Document:

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                                                                   EXHIBIT 10.53

                           VIMRx PHARMACEUTICALS INC.

                         REGISTRATION RIGHTS AGREEMENT

This Registration Rights Agreement (the "Agreement") is dated as of December 17,
1997, and is entered into by and between VIMRx Pharmaceuticals Inc., a Delaware
corporation (the "Company") and Baxter Healthcare Corporation, a Delaware
corporation (the "Purchaser").

                                R E C I T A L S
                                ---------------

A.   The Company and the Purchaser have, on the date hereof, entered into an
Asset Purchase Agreement pursuant to which the Company has issued or will issue
to Purchaser 11,000,000 shares of the Company's common stock, $.001 par value
("Common Stock") and all shares of the Company's Series A Convertible Preferred
Stock ("Preferred Stock").

B.   The parties desire to establish a procedure for the registration and resale
of the Common Stock and the Common Stock issuable upon conversion of the
Preferred Stock held by the Purchaser.

NOW, THEREFORE, in consideration of the mutual agreements, covenants and
releases contained herein, the parties hereto hereby agree as follows:

                               A G R E E M E N T
                               -----------------
1.   Certain Definitions.  As used in this Agreement, the following terms shall
have the following respective meanings:

     (a) "Commission" means the Securities and Exchange Commission or any other
     United States federal agency at the time administering the Securities Act.

     (b) "Holder" means the Purchaser holding Registrable Securities and any
     holder of outstanding Registrable Securities which have not been sold to
     the public, but only if such holder is an assignee or transferee of
     Registration rights as permitted by Section 7.

     (c) "Initiating Holders" means any Holder or Holders who in the aggregate
     hold at least fifty percent (50%) of the Registrable Securities.

     (d) "Register," "Registered," and "Registration" shall refer to a
     registration effected by preparing and filing a registration statement in
     compliance with the Securities Act (a "Registration Statement") and the
     declaration or ordering of the effectiveness of such Registration
     Statement, and qualification and compliance with applicable state
     securities laws.

     (e) "Registrable Securities" means (i) the Common Stock purchased by
     Purchasers pursuant to the Asset Purchase Agreement, and (ii) all Common
     Stock issuable upon conversion of the Preferred Stock in accordance with
     its terms. In the event of any recapitalization by the Company, whether by
     stock split, reverse stock split, stock dividend or the like, such
     additional securities shall be Registrable Securities covered by this
     Agreement.

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     (f) "Registration Expenses" means all expenses incurred by the Company in
     complying with Section 2, including, without limitation, all federal and
     state registration, qualification and filing fees, printing expenses, fees
     and disbursements of counsel for the Company and one special counsel for
     Holders (if different from the Company), whose fees shall be capped at
     $15,000, escrow fees, blue sky fees and expenses, and the expense of any
     audits or financial statement reviews incident to or required by any such
     registration. The Company shall not be required to undertake any audit of
     its financial statements except in connection with its fiscal year end in
     connection with any Registration undertaken pursuant to this Agreement.

     (g) "Securities Act" means the Securities Act of 1933, as amended, or any
     similar federal statute and the rules and regulations of the Commission
     thereunder, all as the same shall be in effect at the time.

     (h) "Selling Expenses" means all underwriting discounts, selling
     commissions, fees and expenses of underwriters' counsel, expenses of
     underwriters and stock transfer taxes applicable to the sale of Registrable
     Securities pursuant to this Agreement, which such Selling Expenses shall be
     prorated among selling stockholders if such Registration includes
     securities other than Registrable Securities.

     (i) "Underwriter" means any underwriter which acts as an underwriter in
     connection with a Registration Statement.

2.   Demand Registration.
------------------------

2.1   Request for Registration. Subject to the remainder of this Agreement, if
the Company shall receive, from Holders who in the aggregate hold more than
thirty percent (30%) of the then outstanding Registrable Securities or any
lesser percent if the reasonably anticipated aggregate offering price to the
public would exceed $5,000,000, at any time after the date of this Agreement, a
written request that the Company effect any Registration with respect to all or
a part of the Registrable Securities for a firm-commitment underwritten offering
thereof, the Company shall (i) promptly, but in any event within 10 days, give
written notice of the proposed Registration to all other Holders and shall (ii)
use its commercially reasonable efforts to effect Registration of the
Registrable Securities specified in such request as soon as practicable,
together with any Registrable Securities of any Holder, joining in such request
as are specified in a written request delivered to the Company within 30 days
after delivery of such written notice from the Company of the proposed
Registration. The Company shall not be obligated to take any action to effect
any such Registration pursuant to this Section 2.1 after the Company has
effected three such Registrations pursuant to this Section 2.1 and each such
Registration has been declared effective.

