
	 
	 	 	 	 	 	 
	 	 	THE BANK OF NEW YORK TRUST 

   COMPANY, N.A., as Trustee	 	 
	 
	 	 	 	 	 	 
	 

	 	By:	 	/s/ Marcella Burgess	 	 
	 

	 	 	 	 

Name: Marcella Burgess
	 	 
	 

	 	 	 	Title:   Assistant Vice President	 	 







15











 





EXHIBIT A




Form of 6.000% Senior Note due 2013




          THIS NOTE IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND
IS REGISTERED IN THE NAME OF THE DEPOSITARY OR A NOMINEE OF THE DEPOSITARY. THIS NOTE IS
EXCHANGEABLE FOR NOTES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE
ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS
A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY, BY A NOMINEE OF THE DEPOSITARY TO THE
DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A
SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH A SUCCESSOR DEPOSITARY.




BIOGEN
IDEC INC.


6.000% Senior Note due 2013




			
	 	 	 
	REGISTERED
	 	PRINCIPAL AMOUNT
	No. Specimen
	 	$450,000,000
	 
	CUSIP: 09062XAA1	 	 
	ISIN: US09062XAA19	 	 






          Biogen Idec Inc., a Delaware corporation (herein called the “Company,” which term includes any
successor Person under the Indenture hereinafter referred to), for value received, hereby promises
to pay to Cede & Co., or registered assigns, the principal sum of $450,000,000 on March 1, 2013
(the “Maturity Date”) (except to the extent redeemed or repaid prior to the Maturity Date) and to
pay interest thereon from March 4, 2008 (the “Original Issue Date”) or from the most recent
Interest Payment Date to which interest has been paid or duly provided for semi-annually at the
rate of 6.000% per annum, on March 1 and September 1 (each such date, an “Interest Payment Date”),
commencing September 1, 2008, until the principal hereof is paid or made available for payment.




          Subject to the limitations set forth in Section 2.2(d)(ii) of the First Supplemental Indenture
(as defined herein), the interest rate payable on the Notes (as defined herein) will be subject to
adjustment from time to time, on the terms set forth in the Indenture, if either Moody’s or S&P
downgrades (or subsequently upgrades) the debt rating assigned to the Notes. If the interest rate
payable on this Note is increased in accordance with the terms hereof and the Indenture, then the
term “interest,” as used in this Note and the Indenture, will be deemed to include any such
additional interest unless the context otherwise requires.




          Payment of Interest. The interest so payable, and punctually paid or made available
for payment, on any Interest Payment Date, will, as provided in the Indenture, be paid, in
immediately available funds, to the Person in whose name this Note (or one or more



A-1 









 






Predecessor
Securities) is registered at the close of business on February 15 or August 15 (whether or not a
Business Day, as defined in the Indenture), as the case may be, next preceding such Interest
Payment Date (the “Regular Record Date”). Any such interest not punctually paid or duly provided
for (“Defaulted Interest”) will forthwith cease to be payable to the Holder on such Regular Record
Date, and such Defaulted Interest, may be paid to the Person in whose name this Note (or one or
more Predecessor Securities) is registered at the close of business on a special record date (the
“Special Record Date”) for the payment of such Defaulted Interest to be fixed by the Trustee,
notice whereof shall be given to Holders of Notes not less than fifteen days prior to such Special
Record Date, or may be paid at any time in any other lawful manner not inconsistent with
requirements of any securities exchange on which the Notes may be listed, and upon such notice as
may be required by such exchange, all as more fully provided in said Indenture.




          Place of Payment. Payment of principal, premium, if any, and interest on this Note
will be made at the Corporate Trust Office of the Trustee or such other office or agency of the
Company as may be designated for such purpose, in such coin or currency of the United States of
America as at the time of payment is legal tender for payment of public and private debts;
provided, however, that each installment of interest, premium, if any, and
principal on this Note may at the Company’s option be paid in immediately available funds by
transfer to an account maintained by the payee located in the United States.




          Time of Payment. In any case where any Interest Payment Date, the Maturity Date or
any date fixed for redemption or repayment of the Notes shall not be a Business Day, then
(notwithstanding any other provision of the Indenture or this Note), payment of principal or
interest, if any, need not be made on such date, but may be made on the next succeeding Business
Day with the same force and effect as if made on such Interest Payment Date, the Maturity Date or
the date so fixed for redemption or repayment, and no interest shall accrue in respect of the
delay.




