BIOGEN, INC. 
 
 
               VOLUNTARY EXECUTIVE SUPPLEMENTAL SAVINGS PLAN 
 
 
 

                             TABLE OF CONTENTS 
 
                                                                  
    Page 
 
ARTICLE 1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     1.1  Purpose and Effective Date . . . . . . . . . . . . . . .
. . .  1 
 
ARTICLE 2 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.1  Base salary. . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.2  Biogen . . . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.3  Board. . . . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.4  Bonus. . . . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.5  Committee. . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.6  Participant. . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.7  Plan . . . . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.8  Savings Plan . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
     2.9  Plan Year. . . . . . . . . . . . . . . . . . . . . . . .
. . .  1 
 
ARTICLE 3 PARTICIPATION. . . . . . . . . . . . . . . . . . . . . .
. . .  2 
     3.1  Eligibility and Participation. . . . . . . . . . . . . .
. . .  2 
     3.2  End of Participation . . . . . . . . . . . . . . . . . .
. . .  2 
 
ARTICLE 4 SAVINGS DEPOSITS BY PARTICIPANTS; EMPLOYER CREDITS . . .
. . .  2 
     4.1  Savings Deposits.. . . . . . . . . . . . . . . . . . . .
. . .  2 
     4.2  Employer Credits.. . . . . . . . . . . . . . . . . . . .
. . .  3 
 
ARTICLE 5 PARTICIPANTS' ACCOUNTS . . . . . . . . . . . . . . . . .
. . .  3 
     5.1  Participant Accounts . . . . . . . . . . . . . . . . . .
. . .  3 
     5.2  Vesting. . . . . . . . . . . . . . . . . . . . . . . . .
. . .  4 
 
ARTICLE 6 DISTRIBUTIONS TO PARTICIPANT . . . . . . . . . . . . . .
. . .  4 
     6.1  Distributions for Financial Hardship . . . . . . . . . .
. . .  4 
     6.2  Distribution Upon Participant's Retirement . . . . . . .
. . .  4 
     6.3  Distribution Upon Death of a Participant . . . . . . . .
. . .  5 
     6.4  Distribution upon Participant's Other Termination of
Employment  5 
     6.5  Installment Distributions in Certain Cases . . . . . . .
. . .  5 
 
ARTICLE 7 MISCELLANEOUS. . . . . . . . . . . . . . . . . . . . . .
. . .  5 
     7.1  Amendment or Termination of Plan . . . . . . . . . . . .
. . .  5 
     7.2  Benefits Not Currently Funded. . . . . . . . . . . . . .
. . .  5 
     7.3  No Assignment. . . . . . . . . . . . . . . . . . . . . .
. . .  6 
     7.4  Responsibilities and Authority of Committee. . . . . . .
. . .  6 
     7.5  Limitation on Rights Created by Plan . . . . . . . . . .
. . .  6 
     7.6  Tax Withholding. . . . . . . . . . . . . . . . . . . . .
. . .  6 
     7.7  Text Controls. . . . . . . . . . . . . . . . . . . . . .
. . .  6 
     7.8  Applicable State Law . . . . . . . . . . . . . . . . . .
. . .  7 

                                 ARTICLE 1 
                               INTRODUCTION 
 
 1.1 Purpose and Effective Date.  The purpose of this plan is
to provide certain designated key executives 
of Biogen (or its subsidiaries) with additional tax-deferred
savings opportunities supplementing those available 
under the Savings Plan.  This plan allows participants whose
compensation exceeds the amount of compensation 
that may be taken into account by the Savings Plan for any
plan year (the Code Section 401(a)(17) limits) to 
make savings deposits hereunder from such excess compensation
with matching Biogen contributions on the 
same basis as is provided in the Savings Plan, and allows
participants to make additional, unmatched savings 
deposits from base salary or bonus if elected by a
participant.  The effective date of this plan is April 18,
1994. 
 
 
                                 ARTICLE 2 
                                DEFINITIONS 
 
 This section contains definitions of terms used in the plan. 
Where the context so requires, the masculine 
includes the feminine, the singular includes the plural, and
the plural includes the singular. 
 
 2.1 Base salary means the base salary established for any
participant by his employer as in effect from 
time to time; the entire amount of a participant's base salary
will be taken into account in accordance with the 
terms of this plan without regard to any dollar limitation on
applicable compensation that may be imposed under 
the Savings Plan. 
 
