Document:

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                                                                   EXHIBIT 10.16

                         NORTHWEST BIOTHERAPEUTICS, INC.

                        1999 EXECUTIVE STOCK OPTION PLAN

        1. PURPOSES OF THE PLAN. The purposes of this 1999 Executive 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 shall be Nonstatutory
Stock Options and subject to the applicable provisions 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) "BOARD" means the Board of Directors of the Company.

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

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

                (e) "COMMON STOCK" means the Common Stock of the Company.

                (f) "COMPANY" means Northwest Biotherapeutics, Inc., a Delaware
corporation.

                (g) "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.

                (h) "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 90 days, unless reemployment 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.

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                (i) "EMPLOYEE" means any person, including officers and
directors, 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 to a
director shall not be sufficient to constitute "employment" of such director by
the Company.

                (j) "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

                (k) "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 ("Nasdaq") System, 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 System
(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.

                (l) "NONSTATUTORY STOCK OPTION" means an Option not intended to
qualify as an incentive stock option, as defined in Section 422 of the Code.

                (m) "OPTION" means a stock option granted pursuant to the Plan.

                (n) "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.

                (o) "OPTIONED STOCK" means the Common Stock subject to an
Option.

                (p) "OPTIONEE" means an Employee or Consultant who receives an
Option.

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

                (r) "PLAN" means this 1999 Executive Stock Option Plan.

                (s) "REPORTING PERSON" means an officer, director, or greater
than 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.

                (t) "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.

                (u) "SHARE" means a share of the Common Stock, as adjusted in
accordance with Section 11 of the Plan.

                (v) "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.

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

        3. STOCK SUBJECT TO THE PLAN. Subject to the provisions of Section 11 of
the Plan, the maximum aggregate number of shares that may be optioned and sold
under the Plan is 586,166 shares of Common Stock. 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 or purchase 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. Shares repurchased by
the Company pursuant to any repurchase right which the Company may have shall
not be available for future grant under the Plan.

        4. ADMINISTRATION OF THE PLAN.

                (a) INITIAL PLAN PROCEDURE. Prior to the date, if any, upon
which the Company becomes subject to the Exchange Act, the Plan shall be
administered by the Board or a Committee appointed by the Board.

                (b) PLAN PROCEDURE AFTER THE DATE, IF ANY, UPON WHICH THE
COMPANY BECOMES SUBJECT TO THE EXCHANGE ACT.

                        (i) MULTIPLE ADMINISTRATIVE BODIES. If permitted by Rule
16b-3, grants under the Plan may be made by different bodies with respect to
directors, non-director officers and Employees or Consultants who are not
Reporting Persons.

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                        (ii) ADMINISTRATION WITH RESPECT TO REPORTING PERSONS.
With respect to grants of Options to Employees who are Reporting Persons, such
grants shall be made by (A) the Board if the Board may make grants to Reporting
Persons under the Plan in compliance with Rule 16b-3, or (B) a Committee
designated by the Board to make grants to Reporting Persons under the Plan,
which Committee shall be constituted in such a manner as to permit grants under
the Plan to comply with Rule 16b-3. Once appointed, 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 the 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 the Committee and thereafter directly make grants to
Reporting Persons under the Plan, all to the extent permitted by Rule 16b-3.

                        (iii) ADMINISTRATION WITH RESPECT TO CONSULTANTS AND
OTHER EMPLOYEES. With respect to grants of Options to Employees or Consultants
who are not Reporting Persons, the Plan shall be administered by (A) the Board
or (B) a Committee designated by the Board, which Committee shall be constituted
in such a manner as to satisfy the legal requirements relating to the
administration of Nonstatutory Stock Option plans, if any, of applicable
corporate and securities laws, of the Code and of any applicable Stock Exchange
(the "Applicable Laws"). Once appointed, 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 the 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 the Committee and thereafter directly administer the Plan, all to the extent
permitted by the Applicable Laws.

                (c) 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(k) 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;

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                        (vii) to determine whether and under what circumstances
an Option may be settled in cash under Section 9(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; and

                        (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.

                (d) EFFECT OF ADMINISTRATOR'S DECISION. All decisions,
determinations and interpretations of the Administrator shall be final and
binding on all holders of Options.

