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  SEATTLE GENETICS, INC.              1998 STOCK OPTION PLAN         



1.  Purposes of the Plan.  


    The purposes of this 1998 Stock Option Plan are to attract and retain the best available personnel for positions of substantial responsibility, to provide
additional incentive to Employees and Consultants of the Company and its Subsidiaries and to promote the success of the Company's business. Options granted under the Plan may be incentive stock
options (as defined under Section 422 of the Code) or non-statutory stock options, as determined by the Administrator at the time of grant of an option and subject to the applicable
provisions of Section 422 of the Code, as amended, and the regulations promulgated thereunder. 


2.  Definitions.  


    As used herein, the following definitions shall apply: 


    (a) "Administrator" means the Board or any of its Committees appointed pursuant to Section 4 of the Plan. 


    (b) "Affiliate" means an entity other than a Subsidiary in which the Company owns an equity interest or which, together
with the Company, is under common control of a third person or entity. 


    (c) "Applicable Laws" means the legal requirements relating to the administration of stock option and restricted stock
purchase plans under applicable U.S. state corporate laws, U.S. federal and applicable state securities laws, the Code, any stock exchange rules or regulations and the applicable laws of any other
country or jurisdiction where Options or Stock Purchase Rights are granted under the Plan, as such laws, rules, regulations and requirements shall be in place from time to time. 



    (d) "Board" means the Board of Directors of the Company. 


    (e) "Code" means the Internal Revenue Code of 1986, as amended. 


    (f)  "Committee" means the Committee appointed by the Board of Directors in accordance with Section 4(a) and
(b) of the Plan. 


    (g) "Common Stock" means the Common Stock of the Company. 


    (h) "Company" means Seattle Genetics, Inc., a Delaware corporation. 



    (i)  "Consultant" means any person, including an advisor, who is engaged by the Company or any Parent or Subsidiary to
render services and is compensated for such services, and any director of the Company whether compensated for such services or not. 


    (j)  "Continuous Status as an Employee or Consultant" means the absence of any interruption or termination of service as
an Employee or Consultant. Continuous Status as an Employee or Consultant shall not be considered interrupted in the case of: (i) sick leave; (ii) military leave; (iii) any other
leave of absence approved by the Administrator, provided that such leave is for a period of not more than ninety (90) days, unless re-employment upon the expiration of such leave is
guaranteed by contract or statute, or unless provided otherwise pursuant to Company policy adopted from time to time; or (iv) in the case of transfers between locations of the Company or
between the Company, its Subsidiaries or their respective successors. For purposes of this Plan, a change in status from an Employee to a Consultant or from a Consultant to an Employee will not
constitute an interruption of Continuous Status as an Employee or Consultant. 


    (k) "Director" means a member of the Board of Directors of the Company. 


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    (l)  "Employee" means any person (including, if appropriate, Officers, Directors and Named Executives) employed by the
Company or any Parent or Subsidiary of the Company, with the status of employment determined based upon such minimum number of hours or periods worked as shall be determined by the Administrator in
its discretion, subject to any requirements of the Code. The payment of a director's fee by the Company to a Director shall not be sufficient to constitute "employment" of such Director by the
Company. 


    (m) "Exchange Act" means the Securities Exchange Act of 1934, as amended. 


    (n) "Fair Market Value" means, as of any date, the fair market value of Common Stock determined as follows: 



     (i) If
the Common Stock is listed on any established stock exchange or a national market system including without limitation the National Market of the National
Association of Securities Dealers, Inc. Automated Quotation System ("Nasdaq"), its Fair Market Value shall be the closing sales price for such stock (or the closing bid, if no sales were
reported), as quoted on such system or exchange, or the exchange with the greatest volume of trading in Common Stock for the last market trading day prior to the time of determination, as reported in
The Wall Street Journal or such other source as the Administrator deems reliable; 


    (ii) If
the Common Stock is quoted on the Nasdaq (but not on the National Market thereof) or regularly quoted by a recognized securities dealer but selling prices are
not reported, its Fair Market Value shall be the mean between the high bid and low asked prices for the Common Stock for the last market trading day prior to the time of determination, as reported in
The Wall Street Journal or such other source as the Administrator deems reliable; or 


    (iii) In
the absence of an established market for the Common Stock, the Fair Market Value thereof shall be determined in good faith by the Administrator. 




