Exhibit 10.60  CUBIST PHARMACEUTICALS, INC.  AMENDED AND RESTATED 1997 EMPLOYEE STOCK PURCHASE PLAN  1.Definitions.  As used in this Amended and Restated 1997
Employee Stock Purchase Plan of Cubist Pharmaceuticals, Inc., the
following terms shall have the meanings respectively assigned to them below:  (a)Base
Compensationmeans annual or annualized base compensation,
exclusive of overtime, bonuses, contributions to employee benefit plans, or
other fringe benefits.  (b)Beneficiarymeans the
person designated as the Participating Employees beneficiary on the
Participating Employees Membership Agreement or other form provided by the Human
Resources department of the Company for such purpose or, if no such beneficiary
is named, the person to whom the Option is transferred by will or under the
applicable laws of descent and distribution.  (c)Boardmeans the
board of directors of the Company, except that, if and so long as the board of
directors of the Company has delegated pursuant to Section 4 its authority
with respect to the Plan to the Committee, then all references in this Plan to
the Board shall refer to the Committee acting in such capacity.  (d)Codemeans the
Internal Revenue Code of 1986, as amended.  (e)Committeemeans the
Compensation Committee of the Board.  (f)Companymeans Cubist
Pharmaceuticals, Inc., a Delaware corporation.  (g)Disabilitymeans, with
respect to any Participating Employee, that an independent medical doctor
(selected by the Companys health or disability insurer) certifies that such
Participating Employee has for four (4) months, consecutive or
non-consecutive, in any twelve-month period been disabled in a manner which
seriously interferes with the performance of his or her responsibilities for
the Company or applicable Related Corporation.  (h)Eligible
Employeemeans a person who is eligible under the provisions
of Section 7 to receive an Option as of a particular Offering Commencement
Date.  (i)Employermeans, as to
any particular Offering Period, the Company and any Related Corporation which
is designated by the Board as a corporation whose Eligible Employees are to
receive Options as of that Offering Periods Offering Commencement Date.  (j)Market
Valuemeans, as of a particular date (i) if the Stock is listed on an
exchange, the closing price of the Stock on such date on such exchange or, if
no trades were reported on such date, the closing price on the most recent
trading day preceding such date, and (ii) if the Stock is not quoted on an
exchange, the price at which the Stock was purchased or sold in the most recent
transaction in the Stock.  (k)Membership
Agreementmeans an agreement or other similar electronic or
hard copy document or form whereby a Participating Employee authorizes an
Employer to withhold payroll deductions from his or her Base Compensation.  (l)Offering
Commencement Datemeans the first business day of an Offering Period
on which Options are granted to Eligible Employees.  (m)Offering
Periodmeans a semi-annual period, running from either January 1 to the
next following June 30 or July 1 to the next following December 31,
during which Options will be offered under the Plan pursuant to a


determination by the
Board.  (n)OfferingTermination Date means the
last business day of an Offering Period, on which Options must, if ever, be
exercised.  (o)Optionmeans an option to purchase shares of
Stock granted under the Plan.  (p)OptionShares means shares of Stock purchasable
under an Option.  (q)ParticipatingEmployee means an Eligible
Employee to whom an Option is granted.  (r)Planmeans this Amended and Restated 1997
Employee Stock Purchase Plan of the Company, as amended from time to time.  (s)RelatedCorporation means any corporation which
is or during the term of the Plan becomes a parent corporation of the Company,
as defined in Section 424(e) of the Code, or a subsidiary corporation of the
Company, as defined in Section 424(f) of the Code.  (t)Retiresmeans termination
of employment with the Company and all Related Corporations at or after attaining
age 65.  (u)Stockmeans the common stock, par value $0.001
per share, of the Company.  2.Purposeof the Plan.  The Plan is intended to encourage ownership
of Stock by employees of the Company and any Related Corporations and to
provide an additional incentive for the employees to promote the success of the
business of the Company and any Related Corporations.  It is intended that the Plan shall be an
employee stock purchase plan within the meaning of Section 423 of the Code.  3.Termof the Plan.  The Plan shall become effective on December
1, 1997 (the Effective Date).  No
Option shall be granted under the Plan after November 30, 2017.  4.Administrationof the Plan.  The Plan shall be administered by the
Board.  The Board shall determine semi-annually,
on or before either December 15 and June 15, whether to grant options under the
Plan with respect to the Offering Period which would otherwise begin as of
January 1 and July 1, respectively.  The
Board shall determine which (if any) Related Corporations shall be Employers as
of each Offering Commencement Date. 
