<PAGE>

                                                                    EXHIBIT 10.3

                                 GENECRAFT, INC.

                                 2002 STOCK PLAN

                             STOCK OPTION AGREEMENT

     Unless otherwise defined herein, the terms defined in the 2002 Stock Plan
shall have the same defined meanings in this Stock Option Agreement.

I.   NOTICE OF STOCK OPTION GRANT

     NAME: ___________________________________________

     ADDRESS: ________________________________________

     The undersigned Optionee has been granted an Option to purchase Common
Stock of the Company, subject to the terms and conditions of the Plan and this
Option Agreement, as follows:

     Date of Grant                    __________________________________________

     Vesting Commencement Date        __________________________________________

     Exercise Price per Share         $_________________________________________

     Total Number of Shares Granted   __________________________________________

     Total Exercise Price             $_________________________________________

     Type of Option:                  ___ Incentive Stock Option

                                      ___ Nonstatutory Stock Option

     Term/Expiration Date:            __________________________________________

     Vesting Schedule:

     This Option shall be exercisable, in whole or in part, according to the
following vesting schedule:

     25% of the Shares subject to the Option shall vest on the one (1) year
anniversary of the Vesting Commencement Date, and 1/48 of the Option shall vest
each month thereafter, subject to Optionee continuing to be a Service Provider
on such dates.

     Termination Period:

     This Option shall be exercisable for three (3) months after Optionee ceases
to be a Service Provider. Upon Optionee's death or Disability, this Option may
be exercised for one (1) year after

<PAGE>

Optionee ceases to be a Service Provider. In no event may Optionee exercise this
Option after the Term/Expiration Date as provided above.

II.  AGREEMENT

     1. Grant of Option. The Plan Administrator of the Company hereby grants to
the Optionee named in the Notice of Grant (the "Optionee"), an option (the
"Option") to purchase the number of Shares set forth in the Notice of Grant, at
the exercise price per Share set forth in the Notice of Grant (the "Exercise
Price"), and subject to the terms and conditions of the Plan, which is
incorporated herein by reference. Subject to Section 15(c) of the Plan, in the
event of a conflict between the terms and conditions of the Plan and this Option
Agreement, the terms and conditions of the Plan shall prevail.

          If designated in the Notice of Grant as an Incentive Stock Option
("ISO"), this Option is intended to qualify as an Incentive Stock Option as
defined in Section 422 of the Code. Nevertheless, to the extent that it exceeds
the $100,000 rule of Code Section 422(d), this Option shall be treated as a
Nonstatutory Stock Option ("NSO").

     2. Exercise of Option.

          (a) Right to Exercise. This Option shall be exercisable during its
term in accordance with the Vesting Schedule set out in the Notice of Grant and
with the applicable provisions of the Plan and this Option Agreement.

          (b) Method of Exercise. This Option shall be exercisable by delivery
of an exercise notice in the form attached as Exhibit A (the "Exercise Notice")
which shall state the election to exercise the Option, the number of Shares with
respect to which the Option is being exercised, and such other representations
and agreements as may be required by the Company. The Exercise Notice shall be
accompanied by payment of the aggregate Exercise Price as to all Exercised
Shares. This Option shall be deemed to be exercised upon receipt by the Company
of such fully executed Exercise Notice accompanied by the aggregate Exercise
Price.

          No Shares shall be issued pursuant to the exercise of an Option unless
such issuance and such exercise complies with Applicable Laws. Assuming such
compliance, for income tax purposes the Shares shall be considered transferred
to the Optionee on the date on which the Option is exercised with respect to
such Shares.

     3. Optionee's Representations. In the event the Shares have not been
registered under the Securities Act of 1933, as amended, at the time this Option
is exercised, the Optionee shall, if required by the Company, concurrently with
the exercise of all or any portion of this Option, deliver to the Company his or
her Investment Representation Statement in the form attached hereto as Exhibit
B.