    (o) "Incentive Stock Option" means an Option intended to qualify as an incentive stock option within the meaning of
Section 422 of the Code, as designated in the applicable written Option Agreement. 


    (p) "Listed Security" means any security of the Company that is listed or approved for listing on a national securities
exchange or designated or approved for designation as a national market system security on an interdealer quotation system by the National Association of Securities Dealers, Inc. 


    (q) "Named Executive" means any individual who, on the last day of the Company's fiscal year, is the chief executive
officer of the Company (or is acting in such capacity) or among the four most highly compensated officers of the Company (other than the chief executive
officer). Such officer status shall be determined pursuant to the executive compensation disclosure rules under the Exchange Act. 



    (r) "Nonstatutory Stock Option" means an Option not intended to qualify as an Incentive Stock Option, as designated in
the applicable written Option Agreement. 


    (s) "Option" means a stock option granted pursuant to the Plan. 


    (t)  "Option Agreement" means a written agreement between an Optionee and the Company reflecting the terms of an Option
granted under the Plan and includes any documents attached to such Option Agreement, including, but not limited to, a notice of stock option grant and a form of exercise notice. 



    (u) "Optioned Stock" means the Common Stock subject to an Option. 


    (v) "Optionee" means an Employee or Consultant who receives an Option. 


    (w) "Parent" means a "parent corporation," whether now or hereafter existing, as defined in Section 424(e) of the
Code, or any successor provision. 


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    (x) "Plan" means this 1998 Stock Option Plan. 


    (y) "Reporting Person" means an officer, director, or greater than ten percent (10%) stockholder of the Company within
the meaning of Rule 16a-2 under the Exchange Act, who is required to file reports pursuant to Rule 16a-3 under the Exchange Act. 


    (z) "Rule 16b-3" means Rule 16b-3 promulgated under the Exchange Act, as the same
may be amended from time to time, or any successor provision. 


    (aa) "Share" means a share of the Common Stock, as adjusted in accordance with Section 12 of the Plan. 


    (bb) "Stock Exchange" means any stock exchange or consolidated stock price reporting system on which prices for the
Common Stock are quoted at any given time. 


    (cc) "Subsidiary" means a "subsidiary corporation," whether now or hereafter existing, as defined in
Section 424(f) of the Code, or any successor provision. 


    (dd) "Ten Percent Holder" means a person who owns stock representing more than ten percent (10%) of the voting power of
all classes of stock of the Company or any Parent or Subsidiary. 


3.  Stock Subject to the Plan.  


    Subject to the provisions of Section 12 of the Plan, the maximum aggregate number of shares that may be optioned and sold under the Plan is 4,400,000
shares of Common Stock, plus an automatic annual increase on the first day of each of the Company's fiscal years beginning in 2002 and ending in 2008 equal to the lesser of (i) 1,200,000
Shares, (ii) four percent (4.0%) of the Shares outstanding on the last
day of the immediately preceding fiscal year, or (iii) such lesser number of shares as is determined by the Board of Directors. The shares may be authorized, but unissued, or reacquired Common
Stock. If an Option should expire or become unexercisable for any reason without having been exercised in full, the unpurchased Shares that were subject thereto shall, unless the Plan shall have been
terminated, become available for future grant under the Plan. In addition, any shares of Common Stock which are retained by the Company upon exercise of an Option in order to satisfy the exercise
price for such Option or any withholding taxes due with respect to such exercise shall be treated as not issued and shall continue to be available under the Plan. 


4.  Administration of the Plan  


    (a) General. The Plan shall be administered by the Board or a Committee, or a combination thereof, as determined by the
Board. The Plan may be administered by different administrative bodies with respect to different classes of Optionees and, if permitted by the Applicable Laws, the Board may authorize one or more
officers (who may (but need not) be Officers) to grant Options to Employees and Consultants. 


    (b) Administration With Respect to Reporting Persons. With respect to Options granted to Reporting Persons and Named
Executives, the Plan may (but need not) be administered so as to permit such Options to qualify for the exemption set forth in Rule 16b-3 and to qualify as performance-based
compensation under Section 162(m) of the Code. 