        5. ELIGIBILITY.

                (a) RECIPIENTS OF GRANTS. Nonstatutory Stock Options may be
granted to Employees and Consultants. 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 a Nonstatutory Stock Option.

                (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 18 of the Plan. It shall
continue in effect for a term of ten years unless sooner terminated under
Section 14 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
years from the date of grant thereof or such shorter term as may be provided in
the Option Agreement.

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        8. 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, however, in the case of
a Nonstatutory Stock Option that is:

                        (i) granted to a person who, at the time of the grant of
such Option, owns stock representing more than 10% of the total combined voting
power of all classes of stock of the Company or any Parent or Subsidiary, the
per Share exercise price shall be no less than 110% of the Fair Market Value per
Share on the date of the grant.

                        (ii) granted to any person, the per Share exercise price
shall be no less than 85% of the Fair Market Value per Share on the date of
grant.

                (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 may consist entirely of (1) cash, (2) check, (3)
promissory note, if permitted by Company policy (subject to the provisions of
Section 153 of the Delaware General Corporation Law), (4) 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, (5)
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, (6) 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, (7) 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 the 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.

        9. 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 and reflected in the Option Agreement, which
may include vesting requirements and/or including performance criteria with
respect to the Company and/or the Optionee; provided, however, that such Option
shall become exercisable at the rate of at least 20% per year over five years
from the date the Option is granted. In the event that any of the Shares issued
upon exercise of an Option should be subject to a right of repurchase in the
Company's favor,

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such repurchase right shall lapse at the rate of at least 20% per year over five
years from the date the Option is granted. Notwithstanding the above, in the
case of an Option granted to an officer, director or Consultant of the Company
or any Parent or Subsidiary of the Company, the Option may become fully
exercisable, or a repurchase right, if any, in favor of the Company shall lapse,
at any time or during any period established by the Administrator.

        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 8(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 11 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.

                (b) TERMINATION OF EMPLOYMENT OR CONSULTING RELATIONSHIP.
Subject to Section 9(c) below, 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 months (or such other period of time not less than 30
days as is determined by the Administrator) 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 the Optionee was not entitled to exercise the Option at the
date of such termination, or if the 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 9(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.

                        (i) Notwithstanding Section 9(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), such Optionee may, but only within twelve 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

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extent that the Optionee was not entitled to exercise the Option at the date of
termination, or if the Optionee does not exercise such Option to the extent so
entitled within the time specified herein, the Option shall terminate.

                        (ii) In the event of termination of an Optionee's
Continuous Status as an Employee or Consultant as a result of a disability which
does not fall within the meaning of total and permanent disability (as set forth
in Section 22(e)(3) of the Code), such Optionee may, but only within six 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 the Optionee was not entitled to exercise the
Option at the date of termination, or if the Optionee does not exercise such
Option to the extent so entitled within six months from the date of termination,
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 since the
date of grant of the Option, or within 30 days following termination of the
Optionee's Continuous Status as an Employee or Consultant, the Option may be
exercised, at any time within six 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 such Optionee's estate or by a person who acquired the
right to exercise the Option by bequest or inheritance, but only to the extent
of the right to exercise that had accrued at the date of death or, if earlier,
the date of termination of the Optionee's Continuous Status as an Employee or
Consultant. To the extent that the Optionee was not entitled to exercise the
Option at the date of death or termination, as the case may be, or if the
Optionee does not exercise such Option to the extent so entitled within the time
specified herein, the Option shall terminate.

                (e) 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.

        10. STOCK WITHHOLDING TO SATISFY WITHHOLDING TAX OBLIGATIONS. At the
discretion of the Administrator, Optionees may satisfy withholding obligations
as provided in this paragraph. When an Optionee incurs tax liability in
connection with an Option, which tax liability is subject to tax withholding
under applicable tax laws, and the Optionee is obligated to pay the Company an
amount required to be withheld under applicable tax laws, the Optionee may
satisfy the withholding tax obligation by one or some combination of the
following methods: (a) by cash or check payment, (b) out of the Optionee's
current compensation, (c) if permitted by the Administrator, in its discretion,
by surrendering to the Company Shares that (i) in the case of Shares previously
acquired from the Company, have been owned by the Optionee for more than six
months on the date of surrender, and (ii) have a Fair Market Value on the date
of surrender equal to or less than the Optionee's marginal tax rate times the
ordinary income recognized, or (d) by electing to have the Company withhold from
the Shares to be issued upon exercise of the Option, if any, that number of
Shares having a Fair Market Value equal to the amount required to be withheld.
For this purpose, the fair market value of the Shares

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to be withheld shall be determined on the date that the amount of tax to be
withheld is to be determined (the "Tax Date").

