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Exhibit 10.83

                     1998 NON-INCENTIVE STOCK OPTION PLAN

                         VIMRX PHARMACEUTICALS INC./*/


                                      FOR

                      DIRECTORS, EMPLOYEES AND CONSULTANTS

                                       OF

                         NEXELL THERAPEUTICS INC./**/
                     (AS AMENDED THROUGH DECEMBER 31, 2000
                 AND AS ADJUSTED TO REFLECT THE JUNE 15, 2000
                     1 FOR 4 REVERSE STOCK SPLIT OF VIMRX)


1.  Purpose of Plan.
---------------------
The purpose of this Non-Incentive Stock Option Plan ("Plan") is to further the
growth and development of Nexell Therapeutics Inc. (collectively with its
subsidiaries, "Nexell"), a majority owned subsidiary of VIMRX Pharmaceuticals
Inc. ("VIMRX"), by encouraging selected employees, directors, consultants,
agents, independent contractors and other persons who contribute and are
expected to contribute materially to Nexell's success to obtain a proprietary
interest in Nexell through the ownership of Nexell's common stock, $.001 par
value ("Nexell Common Stock") by granting them options to purchase Nexell Common
Stock, thereby providing such persons with an added incentive to promote the
best interests of Nexell and affording Nexell a means of attracting to its
service persons of outstanding ability. The Plan provides that, under the
circumstances specified herein, the options granted under the Plan shall be
exercisable for VIMRX's common stock, $.001 par value ("VIMRX Common Stock") in
lieu of Nexell Common Stock.


2.  Stock Subject to the Plan.
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       (a) An aggregate of (i) 250,000 shares of Nexell Common Stock and (ii)
       750,000 shares of VIMRX Common Stock have been reserved for issuance upon
       the exercise of options which may be granted from time to time in
       accordance with the Plan ("Options" and the shares of Nexell Common Stock
       or VIMRX Common Stock, as the case may be, issuable upon exercise of an
       Option, the "Option Shares") subject, however, in each case, to
       adjustment or change pursuant to paragraph 12 hereof.

       (b) Shares issued upon exercise of Options, whether shares of Nexell
       Common Stock or VIMRX Common Stock, may, in whole or in part as the
       Committee shall from time to time determine, be authorized but unissued
       shares or issued shares which have been reacquired by Nexell or VIMRX, as
       the case may be. If, for any reason, an Option shall lapse, expire or
       terminate without having been exercised in full, the unpurchased shares
       covered thereby shall again be available for purposes of the Plan. Unless
       the context otherwise requires, the term "Common Stock" shall refer to
       Nexell Common Stock or VIMRX Common Stock, as the case may be, for which
       the Option shall then be exercisable.

3.  Administration.
--------------------
       (a) The Plan shall be administered by a committee appointed by the Board
       of Directors of VIMRX from among its members or by the Board itself; upon
       the occurrence of a Nexell IPO, or upon VIMRX ceasing to be a majority
       owner of Nexell, the Plan shall be administered by a committee appointed
       by the Board of Directors of Nexell from among its members or by the
       Board itself. As used herein, the term "Committee" shall mean the
       committee actually administering the Plan, which shall be composed of two
       or more Directors who, to the extent practicable, shall be "outside
       directors" as defined in regulations under Section 162(m) of the Internal
       Revenue Code of 1986, as amended (the "Code"), and "non-employee
       directors" as defined by Regulation 240.16b-3 under the Securities
       Exchange Act of 1934, as amended. Such Committee shall have and may
       exercise any and all of the powers relating to the administration of the
       Plan and the grant of Options thereunder as are set forth in subparagraph
       3(b) hereof as the Board of Directors of VIMRX or Nexell, as the case may
       be, shall confer and delegate, which Board shall have the power at any
       time to fill vacancies in, to change the membership of, or to discharge
       the Committee. The Committee shall select one of its members as its
       chairman and shall hold its meetings at such time and at such places as
       it shall deem advisable. A majority of the Committee shall constitute a
       quorum and such majority shall determine its action. Any action may be
       taken without a meeting by written consent of all the members of the

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       *  now known as Nexell Therapeutics, Inc.

       ** now known as Nexell of California, Inc.
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       Committee. The Committee shall keep minutes of its proceedings and shall
       report the same to the Board of Directors of VIMRX or Nexell, as the case
       may be, at the meeting next succeeding.