     4. Lock-Up Period. Optionee hereby agrees that Optionee shall not offer,
pledge, sell, contract to sell, sell any option or contract to purchase,
purchase any option or contract to sell, grant any option, right or warrant to
purchase, lend, or otherwise transfer or dispose of, directly or indirectly, any
Common Stock (or other securities) of the Company or enter into any swap,
hedging


                                      -2-

<PAGE>

or other arrangement that transfers to another, in whole or in part, any of the
economic consequences of ownership of any Common Stock (or other securities) of
the Company held by Optionee (other than those included in the registration) for
a period specified by the representative of the underwriters of Common Stock (or
other securities) of the Company not to exceed one hundred eighty (180) days
following the effective date of any registration statement of the Company filed
under the Securities Act.

          Optionee agrees to execute and deliver such other agreements as may be
reasonably requested by the Company or the underwriter which are consistent with
the foregoing or which are necessary to give further effect thereto. In
addition, if requested by the Company or the representative of the underwriters
of Common Stock (or other securities) of the Company, Optionee shall provide,
within ten (10) days of such request, such information as may be required by the
Company or such representative in connection with the completion of any public
offering of the Company's securities pursuant to a registration statement filed
under the Securities Act. The obligations described in this Section shall not
apply to a registration relating solely to employee benefit plans on Form S-1 or
Form S-8 or similar forms that may be promulgated in the future, or a
registration relating solely to a Commission Rule 145 transaction on Form S-4 or
similar forms that may be promulgated in the future. The Company may impose
stop-transfer instructions with respect to the shares of Common Stock (or other
securities) subject to the foregoing restriction until the end of said one
hundred eighty (180) day period. Optionee agrees that any transferee of the
Option or shares acquired pursuant to the Option shall be bound by this Section.

     5. Method of Payment. Payment of the aggregate Exercise Price shall be by
any of the following, or a combination thereof, at the election of the Optionee:

          (a) cash or check;

          (b) consideration received by the Company under a formal cashless
exercise program adopted by the Company in connection with the Plan; or

          (c) surrender of other Shares which, (i) in the case of Shares
acquired from the Company, either directly or indirectly, have been owned by the
Optionee for more than six (6) months on the date of surrender, and (ii) have a
Fair Market Value on the date of surrender equal to the aggregate Exercise Price
of the Exercised Shares.

     6. Restrictions on Exercise. This Option may not be exercised until such
time as the Plan has been approved by the shareholders of the Company, or if the
issuance of such Shares upon such exercise or the method of payment of
consideration for such shares would constitute a violation of any Applicable
Law.

     7. Non-Transferability of Option. This Option may not be transferred in any
manner otherwise than by will or by the laws of descent or distribution and may
be exercised during the lifetime of Optionee only by Optionee. The terms of the
Plan and this Option Agreement shall be binding upon the executors,
administrators, heirs, successors and assigns of the Optionee.


                                      -3-

<PAGE>

     8. Term of Option. This Option may be exercised only within the term set
out in the Notice of Grant, and may be exercised during such term only in
accordance with the Plan and the terms of this Option.

     9. Tax Obligations.

          (a) Withholding Taxes. Optionee agrees to make appropriate
arrangements with the Company (or the Parent or Subsidiary employing or
retaining Optionee) for the satisfaction of all Federal, state, local and
foreign income and employment tax withholding requirements applicable to the
Option exercise. Optionee acknowledges and agrees that the Company may refuse to
honor the exercise and refuse to deliver Shares if such withholding amounts are
not delivered at the time of exercise.

          (b) Notice of Disqualifying Disposition of ISO Shares. If the Option
granted to Optionee herein is an ISO, and if Optionee sells or otherwise
disposes of any of the Shares acquired pursuant to the ISO on or before the
later of (1) the date two years after the Date of Grant, or (2) the date one
year after the date of exercise, the Optionee shall immediately notify the
Company in writing of such disposition. Optionee agrees that Optionee may be
subject to income tax withholding by the Company on the compensation income
recognized by the Optionee.