 2.2 Biogen means Biogen, Inc., a Massachusetts corporation,
or any successor to all or the major portion 
of its assets or business which assumes the obligations of
Biogen, Inc. under this plan. 
 
 2.3 Board means the Board of Directors of Biogen. 
 
 2.4 Bonus means the amount of compensation paid to a
participant in addition to his base salary and 
designated as such participant's bonus by his employer; the
entire amount of any such bonus will be taken into 
account in accordance with the terms of this plan without
regard to any dollar limitation on applicable 
compensation that may be imposed under the Savings Plan. 
 
 2.5 Committee means the Savings Plan Committee constituted
under the Savings Plan. 
 
 2.6 Participant means an employee of Biogen (or a subsidiary)
who is eligible to participate in this plan in 
accordance with Section 3.1 hereof and who has made a savings
deposit hereunder. 
 
 2.7 Plan means the Biogen, Inc. Voluntary Executive
Supplemental Savings Plan, as set forth in this plan 
instrument, and as it may be amended from time to time. 
 
 2.8 Savings Plan means the Biogen Savings Plan, as amended
from time to time.  Any term defined in the 
Savings Plan will have the same meaning when used in this plan
unless otherwise defined herein. 
 
 2.9 Plan Year means the period commencing April 18, 1994 and
ending December 31, 1994, and the 12- 
month periods commencing on January 1, 1995 and on each
subsequent January 1 while the plan remains in 
effect. 
 
                                 ARTICLE 3 
                               PARTICIPATION 
 
 3.1 Eligibility and Participation.  A person (a) who is an
employee of Biogen (or a subsidiary) and (b) 
who is designated by the committee will be eligible to be a
participant in this plan.  His eligibility will be 
effective as of the date specified by the committee.  An
eligible employee will become a participant hereunder 
when he makes a savings deposit to this plan.  Participation
in this plan is voluntary and no eligible employee 
will be required to participate. 
 
 3.2 End of Participation.  A participant's participation in
this plan will end upon the termination of his 
service as an employee of Biogen (or a subsidiary) because of
death, retirement, or any other reason. 
 
     In addition, a participant's participation will end upon
the committee's specifying that he is no longer 
eligible to participate.  In such event, his participation
will end effective as of the later of the date of the 
committee's action or the date specified by the committee;
provided that no such action will retroactively 
deprive a participant of any amount credited to his account or
any benefit he was entitled to under this plan 
calculated as of the effective date of his termination of
participation. 
 
     Upon the termination of a participant's participation in
this plan in accordance with this section, the 
participant may make no further savings deposits hereunder and
there will be no additional employer matching 
credits to such participant's account.  However, the
participant will be entitled to receive any vested amounts in 
his accounts in accordance with this plan. 
 
     Notwithstanding the preceding provisions of this section,
if a participant's service as an employee of 
Biogen (or a subsidiary) ends but he continues in the position
of Chairman of the Board of Directors of Biogen, 
his participation in this plan will continue and he will be
eligible to continue making savings deposits hereunder 
in accordance with the plan, and for this purpose his regular
remuneration as Chairman will be deemed to be his 
base salary and any bonus he receives as Chairman will be
deemed to be his bonus.  However, he will not be 
eligible to receive any matching employer credits under
Section 4.2 based upon such savings deposits.  He will 
not be considered to have retired or terminated employment for
purposes of Section 6.2 or Section 6.4 until his 
termination of service as Chairman. 
 
 
                                 ARTICLE 4 
            SAVINGS DEPOSITS BY PARTICIPANTS; EMPLOYER CREDITS

 
 4.1 Savings Deposits. 
 
     (a)    Savings Deposits.  Each eligible employee may make
savings deposits to the plan from his base 
salary in any whole percentage of his base salary from a
minimum of 1% to a maximum of 25% by agreeing to 
reduce his base salary by such amount.  In addition, each
eligible employee may make savings deposits to the 
plan from his bonus in any whole percentage of his bonus from
a minimum of 1% to a maximum of 100% by 
agreeing to reduce his bonus by such amount. 
 