    (c) Committee Composition. If a Committee has been appointed pursuant to this Section 4, such Committee shall
continue to serve in its designated capacity until otherwise directed by the Board. From time to time the Board may increase the size of any Committee and appoint additional members thereof, remove
members (with or without cause) and appoint new members in substitution therefor, fill vacancies (however caused) and remove all members of a Committee and thereafter directly administer the Plan, all
to the extent permitted by the Applicable Laws and, in the case of a 


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Committee administering the Plan pursuant to Section 4(b) above, to the extent permitted or required by Rule 16b-3 and Section 162(m) of the Code. 


    (d) Powers of the Administrator. Subject to the provisions of the Plan and in the case of a Committee, the specific
duties delegated by the Board to such Committee, and subject to the approval of any relevant authorities, including the approval, if required, of any Stock Exchange, the Administrator shall have the
authority, in its discretion: 



     (i) to
determine the Fair Market Value of the Common Stock, in accordance with Section 2(n) of the Plan; 


    (ii) to
select the Consultants and Employees to whom Options may from time to time be granted hereunder; 


    (iii) to
determine whether and to what extent Options are granted hereunder; 



    (iv) to
determine the number of shares of Common Stock to be covered by each such Option granted hereunder; 


    (v) to
approve forms of agreement for use under the Plan; 


    (vi) to
determine the terms and conditions, not inconsistent with the terms of the Plan, of any Option granted hereunder; 


   (vii) to
determine whether and under what circumstances an Option may be settled in cash under Section 10(f) instead of Common Stock; 


   (viii) to
reduce the exercise price of any Option to the then current Fair Market Value if the Fair Market Value of the Common Stock covered by such Option shall have
declined since the date the Option was granted; 


    (ix) to
construe and interpret the terms of the Plan and Options granted under the Plan; 


    (x) in
order to fulfill the purposes of the Plan and without amending the Plan, to modify grants of Options to participants who are foreign nationals or employed
outside of the United States in order to recognize differences in local law, tax policies or customs. 




    (e) Effect of Administrator's Decision. All decisions, determinations and interpretations of the Administrator shall be
final and binding on all Optionees. 


5.  Eligibility  


    (a) Recipients of Grants. Nonstatutory Stock Options may be granted to Employees and Consultants. Incentive Stock
Options may be granted only to Employees, provided however that Employees of an Affiliate shall not be eligible to receive Incentive Stock Options. An Employee or Consultant who has been granted an
Option may, if he or she is otherwise eligible, be granted additional Options. 


    (b) Type of Option. Each Option shall be designated in the Option Agreement as either an Incentive Stock Option or a
Nonstatutory Stock Option. However, notwithstanding such designations, to the extent that the aggregate Fair Market Value of the Shares with respect to which Options designated as Incentive Stock
Options are exercisable for the first time by any Optionee during any calendar year (under all plans of the Company or any Parent or Subsidiary) exceeds $100,000, such excess Options shall be treated
as Nonstatutory Stock Options. For purposes of this Section 5(b), Incentive Stock Options shall be taken into account in the order in which they were granted, and the Fair Market Value of the
Shares subject to an Incentive Stock Option shall be determined as of the date of the grant of such Option. 


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    (c) Employment Relationship. The Plan shall not confer upon any Optionee any right with respect to continuation of
employment or consulting relationship with the Company, nor shall it interfere in any
way with such Optionee's right or the Company's right to terminate his or her employment or consulting relationship at any time, with or without cause. 


6.  Term of Plan.  


    The Plan shall become effective upon the earlier to occur of its adoption by the Board of Directors or its approval by the stockholders of the Company as
described in Section 19 of the Plan. It shall continue in effect for a term of ten (10) years unless sooner terminated under Section 15 of the Plan. 


7.  Term of Option.  


    The term of each Option shall be the term stated in the Option Agreement; provided, however, that the term shall be no more than ten (10) years from the
date of grant thereof or such shorter term as may be provided in the Option Agreement. However, in the case of an Incentive Stock Option granted to an Optionee who, at the time the Option is granted,
is a Ten Percent Holder, the term of the Option shall be five (5) years from the date of grant thereof or such shorter term as may be provided in the Option Agreement. 


8.  Limitation on Grants to Employees.  


    Subject to adjustment as provided in Section 12 below, the maximum number of Shares which may be subject to Options granted to any one Employee under
this Plan for any fiscal year of the Company shall be 1,000,000 Shares. 



