Employee Stock Purchase Plan - Gilead Sciences Inc.


                              GILEAD SCIENCES, INC.
 
                          EMPLOYEE STOCK PURCHASE PLAN
 
                           ADOPTED NOVEMBER 15, 1991
                              AMENDED MAY 25, 1994
                     AMENDED AND RESTATED JANUARY 22, 1998
 
                      TERMINATION DATE: NOVEMBER 14, 2001
 
1.  PURPOSE.
 
    (a) The purpose of the Employee Stock Purchase Plan ('the Plan') is to
provide a means by which employees of GILEAD SCIENCES, INC., a Delaware
corporation (the 'Company'), and its Affiliates, as defined in subparagraph
1(c), which are designated as provided in subparagraph 2(b), may be given an
opportunity to purchase stock of the Company.
 
    (b) Plan initially was adopted on November 15, 1991 and subsequently amended
on May 25, 1994 (the 'Initial Plan'). The Initial Plan hereby is amended and
restated in its entirety effective as of January 22, 1998. The terms of the
Initial Plan (other than the aggregate number of shares issuable thereunder)
shall remain in effect and apply to all options granted pursuant to the Initial
Plan.
 
    (c) The word 'Affiliate' as used in the Plan means any parent corporation or
subsidiary corporation of the Company, as those terms are defined in Sections
424(e) and (f), respectively, of the Internal Revenue Code of 1986, as amended
(the 'Code').
 
    (d) The Company, by means of the Plan, seeks to retain the services of its
employees, to secure and retain the services of new employees, and to provide
incentives for such persons to exert maximum efforts for the success of the
Company.
 
    (e) The Company intends that the rights to purchase stock of the Company
granted under the Plan be considered options issued under an 'employee stock
purchase plan' as that term is defined in Section 423(b) of the Code.
 
2.  ADMINISTRATION.
 
    (a) The Plan shall be administered by the Board of Directors (the 'Board')
of the Company unless and until the Board delegates administration to a
Committee, as provided in subparagraph 2(c). Whether or not the Board has
delegated administration, the Board shall have the final power to determine all
questions of policy and expediency that may arise in the administration of the
Plan.
 
    (b) The Board shall have the power, subject to, and within the limitations
of, the express provisions of the Plan:
 
        (i) To determine when and how rights to purchase stock of the Company
    shall be granted and the provisions of each offering of such rights (which
    need not be identical).
 
        (ii) To designate from time to time which Affiliates of the Company
    shall be eligible to participate in the Plan.
 
       (iii) To construe and interpret the Plan and rights granted under it, and
    to establish, amend and revoke rules and regulations for its administration.
    The Board, in the exercise of this power, may correct any defect, omission
    or inconsistency in the Plan, in a manner and to the extent it shall deem
    necessary or expedient to make the Plan fully effective.
 
        (iv) To amend the Plan as provided in paragraph 13.
 
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        (v) Generally, to exercise such powers and to perform such acts as the
    Board deems necessary or expedient to promote the best interests of the
    Company.
 
    (c) The Board may delegate administration of the Plan to a Committee
composed of not fewer than two (2) members of the Board (the 'Committee'). If
administration is delegated to a Committee, the Committee shall have, in
connection with the administration of the Plan, the powers theretofore possessed
by the Board, subject, however, to such resolutions, not inconsistent with the
provisions of the Plan, as may be adopted from time to time by the Board. The
Board may abolish the Committee at any time and revest in the Board the
administration of the Plan.
 
3.  SHARES SUBJECT TO THE PLAN.
 
    Subject to the provisions of paragraph 12 relating to adjustments upon
changes in stock, the stock that may be sold pursuant to rights granted under
the Plan shall not exceed in the aggregate one million two hundred fifty
thousand (1,250,000) shares of the Company's .001 par value common stock (the
'Common Stock'). If any right granted under the Plan shall for any reason
terminate without having been exercised, the Common Stock not purchased under
such right shall again become available for the Plan. The stock subject to the
Plan may be unissued shares or reacquired shares, bought on the market or
otherwise.
 