          General. This Note is one of a duly authorized issue of Securities of the Company,
issued and to be issued in one or more series under an indenture (the “Base Indenture”), dated as
of February 26, 2008, between the Company and The Bank of New York Trust Company, N.A. (herein
called the “Trustee,” which term includes any successor trustee under the Indenture with respect to
a series of which this Note is a part), as supplemented by a First Supplemental Indenture thereto,
dated as of March 4, 2008 (the “First Supplemental Indenture” and, together with the Base
Indenture, the “Indenture”). Reference is hereby made to the Indenture for a statement of the
respective rights, limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Holders of the Securities, and of the terms upon which the Securities are, and are
to be, authenticated and delivered. This Note is one of a duly authorized series of Securities
designated as “6.000% Senior Notes due 2013” (collectively, the “Notes”), initially limited in
aggregate principal amount to $450,000,000.




          Further Issuance. The Company may from time to time, without the consent of the
Holders of the Notes, issue additional Securities (the “Additional Securities”) of this series
having the same ranking and the same interest rate, maturity and other terms as the Notes. Any
Additional Securities of this series and the Notes will constitute a single series under the



A-2 









 






Indenture and all references to the Notes shall include the Additional Securities unless the
context otherwise requires.




          Events of Default. If an Event of Default with respect to the Notes shall have
occurred and be continuing, the principal of the Notes may be declared due and payable in the
manner and with the effect provided in the Indenture.




          Sinking Fund. The Notes are not subject to any sinking fund.




          Optional Redemption. The Notes will be redeemable at any time, at the option of the
Company, in whole or from time to time in part, upon not less than 30 nor more than 60 days’ prior
notice, on any date prior to their Maturity at a redemption price, calculated pursuant to the
Indenture, which includes accrued interest thereon, if any, to, but not including, the Redemption
Date. In the case of any partial redemption, selection of the Notes for redemption will be made by
the Trustee by such methods, as the Trustee in its sole discretion shall deem fair and appropriate.
If any Note is to be redeemed in part only, the notice of redemption relating to such Note shall
state the portion of the principal amount thereof to be redeemed. A new Note in principal amount
equal to the unredeemed portion thereof will be issued in the name of the Holder thereof upon
cancellation of this Note.




          Repurchase upon a Change of Control Triggering Event. Upon the occurrence of a Change
of Control Triggering Event with respect to the Notes, the Company shall be required to make an
offer to repurchase the Notes on the terms set forth in the Indenture.




          Defeasance and Covenant Defeasance. The Indenture contains provisions for defeasance
at any time of (a) the entire indebtedness of the Company on this Note and (b) certain restrictive
covenants and the related Defaults and Events of Default, upon compliance by the Company with
certain conditions set forth therein, which provisions apply to this Note.




          Modification and Waivers; Obligations of the Company Absolute. The Indenture permits,
with certain exceptions as therein provided, the amendment thereof and the modification of the
rights and obligations of the Company and the rights of the Holders of the Securities of each
series. Such amendment may be effected under the Indenture at any time by the Company, and the
Trustee with the consent of the Holders of not less than a majority in aggregate principal amount
of the outstanding Notes of each series affected thereby. The Indenture also contains provisions
permitting the Holders of not less than a majority in aggregate principal amount of the Securities
at the time outstanding, on behalf of the Holders of all outstanding Securities, to waive
compliance by the Company with certain provisions of the Indenture. Furthermore, provisions in the
Indenture permit the Holders of not less than a majority in aggregate principal amount of the
outstanding Securities of individual series to waive on behalf of all of the Holders of Securities
of such individual series certain past defaults under the Indenture and their consequences. Any
such consent or waiver shall be conclusive and binding upon the Holder of this Note and upon all
future Holders of this Note and of any Note issued upon the registration of transfer hereof or in
exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon
this Note.



A-3 









 







          No reference herein to the Indenture and no provision of this Note or of the Indenture shall
alter or impair the obligation of the Company, which is absolute and unconditional, to pay the
principal of and interest on this Note at the time, place, and rate, and in the coin or currency,
herein prescribed.