9.  Option Exercise Price and Consideration  


    (a) The
per share exercise price for the Shares to be issued pursuant to exercise of an Option shall be such price as is determined by the Board and set forth in the
applicable Option Agreement, but shall be subject to the following: 



     (i) In
the case of an Incentive Stock Option that is: 



    (A) granted
to an Employee who, at the time of the grant of such Incentive Stock Option, is a Ten Percent Holder, the per Share exercise price shall be no less than one
hundred ten percent (110%) of the Fair Market Value per Share on the date of grant. 


    (B) granted
to any other Employee, the per Share exercise price shall be no less than one hundred percent (100%) of the Fair Market Value per Share on the date of
grant. 




    (ii) In
the case of a Nonstatutory Stock Option that is: 



    (A) granted
prior to the date, if any, on which the Common Stock becomes a Listed Security, to a person who, at the time of the grant of such Option, is a Ten Percent
Holder, the per Share exercise price shall be no less than one hundred ten percent (110%) of the Fair Market Value per Share on the date of the grant; 



    (B) granted
to a person who, at the time of grant of such Option, is a Named Executive Officer of the Company, the per Share exercise price shall be no less than 100%
of the Fair Market Value per Share on the date of grant if such Option is intended to qualify as performance-based compensation under section 162(m) of the Code; or 


    (C) granted
prior to the date, if any, on which the Common Stock becomes a Listed Security to any person other than a Named Executive or a Ten Percent Holder, the per
Share 




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exercise price shall be no less than 85% of the Fair Market Value per Share on the date of grant if required by the Applicable Laws and, if not so required, shall be such price as is determined by the
Administrator. 




    (iii) Notwithstanding
the foregoing, Options may be granted with a per Share exercise price other than as required above pursuant to a merger or other corporate
transaction. 




    (b) The
consideration to be paid for the Shares to be issued upon exercise of an Option, including the method of payment, shall be determined by the Administrator (and,
in the case of an Incentive Stock Option, shall be determined at the time of grant) and may consist entirely of (i) cash, (ii) check, (iii) if permitted by Company policy and
subject to Section 153 of the Delaware General Corporation Law, a promissory note in the form prescribed by the Company, (iv) other Shares that (x) in the case of Shares acquired
upon exercise of an Option, have been owned by the Optionee for more than six months on the date of surrender or such other period as may be required to avoid a charge to the Company's earnings, and
(y) have a Fair Market Value on the date of surrender equal to the aggregate exercise price of the Shares as to which such Option shall be exercised, (v) authorization for the Company to
retain from the total number of Shares as to which the Option is exercised that number of Shares having a Fair Market Value on the date of exercise equal to the exercise price for the total number of
Shares as to which the Option is exercised, (vi) delivery of a properly executed exercise notice together with such other documentation as the Administrator and the broker, if applicable, shall
require to effect an exercise of the Option and delivery to the Company of the sale or loan proceeds required to pay the exercise price and any applicable income or employment taxes,
(vii) delivery of an irrevocable subscription agreement for the Shares that irrevocably obligates the option holder to take and pay for the Shares not more than twelve months after the date of
delivery of the subscription agreement, (8) any combination of the foregoing methods of payment, or (9) such other consideration and method of payment for the issuance of Shares to the
extent permitted under Applicable Laws. In making its determination as to the type of consideration to accept, the Administrator shall consider if acceptance of such consideration may be reasonably
expected to benefit the Company. 


10.  Exercise of Option  


    (a) Procedure for Exercise; Rights as a Stockholder. Any Option granted hereunder shall be exercisable at such times and
under such conditions as determined by the Administrator, including performance criteria with respect to the Company and/or the Optionee, and as shall be permissible under the terms of the Plan. 


    An
Option may not be exercised for a fraction of a Share. 


    An
Option shall be deemed to be exercised when written notice of such exercise has been given to the Company in accordance with the terms of the Option by the person entitled to
exercise the Option and the Company has received full payment for the Shares with respect to which the Option is exercised. Full payment may, as authorized by the Board, consist of any consideration
and method of payment allowable under Section 9(b) of the Plan. Until the issuance (as evidenced by the appropriate entry on the books of the Company or of a duly authorized transfer agent of
the Company) of the stock certificate evidencing such Shares, no right to vote or receive dividends or any other rights as a stockholder shall exist with respect to the Optioned Stock, not
withstanding the exercise of the Option. The Company shall issue (or cause to be issued) such stock certificate promptly upon exercise of the Option. No adjustment will be made for a dividend or other
right for which the record date is prior to the date the stock certificate is issued, except as provided in Section 12 of the Plan. 