Either such determination may in the discretion of the Board apply to
all subsequent Offering Periods until modified or revoked by the Board.  The Board shall have authority to interpret the
Plan, to prescribe, amend and rescind rules and regulations relating to the
Plan, to determine the terms of Options granted under the Plan, and to make all
other determinations necessary or advisable for the administration of the Plan.  All determinations of the Board under the
Plan shall be final and binding as to all persons having or claiming any
interest in or arising out of the Plan. 
The Board may delegate all or any portion of its authority with respect
to the Plan to the Committee, and thereafter, until such delegation is revoked
by the Board, all powers under the Plan delegated to the Committee shall be
exercised by the Committee.  5.Terminationand Amendment of Plan.  The Board may terminate or amend the Plan at
any time; provided, however, that
the Board may not, without approval by the holders of a majority of the
outstanding shares of Stock, increase the maximum number of shares of Stock
purchasable under the Plan, change the description of employees or classes of
employees eligible to receive Options, or make any other amendment to the Plan
that require approval of the holders of the outstanding shares of Stock under
applicable law, regulation or standards. 
Without limiting the generality of the foregoing but subject to the
foregoing proviso, the Board may amend the Plan from time to time to increase
or decrease the length of any future Offering Periods (e.g., to a nine month period) and to make
all required conforming changes to the Plan; provided,
however,that in no event will the Offering Period exceed 27
months.  No termination of or amendment
to the Plan may adversely affect the rights of a Participating Employee with
respect to any Option held by the Participating Employee as of the date of such
termination or amendment without his or her consent.  2


6.Sharesof Stock Subject to the Plan.  No more than an aggregate of 1,250,000 shares
of Stock may be issued or delivered pursuant to the exercise of Options granted
under the Plan, subject to adjustments made in accordance with Section
9.7.  Shares of Stock to be delivered
upon the exercise of Options may be either shares of Stock which are authorized
but unissued or shares of Stock held by the Company in its treasury.  If an Option expires or terminates for any
reason without having been exercised in full, the unpurchased shares of Stock
subject to the Option shall become available for other Options granted under
the Plan.  The Company shall, at all times
during which Options are outstanding, reserve and keep available shares of
Stock sufficient to satisfy such Options (or, if less, the maximum number still
available for issuance under the foregoing limit), and shall pay all fees and
expenses incurred by the Company in connection therewith.  In the event of any capital change in the
outstanding Stock as contemplated by Section 9.7, the number of shares of Stock
reserved and kept available by the Company shall be appropriately adjusted.  7.PersonsEligible to Receive Options.  Each employee of an Employer shall be granted
an Option on each Offering Commencement Date on which such employee meets all
of the following requirements:  (a)The employee is customarily employed by
an Employer for more than twenty hours per week and for more than five months
per calendar year and, in the case of any Offering Period after the first
Offering Period under the Plan, has been employed by one or more of the
Employers for at least one week prior to the applicable Offering Commencement
Date.  (b)The employee will not, after grant of the
Option, own Stock possessing five percent or more of the total combined voting
power or value of all classes of stock of the Company or of any Related
Corporation.  For purposes of this paragraph
(b), the rules of Section 424(d) of the Code shall apply in determining the
Stock ownership of the employee, and Stock which the employee may purchase
under outstanding options shall be treated as Stock owned by the employee.  (c)Upon grant of the Option, the employees
rights to purchase Stock under all employee stock purchase plans (as defined in
Section 423(b) of the Code) of the Company and its Related Corporations will
not accrue at a rate which exceeds $25,000 of fair market value of the Stock
(determined as of the grant date) for each calendar year in which such option
is outstanding at any time.  The accrual
of rights to purchase Stock shall be determined in accordance with Section
423(b)(8) of the Code.  8.OfferingCommencement Dates.  Options shall be granted on the first business
day of each semi-annual period, running from either January 1 to the next
following June 30 or July 1 to the next following December 31, which is
designated by the Board as an Offering Period. 