4.  GRANT OF RIGHTS; OFFERING.
 
    The Board or the Committee may from time to time grant or provide for the
grant of rights to purchase Common Stock of the Company under the Plan to
eligible employees (an 'Offering') on a date or dates (the 'Offering Date(s)')
selected by the Board or the Committee. Each Offering shall be in such form and
shall contain such terms and conditions as the Board or the Committee shall deem
appropriate. If an employee has more than one right outstanding under the Plan,
unless he or she otherwise indicates in agreements or notices delivered
hereunder: (1) each agreement or notice delivered by that employee will be
deemed to apply to all of his or her rights under the Plan, and (2) a right with
a lower exercise price (or an earlier-granted right, if two rights have
identical exercise prices), will be exercised to the fullest possible extent
before a right with a higher exercise price (or a later-granted right, if two
rights have identical exercise prices) will be exercised. The provisions of
separate Offerings need not be identical, but each Offering shall include
(through incorporation of the provisions of this Plan by reference in the
Offering or otherwise) the substance of the provisions contained in paragraphs 5
through 8, inclusive.
 
5.  ELIGIBILITY.
 
    (a) Rights may be granted only to employees of the Company or, as the Board
or the Committee may designate as provided in subparagraph 2(b), to employees of
any Affiliate of the Company. Except as provided in subparagraph 5(b), an
employee of the Company or any Affiliate shall not be eligible to be granted
rights under the Plan, unless, on the Offering Date, such employee has been in
the employ of the Company or any Affiliate for such continuous period preceding
such grant as the Board or the Committee may require, but in no event shall the
required period of continuous employment be equal to or greater than two (2)
years. In addition, unless otherwise determined by the Board or the Committee
and set forth in the terms of the applicable Offering, no employee of the
Company or any Affiliate shall be eligible to be granted rights under the Plan,
unless, on the Offering Date, such employee's customary employment with the
Company or such Affiliate is at least twenty (20) hours per week and at least
five (5) months per calendar year.
 
    (b) The Board or the Committee may provide that, each person who, during the
course of an Offering, first becomes an eligible employee of the Company or
designated Affiliate will, on a date or dates specified in the Offering which
coincides with the day on which such person becomes an eligible employee or
occurs thereafter, receive a right under that Offering, which right shall
thereafter be deemed to be a
 
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part of that Offering. Such right shall have the same characteristics as any
rights originally granted under that Offering, as described herein, except that:
 
        (i) the date on which such right is granted shall be the 'Offering Date'
    of such right for all purposes, including determination of the exercise
    price of such right;
 
        (ii) the Purchase Period (as defined below) for such right shall begin
    on its Offering Date and end coincident with the end of such Offering; and
 
       (iii) the Board or the Committee may provide that if such person first
    becomes an eligible employee within a specified period of time before the
    end of the Purchase Period (as defined below) for such Offering, he or she
    will not receive any right under that Offering.
 
    (c) No employee shall be eligible for the grant of any rights under the Plan
if, immediately after any such rights are granted, such employee owns stock
possessing five percent (5%) or more of the total combined voting power or value
of all classes of stock of the Company or of any Affiliate. For purposes of this
subparagraph 5(c), the rules of Section 424(d) of the Code shall apply in
determining the stock ownership of any employee, and stock which such employee
may purchase under all outstanding rights and options shall be treated as stock
owned by such employee.
 
    (d) An eligible employee may be granted rights under the Plan only if such
rights, together with any other rights granted under 'employee stock purchase
plans' of the Company and any Affiliates, as specified by Section 423(b)(8) of
the Code, do not permit such employee's rights to purchase stock of the Company
or any Affiliate to accrue at a rate which exceeds twenty-five thousand dollars
($25,000) of fair market value of such stock (determined at the time such rights
are granted) for each calendar year in which such rights are outstanding at any
time.
 
    (e) Officers of the Company and any designated Affiliate shall be eligible
to participate in Offerings under the Plan, provided, however, that the Board
may provide in an Offering that certain employees who are highly compensated
employees within the meaning of Section 423(b)(4)(D) of the Code shall not be
eligible to participate.
 