          Limitation on Suits. As set forth in, and subject to, the provisions of the
Indenture, no Holder of any Note will have any right to institute any proceeding with respect to
the Indenture or for any remedy thereunder, unless such Holder shall have previously given to the
Trustee written notice of a continuing Event of Default with respect to this series, the Holders of
not less than 25% in principal amount of the outstanding Notes shall have made written request, and
offered reasonable indemnity, to the Trustee to institute such proceedings as trustee, and the
Trustee shall not have received from the Holders of a majority in principal amount of the
outstanding Notes a direction inconsistent with such request and shall have failed to institute
such proceeding within 60 days; provided, however, that such limitations do not apply to a suit
instituted by the Holder hereof for the enforcement of payment of the principal of or interest on
this Note on or after the respective due dates expressed herein.




          Authorized Denominations. The Notes are issuable only in registered form without
coupons in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.




          Registration of Transfer or Exchange. As provided in the Indenture and subject to
certain limitations herein and therein set forth, the transfer of this Note is registrable in the
register of the Notes maintained by the Registrar upon surrender of this Note for registration of
transfer, at the office or agency of the Company in any place where the principal of and interest
on this Note are payable, duly endorsed by, or accompanied by a written instrument of transfer in
form satisfactory to the Company and the Registrar, duly executed by the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Notes, of authorized
denominations and for the same aggregate principal amount, will be issued to the designated
transferee or transferees.




          As provided in the Indenture and subject to certain limitations herein and therein set forth,
the Notes are exchangeable for a like aggregate principal amount of Notes of different authorized
denominations, as requested by the Holders surrendering the same.




          No service charge shall be made for any such registration of transfer or exchange, but the
Company may require payment of a sum sufficient to cover any tax or other governmental charge
payable in connection therewith.




          Prior to due presentment of this Note for registration of transfer, the Company, the Trustee
and any agent of the Company or the Trustee may treat the Holder as the owner hereof for all
purposes, whether or not this Note be overdue, and neither the Company, the Trustee nor any such
agent shall be affected by notice to the contrary.




          Defined Terms. All terms used in this Note, which are defined in the Indenture and
are not otherwise defined herein, shall have the meanings assigned to them in the Indenture.




A-4 









 








          Governing Law. This Note shall be governed by and construed in accordance with the
laws of the State of New York, as applied to contracts made and performed within the State of New
York without regard to principles of conflicts of law.




          Unless the certificate of authentication hereon has been executed by the Trustee by manual
signature, this Note shall not be entitled to any benefit under the Indenture or be valid or
obligatory for any purpose.




A-5 









 








     IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed and its seal to
be hereunto affixed and attested.



Dated: March 4, 2008




	 	 	 	 	 
	 	BIOGEN IDEC INC.

 	 
	 	By:  	 	 
	 	 	Name:  		 
	 	 	Title:  		 
	 



Attest:




	 	 	 	 	 
	By:
	 		 	 
	 

	 	 

Name:
	 	 
	 

	 	Title:   	 	 






A-6 









 






TRUSTEE’S CERTIFICATE OF AUTHENTICATION




     This is one of the Notes of the series designated and referred to in the within-mentioned
Indenture, as such is supplemented by the within-mentioned First Supplemental Indenture.



	 	 	 	 	 
	 	THE BANK OF NEW YORK TRUST
    COMPANY, N.A., as Trustee

 	 
	 	By:  	 	 
	 	 	Name: 	 
	 	 	Title:    	 
	 



Dated: March 4, 2008




A-7 









 






ASSIGNMENT



FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and transfer(s) unto




 






 




PLEASE INSERT SOCIAL SECURITY NUMBER OR OTHER IDENTIFYING NUMBER OF ASSIGNEE




                                                                  
              





      



 






 




(Please print or typewrite name and address,

including postal zip code, of assignee)



the within Note and all rights thereunder, and hereby irrevocably constitutes and appoints




 






 






 




to transfer said Note on the books of the Trustee, with full power of substitution in the premises.




	 	 	 	 	 	 	 	 	 
	
Dated: 

	  
	  
	 	 	 	  
	 	 
	 

	 	 	 	 	 	NOTICE: The signature to this assignment must correspond
with the name as written upon the face of the within Note in
every particular, without alteration or enlargement or any
change whatsoever.	 	 
	 
