content: <PAGE>   1
      As filed with the Securities and Exchange Commission on January 12, 2001
  
                                                    REGISTRATION NO. 333 -
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                          ---------------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                      UNDER THE
                               SECURITIES ACT OF 1933
  
                         ----------------------------------
  
                                    BIOGEN, INC.
               (Exact name of Registrant as specified in its charter)
  
          MASSACHUSETTS                                       04-3002117
    (State or other jurisdiction                           (I.R.S. Employer
  of  incorporation or organization)                      Identification No.)
  
                                 14 CAMBRIDGE CENTER
                                 CAMBRIDGE, MA 02142
                                   (617) 679-2000
                      (Address of Principal Executive Offices)
  
                    BIOGEN, INC. 1982 INCENTIVE STOCK OPTION PLAN
                  BIOGEN, INC. 1985 NON-QUALIFIED STOCK OPTION PLAN
                             (Full titles of the plans)
  
                                THOMAS BUCKNUM, ESQ.
                          VICE PRESIDENT - GENERAL COUNSEL
                                    BIOGEN, INC.
                                 14 CAMBRIDGE CENTER
                                 CAMBRIDGE, MA 02142
                                   (617) 679-2000
      (Name, address, including zip code, and telephone number, including area
                             code, of agent for service)
  
                            ----------------------------
  <TABLE>
  <CAPTION>
  
                           CALCULATION OF REGISTRATION FEE
  ==============================================================================================================================
  
                                                                Proposed             Proposed
                                                                maximum               maximum
                  Title of               Amount to be        offering price          aggregate
      securities to be registered        registered(1)        per share(2)       offering price(2)   Amount of registration fee
  ------------------------------------------------------------------------------------------------------------------------------
  <S>              <C>                     <C>                   <C>               <C>                       <C>
     Common Stock, $.01 par value          3,300,000             $51.31            $169,323,000              $42,330.75
  
  ===========================================================================================================================
  </TABLE>
  
    (1)  The number of shares of common stock, par value $.01 per share ("Common
         Stock"), stated above consists of (i) the aggregate number of additional
         shares which may be sold upon the exercise of options which have been
         granted and/or may hereafter be granted under the 1982 Incentive Stock
         Option Plan and the 1985 Non-Qualified Stock Option Plan (the "Plans").
         The maximum number of shares which may be sold upon the exercise of such
         options granted under the Plans are subject to adjustment in accordance
         with certain anti-dilution and other provisions of said Plans.
         Accordingly, pursuant to Rule 416 under the Securities Act of 1933, as
         amended (the "Securities Act"), this Registration Statement covers, in
         addition to the number of shares stated above, an indeterminate number of
         shares which may be subject to grant or otherwise issuable after the
         operation of any such anti-dilution and other provisions.
  
  (2)    This calculation is made solely for the purpose of determining the
         registration fee pursuant to the provisions of Rule 457(h) under the
         Securities Act. The fee is calculated on the basis of the average of the
         high and low sale prices per share of the Common Stock on the National
         Market System of the National Association of Securities Dealers Automated
         Quotation System (NASDAQ) as of a date (January 10, 2001) within 5
         business days prior to filing this Registration Statement.
  
  ================================================================================
  
  <PAGE>   2
  
  
  
                                  EXPLANATORY NOTE
  
  
           This Registration Statement relates to the registration of 3,300,000
  additional shares of Common Stock authorized for issuance under the Biogen, Inc.
  1982 Incentive Stock Option Plan and the Biogen, Inc. 1985 Non-Qualified Stock
  Option Plan. In accordance with the instructional Note to Part I of Form S-8 as
  promulgated by the Securities and Exchange Commission, the information specified
  by Part I of Form S-8 has been omitted from this Registration Statement on Form
  S-8 for offers of Common Stock pursuant to the Plans.
  
  
  <PAGE>   3
  
  
  
  PART II
  
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.
  