6.  RIGHTS; PURCHASE PRICE.
 
    (a) On each Offering Date, each eligible employee, pursuant to an Offering
made under the Plan, shall be granted the right to purchase the number of shares
of Common Stock of the Company purchasable with up to fifteen percent (15%) (or
such lower percentage as the Board determines for a particular Offering) of such
employee's Earnings (as defined in Section 7(a)) during the period which begins
on the Offering Date (or such later date as the Board determines for a
particular Offering) and ends on the date stated in the Offering, which date
shall be no more than twenty-seven (27) months after the Offering Date (the
'Purchase Period'). In connection with each Offering made under this Plan, the
Board or the Committee shall specify a maximum number of shares which may be
purchased by any employee as well as a maximum aggregate number of shares which
may be purchased by all eligible employees pursuant to such Offering. In
addition, in connection with each Offering which contains more than one Exercise
Date (as defined in the Offering), the Board or the Committee may specify a
maximum aggregate number of shares which may be purchased by all eligible
employees on any given Exercise Date under the Offering. If the aggregate
purchase of shares upon exercise of rights granted under the Offering would
exceed any such maximum aggregate number, the Board or the Committee shall make
a pro rata allocation of the shares available in as nearly a uniform manner as
shall be practicable and as it shall deem to be equitable.
 
    (b) In connection with each Offering made under the Plan, the Board or the
Committee may specify a maximum number of shares that may be purchased by any
employee as well as a maximum aggregate number of shares that may be purchased
by all eligible employees pursuant to such Offering. In addition, in connection
with each Offering that contains more than one Purchase Date, the Board or the
Committee may specify a maximum aggregate number of shares which may be
purchased by all eligible employees on
 
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any given Purchase Date under the Offering. If the aggregate purchase of shares
upon exercise of rights granted under the Offering would exceed any such maximum
aggregate number, the Board or the Committee shall make a pro rata allocation of
the shares available in as nearly a uniform manner as shall be practicable and
as it shall deem to be equitable.
 
    (c) The purchase price of stock acquired pursuant to rights granted under
the Plan shall be not less than the lesser of:
 
        (i) an amount equal to eighty-five percent (85%) of the fair market
    value of the stock on the Offering Date; or
 
        (ii) an amount equal to eighty-five percent (85%) of the fair market
    value of the stock on the Exercise Date.
 
7.  PARTICIPATION; WITHDRAWAL; TERMINATION.
 
    (a) An eligible employee may become a participant in an Offering by
delivering a participation agreement to the Company within the time specified in
the Offering, in such form as the Company provides. Each such agreement shall
authorize payroll deductions of up to fifteen percent (15%) (or such lower
percentage as the Board determines for a particular Offering) of such employee's
Earnings during the Purchase Period. 'Earnings' is defined as an employee's
total compensation, including all salary, wages and other remuneration paid to
an employee (including amounts elected to be deferred by the employee, that
would otherwise have been paid, under any cash or deferred arrangement
established by the Company), overtime pay, commissions, bonuses, profit sharing,
any special payments for extraordinary services, provided, however, that the
Board in its sole discretion may limit the above definition from time to time
with respect to each Offering. The payroll deductions made for each participant
shall be credited to an account for such participant under the Plan and shall be
deposited with the general funds of the Company. A participant may reduce,
increase or begin such payroll deductions after the beginning of any Purchase
Period only as provided for in the Offering. A participant may make additional
payments into his or her account only if specifically provided for in the
Offering and only if the participant has not had the maximum amount withheld
during the Purchase Period.
 
    (b) At any time during a Purchase Period a participant may terminate his or
her payroll deductions under the Plan and withdraw from the Offering by
delivering to the Company a notice of withdrawal in such form as the Company
provides. Such withdrawal may be elected at any time prior to the end of the
Purchase Period. Upon such withdrawal from the Offering by a participant, the
Company shall distribute to such participant all of his or her accumulated
payroll deductions (reduced to the extent, if any, such deductions have been
used to acquire stock for the participant) under the Offering, without interest
unless the terms of the Offering specifically so provide, and such participant's
interest in that Offering shall be automatically terminated. A participant's
withdrawal from an Offering will have no effect upon such participant's
eligibility to participate in any other Offerings under the Plan but such
participant will be required to deliver a new participation agreement in order
to participate in subsequent Offerings under the Plan.
 
    (c) Rights granted pursuant to any Offering under the Plan shall terminate
immediately upon cessation of any participating employee's employment with the
Company or an Affiliate, for any reason, and the Company shall distribute to
such terminated employee all of his or her accumulated payroll deductions
(reduced to the extent, if any, such deductions have been used to acquire stock
for the terminated employee), under the Offering, without interest unless the
terms of the Offering specifically so provide.
 