     All amounts by which a participant reduces his base
salary or his bonus hereunder are referred to 
herein as the participant's savings deposits.  The amount by
which a participant's savings deposits for a plan 
year hereunder do not exceed 6% of that portion of his
applicable compensation (as defined in the Savings Plan) 
in excess of the Code Section 401(a)(17) limit applicable to
such plan year are referred to herein as his 
matchable savings deposits; provided, however, that a
participant's matchable savings deposits for any plan year 
will not exceed the limit on elective deferrals for such year
under Code Section 402(g)(1) and (5) reduced by his 
basic savings deposits for such year under the Savings Plan. 
 
     (b)    Sign-Up Procedure for Savings Deposits.  An
eligible employee who wishes to make savings 
deposits must complete an enrollment form specifying the
amount of his savings deposits (with separate 
percentages for his base salary and bonus if desired),
agreeing to reduce his base salary and/or bonus by the 
amount(s) desired, and providing such other information as the
committee may require.  A participant's 
enrollment form electing savings deposits for any plan year
must be filed with the committee at least two weeks 
before the start of such plan year (or no later than April 15,
1994 in the case of the first plan year).  A 
participant may change the amount of his savings deposits by
filing a new enrollment form at least two weeks 
before the start of any subsequent plan year, and the change
will become effective as of the first day of such 
subsequent plan year.  After a plan year has begun, a
participant may not change the amount of savings deposits 
(if any) he had elected for such plan year.  However, if a
participant has an unforeseeable financial hardship (as 
defined in Section 6.1) during a year, the participant may
cancel his savings deposits election for the balance of 
that year. 
 
 4.2 Employer Credits. 
 
     (a)    Amount of Matching Employer Credits.  For each
calendar quarter during a plan year, each 
employer will credit a matching contribution amount to the
account of each participant employed by such 
employer who makes matchable savings deposits during such
calendar quarter.  The employer's matching 
contribution credit will be equal to 25% of the participant's
matchable savings deposits during the calendar 
quarter.   
 
     (b)    Time for Making Employer Matching Credits.  The
employers' matching amounts under 
subsection (a) will be credited to participants' accounts as
soon as practicable after each calendar quarter.   
 
 
                                 ARTICLE 5 
                          PARTICIPANTS' ACCOUNTS 
 
 5.1 Participant Accounts. 
 
     (a)    Savings Deposits Accounts.  Savings deposits by a
participant from his base salary or bonus 
hereunder will be credited to an account in the name of such
participant.  Such account will be called his 
savings deposits account. 
 
     (b)    Employer Matching Credits Accounts.  Employer
credits on a participant's behalf under 
Section 4.2(a) will be credited to an account in the name of
such participant.  Such account will be called his 
employer matching credits account. 
 
     (c)    Participant's Account Value.  A participant's
accounts will be credited with deemed investment 
results as if participant savings deposits and employer
matching credits on a participant's behalf were invested in 
one or more designated mutual funds and all dividends and
distributions on shares of a particular mutual fund 
were reinvested in shares of such fund.  The mutual funds
available for this purpose will be those from time to 
time available as investment options for participants'
accounts under the Savings Plan (other than the Biogen 
stock fund). 
 
     Each participant will indicate with his initial
enrollment form the mutual fund or funds (and the 
proportion in each fund when the participant designates more
than one) he wishes to designate for this purpose.  
Thereafter, a participant may change his designation either
with respect to the deemed investment of future 
savings deposits and matching credits or the deemed transfer
of amounts from a previously designated mutual 
fund to another fund; such a change must be filed with the
committee at least two weeks before the start of a 
plan year and will be effective starting with the first day of
such year.  Such designation will remain in effect 
until subsequently changed by the participant in accordance
with this paragraph. 
 
     Deemed investment results under this subsection will be
credited to a participant's accounts effective as 
of the last day in each calendar quarter. 
 
     The value of a participant's accounts at any point in
time will be his savings deposits and employer 
matching credits on his behalf, increased or decreased by
deemed investment results as provided in this 
subsection (c) through the most recent calendar quarter, and
reduced by any distributions from the participant's 
accounts. 
 
     (d)    Bookkeeping Accounts.  Participants' accounts
(including savings deposits accounts and employer 
matching credits accounts) will be maintained on the books of
the participant's employer for bookkeeping 
purposes only; such accounts will not represent any interest
in any trust or in any segregated asset. 
 
 5.2 Vesting. 
 
     (a)    Savings Deposits Account.  A participant will have
a fully vested interest in his savings deposits 
account at all times. 
 