           The following documents filed by the Registrant with the Commission are
  incorporated herein by reference:
  
           (a)   The Company's Annual Report on Form 10-K for the fiscal year
  ended December 31, 1999.
  
           (b)   The Company's Quarterly Reports on Form 10-Q for the quarters
  ended March 31, 2000, June 30, 2000 and September 30, 2000.
  
           (c)   The description of the Common Stock contained in the Registrant's
  Registration Statement on Form 8-B filed under the Securities Exchange Act of
  1934, including any amendment or report filed for the purpose of updating such
  description.
  
           All reports and other documents filed by the Registrant after the date
  hereof pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
  Exchange Act of 1934 prior to the filing of a post-effective amendment which
  indicates that all securities offered hereby have been sold or which deregisters
  all securities then remaining unsold, shall be deemed to be incorporated by
  reference herein and to be part hereof from the date of filing of such reports
  and documents.
  
  ITEM 4.  DESCRIPTION OF SECURITIES.
  
           Not applicable.
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           The validity of the issuance of the shares of Common Stock registered
  under this Registration Statement has been passed upon for the Company by Mintz,
  Levin, Cohn, Ferris, Glovsky and Popeo, P.C. of Boston, Massachusetts. Members
  of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. ("Mintz Levin") and
  certain members of their families and trusts for their benefit own an aggregate
  of approximately 245 shares of Common Stock of the Company. In addition, a
  member of Mintz Levin is sole trustee of a trust that owns 2,400 shares of
  Common Stock of the Company.
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           Incorporated herein by reference from Registration Statement on Form
  S-3, No. 33-43721.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  ITEM 8.  EXHIBITS.
  
           (4.1)    Form of Common Stock Share Certificate (Filed as Exhibit 4.1
                    to  Registration  Statement  on Form  S-3,  File
                    No.33-51639, and incorporated herein by reference).
  
  <PAGE>   4
  
  
           (4.2)    Articles of Organization, as amended (Filed as Exhibit 3.1 to
                    Annual Report on Form 10-K for the fiscal year ended December
                    31, 1996, File No. 0-12042, and incorporated herein by
                    reference) and as further amended by the Amendment to the
                    Articles of Organization as adopted June 11, 1999 and filed
                    herewith.
  
           (4.3)    By-Laws, as amended (Filed as Exhibit 3.2 to Annual Report on
                    Form 10-K for the year ended December 31, 1992, file No.
                    0-12042, and incorporated herein by reference).
  
           (4.4)    Rights Agreement, dated as of May 8, 1999, between the
                    Registrant and First National Bank of Boston as the Rights
                    Agent, including Certificate of Designation of Series A-1
                    Junior Participating Preferred Stock (Filed as Exhibit 4.1 to
                    Registrant's Form 8-K dated April 27, 1999 and incorporated
                    herein by reference).
  
           (5)      Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                    as to the legality of shares being registered.
  
           (23.1)   Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                    (included in opinion of counsel filed as Exhibit 5).
  
           (23.2)   Consent of Pricewaterhousecoopers LLP
  
           (24)     Power of Attorney to file future amendments (set forth on the
                    signature page of this Registration Statement.)
  
  ITEM 9.  UNDERTAKINGS.
  
  (a)      The undersigned Registrant hereby undertakes:
  
           (1) To file, during any period in which offers or sales are being made,
           a post-effective amendment to this Registration Statement:
  
                    (i)  To include any prospectus required by Section 10(a)(3)
           of the Securities Act of 1933;
  
                    (ii) To reflect in the prospectus any facts or events arising
           after the effective date of the Registration Statement (or the most
           recent post-effective amendment thereof) which, individually or in the
           aggregate, represents a fundamental change in the information set forth
           in the Registration Statement. Notwithstanding the foregoing, any
           increase or decrease in volume of securities offered (if the total
           dollar value of securities offered would not exceed that which was
           registered) and any deviation from the low or high end of the estimated
           maximum offering range may be reflected in the form of prospectus filed
           with the Commission pursuant to Rule 424(b) (Section 230.424(b) of this
           chapter) if, in the aggregate, the changes in volume and price
           represent no more than a 20% change in the maximum aggregate offering
           price set forth in the "Calculation of Registration Fee" table in the
           effective Registration Statement.
  