    (d) Rights granted under the Plan shall not be transferable by a participant
otherwise than by will or the laws of descent and distribution, or by a
beneficiary designation as provided in paragraph 14 and,
 
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otherwise during his or her lifetime, shall be exercisable only by the person to
whom such rights are granted.
 
8.  EXERCISE.
 
    (a) On each exercise date, as defined in the relevant Offering (an 'Exercise
Date'), each participant's accumulated payroll deductions (without any increase
for interest unless the terms of the Offering specifically so provide) will be
applied to the purchase of whole shares of stock of the Company, up to the
maximum number of shares permitted pursuant to the terms of the Plan and the
applicable Offering, at the purchase price specified in the Offering. No
fractional shares shall be issued upon the exercise of rights granted under the
Plan. The amount, if any, of accumulated payroll deductions remaining in each
participant's account after the purchase of shares which is less than the amount
required to purchase one share of stock on the final Exercise Date of an
Offering shall be held in each such participant's account for the purchase of
shares under the next Offering under the Plan, unless such participant withdraws
from such next Offering, as provided in subparagraph 7(b), or is no longer
eligible to be granted rights under the Plan, as provided in paragraph 5, in
which case such amount shall be distributed to the participant after said final
Exercise Date, without interest unless the terms of the Offering specifically so
provide. The amount, if any, of accumulated payroll deductions remaining in any
participant's account after the purchase of shares which is equal to the amount
required to purchase whole shares of stock on the final Exercise Date of an
Offering shall be distributed in full to the participant after such Exercise
Date, without interest unless the terms of the Offering specifically so provide.
 
    (b) No rights granted under the Plan may be exercised to any extent unless
the Plan (including rights granted thereunder) is covered by an effective
registration statement pursuant to the Securities Act of 1933, as amended (the
'Securities Act'). If on an Exercise Date of any Offering hereunder the Plan is
not so registered, no rights granted under the Plan or any Offering shall be
exercised on said Exercise Date and all payroll deductions accumulated during
the purchase period (reduced to the extent, if any, such deductions have been
used to acquire stock) shall be distributed to the participants, without
interest unless the terms of the Offering specifically so provide.
 
    (c) Shares of stock of the Company that are purchased may be registered in
the name of the participant or jointly in the name of the participant and his or
her spouse as joint tenants with right of survivorship or community property.
 
9.  COVENANTS OF THE COMPANY.
 
    (a) During the terms of the rights granted under the Plan, the Company shall
keep available at all times the number of shares of stock required to satisfy
such rights.
 
    (b) The Company shall seek to obtain from each regulatory commission or
agency having jurisdiction over the Plan such authority as may be required to
issue and sell shares of stock upon exercise of the rights granted under the
Plan. If, after reasonable efforts, the Company is unable to obtain from any
such regulatory commission or agency the authority which counsel for the Company
deems necessary for the lawful issuance and sale of stock under the Plan, the
Company shall be relieved from any liability for failure to issue and sell stock
upon exercise of such rights unless and until such authority is obtained.
 
10. USE OF PROCEEDS FROM STOCK.
 
    Proceeds from the sale of stock pursuant to rights granted under the Plan
shall constitute general funds of the Company.
 
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11. RIGHTS AS A STOCKHOLDER.
 
    A participant shall not be deemed to be the holder of, or to have any of the
rights of a holder with respect to, any shares subject to rights granted under
the Plan unless and until certificates representing such shares shall have been
issued.
 
12. ADJUSTMENTS UPON CHANGES IN STOCK.
 
    (a) If any change is made in the stock subject to the Plan, or subject to
any rights granted under the Plan (through merger, consolidation,
reorganization, recapitalization, stock dividend, dividend in property other
than cash, stock split, liquidating dividend, combination of shares, exchange of
shares, change in corporate structure or otherwise), the Plan and outstanding
rights will be appropriately adjusted in the class(es) and maximum number of
shares subject to the Plan and the class(es) and number of shares and price per
share of stock subject to outstanding rights.
 
