<PAGE>

                                                                    EXHIBIT 10.1

                                   AMGEN INC.

                 AMENDED AND RESTATED 1991 EQUITY INCENTIVE PLAN

     1.   PURPOSE.

          (a)  The purpose of the Amended and Restated 1991 Equity Incentive
Plan as amended and restated in March 2003 (the "Plan") is to provide a means by
which employees or directors of and consultants to Amgen Inc., a Delaware
corporation (the "Company"), and its Affiliates, as defined in paragraph 1(b),
directly, or indirectly through Trusts, may be given an opportunity to benefit
from increases in value of the stock of the Company through the granting of (i)
incentive stock options, (ii) nonqualified stock options, (iii) stock bonuses,
and (iv) rights to purchase restricted stock, all as defined below. For purposes
of the incentive stock option rules of Section 422 of the Internal Revenue Code
of 1986, as amended (the "Code"), the Plan is a new plan.

          (b)  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 Code.

          (c)  The Company, by means of the Plan, seeks to retain the services
of persons now employed by or serving as directors or consultants to the
Company, to secure and retain the services of persons capable of filling such
positions, and to provide incentives for such persons to exert maximum efforts
for the success of the Company.

          (d)  The Company intends that the rights issued under the Plan ("Stock
Awards") shall, in the discretion of the Board of Directors of the Company (the
"Board") or any committee to which responsibility for administration of the Plan
has been delegated pursuant to paragraph 2(c), be either (i) stock options
granted pursuant to Sections 5 or 6 hereof, including incentive stock options as
that term is used in Section 422 of the Code ("Incentive Stock Options"), or
options which do not qualify as Incentive Stock Options ("Nonqualified Stock
Options") (together hereinafter referred to as "Options"), or (ii) stock bonuses
or rights to purchase restricted stock granted pursuant to Section 7 hereof.

          (e) The word "Trust" as used in the Plan shall mean a trust created
for the benefit of the employee, director or consultant, his or her spouse, or
members of their immediate family. The word optionee shall mean the person to
whom the option is granted or the employee, director or consultant for whose
benefit the option is granted to a Trust, as the context shall require.

<PAGE>

     2.   ADMINISTRATION.

          (a)  The Plan shall be administered by the Board unless and until the
Board delegates administration to a committee, as provided in paragraph 2(c).

          (b)  The Board shall have the power, subject to, and within the
limitations of, the express provisions of the Plan:

               (1)  To determine from time to time which of the persons eligible
under the Plan shall be granted Stock Awards; when and how Stock Awards shall be
granted; whether a Stock Award will be an Incentive Stock Option, a Nonqualified
Stock Option, a stock bonus, a right to purchase restricted stock, or a
combination of the foregoing; the provisions of each Stock Award granted (which
need not be identical), including the time or times when a person shall be
permitted to purchase or receive stock pursuant to a Stock Award; and the number
of shares with respect to which Stock Awards shall be granted to each such
person.

               (2)  To construe and interpret the Plan and Stock Awards 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 or in any Stock Award, in a manner
and to the extent it shall deem necessary or expedient to make the Plan fully
effective.

               (3)  To amend the Plan as provided in Section 14.

               (4)  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"). One
or more of these members may be non-employee directors and outside directors, if
required and as defined by the provisions of paragraphs 2(e) and 2(f). 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 (except amendment of Section 6 or the options granted thereunder
shall only be by action taken by the Board or a committee of one or more members
of the Board to which such authority has been specifically delegated 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.
Notwithstanding anything else in this paragraph 2(c) to the contrary, at any
time the Board or the Committee may delegate to a committee of one or more
members of the Board the authority to grant or amend options to all employees,
directors or consultants or any portion or class thereof.

          (d)  Notwithstanding anything else in the Plan to the contrary, at any
time the Board or the Committee may authorize by duly adopted resolution one or
more Officers (as defined below) (each a "Delegated Officer") to take the
actions described in paragraph 2(b)(1)

                                        2

<PAGE>

of the Plan with respect to Options only, subject to, and within the limitations
of, the express provisions of the Plan; provided, however, that a Delegated
Officer shall not have the power to (1) grant any Options to himself, any
non-employee director, consultant, Trust, other Delegated Officer or Officer,
(2) determine the time or times when a person shall be permitted to purchase
stock pursuant to the exercise of an Option (i.e., vesting), (3) determine the
exercise price of an Option, or (4) grant any Option to a parent corporation of
the Company, as defined in Section 424(e) of the Code. The resolution
authorizing a Delegated Officer to act as such shall specify the total number of
shares of Common Stock that a Delegated Officer may grant with respect to
Options. The exercise price (including any formula by which such price or prices
may be determined) and the time or times when a person shall be permitted to
purchase stock pursuant to the exercise of an Option shall, however, be set by
the Board or the Committee and not by a Delegated Officer to the extent required
by Delaware General Corporation Law Section 157 or any other applicable law. The
term "Officer" shall include any natural person who is elected as a corporate
officer of the Company by the Board.