                    (iii) To include any material information with respect to the
           plan of distribution not previously disclosed in the Registration
           Statement or any material change to such information in the
           Registration Statement;
  
  <PAGE>   5
  
  
  Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
  Registration Statement is on Form S-3 or Form S-8, and the information required
  to be included in a post-effective amendment by those paragraphs is contained in
  periodic reports filed by the Registrant pursuant to Section 13 or Section 15(d)
  of the Securities Exchange Act of 1934 that are incorporated by reference in
  this Registration Statement.
  
           (2) That, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities at that time shall be deemed to be the initial bona
  fide offering thereof.
  
           (3) To remove from registration by means of a post-effective amendment
  any of the securities being registered which remain unsold at the termination of
  the offering.
  
  (b) The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 that is incorporated by reference in this
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
  (c) Insofar as indemnification for liabilities arising under the Securities Act
  of 1933 may be permitted to directors, officers and controlling persons of the
  Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
  has been advised that in the opinion of the Securities and Exchange Commission
  such indemnification is against public policy as expressed in the Act and is,
  therefore, unenforceable. In the event that a claim for indemnification against
  such liabilities (other than the payment by the Registrant of expenses incurred
  or paid by a director, officer or controlling person of the Registrant in the
  successful defense of any action, suit or proceeding) is asserted by such
  director, officer or controlling person in connection with the securities being
  registered, the Registrant will, unless in the opinion of its counsel the matter
  has been settled by controlling precedent, submit to a court of appropriate
  jurisdiction the question whether such indemnification by it is against public
  policy as expressed in the Act and will be governed by the final adjudication of
  such issue.
  
  
  
  <PAGE>   6
  
  
                                     SIGNATURES
  
  
           Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Registrant certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in Cambridge, Massachusetts on January 12, 2000.
  
  
                                                BIOGEN, INC.
  
  
                                                By: /s/ James Mullen
                                                   -------------------------------
                                                President and
                                                Chief Executive Officer
  
  
  Pursuant to the requirements of the Securities Act of 1933, as amended, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  
  Each person whose signature appears below constitutes and appoints, James
  Mullen, Peter N. Kellogg and Thomas Bucknum, and each of them, his or her true
  and lawful attorneys-in-fact and agents, with full power of substitution and
  resubstitution in each of them, for him or her and in his or her name, place and
  stead, and in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this Registration Statement on Form S-8 of Biogen,
  Inc., and to file the same, with all exhibits thereto and other documents in
  connection therewith, with the Securities and Exchange Commission, granting unto
  said attorneys-in-fact and agents, and each of them, full power and authority to
  do and perform each and every act and thing requisite or necessary to be done in
  or about the premises, as full to all intents and purposes as he or she might or
  could do in person, hereby ratifying and confirming all that said
  attorneys-in-fact and agents or any of them or their or his or her substitute or
  substitutes may lawfully do or cause to be done by virtue hereof.
  
  <TABLE>
  <CAPTION>
  
  SIGNATURE                          TITLE                                   DATE
  ---------                          -----                                   ----
  <S>                                <C>                                     <C>
  /s/ James L. Vincent               Chairman of the Board                   January 12, 2001
  -----------------------------
  James L. Vincent
  
  /s/ James Mullen                   Director, President and Chief           January 12, 2001
  -----------------------------      Executive Officer
  James Mullen
  
  /s/ Peter N. Kellogg               Vice President - Finance and            January 12, 2001
  -----------------------------      Chief Financial Officer (principal
  Peter J. Kellogg                   financial and accounting officer)
  