    (b) In the event of: (1) a dissolution or liquidation of the Company; (2) a
merger or consolidation in which the Company is not the surviving corporation;
(3) a reverse merger in which the Company is the surviving corporation but the
shares of the Company's Common Stock outstanding immediately preceding the
merger are converted by virtue of the merger into other property, whether in the
form of securities, cash or otherwise; or (4) any other capital reorganization
in which more than fifty percent (50%) of the shares of the Company entitled to
vote are exchanged, then, as determined by the Board in its sole discretion (i)
any surviving corporation may assume outstanding rights or substitute similar
rights for those under the Plan, (ii) such rights may continue in full force and
effect, or (iii) participants' accumulated payroll deductions may be used to
purchase Common Stock immediately prior to the transaction described above and
the participants' rights under the ongoing Offering terminated.
 
13. AMENDMENT OF THE PLAN.
 
    (a) The Board at any time, and from time to time, may amend the Plan.
However, except as provided in paragraph 12 relating to adjustments upon changes
in stock, no amendment shall be effective unless approved by the stockholders of
the Company within twelve (12) months before or after the adoption of the
amendment, where the amendment will:
 
        (i) Increase the number of shares reserved for rights under the Plan;
 
        (ii) Modify the provisions as to eligibility for participation in the
    Plan (to the extent such modification requires stockholder approval in order
    for the Plan to obtain employee stock purchase plan treatment under Section
    423 of the Code or to comply with the requirements of Rule 16b-3 promulgated
    under the Exchange Act of 1934, as amended ( the 'Exchange Act')); or
 
       (iii) Modify the Plan in any other way if such modification requires
    stockholder approval in order for the Plan to obtain employee stock purchase
    plan treatment under Section 423 of the Code or to comply with the
    requirements of Rule 16b-3 promulgated under the Exchange Act or any Nasdaq
    or securities exchange listing requirements.
 
The Board may, in its sole discretion, submit any other amendment to the Plan
for stockholder approval. It is expressly contemplated that the Board may amend
the Plan in any respect the Board deems necessary or advisable to provide
eligible employees with the maximum benefits provided or to be provided under
the provisions of the Code and the regulations promulgated thereunder relating
to employee stock purchase plans and/or to bring the Plan and/or rights granted
under it into compliance therewith.
 
    (b) Rights and obligations under any rights granted before amendment of the
Plan shall not be altered or impaired by any amendment of the Plan, except with
the consent of the person to whom such rights were granted or except as
necessary to comply with any laws or governmental regulations or to
 
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ensure that the Plan and/or rights granted under the Plan comply with the
requirements of Section 423 of the Code.
 
14. DESIGNATION OF BENEFICIARY.
 
    (a) A participant may file a written designation of a beneficiary who is to
receive any shares and cash, if any, from the participant's account under the
Plan in the event of such participant's death subsequent to the end of an
Offering but prior to delivery to the participant of such shares and cash. In
addition, a participant may file a written designation of a beneficiary who is
to receive any cash from the participant's account under the Plan in the event
of such participant's death during an Offering.
 
    (b) The participant may change such designation of beneficiary at any time
by written notice. In the event of the death of a participant and in the absence
of a beneficiary validly designated under the Plan who is living at the time of
such participant's death, the Company shall deliver such shares and/or cash to
the executor or administrator of the estate of the participant, or if no such
executor or administrator has been appointed (to the knowledge of the Company),
the Company, in its sole discretion, may deliver such shares and/or cash to the
spouse or to any one or more dependents or relatives of the participant, or if
no spouse, dependent or relative is known to the Company, then to such other
person as the Company may designate.
 
15. TERMINATION OR SUSPENSION OF THE PLAN.
 
    (a) The Board may suspend or terminate the Plan at any time. Unless sooner
terminated, the Plan shall terminate ten (10) years from the date the Plan is
adopted by the Board or approved by the stockholders of the Company, whichever
is earlier. No rights may be granted under the Plan while the Plan is suspended
or after it is terminated.
 
    (b) Rights and obligations under any rights granted while the Plan is in
effect shall not be impaired by suspension or termination of the Plan, except as
expressly provided in the Plan or with the consent of the person to whom such
rights were granted, or except as necessary to comply with any laws or
governmental regulation or to ensure that the Plan and/or rights granted under
the Plan comply with the requirements of Section 423 of the Code.
 
16. EFFECTIVE DATE OF PLAN.
 
    The Plan shall become effective as determined by the Board, but no rights
granted under the Plan shall be exercised unless and until the stockholders of
the Company have approved the Plan.
 
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