        Any surrender by a Reporting Person of previously owned Shares to
satisfy tax withholding obligations arising upon exercise of this Option must
comply with the applicable provisions of Rule 16b-3.

        All elections by an Optionee to have Shares withheld to satisfy tax
withholding obligations shall be made in writing in a form acceptable to the
Administrator and shall be subject to the following restrictions:

                (a) the election must be made on or prior to the applicable Tax
Date;

                (b) once made, the election shall be irrevocable as to the
particular Shares of the Option as to which the election is made; and

                (c) all elections shall be subject to the consent or disapproval
of the Administrator.

        In the event the election to have Shares withheld is made by an Optionee
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 Optionee shall receive the full
number of Shares with respect to which the Option is exercised but such Optionee
shall be unconditionally obligated to tender back to the Company the proper
number of Shares on the Tax Date.

        11. ADJUSTMENTS UPON CHANGES IN CAPITALIZATION, MERGER OR CERTAIN OTHER
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, and 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, 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.

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                (b) DISSOLUTION OR LIQUIDATION. In the event of the proposed
dissolution or liquidation of the Company, the Board shall notify the Optionee
at least 15 days prior to such proposed action. To the extent it has not been
previously exercised, the Option will terminate immediately prior to the
consummation of such proposed action.

                (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
11(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 11).

                (d) CERTAIN DISTRIBUTIONS. In the event of any distribution to
the Company's stockholders of securities of any other entity or other assets
(other than dividends payable in cash or stock of the Company) without receipt
of consideration by the Company, the Administrator may, in its discretion,
appropriately adjust the price per share of Common Stock covered by each
outstanding Option to reflect the effect of such distribution.

        12. 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 and may be exercised or purchased
during the lifetime of the Optionee only by the Optionee.

        13. 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.

        14. AMENDMENT AND TERMINATION OF THE PLAN.

                (a) AUTHORITY TO AMEND OR TERMINATE. 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 Rule 16b-3 (or
any other applicable law or regulation, including the requirements of any

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Stock Exchange), 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.

        15. 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.

        16. 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.

        17. OPTION AGREEMENTS. Options shall be evidenced by Option Agreements
in such form(s) as the Administrator shall approve from time to time.

        18. INFORMATION AND DOCUMENTS TO OPTIONEES. The Company shall provide
financial statements at least annually to each Optionee during the period such
Optionee has one or more Options outstanding, and in the case of an individual
who acquired Shares pursuant to the Plan, during the period such individual owns
such Shares. 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. In
addition, at the time of issuance of any securities under the Plan, the Company
shall provide to the Optionee a copy of the Plan and any agreement(s) pursuant
to which securities granted under the Plan are issued.

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                                                                   EXHIBIT 10.17

                         NORTHWEST BIOTHERAPEUTICS, INC.
                             2001 STOCK OPTION PLAN

        ARTICLE 1. INTRODUCTION.

        The purpose of the Plan is to promote the long-term success of the
Company and the creation of stockholder value by encouraging the attraction and
retention of Employees and Consultants with exceptional qualifications and
linking Employees and Consultants directly to stockholder interests through
increased stock ownership.

        The Plan shall be governed by, and construed in accordance with, the
laws of the State of Washington.

        ARTICLE 2. ADMINISTRATION.

        2.1 COMMITTEE COMPOSITION. The Plan shall be administered by the
Committee. The Committee shall consist exclusively of two or more directors of
the Company, who shall be appointed by the Board. In addition, the composition
of the Committee shall satisfy:

               (a) Such requirements as the Securities and Exchange Commission
        may establish for administrators acting under plans intended to qualify
        for exemption under Rule 16b-3 (or its successor) under the Exchange
        Act; and

               (b) Such requirements as the Internal Revenue Service may
        establish for outside directors acting under plans intended to qualify
        for exemption under Section 162(m)(4)(C) of the Code.