  /s/ Alan Belzer                    Director                                January 12, 2001
  ----------------------------
  Alan Belzer
  
  /s/ Harold W. Buirkle              Director                                January 12, 2001
  ----------------------------
  Harold W. Buirkle
  
  /s/ Mary L. Good                   Director                                January 12, 2001
  ----------------------------
  Mary L. Good
  
  </TABLE>
  <PAGE>   7
  
  
  
  <TABLE>
  <CAPTION>
  <S>                                <C>                                     <C>
  /s/ Thomas F. Keller               Director                                January 12, 2001
  ----------------------------
  Thomas F. Keller
  
  /s/ Roger H. Morley                Director                                January 12, 2001
  ----------------------------
  Roger H. Morley
  
  /s/ Kenneth Murray                 Director                                January 12, 2001
  ----------------------------
  Kenneth Murray
  
  /s/ Phillip A. Sharp               Director                                January 12, 2001
  ----------------------------
  Phillip A. Sharp
  
  /s/ Alan K. Simpson                Director                                January 12, 2001
  ----------------------------
  Alan K. Simpson
  
  /s/ James W. Stevens               Director                                January 12, 2001
  ----------------------------
  James W. Stevens
  
  </TABLE>
  
  
  <PAGE>   8
  
  
                                    BIOGEN, INC.
  
                            INDEX TO EXHIBITS FILED WITH
                           FORM S-8 REGISTRATION STATEMENT
  
  
  EXHIBIT
  NUMBER                              DESCRIPTION
  
  (4.1)    Form of Common Stock Share Certificate (Filed as Exhibit 4.1 to
           Registration Statement on Form S-3, File No.33-51639, and incorporated
           by reference).
  
  (4.2)    Articles of Organization, as amended (Filed as Exhibit 3.1 to Annual
           Report on Form10-K for the fiscal year ended December 31, 1996, File
           No. 0-12042, and incorporated herein by reference) and as further
           amended by the Amendment to the Articles of Organization as adopted
           June 11, 1999 and filed herewith.
  
  (4.3)    By-Laws, as amended (Filed as Exhibit 3.2 to Annual Report on Form 10-K
           for the year ended December 31, 1992, file No. 0-12042, and
           incorporated herein by reference).
  
  (4.4)    Rights Agreement, dated as of May 8, 1989, between the Registrant and
           First National Bank of Boston as the Rights Agent, including
           Certificate of Designation of Series A Junior Participating Preferred
           Stock (Filed as Exhibit 1 to Registration Statement on Form 8-A, File
           No. 0-12042, filed May 26, 1989, and incorporated herein by reference).
  
  (5)      Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. as to
           the legality of shares being registered.
  
  (23.1)   Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
           (included in opinion of counsel filed as Exhibit 5).
  
  (23.2)   Consent of PricewaterhouseCoopers LLP
  
  (24)     Power of Attorney to file future amendments (set forth on the signature
           page of this Registration Statement.)
metadata_documents: [{"type": "S-8", "sequence": "1", "filename": "b37904bis-8.txt", "description": "BIOGEN, INC.", "secsgml_size_bytes": 19439}]
metadata_filer: {"company-data": {"conformed-name": "BIOGEN INC", "cik": "0000714655", "assigned-sic": "2836", "irs-number": "043002117", "state-of-incorporation": "MA", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-53598", "film-number": "1507612"}, "business-address": {"street1": "14 CAMBRIDGE CTR", "city": "CAMBRIDGE", "state": "MA", "zip": "02142", "phone": "6176792000"}, "mail-address": {"street1": "14 CAMBRIDGE CTR", "city": "CAMBRIDGE", "state": "MA", "zip": "02142"}, "former-company": {"former-conformed-name": "BIOGEN NV", "date-changed": "19880622"}}
text: 1
      As filed with the Securities and Exchange Commission on January 12, 2001
  
                                                    REGISTRATION NO. 333 -
  ================================================================================
  
                         SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON, D.C. 20549
  
                          ---------------------------------
  
                                      FORM S-8
                               REGISTRATION STATEMENT
                                      UNDER THE
                               SECURITIES ACT OF 1933
  
                         ----------------------------------
  
                                    BIOGEN, INC.
               (Exact name of Registrant as specified in its charter)
  
          MASSACHUSETTS                                       04-3002117
    (State or other jurisdiction                           (I.R.S. Employer
  of  incorporation or organization)                      Identification No.)
  
