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                                                                    EXHIBIT 10.1




                                  BIOGEN, INC.
                      1985 NON-QUALIFIED STOCK OPTION PLAN
                 (AS AMENDED THROUGH JUNE 28, 1999 AND RESTATED)


I.   PURPOSE OF THE PLAN

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

II.  DEFINITIONS

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

     2. "Affiliate" means 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.

     3. "Committee" means the Stock and Option Plan Administration Committee of
the Board of Directors of the Company.

     4. "Option" means a stock option granted under this Plan.

III. SHARES SUBJECT TO THE PLAN

     The aggregate number of shares as to which Options may be granted from time
to time shall be 40,908,000 of the shares of Common Stock of the Company (par
value $.01); provided, however that such aggregate number shall be reduced by
the number of shares which has been sold under, or may be sold pursuant to
options granted from time to time under, the Company's 1982 Incentive Stock
Option Plan (the "ISO Plan"), to the same extent as if such sales had been made
or options granted pursuant to this Plan.

     If any option granted under this Plan or the ISO Plan 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 this Plan
or the ISO Plan, as the case may be, or expires by reason of lapse of time.

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     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 below, 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. Subject to the provisions of the Plan, Options
may be granted upon such terms and conditions as the Committee may prescribe.

     This Plan is intended to comply in all respects with Rule 16b-3 or its
successors promulgated under the Securities Exchange Act of 1934 ("1934 Act")
with respect to participants who are subject to Section 16 of the 1934 Act, and
any provision in this Plan with respect to such persons contrary to Rule 16b-3
shall be deemed null and void to the extent permissible by law and deemed
appropriate by the Committee.

V.   ELIGIBILITY FOR PARTICIPATION

     The Committee shall determine which employees and Directors shall be
eligible to participate in the Plan. Without limiting the generality of the
foregoing, Options may be awarded for reasons of performance, merit, promotion,
bonus or upon new employees joining the Company or any Affiliate.

     The Committee may grant to one or more such employees or Directors one or
more Options, and shall 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. In no event shall any employee be granted in any calendar
year options to purchase or receive more than 2,400,000 shares of the Company's
Common Stock pursuant to this Plan.

VI.  TERMS AND CONDITIONS OF OPTIONS

     No Option issued pursuant to this Plan shall be an incentive stock option
under Section 422 of the Internal Revenue Code of 1986, as amended. Each Option
shall be set forth in writing in an Option agreement, duly executed on behalf of
the Company and by the person to whom such Option is granted. No Option shall be
deemed to have been granted and 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

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may deem appropriate, including without limitation, subsequent approval by the
shareholders of the Company of this Plan or any amendments thereto. Each such
Option agreement shall be subject to at least the following terms and
conditions:

     A. Option Price: 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 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 Common Stock. Fair market value shall be the average of the
"high" and "low" sale prices as reported in the National Association of
Securities Dealers Automated Quotation System ("NASDAQ") for the date of grant
of the Option or, if none, for the most recent trading date thirty (30) days or
less prior to the date of grant of the Option on which the Common Stock was
traded.

     B. Term of Option: Each Option shall terminate not more than ten (10) years
from the date of the grant thereof, or at such earlier or later time as the
Committee shall expressly resolve.

     C. Date of Exercise: The Committee may prescribe 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.

     D. Cancellation and Repurchase Rights: The Committee may stipulate that any
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.

     E. Medium of Payment: The Option price shall be payable upon the exercise
of the Option. It shall be payable in cash, or, if permitted by the Committee,
in shares or other consideration.

     F. Termination of Employment: An Option holder who ceases (for any reason
other than death or total and permanent disability or termination of employment
for cause) to be an employee or Director of the Company or of an Affiliate may
exercise any Option granted to the extent that the right to purchase shares
thereunder has accrued on the date of such termination. Such Option shall be
exercisable only within three (3) months after such date of termination, or, if
earlier, within the originally prescribed term of the Option, unless the
Committee shall authorize a different period. Employment shall not be deemed
terminated by reason of a transfer to another employer which is the Company or
an Affiliate.

     An Option holder whose employment with the Company or an Affiliate is
terminated by his/her employer for cause or a Director who is removed from the
Board of Directors for cause shall forthwith upon such termination cease to have
any right to exercise any Option. For


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purposes of this paragraph, "cause" shall be deemed to include dishonesty with
respect to the employer, insubordination, substantial malfeasance or
non-feasance of duty, unauthorized disclosure of confidential information, and
conduct substantially prejudicial to the business of the Company or any
Affiliate. The determination of the Committee as to the existence of cause shall
be conclusive.

     An Option holder to whom an Option has been granted under the Plan who is
absent from work with the Company or with an Affiliate because of temporary
disability, or who is on a permitted leave of absence for any purpose, shall
not, during the period of any such absence, be deemed by virtue of such absence
alone, to have terminated his employment with the Company or with an Affiliate
except as the Committee may otherwise expressly provide.

     G. Total and Permanent Disability: If an Option holder ceases to be an
employee or Director of the Company or of an Affiliate by reason of total and
permanent disability, as determined by the Committee, any Option held by him or
her on the date of disability shall be exercisable as to all or any part of the
shares subject to the Option, all of which shares shall be fully vested as of
the date of such disability. A disabled Option holder may exercise such Option
only within a period of one (1) year after the date as of which the Committee
determines that he or she became disabled or within such different period as may
be determined by the Committee, or, if earlier, within the originally prescribed
term of the Option.

