Exhibit 10.57

                                BIOGEN IDEC INC.
                     2006 NON-EMPLOYEE DIRECTORS EQUITY PLAN

                                 First Amendment

      Pursuant to Section 17 of the Biogen Idec Inc. 2006 Non-Employee Directors
Equity Plan (the "Plan"), the following clarifying amendments are hereby made to
Section 7(d) of the Plan, effective as of the Plan's Effective Date:

      1. Section 7(d)(i) is amended to read in its entirety as follows: "In the
event that the Participant's Board service shall terminate on account of the
Retirement of the Participant, each Option granted to such Participant that is
outstanding as of the date of such termination shall become fully exercisable
and shall remain exercisable by the Participant (or, in the event of the
Participant's death while such Option is still outstanding, by the Participant's
legal representatives, heirs or legatees) for the three year period following
such termination (or for such other period as may be provided by the Committee),
but in no event following the expiration of its term."

      2. Section 7(d)(iii) is amended to read in its entirety as follows: "In
the event that the Participant's Board service shall terminate on account of the
Disability of the Participant, each Option granted to such Participant that is
outstanding as of the date of such termination shall become fully exercisable
and shall remain exercisable by the Participant (or such Participant's legal
representatives or, in the event of the Participant's death while such Option is
still outstanding, such Participant's legal representatives, heirs or legatees)
for the one year period following such termination (or for such other period as
may be provided by the Committee), but in no event following the expiration of
its term."

      3. Section 7(d)(vi) is amended to read in its entirety as follows: "In the
event of the Participant's death within six months following the Participant's
termination of Board service for any reason other than (A) Retirement, (B)
death, (C) Disability or (D) For Cause, each Option granted to such Participant
that is vested and outstanding as of the date of death shall remain exercisable
by such Participant's legal representatives, heirs or legatees for the one year
period following the date of death (or for such other period as may be provided
by the Committee), but in no event following the expiration of its term."

      IN WITNESS WHEREOF, Biogen Idec Inc. has caused this instrument of
amendment to be executed by its duly authorized officer this 11th day of October
2006.

                                 BIOGEN IDEC INC.

                                 By:  /s/ Craig E. Schneier
                                      ----------------------------------------
                                      Craig E. Schneier, Ph.D.
                                      Executive Vice President, Human Resources