          (e)  The term "non-employee director" shall mean a member of the Board
who (i) is not currently an officer of the Company or a parent or subsidiary of
the Company (as defined in Rule 16a-1(f) promulgated by the Securities and
Exchange Commission under Section 16 of the Securities Exchange Act of 1934, as
amended (the "Exchange Act")) or an employee of the Company or a parent or
subsidiary of the Company; (ii) does not receive compensation from the Company
or a parent or subsidiary of the Company for services rendered in any capacity
other than as a member of the Board (including a consultant) in an amount
required to be disclosed to the Company's stockholders under Rule 404 of
Regulation S-K promulgated by the Securities and Exchange Commission ("Rule
404"); (iii) does not possess an interest in any other transaction required to
be disclosed under Rule 404; or (iv) is not engaged in a business relationship
required to be disclosed under Rule 404, as all of these provisions are
interpreted by the Securities and Exchange Commission under Rule 16b-3
promulgated under the Exchange Act.

          (f)  The term "outside director," as used in this Plan, shall mean an
administrator of the Plan, whether a member of the Board or of any Committee to
which responsibility for administration of the Plan has been delegated pursuant
to paragraph 2(c), who is considered to be an "outside director" in accordance
with the rules, regulations or interpretations of Section 162(m) of the Code.

          (g)  Any requirement that an administrator of the Plan be a
"non-employee director" or "outside director" shall not apply if the Board or
the Committee expressly declares that such requirement shall not apply.

                                        3

<PAGE>

     3.   SHARES SUBJECT TO THE PLAN.

          (a)  Subject to the provisions of Section 11 relating to adjustments
upon changes in stock, the stock that may be issued pursuant to Stock Awards
granted under the Plan shall not exceed in the aggregate One Hundred Ninety-Two
Million (192,000,000) shares of the Company's $.0001 par value common stock (the
"Common Stock"). If any Stock Award granted under the Plan shall for any reason
expire or otherwise terminate without having been exercised in full, the Common
Stock not purchased under such Stock Award shall again become available for the
Plan. Shares repurchased by the Company pursuant to any repurchase rights
reserved by the Company pursuant to the Plan shall not be available for
subsequent issuance under the Plan.

          (b)  The Common Stock subject to the Plan may be unissued shares or
reacquired shares, bought on the market or otherwise.

          (c)  An Incentive Stock Option may be granted to an eligible person
under the Plan only if the aggregate fair market value (determined at the time
the Incentive Stock Option is granted) of the Common Stock with respect to which
incentive stock options (as defined by the Code) are exercisable for the first
time by such optionee during any calendar year under all such plans of the
Company and its Affiliates does not exceed one hundred thousand dollars
($100,000). If it is determined that an entire Option or any portion thereof
does not qualify for treatment as an Incentive Stock Option by reason of
exceeding such maximum, such Option or the applicable portion shall be
considered a Nonqualified Stock Option.

     4.   ELIGIBILITY.

          (a)  Incentive Stock Options may be granted only to employees
(including officers) of the Company or its Affiliates. A director of the Company
shall not be eligible to receive Incentive Stock Options unless such director is
also an employee of the Company or any Affiliate. Stock Awards other than
Incentive Stock Options may be granted to employees (including officers) or
directors of or consultants to the Company or any Affiliate or to Trusts of any
such employee, director or consultant.

          (b)  A director shall in no event be eligible for the benefits of the
Plan (other than from a Director NQSO under Section 6 of the Plan) unless and
until such director is expressly declared eligible to participate in the Plan by
action of the Board or the Committee, and only if, at any time discretion is
exercised by the Board or the Committee in the selection of a director as a
person to whom Stock Awards may be granted, or in the determination of the
number of shares which may be covered by Stock Awards granted to a director, the
Plan complies with the requirements of Rule 16b-3 promulgated under the Exchange
Act, as from time to time in effect. The Board shall otherwise comply with the
requirements of Rule 16b-3

                                        4

<PAGE>

promulgated under the Exchange Act, as from time to time in effect.
Notwithstanding the foregoing, the restrictions set forth in this paragraph 4(b)
shall not apply if the Board or Committee expressly declares that such
restrictions shall not apply.

          (c)  No person shall be eligible for the grant of an Incentive Stock
Option under the Plan if, at the time of grant, such person owns (or is deemed
to own pursuant to Section 424(d) of the Code) stock possessing more than ten
percent (10%) of the total combined voting power of all classes of stock of the
Company or of any of its Affiliates unless the exercise price of such Incentive
Stock Option is at least one hundred and ten percent (110%) of the fair market
value of the Common Stock at the date of grant and the Incentive Stock Option is
not exercisable after the expiration of five (5) years from the date of grant.

          (d)  Stock Awards shall be limited to a maximum of 2,000,000 shares of
Common Stock per person per calendar year.

     5.   TERMS OF DISCRETIONARY STOCK OPTIONS.

          An option granted pursuant to this Section 5 (a "Discretionary Stock
Option") shall be in such form and shall contain such terms and conditions as
the Board or the Committee shall deem appropriate. The provisions of separate
Options need not be identical, but each Option shall include (through
incorporation of provisions hereof by reference in the Option or otherwise) the
substance of each of the following provisions:

          (a)  No Option shall be exercisable after the expiration of ten (10)
years from the date it was granted.