        2.2 COMMITTEE RESPONSIBILITIES. The Committee shall (a) select the
Employees and Consultants who are to receive Options under the Plan, (b)
determine the type, number, vesting requirements and other features and
conditions of Options, (c) interpret the Plan and (d) make all other decisions
relating to the operation of the Plan. The Committee may adopt such rules or
guidelines as it deems appropriate to implement the Plan. The Committee's
determinations under the Plan shall be final and binding on all persons.

        ARTICLE 3. SHARES AVAILABLE FOR GRANTS.

        3.1 BASIC LIMITATION. Common Shares issued pursuant to the Plan shall be
authorized but unissued shares. The aggregate number of Common Shares issued
pursuant to Options awarded under the Plan shall not exceed (a) __________ plus
(b) the additional Common Shares described in Section 3.2. As of January 1 of
each year, commencing January 1, 2002, the aggregate number of Common Shares
provided in the preceding sentence shall automatically increase by a number
equal to the lesser of (a) 15 percent of the aggregate number of shares
available for granting hereunder for the immediately preceding year, or

<PAGE>   2

(b) _______________________________. The limitation of this Section 3.1 shall be
subject to adjustment pursuant to Article 7.

        3.2 ADDITIONAL SHARES. If Options are forfeited or terminate for any
other reason before being exercised, then the corresponding Common Shares shall
again become available for the grant of Options under the Plan.

        ARTICLE 4. ELIGIBILITY.

        4.1 NONSTATUTORY STOCK OPTIONS. Only Employees and Consultants shall be
eligible for the grant of NSOs.

        4.2 INCENTIVE STOCK OPTIONS. Only Employees who are common-law employees
of the Company, a Parent or a Subsidiary shall be eligible for the grant of
ISOs. In addition, an Employee who owns more than 10% of the total combined
voting power of all classes of outstanding stock of the Company or any of its
Parents or Subsidiaries shall not be eligible for the grant of an ISO unless the
requirements set forth in Section 422(c)(6) of the Code are satisfied.

        ARTICLE 5. OPTIONS.

        5.1 STOCK OPTION AGREEMENT. Each grant of an Option under the Plan shall
be evidenced by a Stock Option Agreement between the Optionee and the Company.
Such Option shall be subject to all applicable terms of the Plan and may be
subject to any other terms that are not inconsistent with the Plan. The
provisions of the various Stock Option Agreements entered into under the Plan
need not be identical.

        5.2 NUMBER OF SHARES. Each Stock Option Agreement shall specify the
number of Common Shares subject to the Option and shall provide for the
adjustment of such number in accordance with Article 7. Options granted to any
Optionee in a single fiscal year of the Company shall not cover more than
100,000 Common Shares, except that Options granted to a new Employee in the
fiscal year of the Company in which his or her service as an Employee first
commences shall not cover more than 200,000 Common Shares. The limitations set
forth in the preceding sentence shall be subject to adjustment in accordance
with Article 7.

        5.3 EXERCISE PRICE. Each Stock Option Agreement shall specify the
Exercise Price; provided that the Exercise Price under an ISO shall in no event
be less than 100% of the Fair Market Value of a Common Share on the date of
grant.

        5.4 EXERCISABILITY AND TERM. Each Stock Option Agreement shall specify
the date or event when all or any installment of the Option is to become
exercisable. The Stock Option Agreement shall also specify the term of the
Option; provided that the term of an ISO shall in no event exceed 10 years from
the date of grant. A Stock Option Agreement may provide for accelerated
exercisability in the event of the Optionee's death, disability or retirement or
other

                                       2
<PAGE>   3

events and may provide for expiration prior to the end of its term in the event
of the termination of the Optionee's service.

        5.5 EFFECT OF CHANGE IN CONTROL. The Committee may determine, at the
time of granting an Option or thereafter, that such Option shall become
exercisable as to all or part of the Common Shares subject to such Option in the
event that a Change in Control occurs with respect to the Company provided that
in the case of an ISO, the acceleration of exercisability shall not occur
without the Optionee's written consent.