2.2. Right of Deferral of Registration. If the Company shall furnish to all such
Holders who joined in the request a certificate signed by the President of the
Company stating that, in the good faith business judgment of the Board of
Directors of the Company, it would be commercially unreasonable for the Company
for any Registration to be effected as requested under this Section 2, the
Company shall have the right, exercisable once with respect to each demand for
Registration, to defer the filing of the Registration Statement with respect to
such offering for a period of not more than 150 days from delivery of the
request of the Initiating Holders.

2.3. Underwriting in Demand Registration.
----------------------------------------

     (a) Notice of Underwriting. The right of any Holder to Registration
     pursuant to Section 2 shall be conditioned upon the agreement of such
     Holder to participate in such underwriting and the inclusion of Registrable
     Securities in the underwriting.

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     (b) Inclusion of Other Holders in Demand Registration. The Company shall be
     entitled to include any other of its securities held by any other person in
     any Registration Statement filed pursuant to this Section 2.

     (c) Selection of Underwriter in Demand Registration. The Company shall
     (together with all holders proposing to distribute their securities through
     such underwriting) enter into an underwriting agreement with the
     representative ("Underwriter's Representative") of the underwriter or
     underwriters selected for such underwriting by the holders of a majority of
     the Registrable Securities being registered by the Initiating Holders and
     reasonably satisfactory to the Company.

     (d) Marketing Limitation in Demand Registration. If the Underwriter's
     Representative advises the Initiating Holders in writing that market
     factors require a limitation of the number of shares to be underwritten,
     the securities held by persons who are not Holders shall be excluded from
     such Registration to the extent required by such limitation. If a
     limitation in the number of shares is still required, the Initiating
     Holders shall so advise all Holders and the number of shares of Registrable
     Securities that may be included in the Registration and underwriting shall
     be excluded pro rata based (as between the holders of Registrable
     Securities) on percentage ownership of the Company. No Registrable
     Securities or other securities excluded from the underwriting by reason of
     this Section 2.3(d) shall be included in such Registration Statement. If
     the number of shares of Registrable Securities so excluded exceeds 20% of
     the number of shares of Registrable Securities which are requested to be
     included in such Registration, then the Initiating Holders shall be
     entitled, on behalf of the Holders, to require, by delivery of a written
     notice to the Underwriter's Representative and the Company, that the
     Registration be deferred for such period of time as the Initiating Holders,
     the Company, and the Underwriter's Representative may mutually agree, but
     in no event to exceed 90 days from delivery of the notice requiring such
     deferral from the Initiating Holders, or alternatively, to request that the
     Registration be terminated in its entirety. In such event, the demand for
     Registration shall be considered to have not been made for purposes of
     counting the number of demands for Registration permitted under Section
     2.1.

     (e) Right of Withdrawal in Demand Registration. If any Holder of
     Registrable Securities or a holder of other securities entitled (upon
     request) to be included in such Registration, disapproves of the terms of
     the underwriting, such person may elect to withdraw therefrom by written
     notice to the Company, the Underwriter's Representative, and the Initiating
     Holders delivered at least seven days prior to the effective date of the
     Registration Statement. The securities so withdrawn shall also be withdrawn
     from the Registration Statement. If by the withdrawal of such securities a
     greater number of Registrable Securities held by other Holders may be
     included in such Registration (up to the maximum of any limitation imposed
     by the underwriters), then the Company shall offer to all Holders who have
     included Registrable Securities in the Registration the right to include
     additional Registrable Securities in the same proportion as that used in
     determining the proportional inclusion under the underwriter limitation in
     Section 2.3(d).

     (f) Inclusion of Company's Securities in Demand Registration. If the
     Underwriter's Representative has not limited the number of Registrable
     Securities or other securities to be underwritten, the Company may include
     its securities for its own account in such Registration and underwriting if
     the Underwriter's Representative so agrees and if the number of Registrable
     Securities and other securities which would otherwise have been included in
     such Registration and underwriting will not thereby be

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     limited, and if the Underwriter's Representative advises the Holders in
     writing that, in such Representative's opinion, the price of the
     Registrable Securities will not be adversely affected thereby.