Following designation by the Board of the initial Offering Period under
the Plan, all succeeding semi-annual periods described above shall be deemed
Offering Periods without need of further Board action unless and until contrary
action shall have been taken by the Board prior to the beginning of what would
otherwise be an Offering Period.  9.Termsand Conditions of Options.  9.1General. 
All Options granted on a particular Offering Commencement Date shall
comply with the terms and conditions set forth in Sections 9.2 through
9.11.  Subject to Sections 7(c) and 9.9,
each Option granted on a particular Offering Commencement Date shall entitle
the Participating Employee to purchase up to that number of shares of Stock
equal to the result of $25,000 (or such lesser amount as is selected by the
Board, prior to the applicable Offering Commencement Date, and applied
uniformly during such Offering Period) divided by the Market Value of one such
share on the Offering Commencement Date and then rounded down, if necessary, to
the nearest whole number.  9.2PurchasePrice. 
The purchase price of Option Shares shall be 85% of the lesser of (a)
the Market Value of the shares of Stock as of the Offering Commencement Date or
(b) the Market Value of the shares of Stock as of the Offering Termination
Date.  9.3Restrictionson Transfer.  (a)Options may not be transferred otherwise
than by will or under the laws of descent and distribution.  An  3


Option may not be
exercised by anyone other than the Participating Employee during the lifetime
of the Participating Employee.  (b)The Participating Employee shall notify
the Company of any transfer of Option Shares within two years of the Offering
Commencement Date for such Option Shares. 
The Company shall have the right to place a legend on all stock
certificates representing Option Shares instructing the transfer agent to
notify the Company of any transfer of such Option Shares.  The Company shall also have the right to
place a legend on all stock certificates representing Option Shares setting
forth or referring to the restriction on transferability of such Option Shares.  9.4Expiration. 
Each Option shall expire at the close of business on the Offering
Termination Date or on such earlier date as may result from the operation of
Sections 9.5 and 9.6.  9.5Termination of Employment of Participating Employee. 
If a Participating Employee ceases for any reason (other than death or
Retirement) to be continuously employed by an Employer, whether due to
voluntary severance, involuntary severance, transfer, or disaffiliation of a
Related Corporation with the Company, his or her Option shall immediately
expire, and the Participating Employees accumulated payroll deductions shall
be returned to the Participating Employee. 
For purposes of this Section 9.5, a Participating Employee shall be
deemed to be employed throughout any leave of absence for military service,
illness or other bona fide purpose which does not exceed the longer of ninety
days or the period during which the Participating Employees reemployment
rights are guaranteed by statute (including without limitation the Veterans
Reemployment Rights Act or similar statute relating to military service) or by
contract.  If the Participating Employee
does not return to active employment prior to the termination of such period,
his or her employment, for purposes of the Plan, shall be deemed to have ended
on the ninety-first day of such leave of absence (or such longer period
guaranteed by statute or by contract as provided above).  9.6Retirementor Death of Participating Employee.  If a Participating Employee Retires or dies,
the Participating Employee or, in the case of death, his or her Beneficiary
shall be entitled to withdraw the Participating Employees accumulated payroll
deductions, or to purchase shares of Stock on the Offering Termination Date to
the extent that the Participating Employee would be so entitled had he or she
continued to be employed by an Employer. 
The number of shares of Stock purchasable shall be limited by the amount
of the Participating Employees accumulated payroll deductions as of the date
of his or her Retirement or death. 
Accumulated payroll deductions shall be applied by the Company toward
the purchase of shares of Stock only if the Participating Employee or, in the
case of death, his or her Beneficiary submits to the Employer not later than
the Offering Termination Date a written request that the deductions be so
applied.  Accumulated payroll deductions
not withdrawn or applied to the purchase of shares of Stock shall be delivered
by the Company to the Participating Employee or Beneficiary within a reasonable
time after the Offering Termination Date.  9.7Capital Changes Affecting the Stock. 