                                 14 CAMBRIDGE CENTER
                                 CAMBRIDGE, MA 02142
                                   (617) 679-2000
                      (Address of Principal Executive Offices)
  
                    BIOGEN, INC. 1982 INCENTIVE STOCK OPTION PLAN
                  BIOGEN, INC. 1985 NON-QUALIFIED STOCK OPTION PLAN
                             (Full titles of the plans)
  
                                THOMAS BUCKNUM, ESQ.
                          VICE PRESIDENT - GENERAL COUNSEL
                                    BIOGEN, INC.
                                 14 CAMBRIDGE CENTER
                                 CAMBRIDGE, MA 02142
                                   (617) 679-2000
      (Name, address, including zip code, and telephone number, including area
                             code, of agent for service)
  
                            ----------------------------
  CALCULATION OF REGISTRATION FEE
  ==============================================================================================================================
  
                                                                Proposed             Proposed
                                                                maximum               maximum
                  Title of               Amount to be        offering price          aggregate
      securities to be registered        registered(1)        per share(2)       offering price(2)   Amount of registration fee
  ------------------------------------------------------------------------------------------------------------------------------
  Common Stock, $.01 par value          3,300,000             $51.31            $169,323,000              $42,330.75
  
  ===========================================================================================================================
  (1)  The number of shares of common stock, par value $.01 per share ("Common
         Stock"), stated above consists of (i) the aggregate number of additional
         shares which may be sold upon the exercise of options which have been
         granted and/or may hereafter be granted under the 1982 Incentive Stock
         Option Plan and the 1985 Non-Qualified Stock Option Plan (the "Plans").
         The maximum number of shares which may be sold upon the exercise of such
         options granted under the Plans are subject to adjustment in accordance
         with certain anti-dilution and other provisions of said Plans.
         Accordingly, pursuant to Rule 416 under the Securities Act of 1933, as
         amended (the "Securities Act"), this Registration Statement covers, in
         addition to the number of shares stated above, an indeterminate number of
         shares which may be subject to grant or otherwise issuable after the
         operation of any such anti-dilution and other provisions.
  
  (2)    This calculation is made solely for the purpose of determining the
         registration fee pursuant to the provisions of Rule 457(h) under the
         Securities Act. The fee is calculated on the basis of the average of the
         high and low sale prices per share of the Common Stock on the National
         Market System of the National Association of Securities Dealers Automated
         Quotation System (NASDAQ) as of a date (January 10, 2001) within 5
         business days prior to filing this Registration Statement.
  
  ================================================================================
  2
  
                                  EXPLANATORY NOTE
  
           This Registration Statement relates to the registration of 3,300,000
  additional shares of Common Stock authorized for issuance under the Biogen, Inc.
  1982 Incentive Stock Option Plan and the Biogen, Inc. 1985 Non-Qualified Stock
  Option Plan. In accordance with the instructional Note to Part I of Form S-8 as
  promulgated by the Securities and Exchange Commission, the information specified
  by Part I of Form S-8 has been omitted from this Registration Statement on Form
  S-8 for offers of Common Stock pursuant to the Plans.
  3
  
  PART II
  
  INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
  
  ITEM 3.  INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE.
  
           The following documents filed by the Registrant with the Commission are
  incorporated herein by reference:
  
           (a)   The Company's Annual Report on Form 10-K for the fiscal year
  ended December 31, 1999.
  
