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                                                                   EXHIBIT 10.52


                                VOTING AGREEMENT

This Voting Agreement ("Agreement") is made this 17th day of December 17, 1997
among Baxter Healthcare Corporation, a Delaware corporation ("Baxter"), Lindsay
A. Rosenwald, M.D., an individual ("Rosenwald"), Paramount Capital Asset
Management Inc., a Delaware corporation ("Paramount"), Donald Drapkin, an
individual ("Drapkin"), Richard L. Dunning, an individual ("Dunning"), Laurence
D. Fink, an individual ("Fink"), and Eric A. Rose, an individual ("Rose"), and
any other signatory set forth on the signature page hereto (collectively, the
"Stockholders").

WHEREAS, the Stockholders each hold shares of the common stock (the "Stock") of
VIMRx Pharmaceuticals Inc., a Delaware corporation (the "Company") or options to
acquire Stock; and

WHEREAS, as a condition to Baxter's agreement to sell its immunotherapy business
relating to certain ex vivo cell therapy to the Company (the "Sale"), and as an
inducement for Baxter to enter into the Asset Purchase Agreement, dated as of
October 10, 1997 (the "Asset Purchase Agreement") among the Company, Baxter, and
BIT Acquistion Corp., a Delaware corporation ("Newco"), the Stockholders and
Baxter have agreed to enter into this Agreement, to be specifically enforceable
against each of them, pursuant to which they agree to vote their shares of the
Stock in the manner and for the purpose specified herein.

NOW, THEREFORE, in consideration of the mutual covenants contained herein,, the
Stockholders and Baxter hereby agree as follows:

1. Voting Agreement. (a) Each of the Stockholders hereby agrees to vote all of
the Stock beneficially owned, directly or indirectly, by him or it (and all
Stock issued pursuant to the exercise of stock options) in favor of the Baxter
nominated director in connection with Baxter's right to nominate a director to
the VIMRx Board of Directors pursuant to Section 6.2(E) of the Asset Purchase
Agreement; provided, however, that nothing contained herein shall prevent any
Stockholder from transferring, selling or otherwise disposing of Stock held by
such Stockholder provided any such transferee agrees in a written instrument
satisfactory to Baxter to be bound by the terms hereof; and further provided,
that the obligations of such transferee shall be void as to any transferee
purchasing Stock pursuant to Rule 144 or a registered offering under the
Securities Act of 1933. It is expressly understood and agreed by each of the
Stockholders and Baxter that this Agreement is intended to, and does hereby,
create and constitute a voting agreement within the meaning of Section 218(c) of
the General Corporation Law of the State of Delaware, as amended, and not a
voting trust agreement under Section 218(a) thereof.

     (b)  Baxter hereby agrees to vote all of the Stock beneficially owned,
directly or indirectly, by it in favor of the nominees for director recommended
by VIMRx's Nominating Committee (or by a majority of the Board of Directors if
there is no Nominating Committee); provided, that nothing contained herein shall
require Baxter to refrain from voting its Stock in favor of the Baxter nominated
director; and provided further, that nothing contained herein shall prevent
Baxter from transferring, selling or otherwise disposing of Stock held by Baxter
provided any such transferee agrees in a written instrument satisfactory to
VIMRx to be bound by the terms hereof; and further provided, that the
obligations of such transferee shall be void as to any transferee purchasing
Stock pursuant to Rule 144 or a registered offering under the Securities Act of
1933.

2.  Irrevocable Proxy. (a) In order to secure each Stockholder's obligation to
vote his or its Stock and other voting securities of the Company in accordance
with the provisions of Section 1(a), each Stockholder (other than Baxter) hereby
appoints Baxter (the "Proxy") as its true and lawful proxy and attorney-in-fact,
with full power of substitution, to vote all of his or its Stock and other
voting securities of the Company as expressly provided for in Section 1(a). The
Proxy may exercise the irrevocable proxy granted to it hereunder at any time

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any party fails to comply with the provisions of this Agreement. The proxies and
powers granted by each Stockholder pursuant to this Section 2 are coupled with
an interest and are given to secure the performance of the Stockholder's
obligations under this Agreement. Such proxies and powers will be irrevocable
with respect to the matters set forth in Section 1 for the term set forth in
Section 5, and, with respect to any individual, will survive the death,
incompetency and disability of such Stockholder.

     (b)  In order to secure Baxter's obligations to vote its Stock and other
voting securities of the Company in accordance with the provisions of Section
1(b), Baxter hereby appoints the Chief Executive Officer of VIMRx (the "Baxter
Proxy") as its true and lawful proxy and attorney-in-fact, with full power of
substitution, to vote all of Baxter's Stock and other voting securities of the
Company as expressly provided for in Section 1(b). The Baxter Proxy may exercise
the irrevocable proxy granted to him hereunder at any time Baxter fails to
comply with the provisions of this Agreement. The proxy and powers granted by
Baxter pursuant to this Section 2 are coupled with an interest and is given to
secure the performance of Baxter's obligations under this Agreement. Such proxy
and powers will be irrevocable with respect to the matters set forth in Section
1 for the term set forth in Section 5.

