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                                                                   Exhibit 4.5

                          CUBIST PHARMACEUTICALS, INC.


                  2002 STOCK IN-LIEU OF CASH COMPENSATION PLAN
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            As Adopted by the Board of Directors on December 13, 2002

1.       PURPOSE AND EFFECTIVE DATE.

         The purpose of the Cubist Pharmaceuticals, Inc. 2002 Stock in-lieu of
Cash Compensation Plan (this "Plan") is to provide to employees of the Company
the opportunity to receive year-end bonuses for fiscal year 2002, if any, and
salary increases for fiscal year 2003, if any, in shares of common stock of the
Company, par value $.001 per share (the "COMMON STOCK") in-lieu of cash. In
addition, this Plan also provides for the directors of the Company to receive a
portion of their fees for services during fiscal year 2002 in shares of Common
Stock in-lieu of cash. This Plan will enable the Company to conserve cash in an
amount equal to the aggregate compensation of each Employee and Director that is
issued in shares of Common Stock pursuant to this Plan.

         This Plan has been adopted as of December 13, 2002 and is effective
immediately and shall terminate on January 31, 2003.

2.       DEFINITIONS.

         "Board" shall mean the Board of Directors of the Company.

         "Company" shall mean Cubist Pharmaceuticals, Inc.

         "Director" shall mean each person who is a director of the Company.

         "Employee" shall mean each person who is an employee of the Company.

3.       ELIGIBILITY; MAXIMUM NUMBER OF SHARES.

         Subject to all of the terms and conditions of the Plan, each Employee
and Director is eligible to participate in the distribution of Common Stock
under the Plan. At no time shall the number of shares of Common Stock issued
under the Plan exceed 250,000 shares of Common Stock.


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4.       ISSUANCE OF SHARES.

         (a) The Company shall issue shares of Common Stock to each Employee and
Director representing a portion of such person's compensation in an amount and
in the manner determined by the Board.

         (b) The Board shall cause the Company to issue the shares of Common
Stock pursuant to clause (a) above on or before January 9, 2003.

5.       EFFECT ON COMPANY RIGHTS.

         Neither the adoption of the Plan, nor any action taken pursuant to its
terms, shall confer upon any Employee or Director any right to continued
employment, nor interfere in any way with the right of the Company to terminate
the employment of any of its employees at any time.

6.       ADMINISTRATION AND INTERPRETATION.

         The Board will have full and exclusive authority to administer the
Plan, to interpret the terms of the Plan, to adopt, amend and rescind rules and
guidelines for the administration of the Plan and to decide all questions and
settle all controversies and disputes which arise in connection with the Plan.
Any determination of the Board under the Plan will be binding and final on all
persons claiming an interest hereunder.

7.       AMENDMENT AND TERMINATION.

         The Board may at any time and from time to time amend or terminate the
Plan in any respect and for any purpose it, in its sole discretion, deems
appropriate or necessary.


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