          (b)  The exercise price of each Incentive Stock Option and each
Nonqualified Stock Option shall be not less than one hundred percent (100%) of
the fair market value of the Common Stock subject to the Option on the date the
Option is granted.

          (c)  The purchase price of Common Stock acquired pursuant to an Option
shall be paid, to the extent permitted by applicable statutes and regulations,
either: (i) in cash at the time the Option is exercised; or (ii) at the
discretion of the Board or the Committee, either at the time of grant or
exercise of the Option (A) by delivery to the Company of shares of Common Stock
that have been held for the period required to avoid a charge to the Company's
reported earnings and valued at the fair market value on the date of exercise,
(B) according to a deferred payment or other arrangement with the person to whom
the Option is granted or to whom the Option is transferred pursuant to paragraph
5(d), or (C) in any other form of legal consideration that may be acceptable to
the Board or the Committee in their discretion; including but not limited to
payment of the purchase price pursuant to a program developed under Regulation T
as promulgated by the Federal Reserve Board which results in the receipt of cash
(or a check) by the Company before Common Stock is issued or the receipt of
irrevocable

                                        5

<PAGE>

instruction to pay the aggregate exercise price to the Company from the sales
proceeds before Common Stock is issued.

     In the case of any deferred payment arrangement, interest shall be payable
at least annually and shall be charged at not less than the minimum rate of
interest necessary to avoid the treatment as interest, under any applicable
provisions of the Code, of any amounts other than amounts stated to be interest
under the deferred payment arrangement.

          (d)  An Option granted to a natural person shall be exercisable during
the lifetime of such person only by such person, provided that such person
during such person's lifetime may designate a Trust to be such person's
beneficiary with respect to any Incentive Stock Options granted after February
25, 1992 and with respect to any Nonqualified Stock Options, and such
beneficiary shall, after the death of the person to whom the Option was granted,
have all the rights that such person has while living, including the right to
exercise the Option. In the absence of such designation, after the death of the
person to whom the Option is granted, the Option shall be exercisable by the
person or persons to whom the optionee's rights under such Option pass by will
or by the laws of descent and distribution.

          (e)  The total number of shares of Common Stock subject to an Option
may, but need not, be allotted in periodic installments (which may, but need
not, be equal). From time to time during each of such installment periods, the
Option may become exercisable ("vest") with respect to some or all of the shares
allotted to that period, and may be exercised with respect to some or all of the
shares allotted to such period and/or any prior period as to which the Option
was not fully exercised. During the remainder of the term of the Option (if its
term extends beyond the end of the installment periods), the Option may be
exercised from time to time with respect to any shares then remaining subject to
the Option. The provisions of this paragraph 5(e) are subject to any Option
provisions governing the minimum number of shares as to which an Option may be
exercised.

          (f)  The Company may require any optionee, or any person to whom an
Option is transferred under paragraph 5(d), as a condition of exercising any
such Option: (i) to give written assurances satisfactory to the Company as to
such person's knowledge and experience in financial and business matters and/or
to employ a purchaser representative who has such knowledge and experience in
financial and business matters, and that such person is capable of evaluating,
alone or together with the purchaser representative, the merits and risks of
exercising the Option; and (ii) to give written assurances satisfactory to the
Company stating that such person is acquiring the Common Stock subject to the
Option for such person's own account and not with any present intention of
selling or otherwise distributing the Common Stock. These requirements, and any
assurances given pursuant to such requirements, shall be inoperative if: (x) the
issuance of the shares upon the exercise of the Option has been registered

                                        6

<PAGE>

under a then currently effective registration statement under the Securities Act
of 1933, as amended (the "Securities Act"); or (y) as to any particular
requirement, a determination is made by counsel for the Company that such
requirement need not be met in the circumstances under the then applicable
securities law.

          (g) An Option shall terminate three (3) months after termination of
the optionee's employment or relationship as a consultant or director with the
Company or an Affiliate, unless: (i) such termination is due to the optionee's
permanent and total disability, within the meaning of Section 422(c)(6) of the
Code and with such permanent and total disability being certified by the Social
Security Administration prior to such termination, in which case the Option may,
but need not, provide that it may be exercised at any time within one (1) year
following such termination of employment or relationship as a consultant or
director; (ii) the optionee dies while in the employ of or while serving as a
consultant or director to the Company or an Affiliate, or within not more than
three (3) months after termination of such employment or relationship as a
consultant or director, in which case the Option may, but need not, provide that
it may be exercised at any time within eighteen (18) months following the death
of the optionee by the person or persons to whom the optionee's rights under
such Option pass by will or by the laws of descent and distribution; or (iii)
the Option by its term specifies either (A) that it shall terminate sooner than
three (3) months after termination of the optionee's employment or relationship
as a consultant or director with the Company or an Affiliate; or (B) that it may
be exercised more than three (3) months after termination of the optionee's
employment or relationship as a consultant or director with the Company or an
Affiliate. This paragraph 5(g) shall not be construed to extend the term of any
Option or to permit anyone to exercise the Option after expiration of its term,
nor shall it be construed to increase the number of shares as to which any
Option is exercisable from the amount exercisable on the date of termination of
the optionee's employment or relationship as a consultant or director.