     (b)    Employer Matching Credits Account.  A participant
will have a vested interest in his employer 
matching credits account that is the same as his vested
interest in his matching contributions account under the 
Savings Plan (if a participant hereunder is not a participant
in the Savings Plan, his vested interest in his 
employer matching credits account will be equal to the vested
percentage he would have under the Savings Plan 
in his matching contributions account if he were a
participant).  Upon a participant's termination of 
employment, any nonvested portion of his employer matching
credits account will be forfeited. 
 
 
                                 ARTICLE 6 
                       DISTRIBUTIONS TO PARTICIPANT 
 
 6.1 Distributions for Financial Hardship.  If a participant
has a serious financial hardship, he may apply 
to the committee for a distribution from the plan prior to his
retirement or other termination of service with his 
employer.  If such application for a hardship distribution is
approved by the committee, the distribution will be 
made as soon as possible after the later of the date specified
in the participant's application or the date of 
approval by the committee.  The amount of the distribution
will be the amount needed to alleviate the 
participant's financial hardship, as determined by the
committee, up to a maximum of the participant's vested 
account balances.  Such a distribution will be made from the
participant's accounts in a single lump-sum 
payment. 
 
     Financial hardship will be limited to the following: 
bankruptcy or impending bankruptcy, unexpected 
and unreimbursed major expenses resulting from illness to
person or accident to person or property, and to 
other types of unforeseeable and unreimbursed expenses of a
major nature that normally would not be 
budgetable.  Financial hardship shall not include foreseeable
expenses such as down payments on a home or 
purchase of an auto or college or other educational expenses. 
 
 6.2 Distribution Upon Participant's Retirement.  Upon
retirement from his employer, the participant will 
receive a single sum payment equal to his account balances,
payable as soon as practicable after the end of the 
calendar quarter in which his date of retirement occurred. 
 
 6.3 Distribution Upon Death of a Participant. 
 
     (a)    In general.  If a participant dies while still an
employee of Biogen (or a subsidiary), his 
beneficiary will receive the amount in the participant's
accounts.  If a participant dies after termination of 
employment with Biogen (or a subsidiary) but before the
complete distribution of his vested accounts hereunder, 
his beneficiary will receive the total vested amount remaining
in his accounts.  Distribution will be made in a 
single sum payment as soon as practicable after the end of the
calendar quarter in which the committee receives 
such evidence of the participant's death and of the right of
any beneficiary to receive payment as it deems 
necessary. 
 
     (b)    Beneficiary.  The beneficiary to receive the
payment described in subsection (a) above will be the 
same person or persons who are to receive benefits payable
upon the participant's death under the Savings Plan.  
If more than one person is a beneficiary, death benefits
hereunder will be paid to them in the same proportions 
as under the Savings Plan. 
 
 6.4 Distribution upon Participant's Other Termination of
Employment.  Upon a participant's 
termination of employment for any reason other than retirement
or death, the participant will receive a single 
sum payment equal to his vested account balances as soon as
practicable after the end of the calendar quarter in 
which the participant's termination of employment occurs. 
 
 6.5 Installment Distributions in Certain Cases. 
Notwithstanding the provisions of Sections 6.2, 6.3 and 
6.4, a participant may, at the time of filing an enrollment
form under Section 4.1(b), designate that the amount 
payable to him (or to his beneficiary in the event of his
death) hereunder will be paid in either 3, 5 or 10 annual 
installment payments, as specified by the participant.  In
addition, with the consent of the committee, a 
participant may subsequently change the form of payment to his
beneficiary (but not the form of payment to 
himself under Section 6.2 or 6.4) by filing a written
instrument with the committee designating the new form of 
payment to the beneficiary.  Where this section is applicable,
the first annual installment payment will be paid 
on the date on specified in Section 6.2, 6.3 or 6.4 (whichever
is applicable) and subsequent annual installments 
will be paid on succeeding anniversaries of the first payment
date.  The amount of each annual installment 
payment will be determined by multiplying the vested amount in
the participant's accounts by a fraction whose 
numerator is one and whose denominator is the number of
remaining annual installment payments. 
 