     H. Death: If an Option holder dies while the Option holder is an employee
or Director of the Company or of an Affiliate, any Option held by him or her at
the date of death shall be exercisable as to all or any part of the shares
subject to the Option, all of which shares shall be fully vested as of the date
of the Option holder's death. A deceased Option holder's legal representatives
or one who acquires the Option by will or by the laws of descent and
distribution may exercise such Option only within a period of one (1) year after
the date of death or within such different period as may be determined by the
Committee, or, if earlier, within the originally prescribed term of the Option.

     I. Exercise of Option and Issue of Shares: Options shall be exercised by
giving written notice to the Company, addressed to the Company at the address
specified in the Option agreement, with which the Option holder shall tender the
Option price. Such written notice shall be signed by the person exercising the
Option, shall state the number of shares 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 Option shares may be delayed by the Company if any law
or regulation requires the Company to take any action with respect to the Option
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 Option shares if prohibited by law or applicable regulation.

     The shares shall, upon issuance, be evidenced by an appropriate certificate
or certificates in respect of paid-up, non-assessable shares.

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     J. 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 and set forth in the
applicable Option agreement. The designation of a beneficiary of an Option by an
Option holder shall not be deemed a transfer prohibited by this paragraph.
Except as provided in the preceding sentence, an Option shall be exercisable,
during an Option holder's lifetime, only by the Option holder (or by 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 Paragraph, or the levy of
any attachment or similar process upon an Option or other such rights, shall be
null and void.

     K. Other Provisions: The Option agreements authorized under the Plan 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.

     L. Non-Employee, Non-Scientific Board Directors' Options: Each Director who
is not (i) an employee of the Company or any of its Affiliates, or (ii) a member
of the Scientific Board of the Company, or (iii) elected pursuant to an
agreement or arrangement between shareholders of the Company or between the
Company and its shareholders, upon first being appointed or elected to the Board
of Directors, and upon every third anniversary thereof, shall be granted an
Option to purchase 30,000 shares of Common Stock. Each such Option shall have an
exercise price equal to the fair market value per share of Common Stock on the
date of grant, as determined under Section VI.A. above, and a term of ten (10)
years, and shall be exercisable as to one-third (1/3) of the shares subject
thereto upon completion of one full year of service on the Board of Directors
after the date of grant, and as to an additional one-third (1/3) upon completion
of each full year of service thereafter. For any such Director serving in office
on December 6, 1991, the first such Option shall be granted on the date on which
the most recent Option previously granted to him, the vesting of which is
contingent upon continued service on the Board of Directors, becomes fully
vested, and subsequent Options under this Paragraph shall be granted on every
third anniversary of such date. Notwithstanding the provision of Section XI
concerning amendment of the Plan, the provisions of this Section VI.L. shall not
be amended more than once every six months, other than to comport with changes
in the Internal Revenue Code of 1986, as amended, the Employee Retirement Income
Security Act, or the rules thereunder. The grants of options under this
Paragraph L are intended to be non-discretionary formula awards within the
meaning of Rule 16b-3(c)(2)(ii). Paragraph F of Article VI, which cancels the
Options of any Participant determined by the Committee to have been terminated
for cause, shall not apply to the awards under this Paragraph L.

     M. Tax Withholding: In the event that any federal, state, or local income
taxes, employment taxes, Federal Insurance Contributions Act ("F.I.C.A.")
withholdings or other

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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 Company's Common Stock, is authorized by the Committee (and
permitted by law), provided, however, that with respect to persons subject to
Section 16 of the 1934 Act, any such withholding arrangement shall be in
compliance with any applicable provisions of Rule 16b-3 promulgated under
Section 16 of the 1934 Act. 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. above, as of the most recent practicable date
prior to 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.

     N. Reload Options: The Committee may authorize reload options ("Reload
Options") to purchase for cash or shares a number of shares of Common Stock. The
number of Reload Options shall equal (i) the number of shares of Common Stock
used to exercise the underlying Options and (ii) to the extent authorized by the
Committee, the number of shares of Common Stock used to satisfy any tax
withholding requirement incident to the exercise of the underlying Options. The
grant of a Reload Option will become effective upon the exercise of underlying
Options through the use of shares of Common Stock held by the optionee for at
least 6 months. Reload Options must be evidenced in Option agreements or
amendments to those agreements. The Option price per share of Common Stock
deliverable upon the exercise of a Reload Option shall be the fair market value
of a share of Common Stock on the date the grant of the Reload Option becomes
effective. The term of each Reload Option shall be equal to the remaining option
term of the underlying Option. No additional Reload Options shall be granted to
Option holders when Options and/or Reload Options are exercised pursuant to the
terms of this Plan following termination of the Option holder's employment or on
account of death or total and permanent disability. All other provisions of this
Plan with respect to Options shall apply equally to Reload Options.

     O. Rights as a Shareholder: No Option holder shall have rights as a
shareholder with respect to any shares 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 United States
Securities Act of 1933, as now in force or hereafter amended ("1933 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 1933 Act, in the
absence of an effective registration

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under such 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 1933 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 shares have not been registered 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
States Securities Act of 1933 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 the outstanding Common Stock, $.01 par value, of the
Company is 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, including Options to be granted pursuant to Article VI L hereof, 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 Options
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 transactions 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

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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.





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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 agreements executed prior to the
effective date of termination.

XI.  AMENDMENT OF THE PLAN

     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 in order to comply with Rule 16b-3 under the 1934
Act such amendment shall require approval by the shareholders. Any amendment
shall not affect any Options theretofore granted and any Option 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 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 of any employee, nor to prevent any
employee from terminating his/her employment with the Company or an Affiliate.

XIII.EFFECTIVE DATE

     This Plan first became effective on January 2, 1985.

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