          (h)  The Option may, but need not, include a provision whereby the
optionee may elect at any time during the term of the optionee's employment or
relationship as a consultant or director with the Company or any Affiliate to
exercise the Option as to any part or all of the shares subject to the Option
prior to the stated vesting dates of the Option. Any shares so purchased from
any unvested installment or Option may be subject to a repurchase right in favor
of the Company or to any other restriction the Board or the Committee determines
to be appropriate.

          (i)  To the extent provided by the terms of an Option, each optionee
may satisfy any federal, state or local tax withholding obligation relating to
the exercise of such Option by any of the following means or by a combination of
such means: (i) tendering a cash payment; (ii) authorizing the Company to
withhold from the shares of the Common Stock

                                        7

<PAGE>

otherwise issuable to the optionee as a result of the exercise of the Option a
number of shares having a fair market value less than or equal to the amount of
the Company's required minimum statutory withholding; or (iii) delivering to the
Company owned and unencumbered shares of the Common Stock having a fair market
value less than or equal to the amount of the Company's required minimum
statutory withholding.

          (j)  Without in any way limiting the authority of the Board or
Committee to make or not to make grants of Discretionary Stock Options under
this Section 5, the Board or Committee shall have the authority (but not an
obligation) to include as part of any Option agreement a provision entitling the
optionee to a further Option (a "Re-Load Option") in the event the optionee
exercises the Option evidenced by the Option agreement, in whole or in part, by
surrendering other shares of Common Stock in accordance with this Plan and the
terms and conditions of the Option agreement. Any such Re-Load Option (i) shall
be for a number of shares equal to the number of shares surrendered as part or
all of the exercise price of such Option; (ii) shall have an expiration date
which is the same as the expiration date of the Option the exercise of which
gave rise to such Re-Load Option; and (iii) shall have an exercise price which
is equal to one hundred percent (100%) of the fair market value of the Common
Stock subject to the Re-Load Option on the date of exercise of the original
Option or, in the case of a Re-Load Option which is an Incentive Stock Option
and which is granted to a 10% stockholder (as defined in paragraph 4(c)), shall
have an exercise price which is equal to one hundred and ten percent (110%) of
the fair market value of the Common Stock subject to the Re-Load Option on the
date of exercise of the original Option.

               Any such Re-Load Option may be an Incentive Stock Option or a
Nonqualified Stock Option, as the Board or Committee may designate at the time
of the grant of the original Option, provided, however, that the designation of
any Re-Load Option as an Incentive Stock Option shall be subject to the one
hundred thousand dollars ($100,000) annual limitation on exercisability of
Incentive Stock Options described in paragraph 3(c) of the Plan and in Section
422(d) of the Code. There shall be no Re-Load Option on a Re-Load Option. Any
such Re-Load Option shall be subject to the availability of sufficient shares
under paragraph 3(a) and shall be subject to such other terms and conditions as
the Board or Committee may determine.

     6.   TERMS OF NON-DISCRETIONARY OPTIONS

          (a)  On January 27 of each year, each person who is at that time an
Eligible Director of the Company, (as defined in paragraph 6(k)), shall
automatically be granted under the Plan, without further action by the Company,
the Board, or the Company's stockholders, a Nonqualified Stock Option (a
"Director NQSO") to purchase sixteen thousand (16,000) shares

                                        8

<PAGE>

of Common Stock on the terms and conditions set forth herein. An Eligible
Director may designate that such Director NQSO be granted in the name of a Trust
instead of in the name of such Eligible Director. The Director NQSO shall be on
the terms and conditions set forth herein and should the date of grant set forth
above be a Saturday, Sunday or legal holiday, such grant shall be made on the
next business day.

          (b)  Each person who becomes an Eligible Director, shall, upon the
date such person first becomes an Eligible Director, automatically be granted
under the Plan, without further action by the Company, the Board, or the
Company's stockholders, a Director NQSO to purchase sixty thousand (60,000)
shares of Common Stock on the terms and conditions set forth herein. An Eligible
Director may designate that such Director NQSO be granted in the name of a Trust
instead of in the name of such Eligible Director. The Director NQSO shall be on
the terms and conditions set forth herein and should the date of grant set forth
above be a Saturday, Sunday or legal holiday, such grant shall be made on the
next business day.

          (c)  Each Director NQSO granted pursuant to this Section 6 (or any
Director Re-Load Option granted pursuant to paragraph 6(j)) shall be in such
form and shall contain such terms and conditions as the Board or the Committee
shall deem appropriate. The provisions of separate Director NQSO's need not be
identical, but each Director NQSO shall include (through incorporation of
provisions hereof by reference in the Director NQSO or otherwise) the substance
of each of the following provisions as set forth in paragraphs 6(d) through
6(j), inclusive.

          (d)  The term of each Director NQSO shall be ten (10) years from the
date it was granted.

          (e)  The exercise price of each Director NQSO shall be one hundred
percent (100%) of the fair market value of the Common Stock subject to such
Director NQSO on the date such Director NQSO is granted.