     (g) Blue Sky in Demand Registration. In the event of any Registration
     pursuant to Section 2, the Company will exercise its best efforts to
     Register and qualify the securities covered by the Registration Statement
     under such other securities or blue sky laws of such jurisdictions (not
     exceeding 20 unless otherwise agreed to by the Company) as shall be
     reasonably appropriate for the distribution of such securities; provided,
     however, that (i) the Company shall not be required to qualify to do
     business or to file a general consent to service of process in any such
     states or jurisdictions, and (ii) notwithstanding anything in this
     Agreement to the contrary, if any jurisdiction in which the securities
     shall be qualified imposes a non-waivable requirement that expenses
     incurred in connection with the qualification of the securities be borne by
     selling shareholders, such expenses shall be payable pro rata by selling
     shareholders.

2.4.  Piggyback Registration.
----------------------------

     (a) Notice of Piggyback Registration and Inclusion of Registrable
     Securities. In the event the Company decides to Register any of its Common
     Stock (other than pursuant to a registration on Form S-4 or S-8 or any
     successor forms), for its own account for cash in a firm commitment
     underwritten offering on a form that would be suitable for a registration
     involving Registrable Securities, the Company shall: (i) promptly, but in
     any event within 10 days of such decision, give each Holder written notice
     thereof (which shall include a list of the jurisdictions in which the
     Company intends to attempt to qualify such securities under the applicable
     blue sky or other state securities laws) and (ii) include in such
     Registration (and any related qualification under blue sky laws or other
     compliance), and in any underwriting involved therein, all the Registrable
     Securities specified in a written request delivered to the Company by any
     Holder within 20 days after delivery of such written notice from the
     Company of the proposed Registration.

     (b) Underwriting in Piggyback Registration. The right of any Holder to
     Registration shall be conditioned upon the agreement of such Holder to
     participate in such underwriting and the inclusion of such Holder's
     Registrable Securities in such underwriting. All Holders proposing to
     distribute their securities through such underwriting shall (together with
     the Company and the other holders distributing their securities through
     such underwriting) enter into an underwriting agreement with the
     Underwriter's Representative for such offering. The Holders shall have no
     right to participate in the selection of the underwriters for an offering
     pursuant to this Section 2.4.

     (c) Marketing Limitation in Piggyback Registration. If the Underwriter's
     Representative advises the Holders seeking registration of Registrable
     Securities pursuant to Section 2.4 in writing that market factors require a
     limitation of the number of shares to be underwritten, the Underwriter's
     Representative may (subject to the allocation priority set forth in Section
     2.4(d)) limit the number of Registrable Securities to be included therein,
     down to complete exclusion.

     (d) Allocation of Shares in Piggyback Registration. If the Underwriter's
     Representative limits the number of shares to be included in a Registration
     pursuant to Section 2.4(c), the number of shares to be included in such
     Registration shall be allocated in the following manner: The shares (other
     than Registrable Securities) held by holders of securities other than
     Registrable Securities requesting and legally entitled to include shares in
     such Registration shall be excluded from such registration and underwriting
     to the extent required by such limitation, but only if permitted by the
     terms of such other registration rights agreement. If a limitation in the
     number of shares is still required, the number of

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     shares of Registrable Securities to be included in the Registration and
     underwriting shall be excluded pro rata (as between the holders of
     Registrable Securities and such other holders of other registration rights)
     based on percentage ownership. No Registrable Securities or other
     securities excluded from the underwriting by reason of this Section 2.4(d)
     shall be included in the Registration Statement.

     (e) Withdrawal in Piggyback Registration. If any holder disapproves of the
     terms of any such underwriting, he may elect to withdraw therefrom by
     written notice to the Company and the underwriter delivered at least seven
     days prior to the effective date of the Registration Statement. Any
     Registrable Securities or other securities excluded or withdrawn from such
     underwriting shall be withdrawn from such Registration. If by the
     withdrawal of such securities a greater number of Registrable Securities
     may be included in such Registration (up to the maximum of any limitation
     imposed by the underwriters), then the Company shall offer to all Holders
     who have included Registrable Securities the right to include additional
     Registrable Securities in the same proportion used in determining the
     proportional inclusion under the underwriter limitation in Section 2.4(d).

