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Exhibit 10.57

    Millennium Pharmaceuticals, Inc.
640 Memorial Drive
Cambridge, MA 02139
Tel 617 679 7000
mlnm.com

        [Millennium logo]

February 28, 2001

Peter F. Smith, Ph.D.
6755 Foxworth Lane
Gurnee, IL 60031

Dear Peter,

        On behalf of Millennium Pharmaceuticals, Inc. (the "Company"), I am
pleased to offer you the position of Senior Vice President, Pre-Clinical
Development reporting to Mark Levin, Acting President, Research and Development.

        1.    Effective Date:    The effective date of your full-time employment
with the Company is to be determined upon your formal acceptance of this offer.
After discussion with the hiring manager, please contact Shana Stevens at
617-551-7889 to confirm your start date.

        2.    Salary:    Your base salary will initially be $265,000 per annum.
Your salary will be paid periodically in accordance with the Company's payroll
procedures. In addition, in accordance with the Company's compensation
practices, you will receive, approximately annually, a salary review which will
be based on your performance, the Company's performance and such other factors
as may be determined by the Company's Board of Directors.

        3.    Success Sharing:    You will be eligible to participate in the
Millennium Success Sharing cash bonus program, which includes a fixed percentage
of salary target for each position, prorated for length of active service in the
calendar year. The funding of the target is based on the Company meeting overall
goals established at the beginning of each calendar year. In the event of
Company performance below or above target, your personal bonus target may vary.
Your individual bonus payment will also vary based on your individual
performance. The target for your position is 25% of your annual salary. Your
manager will work with you to establish your individual goals, which will be the
primary factor in determining your bonus payment. Bonus payments will be made to
eligible and active employees in March of 2002 for the 2001 Success Sharing
Plan.

        4.    Benefits:    You and your dependents will be eligible for the
Company's standard medical, dental, life insurance, disability benefits and
Section 125 cafeteria plan. After the standard waiting periods, you will also be
eligible to participate in the Company's 401(k) and Employee Stock Purchase
plans. You will accrue vacation at the rate of 1.25 days per month of full-time
employment. Standard paid holidays will be observed. Transportation benefits,
including a choice of MBTA pass up to $60 or contributory off-site parking, are
also available. The Company, however, reserves the right to modify its employee
benefit programs from time-to-time.

        5.    Equity Participation, Vesting of Stock:    Subject to approval by
the Company's Board of Directors, you will be granted stock options exercisable
for 120,000 shares of the Company's Common Stock. One third (1/3) of the total
number of stock options will be granted on the last day of the calendar month in
which you commence full-time employment with the Company, and one third will be

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granted on the last day of each of the next two succeeding calendar months. The
exercise price of these stock options will be equal to the fair market value of
Millennium's Common Stock on the date of each grant. All options will vest as to
one fourth (1/4) of the shares on the first anniversary of your commencement of
full-time employment with the Company and as to one forty-eighth (1/48) of the
shares monthly thereafter until all shares are vested, provided that you remain
employed by the Company. In the event of your death, all options will vest
immediately as to all shares. In the event of termination of your employment for
any reason (except as set forth in the preceding sentence), vesting as to all
shares shall cease. Provided that you remain employed by the Company, these
stock options will be exercisable (as to the vested portion) for 10 years from
the date of each grant. A complete description of the terms and conditions of
these stock options are contained in the Company's 2000 Stock Incentive Plan or
will be contained in your stock option grant forms.

        6.    Employment Period:    Your employment with the Company will be
at-will, meaning that you will not be obligated to remain employed by the
Company for any specified period of time; likewise, the Company will not be
obligated to continue your employment for any specific period and may terminate
your employment at any time, with or without cause.

        7.    Employment Eligibility Verification:    Please note that all
persons employed in the United States, are required to complete an Employment
Eligibility Verification Form on the first day of employment and submit an
original document or documents that establish identity and employment
eligibility within three business days of employment. For your convenience, we
are enclosing Form I-9 for your review. You will need to complete Section 1 and
present original document(s) of your choice as listed on the reverse side of the
form once you begin work. Please note: the I-9 form and valid identification are
legal requirements and must be submitted within 3 days of your start date. If
you do not submit the required documentation within the 3-day time frame, by law
we cannot allow you to continue to work.

        8.    Proprietary Information, No Conflicts:    You agree to execute the
Company's standard form of Invention, Non-Disclosure and Non-Competition
Agreement and to be bound by all of the provisions thereof. You hereby represent
that you are not presently bound by any employment agreement, confidential or
proprietary information agreement or similar agreement with any current or
previous employer that would impose any restriction on your acceptance of this
offer or that would interfere with your ability to fulfill the responsibilities
of your position with the Company.

        9.    Medical Surveillance:    As part of Millennium's medical
surveillance program, employees are required to have an initial physical,
provided by an on-site registered nurse. All laboratory employees working with
hazardous chemical, infectious agents, radio labeled materials or animals shall
have access to medical attention, including initial and periodic medical exams
without cost to the employee or loss of pay. An employee may refuse an exam if
he/she signs a release. If you want to decline from having the initial physical,
please notify Human Resources on your first day at New Employee Orientation.
Your initial surveillance examination will be scheduled to take place during the
first week of your employment.