       (b) The Committee shall administer the Plan and, subject to the
       provisions of the Plan, shall have sole authority in its discretion to
       determine the persons to whom, and the time or times at which, Options
       shall be granted; the number of shares to be subject to each such Option;
       the provisions regarding exercisability of each Option; the expiration
       date of each Option; whether the Option shall contain a "cashless
       exercise" provision; whether an Option shall have limited transferability
       as permitted under the Plan; and whether an Option granted to a non-
       employee shall terminate following the non-employee's termination of
       engagement in performing services for Nexell pursuant to Section 9 of the
       Plan.  In making such determinations, the Committee may take into account
       the nature of the services rendered by such persons, their present and
       potential contribution to Nexell's success and such other factors as the
       Committee in its sole discretion may deem relevant.  Subject to the
       express provisions of the Plan, the Committee shall also have authority
       to interpret the Plan; to prescribe, amend and rescind rules and
       regulations relating thereto; to determine the terms and provisions of a
       stock option grant to an option holder, which shall be evidenced by a
       Certificate delivered to such holder; to amend the provisions of
       outstanding Options to provide for accelerated exercisability or the
       extension of the expiration date of such Options; and to make all other
       determinations necessary or advisable for the administration of the Plan,
       all of which determinations shall be conclusive and not subject to
       review.

       (c) The Board of Directors of VIMRX or Nexell, as the case may be, may
       administer the Plan in lieu of and with the same powers as the Committee,
       provided that such administration is consistent with the provisions of
       Section 162(m) of the Code.


4.  Eligibility for Receipt of Options.
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       (a) Options may be granted to any employee, director, consultant, agent,
       independent contractor and other person whom the Committee determines
       will contribute to Nexell's success.

       (b) The maximum number of shares of Nexell Common Stock subject to
       Options which may be granted under the Plan during any calendar year to
       any employee of Nexell is 31,250 shares.


5.  Option Price.
------------------
       (a) The purchase price per share of Nexell Common Stock under each Option
       shall be determined by the Committee, whose determination shall be
       conclusive and not subject to review.

       (b) For purposes of the Plan, unless the Committee determines otherwise,
       the "fair market value" of a share of Nexell Common Stock as of a certain
       date shall be the closing sale price of such Common Stock on The Nasdaq
       Stock Market or, if such Common Stock is not then traded on The Nasdaq
       Stock Market, such national securities exchange on which such Common
       Stock is then traded, on the trading date immediately preceding the date
       the fair market value is being determined. In the event such Common Stock
       is not publicly traded, the Committee may make such determination of fair
       market value based on such factors as it shall deem appropriate.

       (c) For purposes of the Plan, the date of grant of an Option shall be the
       date on which the Committee by resolution duly authorizes the grant of
       such Option.


6.  Term of Options.
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The term of each Option shall be such number of years as the Committee shall
determine, subject to earlier termination as herein provided, but in no event
more than ten years from the date the Option is granted.


7.  Exercise of Options.
-------------------------
       (a) Each Option shall be exercisable for Nexell Common Stock as set forth
       in a Certificate delivered to the option holder; provided, however, that
       in the event (i) Nexell is a majority owned subsidiary of VIMRX on March
       31, 2001, and an initial public offering of Nexell Common Stock under the
       Securities Act of 1933, as amended ("Nexell IPO"), shall not have been
       effected on or before such date or (ii) prior to March 31, 2001, Nexell
       shall have merged with VIMRX or VIMRX shall have acquired all of the
       issued and outstanding capital stock of Nexell, or (iii) the Committee
       shall have determined that it is necessary or desirable in order to
       comply with any applicable federal or state securities law, then, upon
       any such occurrence, each Option shall be exercisable for shares of VIMRX
       Common Stock in lieu of Nexell Common Stock at the rate of three shares
       of VIMRX Common Stock for
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       each share of Nexell Common Stock purchasable under the Option at an
       exercise price per share of VIMRX Common Stock equal to one-third of the
       exercise price per share of Nexell Common Stock set forth in the
       Certificate.

       (b) An Option shall be exercisable to the extent and on the terms and
       conditions determined by the Committee, but in no event shall an Option
       be exercisable prior to March 31, 2001, unless prior thereto (i) a Nexell
       IPO shall have been effected or (ii) Nexell shall have merged with VIMRX
       or VIMRX shall have acquired all of the issued and outstanding capital
       stock of Nexell, in which event VIMRX Common Stock, in lieu of Nexell
       Common Stock, shall thereupon be issuable upon exercise of the Option.

