Exhibit 10.54

December 14, 2006

Robert I. Tepper

c/o Millennium Pharmaceuticals, Inc.

40 Landsdowne Street

Cambridge, MA 02139

Dear Dr. Tepper:

This letter amends the terms of your employment offer letter from Millennium
Pharmaceuticals, Inc. (“Millennium” or the “Company”) dated May 5, 1994 (the
“Letter Agreement”) and memorializes certain other agreements between you and
the Company.  Capitalized terms used herein and not otherwise defined shall have
the meaning given to them in the Letter Agreement.

1.             In consideration of your agreement to remain employed by the
Company as President of R&D through March 31, 2007, or such earlier date as may
be specified by the Company’s Chief Executive Officer but in no event earlier
than March 6, 2007 (the “Termination Date”), you will receive: (a) the Severance
Payment, provided, however, that the Severance Payment shall not be subject to
reduction or cessation as provided in Section 7 of the Agreement, (b) a lump sum
stay incentive payment equal to $225,000 (the “Incentive Payment”) and (c)
provided that you elect continued coverage under federal COBRA law, payment of
the portion of premiums of your group health insurance coverage, including
coverage for your eligible dependents, that Millennium paid prior to the
Termination Date, for a period of 12 months following the Termination Date or
the date on which you become eligible for substantially similar group benefits
at a subsequent employer, whichever is earlier.  The Severance Payment will be
paid periodically in accordance with the Company’s payroll procedures and the
Incentive Payment will be paid to you within three days following the
Termination Date.

2.             In further consideration of your agreement to remain employed by
the Company, if the Termination Date occurs prior to the date on which payments
are made under the Company’s 2006 Success Sharing Bonus Program (the “2006
Program”), you will remain eligible to receive a bonus payment under the Program
at the same time that bonus payments are made to other participants in the
program.  You acknowledge that you will not be eligible for any payment under
the Company’s 2007 Success Sharing Bonus Program.

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Robert I. Tepper

December 14, 2006

Page 2

 

3.             The consideration provided for herein supersedes the
consideration provided for in Section 7 of the Letter Agreement and no
additional amounts shall be payable thereunder.  All amounts that you receive
from the Company hereunder will be subject to all required tax withholding.  In
the event of a material breach of your continuing obligations to the Company,
including under any Inventions, Non-Disclosure and Non-Competition Agreement(s)
or similar agreements that you may have signed during your employment with the
Company, the Company reserves the right to cease the payments described herein.

4.             In consideration of receiving the payments outlined herein, you
hereby release and forever discharge and hold Millennium, as well as its current
and former successors, employees, officers, directors, shareholders, parents,
subsidiaries, affiliates and agents, harmless of all claims or suits of any
nature whatsoever, including, but not limited to, any claims under federal,
state and local laws that prohibit discrimination (including without limitation,
claims of discrimination based on race, age, religion, national origin, sex,
disability or handicap, and sexual orientation) and any claims with respect to
breach of contract (express and/or implied), wrongful termination, Worker
Adjustment and Retraining Notification Act and related state statute
notification obligations, the Older Workers Benefit Protection Act of 1990 and
related state statutes, intentional or negligent infliction of emotional
distress, interference with contractual or advantageous business relations, loss
of consortium, invasion of privacy, defamation, payment of wages, debts, costs
and expenses, attorneys’ fees and other damages, and any claims arising out of
or in any way related to your employment with Millennium, which you now have,
may have, or may have had from the beginning of time to the Termination Date. 
Nothing in this paragraph shall be construed in any way to release Millennium
from its obligation to indemnify you from any third party action brought against
you based on your employment with or service as an officer to Millennium
pursuant to any applicable agreement or applicable law or to reduce or eliminate
any coverage you may have under Millennium’s director and officer liability
policies, if any.  As required by the Older Workers Benefit Protection Act of
1990, you acknowledge:  (i) that you have been advised and given the opportunity
to consult with your own counsel prior to signing this Agreement; (ii) that you
have been given 21 days from the receipt of this Agreement to consider whether
to sign it; (iii) that you have been advised that even after you sign this
Agreement, you may revoke it within 7 days of the date of your signing, by
delivering a signed revocation notice to Millennium’s Senior Vice-President of
Human Resources; (iv) that this Agreement shall not become effective and in
force until eight (8) days after you sign it, and (v) that you will not be
entitled to receive the payments described herein until after the 7-day
revocation period has expired, and that, should you in fact revoke your
acceptance, none of the payments outlined herein will be made.

5.             This Agreement may be amended or modified only by a written
instrument executed by you and Millennium.  This agreement will be interpreted
and enforced in

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Robert I. Tepper

December 14, 2006

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accordance with the laws of the Commonwealth of Massachusetts.  Except as
expressly stated in this letter, the Letter Agreement remains unchanged and in
full force and effect.

*****The remainder of this page is purposefully blank*****

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Robert I. Tepper

December 14, 2006

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Please acknowledge your agreement by countersigning this letter below.

 

Sincerely,

 

 

 

MILLENNIUM PHARMACEUTICALS, INC.

 

 

 

By:

/s/ STEPHEN GANSLER

 

 

Name:

Stephen Gansler

 

Title:

SVP, Human Resources

 

 

AGREED TO:

 

/s/ ROBERT I. TEPPER

 

Robert I. Tepper

 

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