3.  Representations of the Parties.  Each party to this Agreement hereby
represents and warrants to each of the other parties that (a) he or it owns and
has the right to vote the number of shares of the Stock set forth opposite his
name on Exhibit A attached hereto, (b) he or it has full power to enter into
this Agreement, and (c) he or it is not a party to any proxy, voting trust or
other agreement which is inconsistent with or conflicts with the provisions of
this Agreement, and no party will grant any proxy or become party to any voting
trust or other agreement which is inconsistent with or conflicts with the
provisions of this Agreement. All representations and warranties contained
herein or made in writing by any party in connection herewith will survive the
execution and delivery of this Agreement, regardless of any investigation made
by any party.

4.  Specific Performance.  The parties hereto agree that irreparable damage
would occur in the event any provision of this Agreement was not performed in
accordance with the terms hereof and that the parties shall be entitled to
specific performance of the terms hereof, in addition to any other remedy at law
or in equity.

5.  Term.  This Agreement shall remain in effect so long as Baxter shall
continue to own at least 3% of the shares of Stock of the Company, as adjusted
for any additional shares of Stock issued by the Company following the date of
this Agreement, and Baxter's obligations hereunder shall continue so long as
Baxter's representative (if Baxter shall have chosen to designate one) shall
retain a seat on the VIMRx Board of Directors.

6.  WAIVER OF JURY TRIAL.  EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES
ANY AND ALL RIGHTS TO TRIAL BY JURY IN ANY LEGAL PROCEEDING ARISING OUT OF OR
RELATING TO THIS AGREEMENT, AND CONSENTS TO THE GRANTING OF SUCH LEGAL OR
EQUITABLE RELIEF AS IS DEEMED APPROPRIATE BY THE COURT.

7.  General Provisions.

    (a) All of the covenants and agreements contained in this Agreement shall be
    binding upon, and inure to the benefit of, the respective parties and their
    successors, assigns, heirs, executors, administrators and other legal
    representatives, as the case may be. Nothing contained herein shall prevent
    any of the parties hereto from assigning their rights hereunder.

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    (b) This Agreement may be executed in two or more counterparts, each of
    which will be deemed an original but all of which together shall constitute
    one and the same instrument. The parties hereto agree that facsimile
    transmissions of original signatures shall constitute and be accepted as
    original signatures.

    (c) If any provision of this Agreement shall be declared void or
    unenforceable by any court or administrative board of competent
    jurisdiction, such provision shall be deemed to have been severed from the
    remainder of this Agreement and this Agreement shall continue in all
    respects to be valid and enforceable.

    (d) No waiver of any breach of this Agreement extended by any party hereto
    to any other party shall be construed as a waiver of any rights or remedies
    of any other party hereto or with respect to any subsequent breach.

    (e) Whenever the context of this Agreement shall so require, the use of the
    singular number shall include the plural and the use of any gender shall
    include all genders.

    (f) This Agreement shall be governed by and construed in accordance with the
    laws of the State of Delaware, without regard to principles of conflicts of
    law; however, any action or proceeding relating to this Agreement shall be
    brought only in and decided by the federal or state courts in Delaware, such
    courts being a proper forum in which to adjudicate such action or
    proceeding, and each party hereby waives any claim of inconvenient forum.

    (g) The language used in this Agreement shall be deemed to be the language
    chosen by the parties to express their mutual intent and no rule of strict
    construction will be applied against any party.

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IN WITNESS WHEREOF, Baxter and each of the Stockholders has executed this
Agreement as of the date first written above.

                           BAXTER HEALTHCARE CORPORATION

                           BY: /s/ Victor W. Schmitt
                           -------------------------

                           Name: Victor W. Schmitt
                           -----------------------

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


                           VIMRx PHARMACEUTICALS INC.

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

                           Name: Richard L. Dunning
                           ------------------------

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


                           LINDSAY A. ROSENWALD, M.D.

                           /s/ Lindsay A. Rosenwald, M.D.
                           ------------------------------


                           PARAMOUNT CAPITAL ASSET MANAGEMENT INC.

                           By: /s/ Lindsay A. Rosenwald
                           ----------------------------

                           Name: Lindsay A. Rosenwald
                           --------------------------

                           Its: President
                           --------------

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                           DONALD DRAPKIN

                           /s/  Donald Drapkin
                           ---  --------------


                           RICHARD DUNNING

                           /s/  Richard Dunning
                           ---  ---------------


                           LAURENCE D. FINK

                           /s/  Laurence D. Fink
                           ---  ----------------


                           ERIC A. ROSE, M.D.

                           /s/  Eric A. Rose, M.D.
                           ---  ------------------

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                                   EXHIBIT A

                                 NUMBER OF SHARES OF VIMRx
                                 STOCK THAT STOCKHOLDER HAS
STOCKHOLDER                      RIGHT TO VOTE
                                 -------------

BAXTER HEALTHCARE CORPORATION       11,000,000

LINDSAY A. ROSENWALD, M.D.              50,000

PARAMOUNT CAPITAL ASSET
MANAGEMENT INC.                      3,666,666

DONALD DRAPKIN                         150,000

RICHARD L. DUNNING                       3,595

LAURENCE D. FINK                       433,333

ERIC A. ROSE                           328,400

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