       (c) An Option may not be exercised for fractional shares.

       (d) Except as provided in paragraphs 9, 10 and 11 hereof, and unless
       determined otherwise by the Committee, no Option shall be exercisable
       unless the holder thereof shall have been an employee, director,
       consultant, agent, independent contractor or other person employed by or
       engaged in performing services for Nexell continuously from the date of
       grant to the date of exercise.

       (e) The exercise of an Option shall be contingent upon receipt from the
       holder thereof of a written representation that at the time of such
       exercise it is the holder's then present intention to acquire the Option
       Shares for investment and not with a view to the distribution or resale
       thereof (unless a Registration Statement covering the Option Shares shall
       have been declared effective by the Securities and Exchange Commission)
       and payment for the full purchase price of the Option Shares.  The
       Committee may, in its discretion, include a "cashless exercise" provision
       in the applicable Certificate, in which event the holder will be
       permitted to deliver shares of Nexell Common Stock or VIMRX Common Stock,
       as the case may be, with a fair market value equal to the full purchase
       price of the Option Shares being exercised as payment therefor.

       (f) The holder of an Option shall have none of the rights of a
       stockholder with respect to the Option Shares purchasable upon exercise
       of the Option until a certificate for such shares shall have been issued
       to the holder upon due exercise of the Option.

       (g) The proceeds received by Nexell or VIMRX, as the case may be, upon
       exercise of an Option shall be added to the working capital of Nexell or
       VIMRX, as the case may be, and be available for general corporate
       purposes.


8.  Transferability of Options.
--------------------------------
No Option granted pursuant to the Plan shall be transferable otherwise than by
will or the laws of descent or distribution and an Option may be exercised
during the lifetime of the holder only by such holder, provided, however, that
the Committee may provide for transferability of an Option to the holder's
family members or family trusts.


9.  Termination of Employment or Engagement.
---------------------------------------------
       (a) Except as provided in paragraph (b) below, in the event the
       employment of the holder of an Option shall be terminated for any reason
       other than by reason of death or permanent and total disability, or the
       engagement of a non-employee holder of an Option shall be terminated for
       any reason, such holder may, within three months from the date of such
       termination, exercise such Option to the extent such Option was
       exercisable by the holder at the date of such termination; provided,
       however, the Committee, in its discretion, may establish other
       termination provisions with respect to an Option granted to a non-
       employee. Notwithstanding the foregoing, no Option may be exercised
       subsequent to the date of its expiration. Absence on leave approved by
       the employer corporation shall not be considered an interruption of
       employment for any purpose under the Plan. In addition, at the discretion
       of the Committee, the exercisability of an outstanding Option may be
       extended to a date determined by the Committee but not beyond ten years
       from the date of grant.

       (b) Nothing in the Plan or in any Certificate delivered to an option
       holder pursuant hereto shall confer upon any holder any right to continue
       in the employ of Nexell or obligate Nexell to continue the engagement of
       any holder or interfere in any way with the right of Nexell to terminate
       such holder's employment or engagement at any time.


10.  Disability of Holder of Option.
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If the employment of the holder of an Option shall be terminated by reason of
such holder's permanent and total disability, such holder may, within twelve
months from the date of such termination, exercise such option to the extent
such Option was
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exercisable by such holder at the date of such termination. Notwithstanding the
foregoing, no Option may be exercised subsequent to the date of its expiration.


11.  Death of Holder of Option.
--------------------------------
If the holder of any Option shall die while in the employ of, or while
performing services for, Nexell (or within six months following termination of
due to permanent and total disability), the Option theretofore
granted to such person may be exercised, but only to the extent such Option was
exercisable by the holder at the date of death (or, with respect to employees,
the date of termination of employment due to permanent and total disability) by
the legatee or legatees of such person under such person's Last Will, or by such
person's personal representative or distributees, within twelve months from the
date of death, but in no event subsequent to the expiration date of the Option.


12.  Adjustments Upon Changes in Capitalization.
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If at any time after the date of grant of an Option, Nexell or VIMRX shall by
stock dividend, split-up, combination, reclassification or exchange, or through
merger or consolidation or otherwise (other than through the merger of Nexell
into VIMRX), change its shares of common stock into a different number or kind
or class of shares or other securities or property, then the number of shares of
Nexell or VIMRX, as the case may be, covered by such Option and the price per
share thereof shall be proportionately adjusted for any such change by the
Committee whose determination thereon shall be conclusive.