        5.6 MODIFICATION OF OPTIONS. Within the limitations of the Plan, the
Committee may modify outstanding options. The foregoing notwithstanding, no
modification of an Option shall, without the consent of the Optionee, alter or
impair his or her rights or obligations under such Option.

        5.7 BUYOUT PROVISIONS. The Committee may at any time (a) offer to buy
out for a payment in cash or cash equivalents an Option previously granted or
(b) authorize an Optionee to elect to cash out an Option previously granted, in
either case at such time and based upon such terms and conditions as the
Committee shall establish.

        ARTICLE 6. PAYMENT FOR OPTION SHARES.

        6.1 GENERAL RULE. The entire Exercise Price of Common Shares issued upon
exercise of Options shall be payable in cash or cash equivalents at the time
when such Common Shares are purchased, except as follows:

               (a) In the case of an ISO granted under the Plan, payment shall
        be made only pursuant to the express provisions of the applicable Stock
        Option Agreement. The Stock Option Agreement may specify that payment
        may be made in any form(s) described in this Article 6.

               (b) In the case of an NSO, the Committee may at any time accept
        payment in any form(s) described in this Article 6.

        6.2 SURRENDER OF STOCK. To the extent that this Section 6.2 is
applicable, all or any part of the Exercise Price may be paid by surrendering,
or attesting to the ownership of, Common Shares that are already owned by the
Optionee. Such Common Shares shall be valued at their Fair Market Value on the
date when the new Common Shares are purchased under the Plan. The Optionee shall
not surrender, or attest to the ownership of, Common Shares in payment of the
Exercise Price if such action would cause the Company to recognize compensation
expense (or additional compensation expense) with respect to the Option for
financial reporting purposes.

        6.3 EXERCISE/SALE. To the extent that this Section 6.3 is applicable,
all or any part of the Exercise Price and any withholding taxes may be paid by
delivering (on a form prescribed by the Company) an irrevocable direction to a
securities broker approved by the Company to sell all

                                       3
<PAGE>   4

or part of the Common Shares being purchased under the Plan and to deliver all
or part of the sales proceeds to the Company.

        6.4 EXERCISE/PLEDGE. To the extent that this Section 6.4 is applicable,
all or any part of the Exercise Price and any withholding taxes may be paid by
delivering (on a form prescribed by the Company) an irrevocable direction to
pledge all or part of the Common Shares being purchased under the Plan to a
securities broker or lender approved by the Company, as security for a loan, and
to deliver all or part of the loan proceeds to the Company.

        6.5 OTHER FORMS OF PAYMENT. To the extent that this Section 6.5 is
applicable, all or any part of the Exercise Price and any withholding taxes may
be paid in any other form that is consistent with applicable laws, regulations
and rules.

        ARTICLE 7 PROTECTION AGAINST DILUTION.

        7.1 ADJUSTMENTS. In the event of a subdivision of the outstanding Common
Shares, a declaration of a dividend payable in Common Shares, a declaration of a
dividend payable in a form other than Common Shares in an amount that has a
material effect on the price of Common Shares, a combination or consolidation of
the outstanding Common Shares (by reclassification or otherwise) into a lesser
number of Common Shares, a recapitalization, a spin-off or a similar occurrence,
the Committee shall make such adjustments as it, in its sole discretion, deems
appropriate in one or more of:

                (a) The number of Options available for future grants under
        Article 3;

                (b) The limitations set forth in Section 5.2;

                (c) The number of Common Shares covered by each outstanding
        Option; or

                (d) The Exercise Price under each outstanding Option.

Except as provided in this Article 7, an Optionee shall have no rights by reason
of any issue by the Company of stock of any class or securities convertible into
stock of any class, any subdivision or consolidation of shares of stock of any
class, the payment of any stock dividend or any other increase or decrease in
the number of shares of stock of any class.

        7.2 DISSOLUTION OR LIQUIDATION. To the extent not previously exercised,
Options shall terminate immediately prior to the dissolution or liquidation of
the Company.