In the event that, between the Offering Commencement Date and the Offering
Termination Date with respect to an Option, a stock dividend is paid or becomes
payable in respect of the Stock or there occurs a split-up or contraction in
the number of shares of Stock, the number of shares of Stock for which the
Option may thereafter be exercised and the price to be paid for each such share
shall be proportionately adjusted. 
Subject to the provisions of the next sentence, in the event that, after
the Offering Commencement Date, there occurs a reclassification or change of
outstanding shares of Stock or a consolidation or merger of the Company with or
into another corporation or a sale or conveyance, substantially as a whole, of
the property of the Company (collectively, a Corporate Transaction), the
Participating Employee shall be entitled on the Offering Termination Date to
receive shares of Stock or other securities equivalent in kind and value to the
shares of Stock he or she would have held if he or she had exercised the Option
in full immediately prior to such Corporate Transaction and had continued to
hold such shares of Stock (together with all other shares and securities
thereafter issued in respect thereof) until the Offering Termination Date.  Alternatively, in the event of a Corporate
Transaction, the Board may elect to shorten the Offering Period and set a new
Offering Termination Date as of which date the Offering Period then in progress
will terminate.  Such new Offering Period
Termination Date shall be on or before the date of consummation of the
Corporate Transaction and the Board shall notify each Participating Employee in
writing at least 10 days prior to the new Offering Period Termination Date that
his or her Option will be exercised automatically on such new Offering
Termination Date, unless prior to such date, he or she has withdrawn from the
Offering Period as provided herein.  In
the event that there is to occur a recapitalization involving an increase in
the par value of the Stock which would result in a par value exceeding the
exercise price under an  4


outstanding Option, the
Company shall notify the Participating Employee of such proposed
recapitalization immediately upon its being recommended by the Board to the
Companys shareholders, after which the Participating Employee shall have the
right to exercise his or her Option prior to such recapitalization; if the
Participating Employee fails to exercise the Option prior to recapitalization,
the exercise price under the Option shall be appropriately adjusted.  In the event that, after the Offering
Commencement Date, there occurs a dissolution or liquidation of the Company,
except pursuant to a transaction to which Section 424(a) of the Code applies,
each Option shall terminate, but the Participating Employee shall have the
right to exercise his or her Option prior to such dissolution or liquidation.  9.8PayrollDeductions.  (a)A Participating Employee may purchase
shares of Stock under his or her Option during any particular Offering Period
during the Companys defined open enrollment periods by completing and
returning, during the Companys defined open enrollment periods, a Membership
Agreement indicating a percentage (which shall be a full integer between one
and fifteen) of his or her Base Compensation which is to be withheld each pay
period. Open enrollment periods occur semi-annually and are communicated by
Human Resources.  Participating Employees
will not be allowed to enroll in the Plan with respect to a particular Offering
Period once the Offering Period has begun.  (b)Unless the Board decides otherwise prior
to the commencement of an Offering Period, all Participating Employees shall be
permitted to take the following actions during an Offering Period:  (i) no more often than
once per Offering Period, to decrease (but not increase) the percentage of Base
Compensation withheld during an Offering Period by submitting an amended
Membership Agreement to the Companys Human Resources department indicating a
different percentage of Base Compensation to be withheld; and  (ii) no more than once
per Offering Period, cancel his or her Membership Agreement by submitting a
written request to the Companys Human Resources department, in which request
the Participant must either elect to (x) withdraw all, but not less than all,
of his or her accumulated payroll deductions or (y) apply all, but not less
than all, accumulated payroll deductions to the purchase of Shares at the end
of such Offering Period;  Provided, that, to be
effective, the submissions to the Companys Human Resources Department required
by (i) and (ii) must be received by the Companys Human Resources Department by
no later than the close of business on the 15thday of the last month (or the next business
day after the 15thof
the month if the 15thday of the month is not a business day) of the
Offering Period (i.e. December 15thand June 15th).  9.9Exerciseof Options.  On the Offering Termination Date the
Participating Employee may purchase the number of shares of Stock purchasable
by his or her accumulated payroll deductions, or, if less, the maximum number
of shares subject to the Option as provided in Section 9.1, provided that:  (a)If the total number of shares of Stock