     (f) Blue Sky in Piggyback Registration. In the event of any Registration of
     Registrable Securities pursuant to Section 2.4, the Company will exercise
     its best efforts to Register and qualify the securities covered by the
     Registration Statement under such other securities or blue sky laws of such
     jurisdictions (not exceeding 20 unless otherwise agreed to by the Company)
     as shall be reasonably appropriate for the distribution of such securities;
     provided, however, that (i) the Company shall not be required to qualify to
     do business or to file a general consent to service of process in any such
     states or jurisdictions, and (ii) notwithstanding anything in this
     Agreement to the contrary, in the event any jurisdiction in which the
     securities shall be qualified imposes a non-waivable requirement that
     expenses incurred in connection with the qualification of the securities be
     borne by selling stockholders, such expenses shall be payable pro rata by
     selling stockholders.

3.   Expenses of Registration. All Registration Expenses incurred in connection
with all Registrations shall be borne by the Company. Notwithstanding the above,
the Company shall not be required to pay for any expenses of any registration
proceeding begun pursuant to Section 2 if the registration request is
subsequently withdrawn at the request of the Holders of a majority of the
Registrable Securities to be registered (which Holders shall bear such
expenses); provided further, however, that if at the time of such withdrawal,
the Holders have learned of a material adverse change in the condition,
business, properties, prospects or financial condition of the Company from that
known to the Holders at the time of their request, then the Holders shall not be
required to pay any of such expenses and shall retain their rights pursuant to
Section 2. All Selling Expenses shall be borne by the holders of the securities
registered pro rata on the basis of the number of shares registered.

4.   Registration Procedures. The Company will keep each Holder whose
Registrable Securities are included in any Registration pursuant to this
Agreement advised as to the initiation and completion of such Registration. At
its expense the Company will: (a) use its best efforts to keep such Registration
effective for a period of 90 days or until the Holders have completed the
distribution described in the Registration Statement relating thereto, whichever
first occurs; and (b) furnish such number of prospectuses (including
preliminary, amended or supplemented prospectuses) and other documents as a
Holder from time to time may reasonably request. The Company shall file post-
effective amendments or supplements to such Registration Statement as may be
necessary to comply with applicable federal and state securities laws and
regulations, and shall deliver copies of the prospectus contained therein as
provided above.

5.   Information Furnished by Holder. It shall be a condition precedent of the
Company's obligations under this Agreement to a particular Holder that such
Holder of Registrable Securities to be included in any Registration,

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furnish to the Company such information regarding such Holder and the
distribution proposed by such Holder as the Company may reasonably request.

6.   Indemnification.
--------------------

6.1.  Company's Indemnification of Holders. To the extent permitted by law, the
Company will indemnify each Holder, each of their respective officers, directors
and constituent partners and each person controlling such Holder, with respect
to which Registration, qualification or compliance of Registrable Securities has
been effected pursuant to this Agreement, and each underwriter, if any, and each
person who controls any underwriter, against all claims, losses, damages,
liabilities (or actions in respect thereof) to the extent such claims, losses,
damages, liabilities or actions arise out of or are based upon any untrue
statement (or alleged untrue statement) of a material fact contained in any
prospectus, offering circular or other document issued by the Company (including
any related Registration Statement) incident to any such Registration,
qualification or compliance, or are based on any omission (or alleged omission)
to state therein a material fact required to be stated therein or necessary to
make the statements therein not misleading, or any violation by the Company of
any rule or regulation promulgated under the Securities Act applicable to the
Company and relating to action or inaction required of the Company in connection
with any such Registration, qualification or compliance. The Company will also
reimburse each such Holder, officer, director, constituent partner, legal
counsel and underwriter and each person who controls any such Holder or
underwriter, for any legal and any other expenses reasonably incurred in
connection with investigating or defending any such claim, loss, damage,
liability or action; provided, however, that the indemnity contained in this
Section 6 shall not apply to amounts paid in settlement of any such claim, loss,
damage, liability or action if settlement is effected without the consent of the
Company (which consent shall not unreasonably be withheld); and provided,
further, that the Company will not be liable in any such case to the extent that
any such claim, loss, damage, liability or action arises out of or is based upon
any untrue statement (or alleged untrue statement) or omission (or alleged
omission) of a material fact furnished in a writing to the Company by such
Holder, in each case to the extent, but only to the extent, that such untrue
statement (or alleged untrue statement) or omission (or alleged omission) is
made in such Registration Statement, prospectus, offering circular or other
document in reliance upon and in conformity with written information furnished
to the Company by such Holder and stated to be specifically for use in
connection with the offering of securities of the Company.