          (f)  The purchase price of Common Stock acquired pursuant to a
Director NQSO shall be paid, to the extent permitted by applicable statutes and
regulations, either (i) in cash at the time the Director NQSO is exercised; (ii)
by delivery to the Company of shares of Common Stock that have been held for the
period required to avoid a charge to the Company's reported earnings and valued
at their fair market value on the date of exercise; or (iii) pursuant to a
program developed under Regulation T as promulgated by the Federal Reserve Board
which results in the receipt of cash (or a check) by the Company before Common
Stock is issued or the receipt of irrevocable instructions to pay the aggregate
exercise price to the Company from the sales proceeds before Common Stock is
issued.

          (g)  A Director NQSO shall be exercisable during the lifetime of the
Eligible Director with respect to whom it was granted only by the person to whom
it was granted

                                        9

<PAGE>

(whether the Eligible Director or a Trust), provided that such person during the
Eligible Director's lifetime may designate a Trust to be a beneficiary with
respect to the Director NQSO, and such beneficiary shall, after the death of the
Eligible Director to whom the Director NQSO was granted, have all of the rights
designated for such beneficiary. In the absence of such designation, after the
death of the Eligible Director with respect to whom the Director NQSO was
granted, if such Director NQSO was granted to the Eligible Director, the
Director NQSO shall be exercisable by the person or persons to whom the
optionee's rights under such option pass by will or by the laws of descent and
distribution.

          (h)  A Director NQSO shall not vest with respect to an Eligible
Director, or the affiliate of such Eligible Director, as the case may be, (i)
unless the Eligible Director, has, at the date of grant, provided three (3)
years of prior continuous service as an Eligible Director, or (ii) until the
date upon which such Eligible Director has provided one year of continuous
service as an Eligible Director following the date of grant of such Director
NQSO, whereupon such Director NQSO shall become fully vested and exercisable in
accordance with its terms.

          (i)  The Company may require any optionee under this Section 6, or any
person to whom a Director NQSO is transferred under paragraph 6(g), as a
condition of exercising any such option: (i) to give written assurances
satisfactory to the Company as to such person's knowledge and experience in
financial and business matters and/or to employ a purchaser representative who
has such knowledge and experience in financial and business matters, and that
such person is capable of evaluating, alone or together with the purchaser
representative, the merits and risks of exercising the Director NQSO; and (ii)
to give written assurances satisfactory to the Company stating that such person
is acquiring the Common Stock subject to the Director NQSO for such person's own
account and not with any present intention of selling or otherwise distributing
the stock. These requirements, and any assurances given pursuant to such
requirements, shall be inoperative if (i) the issuance of the shares upon the
exercise of the Director NQSO has been registered under a then currently
effective registration statement under the Securities Act of 1933, as amended
(the "Securities Act"), or (ii), as to any particular requirement, a
determination is made by counsel for the Company that such requirement need not
be met in the circumstances under the then applicable securities laws.

          (j)  Subject to the last sentence of this paragraph 6(j), each
Director NQSO shall include a provision entitling the optionee to a further
Nonqualified Stock Option (a "Director Re-Load Option") in the event the
optionee exercises the Director NQSO evidenced by the Director NQSO grant, in
whole or in part, by surrendering other shares of Common Stock in accordance
with the Plan and the terms of the Director NQSO grant. Any such Director
Re-Load Option (i) shall be for a number of shares equal to the number of shares
surrendered as part or all of the exercise price of the original Director NQSO;
(ii) shall have an

                                       10

<PAGE>

expiration date which is the same as the expiration date of the original
Director NQSO; and (iii) shall have an exercise price which is equal to one
hundred percent (100%) of the fair market value of the Common Stock subject to
the Director Re-Load Option on the date of exercise of the original Director
NQSO. Any such Director Re-Load Option shall be subject to the availability of
sufficient shares under paragraph 3(a). There shall be no Director Re-Load
Option on a Director Re-Load Option. Notwithstanding anything else in the Plan
to the contrary, this paragraph 6(j) shall be of no force and effect from and
after June 23, 1998.

          (k) For purposes of this Section 6, the term "Eligible Director" shall
mean a member of the Board who is not an employee of the Company or any
Affiliate, and the term "affiliate" shall mean a person that directly or
indirectly controls, is controlled by, or is under common control with, the
Eligible Director.

     7.   TERMS OF STOCK BONUSES AND PURCHASES OF RESTRICTED STOCK.

          Each stock bonus or restricted stock purchase agreement shall be in
such form and shall contain such terms and conditions as the Board or the
Committee shall deem appropriate. The terms and conditions of stock bonus or
restricted stock purchase agreements may change from time to time, and the terms
and conditions of separate agreements need not be identical, but each stock
bonus or restricted stock purchase agreement shall include (through
incorporation of provisions hereof by reference in the agreement or otherwise)
the substance of each of the following provisions as appropriate:

          (a)  The purchase price under each stock purchase agreement shall be
such amount as the Board or Committee shall determine and designate in such
agreement. Notwithstanding the foregoing, the Board or the Committee may
determine that eligible participants in the Plan may be awarded stock pursuant
to a stock bonus agreement in consideration for past services actually rendered
to the Company or for its benefit.

          (b)  No rights under a stock bonus or restricted stock purchase
agreement shall be assignable by any participant under the Plan, either
voluntarily or by operation of law, except where such assignment is required by
law or expressly authorized by the terms of the applicable stock bonus or
restricted stock purchase agreement.