which all Participating Employees elect to purchase, together with any shares of
Stock already purchased under the Plan, exceeds the total number of shares of
Stock which may be purchased under the Plan pursuant to Section 6, the number
of shares of Stock which each Participating Employee is permitted to purchase
shall be decreased pro rata based on the Participating
Employees accumulated payroll deductions in relation to all accumulated
payroll deductions otherwise to be applied to the purchase of shares of Stock
as of that Offering Termination Date.  (b)If the number of shares of Stock
purchasable includes a fraction, such number shall be adjusted to the next
smaller whole number and the purchase price shall be adjusted accordingly.  Accumulated payroll
deductions not withdrawn in accordance with Section 9.8 shall be automatically
applied by the Company toward the purchase of shares of Stock, except to the
extent that the purchase of shares of Stock will result in the issuance of a
fractional share of Stock, in which case the amount of the accumulated payroll
deductions that would have been applied to the purchase of a fractional share
of Stock will be refunded to the Participating Employee.  .  9.10Issuanceof Stock.  Except as provided below, within a reasonable
time after the Offering Termination  5


Date, the Company shall
deliver or issue to the Participating Employee the number of shares of Stock
purchased by the Participating Employee either in the form of a stock
certificate or, by causing a book entry in the Companys stock records
indicating that such Participating Employee owns such shares.   Shares of Stock will be issued in the
participants name only, or if his or her Membership Agreement so specifies, in
the name of the employee and another person of legal age as joint tenants with
rights of survivorship.  If any law or
applicable regulation of the Securities and Exchange Commission or other body
having jurisdiction in the premises shall require that the Company or the
Participating Employee take any action in connection with the shares of Stock
being purchased under the Option, issuance of such shares shall be postponed
until the necessary action shall have been completed, which action shall be
taken by the Company at its own expense, without unreasonable delay.  The Participating Employee shall have no
rights as a shareholder in respect of shares of Stock which have not been
issued to the Participating Employee.  9.11Returnof Accumulated Payroll Deductions.  In the event that the Participating Employee
or the Beneficiary is entitled to the return of accumulated payroll deductions,
whether by reason of voluntary withdrawal, termination of employment,
Retirement, death, or in the event that accumulated payroll deductions exceed
the price of shares purchased, such amount shall be returned by the Company to
the Participating Employee or the Beneficiary, as the case may be, not later
than within a reasonable time following the Offering Termination Date
applicable to the Option Period in which such deductions were taken.  Accumulated payroll deductions held by the
Company shall not bear interest nor shall the Company be obligated to segregate
the same from any of its other assets.  10.Notices and Other Communications. 
Any notice, demand, request or other communication hereunder to any
party shall be deemed to be sufficient if contained in a written instrument
delivered in person or sent by first class, registered, certified or overnight
mail, postage prepaid, or telecopied with a confirmation copy by regular
certified or overnight mail, addressed or telecopied, as the case may be (i) if
to a Participating Employee, at his or her residence address last filed with
the Company and (ii) if to the Company, at its principal place of business,
addressed to the attention of the General Counsel, or to such other address or
telecopier number, as the case may be, as the addressee may have designated by
notice to the addressor.  All such
notices, requests, demands and other communications shall be deemed to have
been received: (a) in the case of personal delivery, on the date of such
delivery; (b) in the case of mailing, when received by the addressee; and (c)
in the case of facsimile transmission, when confirmed by facsimile machine
report.  In addition, the Company may, at
its sole discretion, deliver any documents related to the Plan by electronic
means or request that the Participating Employee communicate with the Company
with respect to the Plan by electronic means. 
By participating in the Plan, each Participating Employee will have consented
to receive such documents by electronic delivery and, if requested, to agree to
participate in the Plan through an on-line or electronic system established and
maintained by the Company or another third party designed by the Company, and
any such consent shall remain in effect throughout the Participating Employees
term of employee or service with the Company and thereafter until withdrawn in
writing by the Participating Employee.  11.Governing Law.  The Plan and
all Options and actions taken thereunder shall be governed, interpreted and
enforced in accordance with the laws of the State of Delaware without regard to
the conflict of law principles thereof.  6