        7.3 REORGANIZATIONS. In the event that the Company is a party to a
merger or other reorganization, outstanding Options shall be subject to the
agreement of merger or reorganization. Such agreement shall provide for:

                                       4
<PAGE>   5

                (a) The continuation of the outstanding Options by the Company,
        if the Company is a surviving corporation;

                (b) The assumption of the outstanding Options by the surviving
        corporation or its parent or subsidiary;

                (c) The substitution by the surviving corporation or its parent
        or subsidiary of its own options for the outstanding Options;

                (d) Full exercisability or vesting and accelerated expiration of
        the outstanding Options; or

                (e) Settlement of the full value of the outstanding Options in
        cash or cash equivalents followed by cancellation of such Options.

        ARTICLE 8. LIMITATION ON RIGHTS.

        8.1 RETENTION RIGHTS. Neither the Plan nor any Option granted under the
Plan shall be deemed to give any individual a right to remain an Employee or
Consultant. The Company and its Parents, Subsidiaries and Affiliates reserve the
right to terminate the service of any Employee or Consultant at any time, with
or without cause, subject to applicable laws, the Company's Articles of
Incorporation and Bylaws and a written employment agreement (if any).

        8.2 STOCKHOLDERS' RIGHTS. A Participant shall have no dividend rights,
voting rights or other rights as a stockholder with respect to any Common Shares
covered by his or her Option prior to the time when he or she becomes entitled
to receive such Common Shares by filing a notice of exercise and paying the
Exercise Price. No adjustment shall be made for cash dividends or other rights
for which the record date is prior to such time, except as expressly provided in
the Plan.

        8.3 REGULATORY REQUIREMENTS. Any other provision of the Plan
notwithstanding, the obligation of the Company to issue Common Shares under the
Plan shall be subject to all applicable laws, rules and regulations and such
approval by any regulatory body as may be required. The Company reserves the
right to restrict, in whole or in part, the delivery of Common Shares pursuant
to any Option prior to the satisfaction of all legal requirements relating to
the issuance of such Common Shares, to their registration, qualification or
listing or to an exemption from registration, qualification or listing.

        ARTICLE 9. WITHHOLDING TAXES.

        9.1 GENERAL. To the extent required by applicable federal, state, local
or foreign law, an Optionee or his or her successor shall make arrangements
satisfactory to the Company for the satisfaction of any withholding tax
obligations that arise in connection with the Plan. The Company shall not be
required to issue any Common Shares or make any cash payment under the Plan
until such obligations are satisfied.

                                       5
<PAGE>   6

        9.2 SHARE WITHHOLDING. The Committee may permit an Optionee to satisfy
all or part of his or her withholding or income tax obligations by having the
Company withhold all or a portion of any Common Shares that otherwise would be
issued to him or her or by surrendering all or a portion of any Common Shares
that he or she previously acquired. Such Common Shares shall be valued at their
Fair Market Value on the date when taxes otherwise would be withheld in cash.

        ARTICLE 10. FUTURE OF THE PLAN.

        10.1 TERM OF THE PLAN. The Plan, as set forth herein, shall become
effective upon approval by the Company's stockholders. The Plan shall remain in
effect until it is terminated under Section 10.2, except that no ISOs shall be
granted on or after the 10th anniversary of the later of (a) the date when the
Board adopted the Plan or (b) the date when the Board adopted the most recent
increase in the number of Common Shares available under Article 3 which was
approved by the Company's stockholders.

        10.2 AMENDMENT OR TERMINATION. The Board may, at any time and for any
reason, amend or terminate the Plan. An amendment of the Plan shall be subject
to the approval of the Company's stockholders to the extent required by
applicable laws, regulations or rules. The termination of the Plan, or any
amendment thereof, shall not affect any Option previously granted under the
Plan.

        ARTICLE 11. DEFINITIONS.

        11.1 "AFFILIATE" means any entity other than a Subsidiary, if the
Company and/or one or more Subsidiaries own not less than 50% of such entity.

        11.2 "BOARD" means the Company's Board of Directors, as constituted from
time to time.