     10. Entire Agreement; Governing Law. The Plan is incorporated herein by
reference. The Plan and this Option Agreement constitute the entire agreement of
the parties with respect to the subject matter hereof and supersede in their
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee. This agreement is governed by the internal substantive laws but not
the choice of law rules of the State of Washington.

     11. No Guarantee of Continued Service. OPTIONEE ACKNOWLEDGES AND AGREES
THAT THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE HEREOF IS EARNED
ONLY BY CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (NOT THROUGH
THE ACT OF BEING HIRED, BEING GRANTED THIS OPTION OR ACQUIRING SHARES
HEREUNDER). OPTIONEE FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE
TRANSACTIONS CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO
NOT CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A
SERVICE PROVIDER FOR THE VESTING PERIOD, FOR ANY PERIOD, OR AT ALL, AND SHALL
NOT INTERFERE IN ANY WAY WITH OPTIONEE'S RIGHT OR THE COMPANY'S RIGHT TO
TERMINATE OPTIONEE'S RELATIONSHIP AS A SERVICE PROVIDER AT ANY TIME, WITH OR
WITHOUT CAUSE.

     Optionee acknowledges receipt of a copy of the Plan and represents that he
or she is familiar with the terms and provisions thereof, and hereby accepts
this Option subject to all of the terms and provisions thereof. Optionee has
reviewed the Plan and this Option in their entirety, has had an opportunity to
obtain the advice of counsel prior to executing this Option and fully
understands all provisions of the Option. Optionee hereby agrees to accept as
binding, conclusive and final all


                                      -4-

<PAGE>

decisions or interpretations of the Administrator upon any questions arising
under the Plan or this Option. Optionee further agrees to notify the Company
upon any change in the residence address indicated below.

OPTIONEE                                GENECRAFT, INC.


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Signature                               By

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Print Name                              Title


-------------------------------------

-------------------------------------
Residence Address


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<PAGE>

                                    EXHIBIT A

                                 2002 STOCK PLAN

                                 EXERCISE NOTICE

GENECRAFT, INC.
601 Union Street, Suite 4200
Seattle, Washington 98101

Attention: Chief Executive Officer

     1. Exercise of Option. Effective as of today, _____________, _____, the
undersigned ("Optionee") hereby elects to exercise Optionee's option to purchase
_________ shares of the Common Stock (the "Shares") of GeneCraft, Inc. (the
"Company") under and pursuant to the 2002 Stock Plan (the "Plan") and the Stock
Option Agreement dated ____________, ____ (the "Option Agreement").

     2. Delivery of Payment. Purchaser herewith delivers to the Company the full
purchase price of the Shares, as set forth in the Option Agreement, and any and
all withholding taxes due in connection with the exercise of the Option.

     3. Representations of Optionee. Optionee acknowledges that Optionee has
received, read and understood the Plan and the Option Agreement and agrees to
abide by and be bound by their terms and conditions.

     4. Rights as Shareholder. Until the issuance of the Shares (as evidenced by
the appropriate entry on the books of the Company or of a duly authorized
transfer agent of the Company), no right to vote or receive dividends or any
other rights as a shareholder shall exist with respect to the Optioned Stock,
notwithstanding the exercise of the Option. The Shares shall be issued to the
Optionee as soon as practicable after the Option is exercised in accordance with
the Option Agreement. No adjustment shall be made for a dividend or other right
for which the record date is prior to the date of issuance except as provided in
Section 13 of the Plan.

     5. Company's Right of First Refusal Before any Shares held by Optionee or
any transferee (either being sometimes referred to herein as the "Holder") may
be sold or otherwise transferred (including transfer by gift or operation of
law), the Company or its assignee(s) shall have a right of first refusal to
purchase the Shares on the terms and conditions set forth in this Section (the
"Right of First Refusal").