    Exercise
of an Option in any manner shall result in a decrease in the number of Shares that thereafter may be available, both for purposes of the Plan and for sale under the Option,
by the number of Shares as to which the Option is exercised. 


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    (b) Termination of Employment or Consulting Relationship. In the event of termination of an Optionee's Continuous Status
as an Employee or Consultant with the Company, such Optionee may, but only within three (3) months (or such other period of time not less than thirty (30) days as is determined by the
Administrator, with such determination in the case of an Incentive Stock Option being made at the time of grant of the Option and not exceeding three (3) months) after the date of such
termination (but in no event later than the expiration date of the term of such Option as set forth in the Option Agreement), exercise his or her Option to the extent that the Optionee was entitled to
exercise it at the date of such termination. To the extent that Optionee was not entitled to exercise the Option at the date of such termination, or if Optionee does not exercise such Option to the
extent so entitled within the time specified herein, the Option shall terminate. No termination shall be deemed to occur and this Section 10(b) shall not apply if (i) the Optionee is a
Consultant who becomes an Employee; or (ii) the Optionee is an Employee who becomes a Consultant. 


    (c) Disability of Optionee. Notwithstanding the provisions of Section 10(b) above, in the event of termination of
an Optionee's Continuous Status as an Employee or Consultant as a result of his or her total and permanent disability (within the meaning of Section 22(e)(3) of the Code), Optionee may, but
only within twelve (12) months from the date of such termination (but in no event later than the expiration date of the term of such Option as set forth in the Option Agreement), exercise the
Option to the extent otherwise entitled to exercise it at the date of such termination. To the extent that Optionee was not entitled to exercise the Option at the date of termination, or if Optionee
does not exercise such Option to the extent so entitled within the time specified herein, the Option shall terminate. 


    (d) Death of Optionee. In the event of the death of an Optionee during the period of Continuous Status as an Employee or
Consultant, or within thirty (30) days following the termination of the Optionee's Continuous Status as an Employee or Consultant, the Option may be exercised, at any time within six
(6) months following the date of death (but in no event later than the expiration date of the term of such Option as set forth in the Option Agreement), by the Optionee's estate or by a person
who acquired the right to exercise the Option by bequest or inheritance, but only to the extent the Optionee was entitled to exercise the Option at the date of death or, if earlier, the date of
termination of the Continuous Status as an Employee or Consultant. To the extent that Optionee was not entitled to exercise the Option at the date of death or termination, as the case may be, or if
Optionee does not exercise such Option to the extent so entitled within the time specified herein, the Option shall terminate. 


    (e) Extension of Exercise Period. The Administrator shall have full power and authority to extend the period of time for
which an Option is to remain exercisable following termination of an Optionee's Continuous Status as an Employee or Consultant from the periods set forth in Sections 10(b), 10(c) and 10(d) above or in
the Option Agreement to such greater time as the Board shall deem appropriate, provided that in no event shall such Option be exercisable later than the date of expiration of the term of such Option
as set forth in the Option Agreement. 


    (f)  Rule 16b-3. Options granted to Reporting Persons shall comply with Rule 16b-3
and shall contain such additional conditions or restrictions as may be required thereunder to qualify for the maximum exemption for Plan transactions. 


    (g) Buyout Provisions. The Administrator may at any time offer to buy out for a payment in cash or Shares, an Option
previously granted, based on such terms and conditions as the Administrator shall establish and communicate to the Optionee at the time that such offer is made. 


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11.  Taxes.  


    (a) As
a condition of the exercise of an Option granted under the Plan, the Participant (or in the case of the Participant's death, the person exercising the Option)
shall make such arrangements as the Administrator may require for the satisfaction of any applicable federal, state, local or foreign withholding tax obligations that may arise in connection with the
exercise of the Option and the issuance of Shares. The Company shall not be required to issue any Shares under the Plan until such obligations are satisfied. If the Administrator allows the
withholding or surrender of Shares to satisfy a Participant's tax withholding obligations under this Section 11 (whether pursuant to Section 11(c), (d) or (e), or otherwise), the
Administrator shall not allow Shares to be withheld in an amount that exceeds the minimum statutory withholding rates for federal and state tax purposes, including payroll taxes. 


