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                                                                   EXHIBIT 10.63

                                  AMENDMENT TO
                            ASSET TRANSFER AGREEMENT


     This Amendment to the Asset Transfer Agreement dated as of June 30, 1999
(the "Asset Transfer Agreement") is made and entered into as of November 30,
1999 by and among BAXTER HEALTHCARE CORPORATION, a Delaware corporation with
offices at 1627 Lake Cook Road, Deerfield, Illinois 60015 ("Baxter"), NEXELL
THERAPEUTICS INC., a Delaware corporation f/k/a/ VIMRx Pharmaceuticals Inc.
("Nexell"), and NEXELL OF CALIFORNIA, INC., a Delaware corporation f/k/a Nexell
Therapeutics, Inc. ("Nexell California").  Nexell and Nexell California, which
are collectively referred to herein as the "Nexell Group", have offices located
at 9 Parker, Irvine, California 92618.  All capitalized terms used herein and
not defined shall have the respective meanings assigned to them in the Asset
Transfer Agreement.

                                    RECITALS
                                    --------

     A.  Pursuant to the Asset Transfer Agreement, Baxter, Nexell and Nexell
California provided for the transfer of a going concern, i.e. Baxter's cell
                                                         ----
therapies business in the United States and the rest of the world, from Baxter
(and its Affiliates) to Nexell California (and the Nexell European Affiliate).

     B.  The US Asset Transfer Closing occurred on June 30, 1999, and the ROW
Asset Transfer Closing will occur on the date hereof.

     C.  Baxter, Nexell and Nexell California desire to set forth herein certain
acknowledgments relating specifically to the ROW Asset Transfer Closing and to
amend the Asset Transfer Agreement to reflect such terms.

     NOW, THEREFORE, in consideration of the mutual covenants set forth herein,
and other good and valuable consideration, the receipt and sufficiency of which
is hereby acknowledged, the parties agree as follows:

     1.  Schedules.  The parties hereby acknowledge that attached hereto as
         ---------
Schedule 1 are the following schedules delivered in connection with the ROW
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Asset Transfer Closing pursuant to Section 2.4 of the Asset Transfer Agreement:
Schedule of ROW Service Contracts (identifying any outstanding balances due on
any prepaid amounts under the ROW Service Contracts as of the ROW Asset Transfer
Closing); Schedule of finished goods inventory forming part of the ROW
Transferred Assets; Schedule of hardware and related assets forming part of the
ROW Transferred Assets; Schedule of ROW Assigned Agreements forming part of the
ROW Transferred Assets; Schedule of ROW Service Contracts forming part of the
ROW Transferred Assets (including all payments due under the ROW Service
Contracts and the aggregate pro rata share of any outstanding balance due on any
prepaid amounts under any ROW Service Contract); Schedule of ROW Assumed
Liabilities; and a Schedule of ROW Leased Transferred Assets.

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     2.  Purchase Consideration.  The parties acknowledge that certain of the
         ----------------------
ROW Transferred Assets which are in the possession of customers of Baxter or its
Affiliates are not the subject of written agreements between Baxter (or its
Affiliates) and such customers, but that the parties nonetheless desire to
transfer such ROW Transferred Assets on the ROW Asset Transfer Closing Date in
accordance with the Asset Transfer Agreement.

          (a) Section 2.2(B) of the Asset Transfer Agreement is hereby amended
by adding a new paragraph at the end of the existing Section to read as follows:

               Notwithstanding the foregoing, within six months of the ROW Asset
          Transfer Settlement Date or not later than December 31, 1999, as
          applicable under the preceding paragraph of this Section 2.2(B) (the
          "Payment Date"), Nexell California shall be required to pay or cause a
          Nexell European Affiliate to pay to Baxter (or its Affiliates) the ROW
          Transferred Asset Purchase Price only with respect to those ROW
          Transferred Assets as to which Baxter has delivered to Nexell
          California prior to the Payment Date sufficient evidence of good and
          valid title, free and clear of all Encumbrances, except for Permitted
          Encumbrances and the rights of any third party lessee arising under
          applicable leases relating to the Leased Transferred Assets.
          "Sufficient evidence" shall mean (i) an original writing signed by the
          party in possession of the ROW Transferred Assets, stating
          unambiguously that Baxter (or its Affiliates) has such title and that
          such party acknowledges and accepts the transfer of such title to
          Nexell, or (ii) any evidence that Nexell California reasonably deems
          sufficient for the purposes of evidencing title.  If, at any time
          following the Payment Date, Baxter delivers to Nexell California
          sufficient evidence of good and valid title to any ROW Transferred
          Assets for which Nexell California or the Nexell European Affiliate
          has not yet paid, then, within 30 days of receipt of such evidence,
          Nexell California shall pay or cause a Nexell European Affiliate to
          pay to Baxter (or its Affiliates) the ROW Transferred Asset Purchase
          Price with respect to such ROW Transferred Assets.