          (a) Notice of Proposed Transfer. The Holder of the Shares shall
deliver to the Company a written notice (the "Notice") stating: (i) the Holder's
bona fide intention to sell or otherwise transfer such Shares; (ii) the name of
each proposed purchaser or other transferee ("Proposed Transferee"); (iii) the
number of Shares to be transferred to each Proposed Transferee; and (iv) the
bona fide cash price or other consideration for which the Holder proposes to
transfer the

<PAGE>

Shares (the "Offered Price"), and the Holder shall offer the Shares at the
Offered Price to the Company or its assignee(s).

          (b) Exercise of Right of First Refusal. At any time within thirty (30)
days after receipt of the Notice, the Company and/or its assignee(s) may, by
giving written notice to the Holder, elect to purchase all, but not less than
all, of the Shares proposed to be transferred to any one or more of the Proposed
Transferees, at the purchase price determined in accordance with subsection (c)
below.

          (c) Purchase Price. The purchase price ("Purchase Price") for the
Shares purchased by the Company or its assignee(s) under this Section shall be
the Offered Price. If the Offered Price includes consideration other than cash,
the cash equivalent value of the non-cash consideration shall be determined by
the Board of Directors of the Company in good faith.

          (d) Payment. Payment of the Purchase Price shall be made, at the
option of the Company or its assignee(s), in cash (by check), by cancellation of
all or a portion of any outstanding indebtedness of the Holder to the Company
(or, in the case of repurchase by an assignee, to the assignee), or by any
combination thereof within thirty (30) days after receipt of the Notice or in
the manner and at the times set forth in the Notice.

          (e) Holder's Right to Transfer. If all of the Shares proposed in the
Notice to be transferred to a given Proposed Transferee are not purchased by the
Company and/or its assignee(s) as provided in this Section, then the Holder may
sell or otherwise transfer such Shares to that Proposed Transferee at the
Offered Price or at a higher price, provided that such sale or other transfer is
consummated within 120 days after the date of the Notice, that any such sale or
other transfer is effected in accordance with any applicable securities laws and
that the Proposed Transferee agrees in writing that the provisions of this
Section shall continue to apply to the Shares in the hands of such Proposed
Transferee. If the Shares described in the Notice are not transferred to the
Proposed Transferee within such period, a new Notice shall be given to the
Company, and the Company and/or its assignees shall again be offered the Right
of First Refusal before any Shares held by the Holder may be sold or otherwise
transferred.

          (f) Exception for Certain Family Transfers. Anything to the contrary
contained in this Section notwithstanding, the transfer of any or all of the
Shares during the Optionee's lifetime or on the Optionee's death by will or
intestacy to the Optionee's immediate family or a trust for the benefit of the
Optionee's immediate family shall be exempt from the provisions of this Section.
"Immediate Family" as used herein shall mean spouse, lineal descendant or
antecedent, father, mother, brother or sister. In such case, the transferee or
other recipient shall receive and hold the Shares so transferred subject to the
provisions of this Section, and there shall be no further transfer of such
Shares except in accordance with the terms of this Section.

          (g) Termination of Right of First Refusal. The Right of First Refusal
shall terminate as to any Shares upon the earlier of (i) the first sale of
Common Stock of the Company to the general public, or (ii) a Change in Control
in which the successor corporation has equity securities that are publicly
traded.


                                      -2-

<PAGE>

     6. Tax Consultation. Optionee understands that Optionee may suffer adverse
tax consequences as a result of Optionee's purchase or disposition of the
Shares. Optionee represents that Optionee has consulted with any tax consultants
Optionee deems advisable in connection with the purchase or disposition of the
Shares and that Optionee is not relying on the Company for any tax advice.

     7. Restrictive Legends and Stop-Transfer Orders.

          (a) Legends. Optionee understands and agrees that the Company shall
cause the legends set forth below or legends substantially equivalent thereto,
to be placed upon any certificate(s) evidencing ownership of the Shares together
with any other legends that may be required by the Company or by state or
federal securities laws:

          THE SECURITIES REPRESENTED HEREBY HAVE NOT BEEN REGISTERED UNDER THE
          SECURITIES ACT OF 1933 (THE "ACT") AND MAY NOT BE OFFERED, SOLD OR
          OTHERWISE TRANSFERRED, PLEDGED OR HYPOTHECATED UNLESS AND UNTIL
          REGISTERED UNDER THE ACT OR, IN THE OPINION OF COMPANY COUNSEL
          SATISFACTORY TO THE ISSUER OF THESE SECURITIES, SUCH OFFER, SALE OR
          TRANSFER, PLEDGE OR HYPOTHECATION IS IN COMPLIANCE THEREWITH.

          THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO CERTAIN
          RESTRICTIONS ON TRANSFER AND A RIGHT OF FIRST REFUSAL HELD BY THE
          ISSUER OR ITS ASSIGNEE(S) AS SET FORTH IN THE EXERCISE NOTICE BETWEEN
          THE ISSUER AND THE ORIGINAL HOLDER OF THESE SHARES, A COPY OF WHICH
          MAY BE OBTAINED AT THE PRINCIPAL OFFICE OF THE ISSUER. SUCH TRANSFER
          RESTRICTIONS AND RIGHT OF FIRST REFUSAL ARE BINDING ON TRANSFEREES OF
          THESE SHARES.

          THE SHARES REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO RESTRICTIONS
          ON TRANSFER FOR A PERIOD NOT TO EXCEED 180 DAYS FOLLOWING THE
          EFFECTIVE DATE OF THE UNDERWRITTEN PUBLIC OFFERING OF THE COMPANY'S
          SECURITIES AND MAY NOT BE SOLD OR OTHERWISE DISPOSED OF BY THE HOLDER
          WITHOUT THE CONSENT OF THE COMPANY OR THE MANAGING UNDERWRITER.

          (b) Stop-Transfer Notices. Optionee agrees that, in order to ensure
compliance with the restrictions referred to herein, the Company may issue
appropriate "stop transfer" instructions to its transfer agent, if any, and
that, if the Company transfers its own securities, it may make appropriate
notations to the same effect in its own records.

          (c) Refusal to Transfer. The Company shall not be required (i) to
transfer on its books any Shares that have been sold or otherwise transferred in
violation of any of the provisions of this Exercise Notice or (ii) to treat as
owner of such Shares or to accord the right to vote or pay dividends to any
purchaser or other transferee to whom such Shares shall have been so
transferred.


                                      -3-

<PAGE>

     8. Successors and Assigns. The Company may assign any of its rights under
this Exercise Notice to single or multiple assignees, and this Exercise Notice
shall inure to the benefit of the successors and assigns of the Company. Subject
to the restrictions on transfer herein set forth, this Exercise Notice shall be
binding upon Optionee and his or her heirs, executors, administrators,
successors and assigns.

     9. Interpretation. Any dispute regarding the interpretation of this
Exercise Notice shall be submitted by Optionee or by the Company forthwith to
the Administrator which shall review such dispute at its next regular meeting.
The resolution of such a dispute by the Administrator shall be final and binding
on all parties.

     10. Governing Law; Severability. This Exercise Notice is governed by the
internal substantive laws but not the choice of law rules, of the State of
Washington. In the event that any provision hereof becomes or is declared by a
court of competent jurisdiction to be illegal, unenforceable or void, this
Option Agreement will continue in full force and effect.

     11. Entire Agreement. The Plan and Option Agreement are incorporated herein
by reference. This Exercise Notice, the Plan, the Option Agreement and the
Investment Representation Statement constitute the entire agreement of the
parties with respect to the subject matter hereof and supersede in their
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee.

Submitted by:                           Accepted by:
OPTIONEE                                GENECRAFT, INC.


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Signature                               By

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Print Name                              Title

Address:                                Address:

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                                        ----------------------------------------
                                        Date Received


                                      -4-

<PAGE>

                                    EXHIBIT B

                       INVESTMENT REPRESENTATION STATEMENT

OPTIONEE: ______________

COMPANY:  GENECRAFT, INC.