 
                                 ARTICLE 7 
                               MISCELLANEOUS 
 
 7.1 Amendment or Termination of Plan.  Biogen, by action of
the Board (or such committee thereof or 
officer or officers of Biogen to whom the Board has delegated
this authority), at any time and from time to 
time, may amend or modify any or all of the provisions of this
plan or may terminate this plan without the 
consent of any participant (or beneficiary or other person
claiming through a participant).  No termination or 
amendment of the plan may reduce the amounts credited to the
accounts of any participant under the plan 
(including a participant whose employment with the employer
was terminated before such termination or 
amendment).  However, Biogen may change the deemed investment
options under Section 5.1(c), and Biogen 
may upon termination of this plan pay participants' vested
account balances to the participants regardless of 
whether such participants have retired or terminated
employment and may pay such amounts in single sum 
payments regardless of whether participants have elected
installment distributions under Section 6.5. 
 
 7.2 Benefits Not Currently Funded. 
 
     (a)    Nothing in this plan will be construed to create
a trust or to obligate Biogen to segregate a fund, 
purchase an insurance contract or other investment, or in any
other way currently to fund the future payment of 
any benefits hereunder, nor will anything herein be construed
to give any participant or any other person rights 
to any specific assets of Biogen or any other entity. 
However, in order to make provision for its obligations 
hereunder, Biogen may in its discretion purchase an insurance
contract or other investment; any such contract or 
investment will be a general asset belonging to Biogen, and no
participant or beneficiary will have any rights to 
any such asset.  The rights of a participant or beneficiary
hereunder will be solely those of a general, unsecured 
creditor of his employer. 
 
     (b)    Notwithstanding subsection (a) above, Biogen in
its sole discretion may establish a grantor trust of 
which it is treated as the owner under Code Section 671 to
provide for the payment of benefits hereunder, 
subject to such terms and conditions as Biogen may deem
necessary or advisable to ensure that benefits are not 
includable, by reason of the trust, in the taxable income of
trust beneficiaries before actual distribution and that 
the existence of the trust does not cause the plan or any
other arrangement to be considered funded for purposes 
of Title I of ERISA. 
 
 7.3 No Assignment.  No participant or beneficiary will have
any power or right to transfer, assign, 
anticipate or otherwise encumber any benefit or amount payable
under this plan, nor shall any such benefit or 
amount payable be subject to seizure or attachment by any
creditor of a participant or a beneficiary, or to any 
other legal, equitable or other process, or be liable for, or
subject to, the debts, liabilities or other obligations of 
a participant or beneficiary except as otherwise required by
law. 
 
 7.4 Responsibilities and Authority of Committee.  The
committee will control and manage the operation 
and administration of the plan except to the extent that such
responsibilities are specifically assigned hereunder 
to Biogen or the Board. 
 
     The committee will have all powers and authority
necessary or appropriate to carry out its 
responsibilities for the operation and administration of the
plan.  It will interpret and apply all plan provisions 
and may correct any defect, supply any omission or reconcile
any inconsistency or ambiguity in such manner as 
it deems advisable.  It will make all final determinations
concerning eligibility, benefits and rights hereunder, 
and all other matters concerning plan administration and
interpretation.  All determinations and actions of the 
committee will be conclusive and binding upon all persons,
except as otherwise provided herein or by law, and 
except that the committee may revoke or modify a determination
or action previously made in error.  Any 
action or inaction by the committee will be reviewable (by a
court or otherwise) only for an abuse of discretion.  
 
     Biogen will be the "plan administrator" and the "named
fiduciary" for purposes of the Employee 
Retirement Income Security Act of 1974, as amended. 
 
 7.5 Limitation on Rights Created by Plan.  Nothing appearing
in the plan will be construed (a) to give 
any person any benefit, right or interest except as expressly
provided herein, or (b) to create a contract of 
employment or to give any employee the right to continue as an
employee or to affect or modify his terms of 
employment in any way.  
 
 7.6 Tax Withholding.  Any payment hereunder to a participant
or beneficiary will be subject to 
withholding of income and other taxes to the extent required
by law. 
 
 7.7 Text Controls.  Headings and titles are for convenience
only, and the text will control in all matters.  
 
 7.8 Applicable State Law.  To the extent that state law
applies, the provisions of the plan will be 
construed, enforced and administered according to the laws of
the Commonwealth of Massachusetts. 
 
 
                                BIOGEN, INC. 
 
 
 
                                By:                          
              
 
 
391899.1