          (b) Section 2.2(C) of the Asset Transfer Agreement is hereby amended
by adding a new paragraph at the end of the existing Section to read as follows:

               Notwithstanding the foregoing, over the three year period or not
          later than December 31, 1999, as applicable under the preceding
          paragraph of this Section 2.2(C) (the "Leased Transferred Assets
          Payment Date"), Nexell California shall be required to pay or cause a
          Nexell European Affiliate to pay to Baxter (or its Affiliates) the
          Leased Transferred Asset Purchase Price only with respect to those
          Leased Transferred Assets as to

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          which Baxter has delivered to Nexell California prior to the Payment
          Date sufficient evidence of good and valid title, free and clear of
          all Encumbrances, except for Permitted Encumbrances and the rights of
          any third party lessee arising under applicable leases relating to the
          Leased Transferred Assets. "Sufficient evidence" shall mean (i) an
          original writing signed by the party in possession of the Leased
          Transferred Assets, stating unambiguously that Baxter (or its
          Affiliates) has such title and that such party acknowledges and
          accepts the transfer of such title to Nexell, or (ii) any evidence
          that Nexell California reasonably deems sufficient for the purposes of
          evidencing title. If, at any time following the Leased Transferred
          Assets Payment Date, Baxter delivers to Nexell California sufficient
          evidence of good and valid title to any Leased Transferred Assets for
          which Nexell California or the Nexell European Affiliate has not yet
          paid, then, within 30 days of receipt of such evidence, Nexell
          California shall pay or cause a Nexell European Affiliate to pay to
          Baxter (or its Affiliates) the Leased Transferred Asset Purchase Price
          with respect to such Leased Transferred Assets.

     3.   Agreement Relating to European Commercial Contracts.  The parties
          ---------------------------------------------------
hereby acknowledge that Baxter and the Nexell European Affiliate have entered
into an agreement relating to Baxter European commercial contracts (the
"Commercial Contract Agreement"), because all such contracts have not been
delivered to Nexell California in accordance with Section 2.4 of the Asset
Transfer Agreement, and the parties nonetheless desire to transfer Baxter's
assets on the ROW Asset Transfer Closing Date in accordance with the Asset
Transfer Agreement.  Under this agreement, Baxter Affiliates will act to a
limited degree as non-exclusive distributors for Nexell's cell therapies
products for a period of time following the ROW Asset Transfer Closing Date, in
accordance with their terms and conditions.  The terms of Section 3.3 of the
Asset Transfer Agreement shall not be modified by this Paragraph 3.

     4.   Tender Agreements.
          -----------------

         (a) The parties hereby acknowledge that Baxter Affiliates and the
Nexell European Affiliate have entered into certain agreements relating to
Baxter tenders (the "Tender Agreements") pursuant to which Baxter will remain a
party to certain tenders with the Governments of France, Italy, Portgual and
Spain relating to the provision and servicing of cell therapies products,
equipment, apparatus and instruments ("Tenders") because such Tenders have not
been delivered to Nexell California in accordance with Section 2.4 of the Asset
Transfer Agreement, and the parties nonetheless desire to transfer Baxter's
assets on the ROW Asset Transfer Closing Date in accordance with the Asset
Transfer Agreement.  The parties further acknowledge that Baxter Affiliates and
the Nexell European Affiliate have entered into certain business transfer
agreements (the "Business Transfer Agreements") reciting the transfer of the ROW
Transferred Assets in France, Italy, Portugal and Spain in accordance with the
Asset Transfer Agreement.

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          (b) Section 2.1(A)(ii) of the Asset Transfer Agreement is hereby
amended and restated in its entirety to read as follows:

               (ii)  At the ROW Asset Transfer Closing, all of Baxter's (or its
          Affiliates') right, title and interest in and to the ROW Transferred
          Assets, except for Baxter's (and its Affiliates') right, title and
          interest in and to certain tenders with the Governments of France,
          Italy, Spain, Portugal and Finland identified in those certain
          agreements entered into as of the ROW Asset Transfer Closing Date
          between Affiliates of Baxter and the Nexell European Affiliate
          pursuant to which Baxter will remain a party to such tenders (the
          "Tender Agreements").  The sale, assignment, transfer and delivery by
          Baxter (and its Affiliates) to Nexell California of such tenders shall
          be governed by the terms and conditions of the Tender Agreements.

          (c) Notwithstanding anything herein to the contrary, the Tenders shall
continue to be included in the definition of "ROW Transferred Assets" as "ROW
Service Contracts" for all purposes of the Asset Transfer Agreement.

     5.   Key European Employees.
          ----------------------

          (a) The parties hereby acknowledge that, of the European Key Employees
identified on Schedule 13 to the Asset Transfer Agreement, only those employees
identified on Schedule 4(a) hereto have chosen to be hired by the Nexell
              -------------
European Affiliate.