SECURITY: COMMON STOCK

AMOUNT:   ______________

DATE:     ______________

     In connection with the purchase of the above-listed Securities, the
undersigned Optionee represents to the Company the following:

     (a) Optionee is aware of the Company's business affairs and financial
condition and has acquired sufficient information about the Company to reach an
informed and knowledgeable decision to acquire the Securities. Optionee is
acquiring these Securities for investment for Optionee's own account only and
not with a view to, or for resale in connection with, any "distribution" thereof
within the meaning of the Securities Act of 1933, as amended (the "Securities
Act").

     (b) Optionee acknowledges and understands that the Securities constitute
"restricted securities" under the Securities Act and have not been registered
under the Securities Act in reliance upon a specific exemption therefrom, which
exemption depends upon, among other things, the bona fide nature of Optionee's
investment intent as expressed herein. In this connection, Optionee understands
that, in the view of the Securities and Exchange Commission, the statutory basis
for such exemption may be unavailable if Optionee's representation was
predicated solely upon a present intention to hold these Securities for the
minimum capital gains period specified under tax statutes, for a deferred sale,
for or until an increase or decrease in the market price of the Securities, or
for a period of one year or any other fixed period in the future. Optionee
further understands that the Securities must be held indefinitely unless they
are subsequently registered under the Securities Act or an exemption from such
registration is available. Optionee further acknowledges and understands that
the Company is under no obligation to register the Securities. Optionee
understands that the certificate evidencing the Securities will be imprinted
with any legend required under applicable state securities laws.

     (c) Optionee is familiar with the provisions of Rule 701 and Rule 144, each
promulgated under the Securities Act, which, in substance, permit limited public
resale of "restricted securities" acquired, directly or indirectly from the
issuer thereof, in a non-public offering subject to the satisfaction of certain
conditions. Rule 701 provides that if the issuer qualifies under Rule 701 at the
time of the grant of the Option to the Optionee, the exercise will be exempt
from registration under the Securities Act. In the event the Company becomes
subject to the reporting requirements of

<PAGE>

Section 13 or 15(d) of the Securities Exchange Act of 1934, ninety (90) days
thereafter (or such longer period as any market stand-off agreement may require)
the Securities exempt under Rule 701 may be resold, subject to the satisfaction
of certain of the conditions specified by Rule 144, including: (1) the resale
being made through a broker in an unsolicited "broker's transaction" or in
transactions directly with a market maker (as said term is defined under the
Securities Exchange Act of 1934); and, in the case of an affiliate, (2) the
availability of certain public information about the Company, (3) the amount of
Securities being sold during any three month period not exceeding the
limitations specified in Rule 144(e), and (4) the timely filing of a Form 144,
if applicable.

          In the event that the Company does not qualify under Rule 701 at the
time of grant of the Option, then the Securities may be resold in certain
limited circumstances subject to the provisions of Rule 144, which requires the
resale to occur not less than one year after the later of the date the
Securities were sold by the Company or the date the Securities were sold by an
affiliate of the Company, within the meaning of Rule 144; and, in the case of
acquisition of the Securities by an affiliate, or by a non-affiliate who
subsequently holds the Securities less than two years, the satisfaction of the
conditions set forth in sections (1), (2), (3) and (4) of the paragraph
immediately above.

     (d) Optionee further understands that in the event all of the applicable
requirements of Rule 701 or 144 are not satisfied, registration under the
Securities Act, compliance with Regulation A, or some other registration
exemption will be required; and that, notwithstanding the fact that Rules 144
and 701 are not exclusive, the Staff of the Securities and Exchange Commission
has expressed its opinion that persons proposing to sell private placement
securities other than in a registered offering and otherwise than pursuant to
Rules 144 or 701 will have a substantial burden of proof in establishing that an
exemption from registration is available for such offers or sales, and that such
persons and their respective brokers who participate in such transactions do so
at their own risk. Optionee understands that no assurances can be given that any
such other registration exemption will be available in such event.

                                        Signature of Optionee:


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                                        Date:                             ,
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                                      -2-