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.











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











Robert I. Tepper
December 14, 2006


Page
3


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*****











Robert I. Tepper
December 14, 2006
Page 4


 


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