           (b)   The Company's Quarterly Reports on Form 10-Q for the quarters
  ended March 31, 2000, June 30, 2000 and September 30, 2000.
  
           (c)   The description of the Common Stock contained in the Registrant's
  Registration Statement on Form 8-B filed under the Securities Exchange Act of
  1934, including any amendment or report filed for the purpose of updating such
  description.
  
           All reports and other documents filed by the Registrant after the date
  hereof pursuant to Sections 13(a), 13(c), 14 and 15(d) of the Securities
  Exchange Act of 1934 prior to the filing of a post-effective amendment which
  indicates that all securities offered hereby have been sold or which deregisters
  all securities then remaining unsold, shall be deemed to be incorporated by
  reference herein and to be part hereof from the date of filing of such reports
  and documents.
  
  ITEM 4.  DESCRIPTION OF SECURITIES.
  
           Not applicable.
  
  ITEM 5.  INTERESTS OF NAMED EXPERTS AND COUNSEL.
  
           The validity of the issuance of the shares of Common Stock registered
  under this Registration Statement has been passed upon for the Company by Mintz,
  Levin, Cohn, Ferris, Glovsky and Popeo, P.C. of Boston, Massachusetts. Members
  of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. ("Mintz Levin") and
  certain members of their families and trusts for their benefit own an aggregate
  of approximately 245 shares of Common Stock of the Company. In addition, a
  member of Mintz Levin is sole trustee of a trust that owns 2,400 shares of
  Common Stock of the Company.
  
  ITEM 6.  INDEMNIFICATION OF DIRECTORS AND OFFICERS.
  
           Incorporated herein by reference from Registration Statement on Form
  S-3, No. 33-43721.
  
  ITEM 7.  EXEMPTION FROM REGISTRATION CLAIMED.
  
           Not applicable.
  
  ITEM 8.  EXHIBITS.
  
           (4.1)    Form of Common Stock Share Certificate (Filed as Exhibit 4.1
                    to  Registration  Statement  on Form  S-3,  File
                    No.33-51639, and incorporated herein by reference).
  4
  
           (4.2)    Articles of Organization, as amended (Filed as Exhibit 3.1 to
                    Annual Report on Form 10-K for the fiscal year ended December
                    31, 1996, File No. 0-12042, and incorporated herein by
                    reference) and as further amended by the Amendment to the
                    Articles of Organization as adopted June 11, 1999 and filed
                    herewith.
  
           (4.3)    By-Laws, as amended (Filed as Exhibit 3.2 to Annual Report on
                    Form 10-K for the year ended December 31, 1992, file No.
                    0-12042, and incorporated herein by reference).
  
           (4.4)    Rights Agreement, dated as of May 8, 1999, between the
                    Registrant and First National Bank of Boston as the Rights
                    Agent, including Certificate of Designation of Series A-1
                    Junior Participating Preferred Stock (Filed as Exhibit 4.1 to
                    Registrant's Form 8-K dated April 27, 1999 and incorporated
                    herein by reference).
  
           (5)      Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                    as to the legality of shares being registered.
  
           (23.1)   Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
                    (included in opinion of counsel filed as Exhibit 5).
  
           (23.2)   Consent of Pricewaterhousecoopers LLP
  
           (24)     Power of Attorney to file future amendments (set forth on the
                    signature page of this Registration Statement.)
  
  ITEM 9.  UNDERTAKINGS.
  
