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                                                                   EXHIBIT 10.23

                                  BIOGEN, INC.
                    1987 SCIENTIFIC BOARD STOCK OPTION PLAN
      (As amended and restated through December 14, 2001, effective as of
                               December 31, 2001)


I.   PURPOSE OF THE PLAN

     The Plan is intended to encourage ownership of shares of the Common Stock
by members of the Scientific Board of the Company and to provide an additional
incentive to those Scientific Board members to promote the success of the
Company and its Affiliates.

II.  DEFINITIONS

     1.   "Affiliate" means (a) a corporation in respect of which the Company
owns directly or indirectly fifty percent (50%) or more of the voting shares
thereof or which is otherwise controlled by the Company; or (b) to the extent
not inconsistent with Section 424 of the Code, an unincorporated trade or
business controlled by the Company which has elected, for federal income tax
purposes, to be either (i) classified as an association taxable as a corporation
or (ii) disregarded as an entity separate from its owner (as provided in Section
301.7701-3 of the federal income tax regulations). For purposes of this
definition, the Company shall be deemed to control another entity if the Company
possesses, directly or indirectly, the power to direct or cause the direction of
the management and policies of such entity, whether through ownership of voting
securities, by contract or otherwise.

     2.   "Code" means the Internal Revenue Code of 1986, as amended from time
to time.

     3.   "Committee" means the Stock and Option Plan Administration Committee
of the Board of Directors of the Company or, if such committee ceases to exist,
the Board of Directors of the Company or a committee thereof to which
responsibility for administering the Plan shall have been delegated.

     4.   "Common Stock" means the common stock of the Company, par value $0.01
per share.

     5.   "Company" means Biogen, Inc., a Massachusetts corporation.

     6.   "Exchange Act" means the United States Securities Exchange Act of
1934, as amended from time to time.

     7.   "Fair Market Value" shall have the meaning set forth in Section VI.A.

     8.   "Member" means a member of the Scientific Board of the Company.

     9.   "Option" means a stock option granted under the Plan.

     10.  "Option Certificate" means a certificate delivered to an Option holder
by the



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Company pursuant to the Plan, in such form as the Committee shall approve, which
sets forth the terms and conditions of an Option.

     11.  "Plan" means this 1987 Scientific Board Stock Option Plan, as amended
and restated from time to time.

     12.  "Securities Act" means the United States Securities Act of 1933, as
amended from time to time.

III  SHARES SUBJECT TO THE PLAN

     The aggregate number of shares as to which Options may be granted from time
to time shall be 3,000,000 shares of the Common Stock.

     If any Option ceases to be "outstanding", in whole or in part, other than
by reason of the exercise of such Option, the shares which were subject to such
Option shall be available for the granting of other Options. Any Option shall be
treated as "outstanding" until such Option is exercised in full, terminates
under the provisions of the Plan or expires by reason of lapse of time.

     The aggregate number of shares as to which Options may be granted shall be
subject to change only by means of an amendment adopted in accordance with
Article XI, subject to the provisions of Article VIII.

IV.  ADMINISTRATION OF THE PLAN

     The Plan shall be administered by the Committee. The membership of the
Committee shall be determined, and shall be subject to change without cause and
without notice from time to time, by the Board of Directors of the Company.

     The Committee is authorized to interpret the provisions of the Plan or of
any Option and to make all rules and determinations necessary or advisable for
the administration of the Plan. The interpretation and construction by the
Committee of any provision of the Plan or of any Option granted under it shall
be final. The Committee's determinations under the Plan do not need to be
uniform and may be made by it selectively among persons who receive, or are
eligible to receive, Options under the Plan (whether or not such persons are
similarly situated). Subject to the provisions of the Plan, Options may be
granted upon such terms and conditions as the Committee may prescribe.

V.   ELIGIBILITY FOR PARTICIPATION

     The Committee shall determine which Members shall be eligible to
participate in the Plan. Without limited the generality of the foregoing,
Options may be awarded for reasons of performance, merit, bonus or upon new
Members joining the Scientific Board of the Company.