13.  Acceleration of Exercisability Upon Change in Control.
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Upon the occurrence of a "change in control" of Nexell (as defined below), all
outstanding Options shall become immediately fully exercisable.  For purposes of
the Plan, a "change in control" of Nexell shall mean (i) the acquisition at any
time by a "person" or "group" (as such terms are used Sections 13(d) and
14(d)(2) of the Exchange Act of beneficial ownership (as defined in Rule 13d-3
under the Exchange Act), directly or indirectly, of securities representing 50%
or more of the combined voting power in the election of directors of the then
outstanding securities of Nexell or any successor of Nexell; (ii) the
termination of service of directors, during any period of two consecutive years
or less, of individuals who at the beginning of such period constituted a
majority of the Board of Directors of Nexell or any successor of Nexell, for any
reason other than death, permanent and total disability or retirement, unless
the election of or nomination for election of each new director during such
period was approved by a vote of at least two-thirds of the directors still in
office who were directors at the beginning of the period; (iii) approval by the
stockholders of Nexell or any successor of Nexell of any merger, consolidation,
or statutory share exchange as a result of which the Nexell Common Stock shall
be changed, converted or exchanged (other than a merger, consolidation or share
exchange with VIMRX or a wholly-owned subsidiary of VIMRX) or liquidation of
Nexell or any successor of Nexell, or any sale or disposition of 80% or more of
the assets or earning power of Nexell or any successor of Nexell, except to
VIMRX; or (iv) approval by the stockholders of Nexell of any merger,
consolidation, or statutory share exchange to which Nexell is a party as a
result of which the persons who were stockholders immediately prior to the
effective date of the merger, consolidation or share exchange shall have
beneficial ownership of less than 50% of the combined voting power in the
election of directors of the surviving corporation; provided, however, that no
change in control shall be deemed to have occurred if, prior to such time as a
change in control would otherwise be deemed to have occurred, the Board of
Directors of VIMRX or Nexell, as the case may be, deems otherwise.


14.  Issuance of Rights Under Options.
---------------------------------------
Neither anything contained in the Plan nor in any resolution adopted or to be
adopted by the Committee, the Board of Directors of VIMRX or Nexell, as the case
may be, or the stockholders of VIMRX or Nexell, as the case may be, shall
constitute the issuance of any rights under any Option.  The issuance of such
rights shall take place only upon the delivery of a written Certificate by and
on behalf of Nexell and/or VIMRX, as the case may be, to the person to whom the
Option shall be granted, setting forth the terms and provisions of the option
granted.


15.  Withholding Taxes.
------------------------
Whenever under the Plan shares are to be issued in satisfaction of the exercise
of Options granted thereunder, Nexell or VIMRX, as the case may be, shall have
the right to require the recipient to remit an amount sufficient to satisfy
federal, state and local withholding tax requirements prior to the delivery of
any certificate or certificates for such shares.


16.  Termination and Amendment.
--------------------------------
This Plan is subject to approval by the stockholders of VIMRX, shall terminate
on December 31, 2007, and no Option shall be granted under the Plan after such
date.  The Board of Directors of VIMRX or Nexell, as the case may be, may at any
time prior to such date terminate the Plan or make such modifications or
amendments thereto as it shall deem advisable, provided,
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however, that approval of the shareholders of Nexell (in the event that at such
time options to purchase only shares of Nexell Common Stock are issuable under
this Plan) and/or VIMRX (in the event that at such time options to purchase only
shares of VIMRX Common Stock are issuable under this Plan) or Nexell and VIMRX
(in the event that at such time options to purchase shares of Nexell Common
Stock, or in the alternative, shares of VIMRX Common Stock, are issuable under
this Plan) shall be required:

          (i)   to increase the number of shares reserved for issuance under the
          Plan;

          (ii)  to materially increase the benefits accruing to participants
          under the plan

          (iii) to materially modify the requirements of eligibility for
          participation in the Plan; or

          (iv)  if otherwise required to comply with the incentive stock option
          provisions of Section 162(m) of the Code or the listed company
          requirements of The Nasdaq Stock Market or of a national securities
          exchange on which the Option Shares are then traded, and, provided,
          further, that no modification or amendment shall adversely affect the
          rights of a holder of an Option previously granted under the Plan
          without such holder's written consent.