    (b) In
the case of an Employee and in the absence of any other arrangement, the Employee shall be deemed to have directed the Company to withhold or collect from his or
her compensation an amount sufficient to satisfy such tax obligations from the next payroll payment otherwise payable after the date of an exercise of the Option. 


    (c) This
Section 11(c) shall apply only after the date, if any, upon which the Common Stock becomes a Listed Security. In the case of a Participant other than an
Employee (or in the case of an Employee where the next payroll payment is not sufficient to satisfy such tax obligations, with respect to any remaining tax obligations), in the absence of any other
arrangement and to the extent permitted under the Applicable Laws, the Participant shall be deemed to have elected to have the Company withhold from the Shares to be issued upon exercise of the Option
or Stock Purchase Right that number of Shares having a Fair Market Value determined as of the applicable Tax Date (as defined below) equal to the amount required to be withheld. For purposes of this
Section 11, the Fair Market Value of the Shares to be withheld shall be determined on the date that the amount of tax to be withheld is to be determined under the Applicable Laws (the
"Tax Date"). 


    (d) If
permitted by the Administrator, in its discretion, a Participant may satisfy his or her tax withholding obligations upon exercise of an Option by surrendering to
the Company Shares that have a Fair Market Value determined as of the applicable Tax Date equal to the amount required to be withheld. In the case of shares previously acquired from the Company that
are surrendered under this Section 11(d), such Shares must have been owned by the Participant for more than six (6) months on the date of surrender (or such other period of time as is
required for the Company to avoid adverse accounting charges). 


    (e) Any
election or deemed election by a Participant to have Shares withheld to satisfy tax withholding obligations under Section 11(c) or (d) above shall
be irrevocable as to the particular Shares as to which the election is made and shall be subject to the consent or disapproval of the Administrator. Any election by a Participant under
Section 11(d) above must be made on or prior to the applicable Tax Date. 


    (f)  In
the event an election to have Shares withheld is made by a Participant and the Tax Date is deferred under Section 83 of the Code because no election is
filed under Section 83(b) of the Code, the Participant shall receive the full number of Shares with respect to which the Option or Stock Purchase Right is exercised but such Participant shall
be unconditionally obligated to tender back to the Company the proper number of Shares on the Tax Date. 


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12.  Adjustments Upon Changes in Capitalization; Corporate Transactions  


    (a) Changes in Capitalization. Subject to any required action by the stockholders of the Company, the number of shares
of Common Stock covered by each outstanding Option, the number of shares of Common Stock that have been authorized for issuance under the Plan but as to which no Options have yet been granted or that
have been returned to the Plan upon cancellation or expiration of an Option, and the numbers of shares set forth in Sections 3(a)(i) and 8 above, as well as the price per share of Common Stock
covered by each such outstanding Option, shall be proportionately adjusted for any increase or decrease in the number of issued shares of Common Stock resulting from a stock split, reverse stock
split, stock dividend, combination, recapitalization or reclassification of the Common Stock, or any other increase or decrease in the number of issued shares of Common Stock effected without receipt
of consideration by the Company; provided, however, that conversion of any convertible securities of the Company shall not be deemed to have been "effected without receipt of consideration." Such
adjustment shall be made by the Board, whose determination in that respect shall be final, binding and conclusive. Except as expressly provided herein, no issuance by the Company of shares of stock of
any class, or securities convertible into shares of stock of any class, shall affect, and no adjustment by reason thereof shall be made with respect to, the number or price of shares of Common Stock
subject to an Option. 


    (b) Dissolution or Liquidation. In the event of the proposed dissolution or liquidation of the Company, the Option will
terminate immediately prior to the consummation of such proposed action, unless otherwise provided by the Administrator. The Administrator may, in the exercise of its sole discretion in such
instances, declare that any Option shall terminate as of a date fixed by the Administrator and give each Optionee the right to exercise his or her Option as to all of the Optioned Stock, including
Shares as to which the Option would not otherwise be exercisable. 