        10.    New Employee Orientation:    On the first Monday of your
employment with the Company, you should arrive at our 75 Sidney Street at
location for New Employee Orientation. Millennium is located at University Park
at 75 Sidney Street, and orientation is held on the 1st floor. If taking the
MBTA you will get off at the Central Square stop on the Red Line. Directions for
driving are enclosed. Millennium will reimburse you for any parking expenses.
Orientation will begin promptly at 8:30 a.m.

        11.    Sign-on Bonus:    The Company will pay you a bonus of $50,000 on
the date of the first paycheck following commencement of your full time
employment. Should you terminate for any reason within 12 months of your
starting date after having received your bonus, the Company reserves the right
to seek repayment of all or a pro-rata portion of your bonus.

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        12.    Loan:    The Company will loan you a total of $50,000, payable to
you on the date of your first paycheck following commencement of your full time
employment. This loan (with interest), which will be forgivable over a two-year
period, will be granted pursuant to the terms and conditions of a loan agreement
which will be forwarded to you under separate cover. One-half of the principal
and interest will be forgiven on the one year anniversary of your full-time
employment with the Company, and one twenty-fourth (1/24) of the loan will be
forgiven at the end of each full month thereafter until the entire loan has been
forgiven, provided that you remain employed by the Company. In the event of your
termination from the Company, the principal balance and interest will be due.
The loan will be secured by a second mortgage on your principal residence.

        13.    Severance:    In the event that your employment is terminated by
the Company other than for Justifiable Cause (as defined below, the Company will
pay you a severance payment (the "Severance Payment") equal to 12 months' salary
(no stock vesting). The Severance Payment will be payable periodically in
accordance with the Company's payroll procedures as then in effect and the
Company's Obligation to make the Severance Payment will cease in the event that
you accept other employment. In the event your employment is terminated by the
Company for Justifiable Cause (as defined below) or voluntarily by you, you will
not be entitled to any Severance Payment.

        For purposes hereof, the term "Justifiable Cause" shall mean the
occurrence of any of the following events: (I) your conviction of, or pleas of
nolo contendere with respect to a felony or a crime involving moral turpitude,
(ii) your commission of an act of personal dishonesty or breach of fiduciary
duty involving personal profit in connection with the Company, (iii) your
commission of an act, or failure to act, which the Board of Directors of the
Company shall reasonably have found to have involved willful misconduct or gross
negligence on your part, in the conduct of your duties hereunder, (iv) habitual
absenteeism, alcoholism or drug dependence on your part which interferes with
the performance of your duties hereunder, (v) your willful and material breach
or refusal to perform your services as provided herein, (vi) any other material
breach by you of the provisions hereof or (vii) your willful and material
failure or refusal to carry out a direct request of the Board of Directors of
Chief Executive Officer. In the event that the company terminates your
employment for Justifiable Cause, the Company will provide you with a statement
of the basis for such termination and an opportunity to respond thereto.

        14.    Relocation Expenses:    Upon your acceptance of this offer, you
are eligible for reimbursement of the following expenses associated with your
relocation. Specific relocation information will follow from MSI, Millennium's
relocation company.

•Reimbursement for expenses associated with direct-route transportation to
Cambridge.

•The cost of packing, moving, 60 days' temporary storage, and unloading of your
household goods and effects using a certified carrier of the Company's choice.

•Temporary housing for six months upon your arrival in the Boston area or $3,000
(grossed up) lump sum if housing is not used.

•Destination services provided by Corporate Real Estate Services, a division of
Hunneman Coldwell Banker.

•The Company will provide a lump sum allowance of $5,000 (grossed up) to cover
additional relocation related expenses. This sum will be paid to you by MSI once
you submit a request for payment.

Should you voluntarily resign from the Company within one year of relocating,
the Company reserves the right to seek repayment of the entire amount.

•Two house-hunting trips for up to eight (8) days for the purpose of locating
suitable housing.

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•Delivery of car before final move date

        Should you voluntarily resign from the Company within one year of
relocating, the Company reserves the right to seek repayment of all reimbursed
relocation expenses.

        Peter, all of us here at Millennium are very enthusiastic about you
commitment to joining the Company and have the highest expectation of your
future contributions.

        Please indicate your acceptance of the foregoing by signing the enclosed
copy of this letter and returning it to Shani Stickney no later than March 8,
2001. After that date, the offer will lapse.

Very truly yours,
MILLENNIUM PHARMACEUTICALS, INC.

/s/  LINDA K. PINE      

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Linda K. Pine
Sr. Vice President, Human Resources    
The foregoing is signed and accepted as of the date first above written by:
/s/  PETER F. SMITH      

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Peter F. Smith, Ph.D.
 
3/5/01

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Date

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Exhibit 10.57