     The Committee may grant to one or more such Members one or more Options,
and shall


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designate the number of shares to be optioned under each Option so granted;
provided, however, that no Options shall be granted after December 31, 2002.

VI.  TERMS AND CONDITIONS OF OPTIONS

     No Option issued pursuant to the Plan shall be an incentive stock option
under Section 422 of the Code. No purported grant of any Option shall be
effective until such Option shall have been approved by the Committee. The
Committee may provide that Options be granted subject to such conditions as the
Committee may deem appropriate, including without limitation, subsequent
approval by the shareholders of the Company of the Plan or any amendments
thereto. Each Option shall be subject to at least the following terms and
conditions:

     A.   OPTION PRICE: Each Option Certificate shall state the Option price per
share of the Common Stock covered by such Option grant. Except as otherwise
determined by the Committee, the Option price per share for Options granted
under the Plan shall be equal to the fair market value per share of Common Stock
(the "Fair Market Value") on the date of grant of the Option; provided, however,
that in no event shall the Option price be less than the par value per share of
the Common Stock. Fair Market Value shall be calculated as follows: (i) if the
Common Stock is listed on a national securities exchange or traded on the Nasdaq
National Market or the Nasdaq SmallCap Market AND sale prices are regularly
reported for the Common Stock, then the Fair Market Value shall be the
arithmetic mean between the "high" and "low" sale prices for the Common Stock
reported on the applicable composite tape or other comparable reporting system
on the date of grant, or if the date of grant is not a trading day, on the most
recent trading day immediately prior to the date of grant; or (ii) if sale
prices are not regularly reported for the Common Stock as described in clause
(i) above but bid and asked prices for the Common Stock are regularly reported,
then the Fair Market Value shall be the arithmetic mean between the closing or
last bid and asked prices for the Common Stock on the date of grant or, if the
date of grant is not a trading day, on the most recent trading day immediately
prior to the date of grant; or (iii) if sale prices are not regularly reported
for the Common Stock as described in clause (i) or (ii) above, then the Fair
Market Value shall be such value as the Committee in good faith determines.

     B.   NUMBER OF SHARES: Each Option Certificate shall state the number of
shares of the Common Stock to which it pertains.

     C.   TERM OF OPTION: Each Option Certificate shall state the term of the
Option which shall be ten (10) years from the date of the grant thereof or at
such earlier or later time as the Committee shall expressly state in the Option
Certificate.

     D.   DATE OF EXERCISE: Each Option Certificate shall state the date or
dates on which the Option becomes exercisable, and may provide that the Option
rights accrue or become exercisable in installments over a period of months or
years, or upon the attainment of stated goals or events or through other
circumstances or programs approved by the Committee. The Committee shall have
the right to accelerate the date of exercise of any installment of any Option.


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     E.   CANCELLATION AND REPURCHASE RIGHTS: An Option Certificate may
stipulate that an Option which becomes exercisable shall be subject to
cancellation or that shares purchased upon the exercise of such Option shall be
subject to repurchase rights in favor of the Company. In such event the
Committee shall determine the date or dates, or event or events, upon which such
cancellation or repurchase rights shall become effective or shall lapse, as the
case may be and those provisions shall be set forth in the Option Certificate.

     F.   MEDIUM OF PAYMENT: The option price shall be payable upon the exercise
of the Option. It shall be payable (a) in United States dollars in cash or by
check, (b) if permitted by the Committee, in shares of the Common Stock held by
the Option holder for at least six months having a fair market value (determined
in the manner provided in Section VI.A as of the date of exercise) equal to the
cash exercise price of the Option, (c) at the discretion of the Committee, by
delivery of the Option holder's personal note, for full, partial or no recourse,
bearing interest payable not less than annually at market rate on the date of
exercise and no less than 100% of the applicable Federal rate, as defined in
Section 1274(d) of the Code, with or without the pledge of shares of the Common
Stock as collateral, (d) at the discretion of the Committee, in accordance with
a cashless exercise program established with a securities brokerage firm, or (e)
at the discretion of the Committee, by any combination of (a), (b), (c) and (d)
above.