    (c) Merger or Sale of Assets. In the event of a proposed sale of all or substantially all of the Company's assets or a
merger of the Company with or into another corporation where the successor corporation issues its securities to the Company's stockholders, each outstanding Option shall be assumed or an equivalent
option or right shall be substituted by such successor corporation or a parent or subsidiary of such successor corporation, unless the successor corporation does not agree to assume the Option or to
substitute an equivalent option, in which case such Option shall terminate upon the consummation of the merger or sale of assets. For purposes of this Section 12(c), an Option shall be
considered assumed, without limitation, if, at the time of issuance of the stock or other consideration upon such
merger or sale of assets, each Optionee would be entitled to receive upon exercise of an Option the same number and kind of shares of stock or the same amount of property, cash or securities as the
Optionee would have been entitled to receive upon the occurrence of such transaction if the Optionee had been, immediately prior to such transaction, the holder of the number of Shares of Common Stock
covered by the Option at such time (after giving effect to any adjustments in the number of Shares covered by the Option as provided for in this Section 12). 



13.  Non-Transferability of Options.  


    Options may not be sold, pledged, assigned, hypothecated, transferred, or disposed of in any manner other than by will or by the laws of descent or
distribution, provided that, after the date, if any, upon which the Common Stock becomes a Listed Security, the Administrator may in its discretion grant transferable Nonstatutory Stock Options
pursuant to Option Agreements specifying (i) the manner in which such Nonstatutory Stock Options are transferable and (ii) that any such transfer shall be subject to the Applicable Laws.
The designation of a beneficiary by an Optionee will not constitute a transfer. An Option may be exercised, during the lifetime of the holder of the Option, only by such holder or a transferee
permitted by this Section 13. 


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14.  Time of Granting Options.  


    The date of grant of an Option shall, for all purposes, be the date on which the Administrator makes the determination granting such Option, or such other date
as is determined by the Board. Notice of the determination shall be given to each Employee or Consultant to whom an Option is so granted within a reasonable time after the date of such grant. 


15.  Amendment and Termination of the Plan  


    (a) Amendment and Termination. The Board may at any time amend, alter, suspend or discontinue the Plan, but no
amendment, alteration, suspension or discontinuation shall be made that would impair the
rights of any Optionee under any grant theretofore made, without his or her consent. In addition, to the extent necessary and desirable to comply with the Applicable Laws, the Company shall obtain
stockholder approval of any Plan amendment in such a manner and to such a degree as required. 


    (b) Effect of Amendment or Termination. No amendment or termination of the Plan shall adversely affect Options already
granted, unless mutually agreed otherwise between the Optionee and the Board, which agreement must be in writing and signed by the Optionee and the Company. 



16.  Conditions Upon Issuance of Shares.  


    Shares shall not be issued pursuant to the exercise of an Option unless the exercise of such Option and the issuance and delivery of such Shares pursuant
thereto shall comply with all relevant provisions of law, including, without limitation, the Securities Act of 1933, as amended, the Exchange Act, the rules and regulations promulgated thereunder, and
the requirements of any Stock Exchange. As a condition to the exercise of an Option, the Company may require the person exercising such Option to represent and warrant at the time of any such exercise
that the Shares are being purchased only for investment and without any present intention to sell or distribute such Shares if, in the opinion of counsel for the Company, such a representation is
required by law. 


17.  Reservation of Shares.  


    The Company, during the term of this Plan, will at all times reserve and keep available such number of Shares as shall be sufficient to satisfy the
requirements of the Plan. The inability of the Company to obtain authority from any regulatory body having jurisdiction, which authority is deemed by the Company's counsel to be necessary to the
lawful issuance and sale of any Shares hereunder, shall relieve the Company of any liability in respect of the failure to issue or sell such Shares as to which such requisite authority shall not have
been obtained. 


18.  Agreements.  


    Options shall be evidenced by Option Agreements in such form as the Administrator shall approve from time to time. 


19.  Stockholder Approval.  


    Continuance of the Plan shall be subject to approval by the stockholders of the Company within twelve (12) months before or after the date the Plan, or
an amendment to the Plan, is adopted. Such stockholder approval shall be obtained in the degree and manner required under the Applicable Laws. All Options issued under the Plan shall become void in
the event such approval is not obtained. 


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20.  Information to Optionees. 


    the
extent required by the Applicable Laws, the Company shall provide financial statements at least annually to each Optionee during the period such Optionee has one or more Options
outstanding. The Company shall not be required to provide such information if the issuance of Options under the Plan is limited to key employees whose duties in connection with the Company assure
their access to equivalent information. 


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SEATTLE GENETICS, INC. 1998 STOCK OPTION PLAN