	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	Signature Guarantee
	 	 	 	 	 	 







A-8 












 





EXHIBIT B




Form of 6.875% Senior Note due 2018




          THIS NOTE IS A GLOBAL SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND
IS REGISTERED IN THE NAME OF THE DEPOSITARY OR A NOMINEE OF THE DEPOSITARY. THIS NOTE IS
EXCHANGEABLE FOR NOTES REGISTERED IN THE NAME OF A PERSON OTHER THAN THE DEPOSITARY OR ITS NOMINEE
ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS
A WHOLE BY THE DEPOSITARY TO A NOMINEE OF THE DEPOSITARY, BY A NOMINEE OF THE DEPOSITARY TO THE
DEPOSITARY OR ANOTHER NOMINEE OF THE DEPOSITARY OR BY THE DEPOSITARY OR ANY SUCH NOMINEE TO A
SUCCESSOR DEPOSITARY OR A NOMINEE OF SUCH A SUCCESSOR DEPOSITARY.




BIOGEN IDEC INC.




6.875% Senior Note due 2018




	 	 	 
	REGISTERED

	 	 $550,000,000
	No. Specimen
	 	 
	 
	 	 
	CUSIP: 09062XAB9
	 	 
	ISIN: US09062XAB91
	 	 






          Biogen Idec Inc., a Delaware corporation (herein called the “Company,” which term includes any
successor Person under the Indenture hereinafter referred to), for value received, hereby promises
to pay to Cede & Co., or registered assigns, the principal sum of $550,000,000 on March 1, 2018
(the “Maturity Date”) (except to the extent redeemed or repaid prior to the Maturity Date) and to
pay interest thereon from March 4, 2008 (the “Original Issue Date”) or from the most recent
Interest Payment Date to which interest has been paid or duly provided for semi-annually at the
rate of 6.875% per annum, on March 1 and September 1 (each such date, an “Interest Payment Date”),
commencing September 1, 2008, until the principal hereof is paid or made available for payment.




          Subject to the limitations set forth in Section 2.2(d)(ii) of the First Supplemental Indenture
(as defined herein), the interest rate payable on the Notes (as defined herein) will be subject to
adjustment from time to time, on the terms set forth in the Indenture, if either Moody’s or S&P
downgrades (or subsequently upgrades) the debt rating assigned to the Notes.




          If the interest rate payable on this Note is increased in accordance with the terms hereof and
the Indenture, then the term “interest,” as used in this Note and the Indenture, will be deemed to
include any such additional interest unless the context otherwise requires.




          Payment of Interest. The interest so payable, and punctually paid or made available
for payment, on any Interest Payment Date, will, as provided in the Indenture, be paid, in
immediately available funds, to the Person in whose name this Note (or one or more



B-1









 






Predecessor Securities) is registered at the close of business on February 15 or August 15
(whether or not a Business Day, as defined in the Indenture), as the case may be, next preceding
such Interest Payment Date (the “Regular Record Date”). Any such interest not punctually paid or
duly provided for (“Defaulted Interest”) will forthwith cease to be payable to the Holder on such
Regular Record Date, and such Defaulted Interest, may be paid to the Person in whose name this Note
(or one or more Predecessor Securities) is registered at the close of business on a special record
date (the “Special Record Date”) for the payment of such Defaulted Interest to be fixed by the
Trustee, notice whereof shall be given to Holders of Notes not less than fifteen days prior to such
Special Record Date, or may be paid at any time in any other lawful manner not inconsistent with
requirements of any securities exchange on which the Notes may be listed, and upon such notice as
may be required by such exchange, all as more fully provided in said Indenture.




          Place of Payment. Payment of principal, premium, if any, and interest on this Note
will be made at the Corporate Trust Office of the Trustee or such other office or agency of the
Company as may be designated for such purpose, in such coin or currency of the United States of
America as at the time of payment is legal tender for payment of public and private debts;
provided, however, that each installment of interest, premium, if any, and
principal on this Note may at the Company’s option be paid in immediately available funds by
transfer to an account maintained by the payee located in the United States.




          Time of Payment. In any case where any Interest Payment Date, the Maturity Date or
any date fixed for redemption or repayment of the Notes shall not be a Business Day, then
(notwithstanding any other provision of the Indenture or this Note), payment of principal or
interest, if any, need not be made on such date, but may be made on the next succeeding Business
Day with the same force and effect as if made on such Interest Payment Date, the Maturity Date or
the date so fixed for redemption or repayment, and no interest shall accrue in respect of the
delay.