6.2.  Holder's Indemnification of Company. To the extent permitted by law, each
Holder will, if Registrable Securities held by such Holder are included in the
securities as to which such Registration, qualification or compliance is being
effected pursuant to this Agreement, indemnify the Company, each of its
directors and officers, each legal counsel and independent accountant of the
Company, each underwriter, if any, of the Company's securities covered by such a
Registration Statement, each person who controls the Company or such underwriter
within the meaning of the Securities Act, and each other such Holder, its
officers, directors, constituent partners and legal counsel and each person
controlling such other Holder, against all claims, losses, damages and
liabilities (or actions in respect thereof) arising out of or based upon any
untrue statement (or alleged untrue statement) of a material fact contained in
any such Registration Statement, prospectus, offering circular or other document
issued by the Company, or any omission (or alleged omission) to state therein a
material fact required to be stated therein or necessary to make the statements
therein not misleading, or any violation by such Holder of any rule or
regulation promulgated under the Securities Act applicable to such Holder and
relating to action or inaction required of such Holder in connection with any
such Registration, qualification or compliance; and each Holder will also
reimburse the Company, such Holders, such directors, officers, partners,
persons, law and accounting firms, underwriters and control persons for any
legal and any other expenses reasonably incurred in connection with
investigating or defending any such claim, loss, damage, liability or action, in
each case to the extent, but only to the extent, that such untrue statement (or
alleged untrue

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statement) or omission (or alleged omission) is made in such Registration
Statement, prospectus, offering circular or other document in reliance upon and
in conformity with written information furnished to the Company by such Holder
and stated to be specifically for use in connection with the offering of
securities of the Company. The liability of the Holder under this paragraph
shall be limited to the aggregate proceeds received by such Holder from the sale
of Registrable Securities sold under the Registration Statement.

6.3.  Indemnification Procedure. Promptly after receipt by an indemnified party
under this Section 6 of notice of the commencement of any action, such
indemnified party will, if a claim in respect thereof is to be made against an
indemnifying party under this Section 6, notify the indemnifying party in
writing of the commencement thereof and generally summarize such action. The
indemnifying party shall have the right to participate in and to assume the
defense of such claim, and shall be entitled to select counsel for the defense
of such claim with the approval of the indemnified parties, which approval shall
not be unreasonably withheld; provided, however, that the indemnified party may
participate in such defense, and the indemnified parties collectively shall be
entitled to retain a separate counsel for purposes of such action, at the
indemnifying party's expense if a majority in interest of the indemnified
parties conclude in good faith that representation of such indemnified parties
by counsel selected by the indemnifying party would be inappropriate due to
actual or potential differing interests between such indemnifying party and any
or the indemnified parties. The failure to notify an indemnifying party promptly
of the commencement of any such action, if prejudicial to the ability of the
indemnifying party to defend such action, shall relieve such indemnifying party
of any liability to the indemnified party under this Section 6, but the omission
so to notify the indemnifying party will not relieve such party of any liability
that such party may have to any indemnified party other than under this Section
6. No indemnifying party, in the defense of any such claim or litigation shall
consent to entry of any judgment or enter into any settlement (i) which does not
include as an unconditional term thereof the giving by the claimant or plaintiff
to the indemnified party of a release from all liability in respect to such
claim or litigation and (ii) except with the consent of each indemnified party,
which consent shall not be unreasonably withheld.

6.4. Other Securities. It shall be a condition to the Company's obligations
under this Agreement to include Registrable Securities of a Holder in any
Registration pursuant to this Agreement that such Holder agree to substantially
the indemnification provisions set forth in this Section.

7. Transfer of Registration Rights. The rights to cause the Company to register
securities granted by the Company under this Agreement to the Holders may be
assigned by any Holder (a) to any Affiliate of such Holder (as defined in Rule
405 under the Securities Act) or (b) to a transferee or assignee of any
Registrable Securities, not sold to the public, acquiring at least 20% of such
Holder's Registrable Securities; provided, however, that (i) the Company must be
given written notice of said transfer, stating the name and address of said
transferee or assignee and identifying the securities with respect to which such
Registration rights are being assigned, and (ii) the transferee or assignee of
such rights must not be a direct competitor of the Company.