          (b) Section 13 of the Asset Transfer Agreement is hereby amended by
adding a new subsection following existing subsection (B) to read as follows:

               (C)  Except to the extent otherwise provided herein, neither
          Nexell California nor the Nexell European Affiliate shall assume any
          obligations arising under any Plans which Baxter maintains relating to
          any European Key Employees.  The active participation of the European
          Key Employees who choose to be hired by the Nexell European Affiliate
          in the Plans shall terminate as of the ROW Asset Transfer Closing
          Date, in each case except to the extent that any rights under the
          Plans shall have vested, or may vest upon fulfillment of certain
          conditions, in accordance with the terms contained therein; provided,
          however, that the European Key Employees who choose to be hired by the
          Nexell European Affiliate shall be 100% vested in their account
          balances under Baxter's Savings Plan and in their accrued benefits
          under the Baxter International Inc. and Subsidiaries Pension Plan.

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     6.  Representations and Warranties.  Baxter hereby makes to Nexell
         ------------------------------
California those representations and warranties that are set forth in Section 6
of the Asset Transfer Agreement as of the ROW Asset Transfer Closing Date.
Nexell California hereby makes to Baxter those representations and warranties
that are set forth in Section 7 of the Asset Transfer Agreement as of the ROW
Asset Transfer Closing Date.

     7.  Further Assurances and Cooperation.  Each party covenants and warrants
         ----------------------------------
that, on and following the ROW Asset Transfer Closing Date, it shall, whenever
and as often as it shall be reasonably requested to do so by another party to
this Amendment, execute, acknowledge and deliver or cause to be executed,
acknowledged and delivered, any and all such further documents and instruments
as may be reasonably necessary, expedient or proper in order to carry out and
effectuate the transactions contemplated by this Amendment and to complete any
and all of the conveyances, transfers, sale and assignments provided for in the
Asset Transfer Agreement and this Amendment.  These documents and instruments
shall include, but not be limited to, the Tender Documentation as defined in the
Tender Agreements, the Commercial Contract Documentation as defined in the
agreement relating to European commercial contracts, and the other documents and
instruments conemplated to be provided pursuant to the Commercial Contract
Agreement, the Tender Agreements and the Business Transfer Agreements.

     8.  Effect of Amendment.  The Asset Transfer Agreement and this Amendment
         -------------------
shall be read together and shall have the same effect as if the provisions of
the Agreement and this Amendment were contained in one document.  Except as
amended by this Amendment, the Agreement shall remain in full force and effect
and the terms and conditions thereof shall remain as originally written.

     9.  Dispute Resolution.  The terms of Section 23.6 of the Asset Transfer
         ------------------
Agreement shall apply equally to disputes under this Amendment, and the word
"Agreement" where used in such Section 23.6 shall be interpreted to mean the
Asset Transfer Agreement and this Amendment.

     10. Governing Law; Jurisdiction.  This Amendment shall be governed by and
         ---------------------------
construed in accordance with the internal laws of the State of Delaware, without
application of conflicts of law principles, and, subject to Section 23.6 of the
Asset Transfer Agreement, each party hereby submits to the jurisdiction and
venue of any state or federal court in the State of Delaware.  To the extent
permissible by law, each of the parties hereby waives, releases and agrees not
to assert, and agrees to cause its Affiliates to waive, release and not assert,
any rights such party or its Affiliates may have under any foreign law or
regulation that would be inconsistent with the terms of this Agreement as
governed by Delaware law.

     11. Counterparts; Facsimile Signature.  This Amendment may be signed in
         ---------------------------------
any number of counterparts which taken together shall constitute one and the
same instrument.  This Amendment may be executed and delivered by exchange of
facsimile copies showing the signatures of the parties hereto, and those
signatures need not be affixed to the same copy.  The facsimile copies showing
the signatures of the parties will constitute originally signed copies of the
same agreement requiring no further execution.

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     12.  Schedules.  The schedules referred to in this Amendment are attached
          ---------
hereto and incorporated herein by reference as if fully set forth herein.

          IN WITNESS WHEREOF, the undersigned have executed this Amendment to
Asset Transfer Agreement as of the date first above written.


                              BAXTER HEALTHCARE CORPORATION


                              By:    /s/ Steven J. Meyer
                                     ---------------------------------
                              Name:  Steven J. Meyer
                                     ---------------------------------
                              Title: Treasurer
                                     ---------------------------------



                              NEXELL THERAPEUTICS INC.


                              By:    /s/ L. William McIntosh
                                     ---------------------------------
                              Name:  L. William McIntosh
                                     ---------------------------------
                              Title: President and COO
                                     ---------------------------------



                              NEXELL OF CALIFORNIA, INC.


                              By:    /s/ L. William McIntosh
                                     ---------------------------------
                              Name:  L. William McIntosh
                                     ---------------------------------
                              Title: CEO
                                     ---------------------------------

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SCHEDULE 1
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ROW ASSET TRANSFER SCHEDULES

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SCHEDULE 4(a)
-------------

KEY EUROPEAN EMPLOYEES