  (a)      The undersigned Registrant hereby undertakes:
  
           (1) To file, during any period in which offers or sales are being made,
           a post-effective amendment to this Registration Statement:
  
                    (i)  To include any prospectus required by Section 10(a)(3)
           of the Securities Act of 1933;
  
                    (ii) To reflect in the prospectus any facts or events arising
           after the effective date of the Registration Statement (or the most
           recent post-effective amendment thereof) which, individually or in the
           aggregate, represents a fundamental change in the information set forth
           in the Registration Statement. Notwithstanding the foregoing, any
           increase or decrease in volume of securities offered (if the total
           dollar value of securities offered would not exceed that which was
           registered) and any deviation from the low or high end of the estimated
           maximum offering range may be reflected in the form of prospectus filed
           with the Commission pursuant to Rule 424(b) (Section 230.424(b) of this
           chapter) if, in the aggregate, the changes in volume and price
           represent no more than a 20% change in the maximum aggregate offering
           price set forth in the "Calculation of Registration Fee" table in the
           effective Registration Statement.
  
                    (iii) To include any material information with respect to the
           plan of distribution not previously disclosed in the Registration
           Statement or any material change to such information in the
           Registration Statement;
  5
  
  Provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do not apply if the
  Registration Statement is on Form S-3 or Form S-8, and the information required
  to be included in a post-effective amendment by those paragraphs is contained in
  periodic reports filed by the Registrant pursuant to Section 13 or Section 15(d)
  of the Securities Exchange Act of 1934 that are incorporated by reference in
  this Registration Statement.
  
           (2) That, for the purpose of determining any liability under the
  Securities Act of 1933, each such post-effective amendment shall be deemed to be
  a new registration statement relating to the securities offered therein, and the
  offering of such securities at that time shall be deemed to be the initial bona
  fide offering thereof.
  
           (3) To remove from registration by means of a post-effective amendment
  any of the securities being registered which remain unsold at the termination of
  the offering.
  
  (b) The undersigned Registrant hereby undertakes that, for purposes of
  determining any liability under the Securities Act of 1933, each filing of the
  Registrant's annual report pursuant to Section 13(a) or Section 15(d) of the
  Securities Exchange Act of 1934 that is incorporated by reference in this
  Registration Statement shall be deemed to be a new registration statement
  relating to the securities offered therein, and the offering of such securities
  at that time shall be deemed to be the initial bona fide offering thereof.
  
  (c) Insofar as indemnification for liabilities arising under the Securities Act
  of 1933 may be permitted to directors, officers and controlling persons of the
  Registrant pursuant to the foregoing provisions, or otherwise, the Registrant
  has been advised that in the opinion of the Securities and Exchange Commission
  such indemnification is against public policy as expressed in the Act and is,
  therefore, unenforceable. In the event that a claim for indemnification against
  such liabilities (other than the payment by the Registrant of expenses incurred
  or paid by a director, officer or controlling person of the Registrant in the
  successful defense of any action, suit or proceeding) is asserted by such
  director, officer or controlling person in connection with the securities being
  registered, the Registrant will, unless in the opinion of its counsel the matter
  has been settled by controlling precedent, submit to a court of appropriate
  jurisdiction the question whether such indemnification by it is against public
  policy as expressed in the Act and will be governed by the final adjudication of
  such issue.
  6
  
                                     SIGNATURES
  
           Pursuant to the requirements of the Securities Act of 1933, as amended,
  the Registrant certifies that it has reasonable grounds to believe that it meets
  all of the requirements for filing on Form S-8 and has duly caused this
  Registration Statement to be signed on its behalf by the undersigned, thereunto
  duly authorized, in Cambridge, Massachusetts on January 12, 2000.
  
                                                BIOGEN, INC.
  
                                                By: /s/ James Mullen
                                                   -------------------------------
                                                President and
                                                Chief Executive Officer
  
  Pursuant to the requirements of the Securities Act of 1933, as amended, this
  Registration Statement has been signed by the following persons in the
  capacities and on the dates indicated.
  