8.  Market Stand-off. Purchaser hereby agrees that, if so requested by the
Company and the Underwriter's Representative (if any), Purchaser shall not sell,
make any short sale of, grant any option for the purchase of, or otherwise
transfer, without the prior written consent of the Company or the Underwriter's
Representative, any securities of the Company (other than those included in the
Registration) during the 120-day period following the effective date of a
Registration Statement of the Company filed under the Securities Act. The
Company may impose stop-transfer instructions with respect to securities subject
to the foregoing restriction.

9.  [NOT USED]

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10.  Rule 144 Reporting. With a view to making available the benefits of certain
rules and regulations of the Commission which may at any time permit the sale of
the Registrable Securities to the public without Registration, the Company
agrees to:

     (a) Make and keep public information available, as those terms are
     understood and defined in Rule 144 under the Securities Act, at all times;

     (b) Use its best efforts to file with the Commission in a timely manner all
     reports and other documents required of the Company under the Securities
     Act and the Securities Exchange Act of 1934, as amended;

     (c) Furnish to the Holders of Registrable Securities forthwith upon request
     a written statement by the Company as to its compliance with the reporting
     requirements of said Rule 144, and of the Securities Act and the Securities
     Exchange Act of 1934, a copy of the most recent annual or quarterly report
     of the Company, and such other reports and documents of the Company as a
     Holder may reasonably request in availing itself of any rule or regulation
     of the Commission allowing such Holder to sell any such securities without
     Registration.

11.  Severability.  If any provision of this Agreement is held to be
unenforceable, it shall be adjusted rather than voided to achieve its intent to
the maximum extent possible, and the remaining provisions of this Agreement
shall be enforced to the maximum extent possible.

12.  Notices.  All notices, communications and deliveries under this Agreement
shall be made in writing signed by the party making the same, shall be made
either by personal delivery (including couriers such as Federal Express) or by
registered mail, postage prepaid, or facsimile transmission and shall be deemed
to give delivery on the date delivered if delivered in person or by facsimile or
on the seventh day after mailing if mailed, addressed as follows:

If to:
             the Company:   VIMRx Pharmaceuticals Inc.
                            2751 Centerville Road Wilmington, DE 19808
                            Attn:  President Facsimile:  (302) 998-3794

             with a copy to:

             Lowell S. Lifschultz, Esq.
             Epstein Becker & Green
             250 Park Avenue New York, NY 10177
             Facsimile:  (212) 661-0989

the Holder:  Baxter Healthcare Corporation
             1627 Lake Cook Road
             Deerfield, IL 60015
             Attn:  Victor W. Schmitt
             Facsimile:  (847) 940-6271

             with a copy to:

             Christopher A. Lause
             Seyfarth, Shaw, Fairweather & Geraldson
             55 East Monroe Street
             Chicago, IL 60603
             Facsimile:  (312) 269-8869

                                       8
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13.  Assignment.  Except as otherwise permitted by this Agreement, no assignment
or transfer, in whole or in part, by a Holder of his rights under this Agreement
shall be made except with the prior written consent of the Company, which
consent shall not be unreasonably withheld. This Agreement shall be binding upon
and shall inure to the benefit of the parties hereto and their respective legal
representatives, heirs, descendants and permitted successors and assigns.

14. Controlling Law; Integrations; Amendments; Waiver. This Agreement shall be
construed and enforced in accordance with the laws of the State of Delaware
applicable to agreements among Delaware residents made and to be performed
entirely within the State of Delaware. This Agreement supersedes all prior
negotiations, agreements, and understandings among the parties with respect to
the subject matter hereof, and constitutes the entire agreement among the
parties with respect such subject matter. This Agreement may not be altered or
amended except in writing signed by the Company and by the holders of not less
than 66-2/3% of the then outstanding Registrable Securities. The failure of any
party hereto at any time to require performance of any provision of this
Agreement shall in no manner be deemed a waiver of the right to require
performance of the same in the future.

15.  Counterparts.  This Agreement may be executed in two or more counterparts,
each of which shall constitute an original, but all of which taken together
shall constitute one and the same document. Facsimile transmission of a
signature shall be deemed an original for all purposes.

IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of the
day and year first above written.