     G.   EXERCISE OF OPTION AND ISSUE OF SHARES: Options shall be exercised by
giving written notice to the Company or its designee, together with provision
for payment of the Option price in accordance with Section VI.F. Such written
notice shall be signed by the person exercising the Option, shall state the
number of shares of the Common Stock with respect to which the Option is being
exercised, and shall contain any warranty required by Article VII of the Plan.
The issuance of the shares of the Common Stock upon exercise of the Option may
be delayed by the Company if any law or regulation may be delayed by the Company
if any law or regulation requires the Company to take any action with respect to
the shares prior to the issuance thereof. Without limiting the generality of the
foregoing, nothing contained herein shall be deemed to require the Company to
issue any shares of the Common Stock if prohibited by law or applicable
regulation.

     The shares of the Common Stock shall, upon issuance, be paid-up,
non-assessable shares.

     H.   ASSIGNABILITY AND TRANSFERABILITY OF OPTION: By its terms, an Option
granted to an Option holder shall not be transferable by such Option holder
other than (i) by will or by the laws of descent and distribution, or (ii)
pursuant to a qualified domestic relations order, as defined by the Code or
Title 1 of the Employee Retirement Income Security Act or the rules thereunder,
or (iii) as otherwise determined by the Committee. The designation of a
beneficiary of an Option by an Option holder shall not be deemed a transfer
prohibited by this Section. Except as provided in the preceding sentence, an
Option shall be exercisable, during an Option holder's lifetime, only by the
Option holder (or his or her legal representative) and shall not be assigned,
pledged, or hypothecated in any way (whether by operation of law or otherwise)
and shall not be subject to execution, attachment or similar process. Any
attempted transfer, assignment, pledge, hypothecation, or other disposition of
any Option or of any rights granted thereunder contrary to the provisions of
this Section, or the levy of any attachment or similar process upon an Option or
other such rights, shall be null and void.



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     I.   OTHER PROVISIONS: The Option Certificates shall be subject to such
other terms and conditions, including, without limitation, restrictions upon the
exercise of the Option, as the Committee shall deem advisable.

     J.   TAX WITHHOLDING: In the event that any federal, state, or local income
taxes, employment taxes, Federal Insurance Contributions Act withholdings or
other amounts are required by applicable law or governmental regulation to be
withheld from the Option holder's salary in connection with the exercise of an
Option, the Option holder shall advance in cash to the Company, or to any
Affiliate of the Company which employs or employed the Option holder, the amount
of such withholdings unless a different withholding arrangement, including the
use of shares of the Common Stock, is authorized by the Committee (and permitted
by law); provided, however, that with respect to persons subject to Section 16
of the Exchange Act, any such withholding arrangement shall be in compliance
with any applicable provisions of Rule 16b-3 promulgated under Section 16 of the
Exchange Act. If the Committee allows withholding through use of shares of the
Common Stock, it shall be only to the statutory minimum amount. For purposes
hereof, the fair market value of the shares withheld for purposes of payroll
withholding shall be determined in the manner provided in Section VI.A as of the
date of exercise. If the fair market value of the shares withheld is less than
the amount of payroll withholdings required, the Option holder may be required
to advance the difference in cash to the Company or the Affiliate employer.

     K.   RIGHTS AS A SHAREHOLDER: No Option holder shall have rights as a
shareholder with respect to any shares of the Common Stock covered by such
Option except as to such shares as have been registered in the Company's share
register in the name of such person upon the due exercise of the Option.

VII. PURCHASE FOR INVESTMENT

     If and to the extent that the issuance of shares pursuant to the exercise
of Options is deemed by the Company to be subject to the Securities Act, or to
the securities law of any other jurisdiction, the Company shall be under no
obligation to issue shares covered by such exercise unless the person or persons
who exercises or who exercise such Option shall make such warranty or take such
action as may be required by any applicable securities law of any applicable
jurisdiction and shall, in the case of the applicability of the Securities Act,
in the absence of an effective registration under the Securities Act with
respect to such shares, warrant to the Company, at the time of such exercise,
that such person is or that they are acquiring the shares to be issued to such
person or to them, pursuant to such exercise of the Option, for investment and
not with a view to, or for sale in connection with, the distribution of any such
shares; and in such events the person or persons acquiring such shares shall be
bound by the provisions of a legend endorsed upon any share certificates
expressing the requirements of any applicable non-United States securities law,
or, in cases deemed governed by the Securities Act, substantially the following
legend, which shall be endorsed upon the certificate or certificates evidencing
the shares issued by the Company pursuant to such exercise:

          "The securities represented by this certificate have not been
          registered


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          under the securities laws of any country, including the United States
          Securities Act of 1933, as amended, and the Company may refuse to
          permit the sale or transfer of all or any of the shares until (1) the
          Company has received an opinion of counsel satisfactory to the Company
          that any such transfer is exempt from registration under all
          applicable securities laws or (2) in the case of sales or transfers to
          which the united Sates Securities Act of 1933, as amended, is
          applicable, unless a registration statement with respect to such
          shares shall be effective under such Act, as amended."

Without limiting the generality of the foregoing, the Company may delay issuance
of the shares until completion of any action or obtaining of any consent which
the Company deems necessary under any applicable law (including without
limitation state securities or "blue sky" laws).

VIII. ADJUSTMENTS UPON CHANGES IN CAPITALIZATION

     In the event that outstanding shares of the Common Stock are changed into
or exchanged for a different number or kind of shares or other securities of the
Company or of another corporation by reason of any reorganization, merger,
consolidation, recapitalization, reclassification, change in par value, stock
split-up, combination of shares or dividend payable in capital stock, or the
like, appropriate adjustment shall be made in the number and kind of shares for
the purchase of which Options may be granted under the Plan, and, in addition,
appropriate adjustment shall be made in the number and kind of shares and in the
option price per share subject to outstanding Options so that each Option holder
shall be in a position equivalent to the position the Option holder would have
been in had the Option holder exercised the Option immediately prior to the
applicable event.

IX.  DISSOLUTION OR LIQUIDATION OF THE COMPANY

     Upon the dissolution or liquidation of the Company other than in connection
with a transaction to which the preceding Article VIII is applicable, all
Options granted hereunder shall terminate and become null and void; provided,
however, that if the rights hereunder of an Option holder or one who acquired an
Option by will or by the laws of descent and distribution have not otherwise
terminated and expired, the Option holder or such person shall have the right
immediately prior to such dissolution or liquidation to exercise any Option
granted hereunder to the extent that the right to purchase shares thereunder has
accrued as of the date of exercise immediately prior to such dissolution or
liquidation.

X.   TERMINATION OF THE PLAN

     Unless the Committee shall decide to reduce or, subject to shareholder
approval, if required under Article XI, to extend the duration of the Plan, the
Plan shall terminate on December 31, 2002. Termination of the Plan shall not
affect any Options granted or any Option Certificates or agreements executed
prior to the effective date of termination.

XI.  AMENDMENT OF THE PLAN



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     The Plan may be amended by the Committee or the Board of Directors of the
Company; provided, however, that if the scope of any amendment is such as to
require shareholder approval then such amendment shall require approval by the
shareholders. Any amendment shall not affect any Options theretofore granted and
any Option Certificates or agreements theretofore executed by the Company and
any Option holder unless such amendment shall expressly so provide. No amendment
shall adversely affect any Option holder with respect to an outstanding Option
without the written consent of such Option holder. With the consent of the
Option holder affected, the Committee may amend any outstanding Option
Certificate or agreement in a manner not inconsistent with the Plan, including,
without limitation, to accelerate the date of exercise of any installment of any
Option.

XII. EMPLOYMENT RELATIONSHIP

     Nothing herein contained shall be deemed to prevent the Company or an
Affiliate from terminating the employment or consultancy of any Member, nor to
present any Member from terminating his employment or consultancy with the
Company or an Affiliate.

XIII. EFFECTIVE DATE

     The Plan first became effective on March 6, 1987.

XIV. GOVERNING LAW

     The Plan shall be construed and enforced in accordance with the laws of The
Commonwealth of Massachusetts.



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