          General. This Note is one of a duly authorized issue of Securities of the Company,
issued and to be issued in one or more series under an indenture (the “Base Indenture”), dated as
of February 26, 2008, between the Company and The Bank of New York Trust Company, N.A. (herein
called the “Trustee,” which term includes any successor trustee under the Indenture with respect to
a series of which this Note is a part), as supplemented by a First Supplemental Indenture thereto,
dated as of March 4, 2008 (the “First Supplemental Indenture” and, together with the Base
Indenture, the “Indenture”). Reference is hereby made to the Indenture for a statement of the
respective rights, limitations of rights, duties and immunities thereunder of the Company, the
Trustee and the Holders of the Securities, and of the terms upon which the Securities are, and are
to be, authenticated and delivered. This Note is one of a duly authorized series of Securities
designated as “6.875% Senior Notes due 2018” (collectively, the “Notes”), initially limited in
aggregate principal amount to $550,000,000.




          Further Issuance. The Company may from time to time, without the consent of the
Holders of the Notes, issue additional Securities (the “Additional Securities”) of this series
having the same ranking and the same interest rate, maturity and other terms as the Notes. Any
Additional Securities of this series and the Notes will constitute a single series under the




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Indenture and all references to the Notes shall include the Additional Securities unless the
context otherwise requires.




          Events of Default. If an Event of Default with respect to the Notes shall have
occurred and be continuing, the principal of the Notes may be declared due and payable in the
manner and with the effect provided in the Indenture.




          Sinking Fund. The Notes are not subject to any sinking fund.




          Optional Redemption. The Notes will be redeemable at any time, at the option of the
Company, in whole or from time to time in part, upon not less than 30 nor more than 60 days’ prior
notice, on any date prior to their Maturity at a redemption price, calculated pursuant to the
Indenture, which includes accrued interest thereon, if any, to, but not including, the Redemption
Date. In the case of any partial redemption, selection of the Notes for redemption will be made by
the Trustee by such methods, as the Trustee in its sole discretion shall deem fair and appropriate.
If any Note is to be redeemed in part only, the notice of redemption relating to such Note shall
state the portion of the principal amount thereof to be redeemed. A new Note in principal amount
equal to the unredeemed portion thereof will be issued in the name of the Holder thereof upon
cancellation of this Note.



          Repurchase upon a Change of Control Triggering Event. Upon the occurrence of a Change
of Control Triggering Event with respect to the Notes, the Company shall be required to make an
offer to repurchase the Notes on the terms set forth in the Indenture.



          Defeasance and Covenant Defeasance. The Indenture contains provisions for defeasance
at any time of (a) the entire indebtedness of the Company on this Note and (b) certain restrictive
covenants and the related Defaults and Events of Default, upon compliance by the Company with
certain conditions set forth therein, which provisions apply to this Note.



          Modification and Waivers; Obligations of the Company Absolute. The Indenture permits,
with certain exceptions as therein provided, the amendment thereof and the modification of the
rights and obligations of the Company and the rights of the Holders of the Securities of each
series. Such amendment may be effected under the Indenture at any time by the Company, and the
Trustee with the consent of the Holders of not less than a majority in aggregate principal amount
of the outstanding Notes of each series affected thereby. The Indenture also contains provisions
permitting the Holders of not less than a majority in aggregate principal amount of the Securities
at the time outstanding, on behalf of the Holders of all outstanding Securities, to waive
compliance by the Company with certain provisions of the Indenture. Furthermore, provisions in the
Indenture permit the Holders of not less than a majority in aggregate principal amount of the
outstanding Securities of individual series to waive on behalf of all of the Holders of Securities
of such individual series certain past defaults under the Indenture and their consequences. Any
such consent or waiver shall be conclusive and binding upon the Holder of this Note and upon all
future Holders of this Note and of any Note issued upon the registration of transfer hereof or in
exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon
this Note.



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          No reference herein to the Indenture and no provision of this Note or of the Indenture shall
alter or impair the obligation of the Company, which is absolute and unconditional, to pay the
principal of and interest on this Note at the time, place, and rate, and in the coin or currency,
herein prescribed.