The Company:  VIMRx Pharmaceuticals Inc.,
                             a Delaware corporation

              By /s/ Richard L. Dunning
              -- ----------------------

              Its President & CEO
              --- ---------------

The Holder:   Baxter Healthcare Corporation

              By /s/ Victor W. Schmitt
              -- ---------------------

              Its President, Venture Management
              --- -----------------------------

                                       9<PAGE>

                                                                   EXHIBIT 10.54

                            NEXELL THERAPEUTICS INC.
                      NON-INCENTIVE STOCK OPTION AGREEMENT

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

To:       Joseph A. Mollica

          We are pleased to notify you that by the determination of the Stock
Option Plan Committee (herein called the "Committee") a non-incentive stock
option to purchase 50,000 shares of the Common Stock of Nexell Therapeutics Inc.
(herein called the "Company") at a price of $1.375 per share has this 9th day of
November, 1999 been granted to you under the Company's 1997 Incentive and Non-
Incentive Stock Option Plan (herein called the "Plan"). This option may be
exercised only upon the terms and conditions set forth below.

          1.  Purpose of Option.
              -----------------

          The purpose of the Plan under which this non-incentive stock option
has been granted is to further the growth and development of the Company and its
subsidiaries by encouraging key employees, directors, consultants, agents,
independent contractors and other persons who contribute and are expected to
contribute materially to the Company's success to obtain a proprietary interest
in the Company through the ownership of stock, thereby providing such persons
with an added incentive to promote the best interests of the Company, and
affording the Company a means of attracting to its service persons of
outstanding ability.

          2.  Acceptance of Option Agreement.
              ------------------------------

          Your execution of this non-incentive stock option agreement will
indicate your acceptance of and your willingness to be bound by its terms; it
imposes no obligation upon you to purchase any of the shares subject to this
option. Your obligation to purchase shares can arise only upon your exercise of
the option in the manner set forth in paragraph 4 hereof.

          3.  When Option May Be Exercised.
              ----------------------------

          The option granted you hereunder shall be exercisable as follows:

              (i)   From and after November 9, 2000, options to purchase 12,500
                    shares shall become exercisable;

              (ii)  From and after November 9, 2001, options to purchase 25,000
                    shares (i.e., an additional 12,500 shares) shall become
                    exercisable;

              (iii) From and after November 9, 2002 options to purchase 37,500
                    shares (i.e., an additional 12,500 shares) shall become
                    exercisable; and

              (iv)  From and after November 9, 2003, options to purchase all
                    shares subject to this non-incentive stock option agreement
                    shall become exercisable.

                                       1
<PAGE>

          This option may not be exercised for less than ten shares at any one
time (or the remaining shares then purchasable if less than ten) and expires at
the end of ten years from the date of grant whether or not it has been duly
exercised (hereinafter, the "Option Expiration Date"), unless sooner terminated
as provided in paragraphs 5, 6 or 7 hereof.

          4.  How Option May Be Exercised.
              ---------------------------

          This option is exercisable by a written notice signed by you and
delivered to the Company at its executive offices, signifying your election to
exercise the option. The notice must state the number of shares of Common Stock
as to which your option is being exercised, must contain a statement by you (in
a form acceptable to the Company) that such shares are being acquired by you for
investment and not with a view to their distribution or resale (unless a
Registration Statement covering the shares purchased has been declared effective
by the Securities and Exchange Commission) and must be accompanied by cash or a
check to the order of the Company for the full purchase price of the shares
being purchased, plus such amount, if any, as is required for withholding taxes.
Notwithstanding the foregoing, this option may also be exercised pursuant to the
following "cashless exercise" provision.

          In lieu of paying for the shares purchasable under this option by cash
or check, you may (i) deliver previously owned shares of Common Stock with a
fair market value equal to the full purchase price of the shares being purchased
under this option, or (ii) request that the Company withhold shares of Common
Stock issuable upon exercise of this option with a fair market value equal to
the full purchase price of the shares being purchased under this option (thereby
reducing the number of shares issuable upon exercise of this option). For
purposes of this option, unless the Committee determines otherwise, the "fair
market value" of a share of Common Stock as of a certain date shall be the
closing sale price of the Common Stock on The Nasdaq Stock Market or, if the
Common Stock is not then traded on The Nasdaq Stock Market, such national
securities exchange on which the Common Stock is then traded, on the trading
date immediately preceding the date fair market value is being determined. The
Committee may make such other determination of fair market value, based on other
factors, as it shall deem appropriate.

          If notice of the exercise of this option is given by a person or
persons other than you, the Company may require, as a condition to the exercise
of this option, the submission to the Company of appropriate proof of the right
of such person or persons to exercise this option.