        11.3 "CHANGE IN CONTROL" shall mean:

               (a) The execution of an agreement by the Company or the
        stockholders of the Company providing for the merger or consolidation of
        the Company with or into another entity or any other corporate
        reorganization, if more than 50% of the combined voting power of the
        continuing or surviving entity's securities outstanding immediately
        after such merger, consolidation or other reorganization is owned by
        persons who were not stockholders of the Company immediately prior to
        such merger, consolidation or other reorganization;

               (b) The execution of an agreement by the Company or the
        stockholder of the Company providing for the sale, transfer or other
        disposition of all or substantially all of the Company's assets;

                                       6
<PAGE>   7

               (c) A change in the composition of the Board, as a result of
        which fewer than 50% of the incumbent directors are directors who either
        (i) had been directors of the Company on the date 24 months prior to the
        date of the event that may constitute a Change in Control (the "original
        directors") or (ii) were elected, or nominated for election, to the
        Board with the affirmative votes of at least a majority of the aggregate
        of the original directors who were still in office at the time of the
        election or nomination and the directors whose election or nomination
        was previously so approved; or

               (d) Any transaction as a result of which any person is the
        "beneficial owner" (as defined in Rule 13d-3 under the Exchange Act),
        directly or indirectly, of securities of the Company representing at
        least 40% of the total voting power represented by the Company's then
        outstanding voting securities. For purposes of this Subsection (d), the
        term "person" shall have the same meaning as when used in Sections 13(d)
        and 14(d) of the Exchange Act but shall exclude (i) a trustee or other
        fiduciary holding securities under an employee benefit plan of the
        Company or of a Parent or Subsidiary and (ii) a corporation owned
        directly or indirectly by the stockholders of the Company in
        substantially the same proportions as their ownership of the common
        stock of the Company.

A transaction shall not constitute a Change in Control if its sole purpose is to
change the state of the Company's incorporation or to create a holding company
that will be owned in substantially the same proportions by the persons who held
the Company's securities immediately before such transaction.

        11.4   "CODE" means the Internal Revenue Code of 1986, as amended.

        11.5 "COMMITTEE" means a committee of the Board, as described in Article
2.

        11.6 "COMMON SHARE" means one share of the common stock of the Company,
no par value per share.

        11.7 "COMPANY" means Northwest Biotherapeutics, Inc., a Delaware
corporation.

        11.8 "CONSULTANT" means a consultant or adviser who provides bona fide
services to the Company, a Parent, a Subsidiary or an Affiliate as an
independent contractor. Service as a Consultant shall be considered employment
for all purposes of the Plan, except as provided in Section 4.2.

        11.9 "EMPLOYEE" means a common-law employee of the Company, a Parent, a
Subsidiary or an Affiliate.

        11.10 "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

                                       7
<PAGE>   8

        11.11 "EXERCISE PRICE" means the amount for which one Common Share may
be purchased upon exercise of such Option, as specified in the applicable Stock
Option Agreement.

        11.12 "FAIR MARKET VALUE" means the market price of Common Shares,
determined by the Committee in good faith on such basis as it deems appropriate.
Whenever possible, the determination of Fair Market Value by the Committee shall
be based on the prices reported in the Wall Street Journal. Such determination
shall be conclusive and binding on all persons.

        11.13 "ISO" means an incentive stock option described in Section 422(b)
of the Code.

        11.14 "NSO" means a stock option not described in Sections 422 or 423 of
the Code.

        11.15 "OPTION" means an ISO or NSO granted under the Plan and entitling
the holder to purchase Common Shares.

        11.16  "OPTIONEE" means an individual or estate who holds an Option.

        11.17 "PARENT" means any corporation (other than the Company) in an
unbroken chain of corporations ending with the Company, if each of the
corporations other than the Company owns stock possessing 50% or more of the
total combined voting power of all classes of stock in one of the other
corporations in such chain. A corporation that attains the status of a Parent on
a date after the adoption of the Plan shall be considered a Parent commencing as
of such date.

        11.18 "PLAN" means this Northwest Biotherapeutics, Inc. 2001 Stock
Option Plan, as amended from time to time.

        11.19 "STOCK OPTION AGREEMENT" means the agreement between the Company
and an Optionee that contains the terms, conditions and restrictions pertaining
to his or her Option.

        11.20 "SUBSIDIARY" means any corporation (other than the Company) in an
unbroken chain of corporations beginning with the Company, if each of the
corporations other than the last corporation in the unbroken chain owns stock
possessing 50% or more of the total combined voting power of all classes of
stock in one of the other corporations in such chain. A corporation that attains
the status of a Subsidiary on a date after the adoption of the Plan shall be
considered a Subsidiary commencing as of such date.

                                       8

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