          Limitation on Suits. As set forth in, and subject to, the provisions of the
Indenture, no Holder of any Note will have any right to institute any proceeding with respect to
the Indenture or for any remedy thereunder, unless such Holder shall have previously given to the
Trustee written notice of a continuing Event of Default with respect to this series, the Holders of
not less than 25% in principal amount of the outstanding Notes shall have made written request, and
offered reasonable indemnity, to the Trustee to institute such proceedings as trustee, and the
Trustee shall not have received from the Holders of a majority in principal amount of the
outstanding Notes a direction inconsistent with such request and shall have failed to institute
such proceeding within 60 days; provided, however, that such limitations do not apply to a suit
instituted by the Holder hereof for the enforcement of payment of the principal of or interest on
this Note on or after the respective due dates expressed herein.



          Authorized Denominations. The Notes are issuable only in registered form without
coupons in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.



          Registration of Transfer or Exchange. As provided in the Indenture and subject to
certain limitations herein and therein set forth, the transfer of this Note is registrable in the
register of the Notes maintained by the Registrar upon surrender of this Note for registration of
transfer, at the office or agency of the Company in any place where the principal of and interest
on this Note are payable, duly endorsed by, or accompanied by a written instrument of transfer in
form satisfactory to the Company and the Registrar, duly executed by the Holder hereof or his
attorney duly authorized in writing, and thereupon one or more new Notes, of authorized
denominations and for the same aggregate principal amount, will be issued to the designated
transferee or transferees.



          As provided in the Indenture and subject to certain limitations herein and therein set forth,
the Notes are exchangeable for a like aggregate principal amount of Notes of different authorized
denominations, as requested by the Holders surrendering the same.



          No service charge shall be made for any such registration of transfer or exchange, but the
Company may require payment of a sum sufficient to cover any tax or other governmental charge
payable in connection therewith.



          Prior to due presentment of this Note for registration of transfer, the Company, the Trustee
and any agent of the Company or the Trustee may treat the Holder as the owner hereof for all
purposes, whether or not this Note be overdue, and neither the Company, the Trustee nor any such
agent shall be affected by notice to the contrary.



          Defined Terms. All terms used in this Note, which are defined in the Indenture and
are not otherwise defined herein, shall have the meanings assigned to them in the Indenture.



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          Governing Law. This Note shall be governed by and construed in accordance with the
laws of the State of New York, as applied to contracts made and performed within the State of New
York without regard to principles of conflicts of law.



          Unless the certificate of authentication hereon has been executed by the Trustee by manual
signature, this Note shall not be entitled to any benefit under the Indenture or be valid or
obligatory for any purpose.



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          IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed and its seal to
be hereunto affixed and attested.



Dated: March 4, 2008




	 	 	 	 	 
	 	BIOGEN IDEC INC.

 	 
	 	By:  	 	 
	 	 	Name:  		 
	 	 	Title:  		 
	 



Attest:




	 	 	 	 	 
	By:
	 		 	 
	 

	 	 

Name:
	 	 
	 

	 	Title:   	 	 






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TRUSTEE’S CERTIFICATE OF AUTHENTICATION




          This is one of the Notes of the series designated and referred to in the within-mentioned
Indenture, as such is supplemented by the within-mentioned First Supplemental Indenture.




	 	 	 	 	 
	 	THE BANK OF NEW YORK TRUST

   COMPANY, N.A., as Trustee

 	 
	 	By:  	 	 
	 	 	Name: 	 
	 	 	Title:    	 
	 



Dated: March 4, 2008




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ASSIGNMENT



FOR VALUE RECEIVED, the undersigned hereby sell(s), assign(s) and transfer(s) unto



 





 





PLEASE INSERT SOCIAL SECURITY NUMBER OR OTHER IDENTIFYING NUMBER OF ASSIGNEE




                                                                  
              



 





 





(Please print or typewrite name and address,

including postal zip code, of assignee)



the within Note and all rights thereunder, and hereby irrevocably constitutes and appoints



 





 





 




to transfer said Note on the books of the Trustee, with full power of substitution in the premises.




	 	 	 	 	 	 	 
	Dated:
	 	 	 	 	 	 
	 

	 	 
	 	 	 	 
	 

	 	 	 	 	 	NOTICE: The signature to this assignment must correspond
with the name as written upon the face of the within Note in
every particular, without alteration or enlargement or any
change whatsoever.
	 
	 	 	 	 	 	 
	 	 	 
	Signature Guarantee
	 	 







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