VERTEX PHARMACEUTICALS INC / MA
EXHIBIT 10.7
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<TYPE>EX-10.7
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<FILENAME>a2145707zex-10_7.txt
<DESCRIPTION>EXHIBIT 10.7
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                                                                    EXHIBIT 10.7

                                               November 8, 2004






Re:  Amendment to Change of Control Agreement

Dear [______],

       The Change of Control Agreement dated as of March 7, 2003 between you and
Vertex Pharmaceuticals Incorporated (the "AGREEMENT") hereby is amended,
effective November 8, 2004, as follows:

1.     Insert a new Section I.7, which shall state in its entirety:

       I.7  "PRO-RATA SHARE OF RESTRICTED STOCK" shall mean, for any grant of
            restricted stock as to which the Company's repurchase right lapses
            ratably over a specified period (e.g. in equal annual increments
            over four years), that number of shares as to which the Company's
            repurchase right with respect to those shares would have lapsed if
            the Executive's employment by the Company had continued an
            additional 18 month period. For any other shares of restricted
            stock, "Pro-Rata Share of Restricted Stock" shall mean, as to any
            shares of restricted stock which were granted on the same date and
            as to which the Company's repurchase right lapses on the same date,
            that portion of such shares calculated by multiplying the number of
            shares by a fraction, the numerator of which is the number of days
            that have passed since the date of grant, plus the number of days in
            18 months, and the denominator of which is the total number of days
            from the date of the grant until the date (without regard to any
            provisions for earlier vesting upon achievement of a specified goal)
            on which the Company's repurchase right would lapse under the terms
            of the grant.

2.     Delete Section 2, "Accelerated Vesting," in its entirety, and substitute
       the following therefor:

       2.   ACCELERATED VESTING

            (a)  Stock options for the purchase of the Company's securities held
                 by you as of the Termination Date and not then exercisable
                 shall be deemed to have been held by you for an additional 18
                 months, for purposes of calculating the number of options which
                 are exercisable on the Termination Date. The options to which
                 this accelerated vesting applies shall remain exercisable


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                 until the earlier of (a) the end of the 90-day period
                 immediately following the Termination Date, or (b) the date the
                 stock option(s) would otherwise expire; and

            (b)  the Company's lapsing repurchase right with respect to shares
                 of restricted stock held by you shall lapse with respect to the
                 Pro-Rata Share of Restricted Stock.

            (c)  Notwithstanding anything to the contrary in this agreement, the
                 terms of any option agreement or restricted stock agreement
                 shall govern the acceleration, if any, of vesting or lapsing of
                 the Company's repurchase rights, as applicable, except to the
                 extent that the terms of this agreement are more favorable to
                 you.


       As so amended, the Change of Control Agreement shall remain in full force
and effect.

       If you agree to the foregoing amendment, please so indicate by signing
and returning the enclosed copy of this letter.


                                         VERTEX PHARMACEUTICALS INCORPORATED



                                         By:
                                            ------------------------------------
                                            Joshua S. Boger
                                            Chairman and Chief Executive Officer


Accepted and Agreed:


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                                   SCHEDULE 1
               PARTIES TO AMENDMENT TO CHANGE OF CONTROL AGREEMENT


                                    John Alam
                                   Lynne Brum
                                  Pamela Fritz
                                  Peter Mueller
                                   Mark Murcko
                                 Steven Schmidt
                                  John Thomson
                                 Jeffrey Wilson

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