          (c)  The purchase price of stock acquired pursuant to a stock purchase
agreement shall be paid either: (i) in cash at the time of purchase; (ii) at the
discretion of the Board or the Committee, according to a deferred payment or
other arrangement with the person to whom the Common Stock is sold; or (iii) in
any other form of legal consideration that may be acceptable to the Board or the
Committee in their discretion; including but not limited to payment of the
purchase price pursuant to a program developed under Regulation T as

                                       11

<PAGE>

promulgated by the Federal Reserve Board which results in the receipt of cash
(or a check) by the Company before Common Stock is issued or the receipt of
irrevocable instruction to pay the aggregate exercise price of the Company from
the sales proceeds before Common Stock is issued. Notwithstanding the foregoing,
the Board or the Committee to which administration of the Plan has been
delegated may award Common Stock pursuant to a stock bonus agreement in
consideration for past services actually rendered to the Company or for its
benefit.

          (d)  Shares of Common Stock sold or awarded under the Plan may, but
need not, be subject to a repurchase option in favor of the Company in
accordance with a vesting schedule to be determined by the Board or the
Committee.

          (e)  In the event a person ceases to be an employee of or ceases to
serve as a director or consultant to the Company or an Affiliate, the Company
may repurchase or otherwise reacquire any or all of the shares of Common Stock
held by that person which have not vested as of the date of termination under
the terms of the stock bonus or restricted stock purchase agreement between the
Company and such person.

          (f)  To the extent provided by the terms of stock bonus or restricted
stock purchase agreement, a participant may satisfy any federal, state or local
tax withholding obligation relating to the lapsing of a repurchase option in
favor of the Company or vesting of a stock bonus or a restricted stock award by
any of the following means or by a combination of such means: (i) tendering a
cash payment; (ii) authorizing the Company to withhold from the shares of the
Common Stock otherwise deliverable to a participant as a result of the lapsing
of a repurchase option in favor of the Company or the vesting of a stock bonus
or a restricted stock award a number of shares having a fair market value less
than or equal to the amount of the Company's required minimum statutory
withholding; or (iii) delivering to the Company owned and unencumbered shares of
the Common Stock having a fair market value less than or equal to the amount of
the Company's required minimum statutory withholding.

     8.   COVENANTS OF THE COMPANY.

          (a)  During the terms of the Stock Awards granted under the Plan, the
Company shall keep available at all times the number of shares of Common Stock
required to satisfy such Stock Awards up to the number of shares of Common Stock
authorized under the Plan.

          (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 Common Stock under the Stock Awards granted under the
Plan; provided, however, that this undertaking shall not require the Company to
register under the Securities Act either the Plan, any Stock Award granted under
the Plan or any Common Stock issued or issuable

                                       12

<PAGE>

pursuant to any such Stock Award. If, after reasonable efforts, the Company is
unable to obtain from any such regulatory commission or agency the authority
that counsel for the Company deems necessary for the lawful issuance and sale of
Common Stock under the Plan, the Company shall be relieved from any liability
for failure to issue and sell Common Stock upon exercise of such Stock Awards
unless and until such authority is obtained.

     9.   USE OF PROCEEDS FROM COMMON STOCK.

          Proceeds from the sale of Common Stock pursuant to Stock Awards
granted under the Plan shall constitute general funds of the Company.

     10.  MISCELLANEOUS.

          (a)  The Board or Committee shall have the power to accelerate the
time during which a Stock Award may be exercised or the time during which a
Stock Award or any part thereof will vest, notwithstanding the provisions in the
Stock Award stating the time during which it may be exercised or the time during
which it will vest. Each Discretionary Stock Option providing for vesting
pursuant to paragraph 5(e) shall also provide that if the employee's employment
or a director's or consultant's affiliation with the Company or an Affiliate of
the Company is terminated by reason of death or disability (within the meaning
of Title II or XVI of the Social Security Act or comparable statute applicable
to an Affiliate and with such permanent and total disability certified by (i)
the Social Security Administration, (ii) the comparable governmental authority
applicable to an Affiliate, (iii) such other body having the relevant
decision-making power applicable to an Affiliate or (iv) an independent medical
advisor appointed by the Company, as applicable, prior to such termination),
then the vesting schedule of Discretionary Stock Options granted to such
employee, director or consultant or to the Trusts of such employee, director or
consultant shall be accelerated by twelve months for each full year the employee
has been employed by or the director or consultant has been affiliated with the
Company and/or an Affiliate of the Company.

          (b)  Neither an optionee nor any person to whom an Option is
transferred under the provisions of the Plan shall be deemed to be the holder
of, or to have any of the rights of a holder with respect to, any shares subject
to such Option unless and until such person has satisfied all requirements for
exercise of the Option pursuant to its terms.

          (c)  Nothing in the Plan or any instrument executed or Stock Award
granted pursuant thereto shall confer upon any eligible employee, consultant,
director, optionee or holder of Stock Awards under the Plan any right to
continue in the employ of the Company or any Affiliate or to continue acting as
a consultant or director or shall affect the right of the Company or any
Affiliate to terminate the employment or consulting relationship or

                                       13

<PAGE>

directorship of any eligible employee, consultant, director, optionee or holder
of Stock Awards under the Plan with or without cause. In the event that a holder
of Stock Awards under the Plan is permitted or otherwise entitled to take a
leave of absence, the Company shall have the unilateral right to (i) determine
whether such leave of absence will be treated as a termination of employment or
relationship as consultant or director for purposes hereof, and (ii) suspend or
otherwise delay the time or times at which exercisability or vesting would
otherwise occur with respect to any outstanding Stock Awards under the Plan.