          Certificates for shares of the Common Stock so purchased will be
issued as soon as practicable. The Company, however, shall not be required to
issue or deliver a certificate for any shares until it has complied with all
requirements of the Securities Act of 1933, the Securities Exchange Act of 1934,
any stock exchange on which the Company's Common Stock may then be listed and
all applicable state laws in connection with the issuance or sale of such shares
or the listing of such shares on said exchange. Until the issuance of the
certificate for such shares, you or such other person as may be entitled to
exercise this option shall have none of the rights of a stockholder with respect
to shares subject to this option.

          The Company shall have the right to require you, or such other person
as may be permitted to exercise this option, to remit to the Company an amount
sufficient to satisfy federal,

                                       2
<PAGE>

state and local withholding tax requirements prior to the delivery of any
certificate or certificates for shares of Common Stock issuable upon exercise of
this option.

          5.  Termination of Employment or Engagement.
              ---------------------------------------

          If your employment with the Company (or a subsidiary thereof) is
terminated for any reason other than by death or disability, or if you are not
an employee of the Company and your engagement by the Company (or a subsidiary)
is terminated for any reason, you may exercise that portion of this option which
was exercisable by you at the date of such termination, provided, however, that
such exercise occurs prior to the Option Expiration Date.

          6.  Disability.
              ----------

          If your employment with the Company (or a subsidiary thereof) is
terminated by reason of your disability, you may exercise, within twelve months
from the date of such termination, that portion of this option which was
exercisable by you at the date of such termination, provided, however, that such
exercise occurs prior to the Option Expiration Date.

          7.  Death.
              -----

          If you die while employed by the Company (or a subsidiary thereof) or
within six months after termination of your employment due to disability, that
portion of this option which was exercisable by you at the date of your death
may be exercised by your legatee or legatees under your Will, or by your
personal representatives or distributees, within twelve months from the date of
your death, but in no event after the Option Expiration Date.

          8.  Non-Transferability of Option.
              -----------------------------

          This option shall not be transferable except by Will or the laws of
descent and distribution, and may be exercised during your lifetime only by you.

          9.  Adjustments upon Changes in Capitalization.
              ------------------------------------------

          If at any time after the date of grant of this option, the Company
shall, by stock dividend, split-up, combination, reclassification or exchange,
or through merger or consolidation, or otherwise, 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 covered by this option and the price of each
such share shall be proportionately adjusted for any such change by the
Committee, whose determination shall be conclusive.

          10.  Acceleration of Exercisability Upon Change in Control.
               -----------------------------------------------------

          Upon the occurrence of a "change in control" of the Company (as
defined below), this option shall become immediately fully exercisable. For
purposes of this option, a "change in control" of the Company shall mean (i) the
acquisition at any time by a "person" or "group" (as such terms are used in
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

                                       3
<PAGE>

representing 50% or more of the combined voting power in the election of
directors of the then outstanding securities of the Company or any successor of
the Company; (ii) the termination of service of directors, for any reason other
than death, disability or retirement from the Board 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, 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 the Company of any merger, consolidation, or statutory share
exchange as a result of which the Common Stock shall be changed, converted or
exchanged (other than a merger, consolidation or share exchange with a wholly-
owned Subsidiary) or liquidation of the Company or any sale or disposition of
80% or more of the assets or earning power of the Company; or (iv) approval by
the stockholders of the Company of any merger, consolidation, or statutory share
exchange to which the Company 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 Company's Board of Directors deems otherwise.

          11.  Subject to Terms of the Plan.
               ----------------------------

          This non-incentive stock option agreement shall be subject in all
respects to the terms and conditions of the Plan and in the event of any
question or controversy relating to the terms of the Plan, the decision of the
Committee shall be conclusive.

          12.  Tax Status.
               ----------

          This option does not qualify as an "incentive stock option" under the
provisions of Section 422A of the Internal Revenue Code of 1986, as amended, and
the income tax implications of your receipt of a non-incentive stock option and
your exercise of such an option should be discussed with your tax counsel.

                                    Sincerely yours,

                                    NEXELL THERAPEUTICS INC.

                                    By:  /s/ William A. Albright
                                         -----------------------
                                         Name:   William A. Albright
                                                 -------------------
                                         Title:  Chief Financial Officer
                                                 -----------------------
Agreed to and accepted this
9th day of November, 1999

 /s/ Joseph A. Mollica
---------------------------
Joseph A. Mollica, Optionee

                                       4

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