  Each person whose signature appears below constitutes and appoints, James
  Mullen, Peter N. Kellogg and Thomas Bucknum, and each of them, his or her true
  and lawful attorneys-in-fact and agents, with full power of substitution and
  resubstitution in each of them, for him or her and in his or her name, place and
  stead, and in any and all capacities, to sign any and all amendments (including
  post-effective amendments) to this Registration Statement on Form S-8 of Biogen,
  Inc., and to file the same, with all exhibits thereto and other documents in
  connection therewith, with the Securities and Exchange Commission, granting unto
  said attorneys-in-fact and agents, and each of them, full power and authority to
  do and perform each and every act and thing requisite or necessary to be done in
  or about the premises, as full to all intents and purposes as he or she might or
  could do in person, hereby ratifying and confirming all that said
  attorneys-in-fact and agents or any of them or their or his or her substitute or
  substitutes may lawfully do or cause to be done by virtue hereof.
  SIGNATURE                          TITLE                                   DATE
  ---------                          -----                                   ----
  /s/ James L. Vincent               Chairman of the Board                   January 12, 2001
  -----------------------------
  James L. Vincent
  
  /s/ James Mullen                   Director, President and Chief           January 12, 2001
  -----------------------------      Executive Officer
  James Mullen
  
  /s/ Peter N. Kellogg               Vice President - Finance and            January 12, 2001
  -----------------------------      Chief Financial Officer (principal
  Peter J. Kellogg                   financial and accounting officer)
  
  /s/ Alan Belzer                    Director                                January 12, 2001
  ----------------------------
  Alan Belzer
  
  /s/ Harold W. Buirkle              Director                                January 12, 2001
  ----------------------------
  Harold W. Buirkle
  
  /s/ Mary L. Good                   Director                                January 12, 2001
  ----------------------------
  Mary L. Good
  7
  /s/ Thomas F. Keller               Director                                January 12, 2001
  ----------------------------
  Thomas F. Keller
  
  /s/ Roger H. Morley                Director                                January 12, 2001
  ----------------------------
  Roger H. Morley
  
  /s/ Kenneth Murray                 Director                                January 12, 2001
  ----------------------------
  Kenneth Murray
  
  /s/ Phillip A. Sharp               Director                                January 12, 2001
  ----------------------------
  Phillip A. Sharp
  
  /s/ Alan K. Simpson                Director                                January 12, 2001
  ----------------------------
  Alan K. Simpson
  
  /s/ James W. Stevens               Director                                January 12, 2001
  ----------------------------
  James W. Stevens
  8
  
                                    BIOGEN, INC.
  
                            INDEX TO EXHIBITS FILED WITH
                           FORM S-8 REGISTRATION STATEMENT
  
  EXHIBIT
  NUMBER                              DESCRIPTION
  
  (4.1)    Form of Common Stock Share Certificate (Filed as Exhibit 4.1 to
           Registration Statement on Form S-3, File No.33-51639, and incorporated
           by reference).
  
  (4.2)    Articles of Organization, as amended (Filed as Exhibit 3.1 to Annual
           Report on Form10-K for the fiscal year ended December 31, 1996, File
           No. 0-12042, and incorporated herein by reference) and as further
           amended by the Amendment to the Articles of Organization as adopted
           June 11, 1999 and filed herewith.
  
  (4.3)    By-Laws, as amended (Filed as Exhibit 3.2 to Annual Report on Form 10-K
           for the year ended December 31, 1992, file No. 0-12042, and
           incorporated herein by reference).
  
  (4.4)    Rights Agreement, dated as of May 8, 1989, between the Registrant and
           First National Bank of Boston as the Rights Agent, including
           Certificate of Designation of Series A Junior Participating Preferred
           Stock (Filed as Exhibit 1 to Registration Statement on Form 8-A, File
           No. 0-12042, filed May 26, 1989, and incorporated herein by reference).
  
  (5)      Opinion of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. as to
           the legality of shares being registered.
  
  (23.1)   Consent of Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C.
           (included in opinion of counsel filed as Exhibit 5).
  
  (23.2)   Consent of PricewaterhouseCoopers LLP
  
  (24)     Power of Attorney to file future amendments (set forth on the signature
           page of this Registration Statement.)