          (d)  Notwithstanding any provision of the Plan to the contrary, the
Board or the Committee shall have the power to condition the grant or vesting of
stock bonuses and rights to purchase restricted stock under the Plan upon the
attainment of performance goals, determined by the Board or the Committee in
their respective sole discretion, with respect to any one or more of the
following business criteria with respect to the Company, any Affiliate, any
division, any operating unit or any product line: (i) return on capital, assets
or equity, (ii) sales or revenue, (iii) net income, (iv) cash flow, (v) earnings
per share, (vi) adjusted earnings or adjusted net income as defined below, (vii)
working capital, (vii) total shareholder return, (ix) economic value or (x)
product development, research, in-licensing, out-licensing, litigation, human
resources, information services, manufacturing, manufacturing capacity,
production, inventory, site development, plant, building or facility
development, government relations, product market share, mergers, acquisitions
or sales of assets or subsidiaries. "Adjusted net income" and "adjusted
earnings" shall mean net income or earnings, as the case may be, for the
relevant performance period computed in accordance with accounting principles
generally accepted in the U.S. which may be adjusted by the Committee, as
specified in writing, for such performance period, at the time a performance
goal is established for the performance period, for the following: (a) any item
of significant gain or loss for the performance period determined to be related
to a change in accounting principle as reflected in the Company's audited
consolidated financial statements, (b) amortization expenses associated with
acquired intangible assets, (c) expenses associated with acquired in-process
research and development and (d) any other items of significant income or
expense which are determined to be appropriate adjustments and are specified in
writing by the Committee at the time the goal is established for the performance
period. With respect to any stock bonuses or rights to purchase restricted stock
granted to persons who are or who may be "covered employees" within the meaning
of Section 162(m) of the Code, the Board or the Committee shall have the power
to grant such awards upon terms and conditions that qualify such awards as
"qualified performance-based compensation" within the meaning of Section 162(m)
of the Code. Stock bonuses and rights to purchase restricted stock made in
accordance with this paragraph 10(d) shall contain the terms

                                       14

<PAGE>

and conditions of Section 7 above.

     11.  ADJUSTMENTS UPON CHANGES IN COMMON STOCK.

          If any change is made in the Common Stock subject to the Plan, or
subject to any Stock Award 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 other transaction
not involving the receipt of consideration by the Company), the Plan and
outstanding Stock Awards will be appropriately adjusted in the class(es) and
maximum number of shares subject to the Plan, the maximum number of shares which
may be granted to a participant in a calendar year, the class(es) and number of
shares and price per share of stock subject to outstanding Stock Awards, and the
number of shares of Common Stock to be granted as provided for in paragraphs
6(a) and 6(b). Such adjustment shall be made by the Board or the Committee, the
determination of which shall be final, binding and conclusive. (The conversion
of any convertible securities of the Company shall not be treated as a
"transaction not involving the receipt of consideration".)

     12.  CHANGE OF CONTROL.

          (a)  Notwithstanding anything to the contrary in this Plan, in the
event of a Change in Control (as hereinafter defined), then, to the extent
permitted by applicable law: (i) the time during which Stock Awards become
vested shall automatically be accelerated so that the unvested portions of all
Stock Awards shall be vested prior to the Change in Control and (ii) the time
during which the Options may be exercised shall automatically be accelerated to
prior to the Change in Control. Upon and following the acceleration of the
vesting and exercise periods, at the election of the holder of the Stock Award,
the Stock Award may be: (x) exercised (with respect to Options) or, if the
surviving or acquiring corporation agrees to assume the Stock Awards or
substitute similar stock awards, (y) assumed; or (z) replaced with substitute
stock awards. Options not exercised, substituted or assumed prior to or upon the
Change in Control shall be terminated.

          (b)  For purposes of the Plan, a "Change of Control" shall be deemed
to have occurred at any of the following times:

               (i)  upon the acquisition (other than from the Company) by any
person, entity or "group," within the meaning of Section 13(d)(3) or 14(d)(2) of
the Exchange Act (excluding, for this purpose, the Company or its affiliates, or
any employee benefit plan of the Company or its affiliates which acquires
beneficial ownership of voting securities of the Company), of beneficial
ownership (within the meaning of Rule 13d-3 promulgated under the

                                       15

<PAGE>

Exchange Act) of fifty percent (50%) or more of either the then outstanding
shares of Common Stock or the combined voting power of the Company's then
outstanding voting securities entitled to vote generally in the election of
directors; or

               (ii)  at the time individuals who, as of April 2, 1991,
constitute the Board (the "Incumbent Board") cease for any reason to constitute
at least a majority of the Board, provided that any person becoming a director
subsequent to April 2, 1991, whose election, or nomination for election by the
Company's stockholders, was approved by a vote of at least a majority of the
directors then comprising the Incumbent Board (other than an election or
nomination of an individual whose initial assumption of office is in connection
with an actual or threatened election contest relating to the election of the
Directors of the Company, as such terms are used in Rule 14a-11 of Regulation
14A promulgated under the Exchange Act) shall be, for purposes of the Plan,
considered as though such person were a member of the Incumbent Board; or

               (iii) immediately prior to the consummation by the Company of a
reorganization, merger, consolidation, (in each case, with respect to which
persons who were the stockholders of the Company immediately prior to such
reorganization, merger or consolidation do not, immediately thereafter, own more
than fifty percent (50%) of the combined voting power entitled to vote generally
in the election of directors of the reorganized, merged or consolidated
company's then outstanding voting securities) or a liquidation or dissolution of
the Company or of the sale of all or substantially all of the assets of the
Company; or

               (iv)  the occurrence of any other event which the Incumbent Board
in its sole discretion determines constitutes a Change of Control.

     13.  QUALIFIED DOMESTIC RELATIONS ORDERS

          (a)  Anything in the Plan to the contrary notwithstanding, rights
under Stock Awards may be assigned to an Alternate Payee to the extent that a
QDRO so provides. (The terms "Alternate Payee" and "QDRO" are defined in
paragraph 13(c) below.) The assignment of a Stock Award to an Alternate Payee
pursuant to a QDRO shall not be treated as having caused a new grant. The
transfer of an Incentive Stock Option to an Alternate Payee may, however, cause
it to fail to qualify as an Incentive Stock Option. If a Stock Award is assigned
to an Alternate Payee, the Alternate Payee generally has the same rights as the
grantee under the terms of the Plan; provided however, that (i) the Stock Award
shall be subject to the same vesting terms and exercise period as if the Stock
Award were still held by the grantee, (ii) an Alternate Payee may not transfer a
Stock Award and (iii) an Alternate Payee is ineligible for Re-Load Options
described at paragraph 5(j) or Director Re-Load Options described at paragraph

                                       16

<PAGE>

6(j).

          (b)  In the event of the Plan administrator's receipt of a domestic
relations order or other notice of adverse claim by an Alternate Payee of a
grantee of a Stock Award, transfer of the proceeds of the exercise of such Stock
Award, whether in the form of cash, stock or other property, may be suspended.
Such proceeds shall thereafter be transferred pursuant to the terms of a QDRO or
other agreement between the grantee and Alternate Payee. A grantee's ability to
exercise a Stock Award may be barred if the Plan administrator receives a court
order directing the Plan administrator not to permit exercise.

          (c)  The word "QDRO" as used in the Plan shall mean a court order (i)
that creates or recognizes the right of the spouse, former spouse or child (an
"Alternate Payee") of an individual who is granted a Stock Award to an interest
in such Stock Award relating to marital property rights or support obligations
and (ii) that the administrator of the Plan determines would be a "qualified
domestic relations order," as that term is defined in section 414(p) of the Code
and section 206(d) of the Employee Retirement Income Security Act ("ERISA"), but
for the fact that the Plan is not a plan described in section 3(3) of ERISA.

     14.  AMENDMENT OF THE PLAN.

          (a)  The Board at any time, and from time to time, may amend the Plan.
However, except as provided in Section 10 relating to adjustments upon changes
in the Common 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 Stock Awards
under the Plan;

               (ii)  modify the requirements as to eligibility for participation
in the Plan (to the extent such modification requires stockholder approval in
order for the Plan to satisfy the requirements of Section 422(b) of the Code);
or

               (iii) modify the Plan in any other way if such modification
requires stockholder approval in order for the Plan to satisfy the requirements
of Section 422(b) of the Code.

          (b)  The Board may in its sole discretion submit any other amendment
to the Plan for stockholder approval, including, but not limited to, amendments
to the Plan intended to satisfy the requirements of Section 162(m) of the Code
and the regulations promulgated thereunder regarding the exclusion of
performance-based compensation from the limit on corporate deductibility of
compensation to certain executive officers.

          (c)  It is expressly contemplated that the Board may amend the Plan in
any respect the Board deems necessary or advisable to provide optionees with the
maximum

                                       17

<PAGE>

benefits provided or to be provided under the provisions of the Code and the
regulations promulgated thereunder relating to employee Incentive Stock Options
and/or to bring the Plan and/or Options granted under it into compliance
therewith.

          (d) Rights and obligations under any Stock Award granted before
amendment of the Plan shall not be impaired by any amendment of the Plan,
unless: (i) the Company requests the consent of the person to whom the Stock
Award was granted; and (ii) such person consents in writing.

     15.  TERMINATION OR SUSPENSION OF THE PLAN.

          (a)  The Board may suspend or terminate the Plan at any time. No Stock
Awards may be granted under the Plan while the Plan is suspended or after it is
terminated. No Incentive Stock Options may be granted under the Plan after
February 22, 2009.

          (b)  Rights and obligations under any Stock Awards granted while the
Plan is in effect shall not be impaired by suspension or termination of the
Plan, except with the consent of the person to whom the Stock Award was granted.

     16.  EFFECTIVE DATE OF PLAN.

          The Plan shall become effective as determined by the Board.

                                       18