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                                                                   Exhibit 10.34

                            EQUITY RIGHT PURCHASE AND

                           LICENSE AMENDMENT AGREEMENT

      THIS EQUITY RIGHT PURCHASE AND LICENSE AMENDMENT AGREEMENT ("Agreement")
is entered into December 30, 2003 ("Effective Date") by and between IGEN
International, Inc. ("IGEN"), and Wellstat Therapeutics Corporation, formerly
known as Pro-Neuron, Inc. ("Company"). Capitalized terms not defined herein
shall have the meaning ascribed to them in the 1993 Agreement (as defined
herein).

      WHEREAS, on December 14, 1993, IGEN and the Company entered into a term
sheet agreement for the consolidation of cancer research projects (as amended,
the "1993 Agreement");

      WHEREAS, pursuant to the 1993 Agreement, in the event that no Major
Financing is conducted prior to December 31, 2003, certain payments made by IGEN
to the Company would be treated as an equity investment and converted into 4.5%
of the Company's fully diluted equity ("Equity Right");

      WHEREAS, the Company has agreed to repurchase from IGEN, and IGEN agrees
to sell to the Company, the Equity Right;

      WHEREAS, under the 1993 Agreement IGEN granted the Company an exclusive,
worldwide, perpetual license to all of IGEN's interest in the IGEN prodrug
cancer program, including certain patents and patent applications outside the
field of diagnostics, that specifically excluded IGEN's rights and patents using
catalytic antibodies (Abzymes) for all fields of use, including cancer
therapeutics (the "IGEN License")

      WHEREAS, under the 1993 Agreement IGEN agreed to assign its 50% interest
in ProGen to the Company;

      WHEREAS, under the 1993 Agreement the Company granted IGEN an exclusive,
worldwide perpetual license under certain know-how, trade secrets, patents and
patent applications in the field of research, industrial and clinical diagnostic
markers except clinical diagnostic use in a centralized setting (reference
laboratories, central laboratories in hospitals and blood banks) (the "Company
License");

      WHEREAS, the 1993 Agreement contains certain royalty provisions in the
event that one party commercializes technology licensed or otherwise acquired
from the other party; and

      WHEREAS, Company and IGEN desire to terminate the licenses and royalty
obligations provided for by the 1993 Agreement,
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      NOW, THEREFORE, in consideration of the premises and the mutual covenants
set forth herein, and intending to amend the 1993 Agreement to the extent
applicable, the parties agree as follows:

                                   ARTICLE I

                        Purchase and Sale of Equity Right

      Section 1.1 Purchase and Sale. At the Closing, pursuant to and in full
satisfaction of the obligations under Section 6 of the 1993 Agreement, IGEN
shall sell to the Company, and the Company shall purchase from IGEN, upon the
terms and subject to the conditions set forth herein, the Equity Right for an
aggregate price (the "Purchase Price") equal to $1,700,000 (the "Transaction").
From and after the Closing of the Transaction, Section 6 of the 1993 Agreement
shall have no further force or effect.

                                   ARTICLE II

                     Agreements Regarding the 1993 Agreement

      Section 2.1 IGEN License. The Company and IGEN agree that, as of the
Closing, the IGEN License granted under Section 2 of the 1993 Agreement,
together with any obligation to pay royalties thereunder, shall be terminated
and shall be of no further force or effect. The parties agree that "IGEN's
pro-drug cancer program" as used in the IGEN License shall mean the worldwide
rights in the cancer field conferred by the patent listed on Exhibit "A",
attached hereto and incorporated by reference herein, but shall exclude the use
of catalytic antibodies (Abzymes). In accordance with the last sentence of
Section 3 of the 1993 Agreement (but specifically excluding the grant-back
provisions of such sentence), IGEN's diagnostic rights in the IGEN pro-drug
cancer program shall continue to be retained by IGEN.

      Section 2.2 Company License. The Company and IGEN agree that, as of the
Closing, the Company License granted under Section 3 of the 1993 Agreement,
together with any obligation to pay royalties thereunder and the grant-back
provisions of the last sentence of Section 3 of the 1993 Agreement, shall be
terminated.

      Section 2.3 ProGen Interest. IGEN hereby acknowledges and reconfirms the
assignment of all of its right, title and interest in and to its fifty percent
(50%) ownership interest in that certain joint venture commonly known as
"ProGen" to Pro-Neuron (n/k/a Wellstat Therapeutics Corporation). In accordance
with the last sentence of Section 3 of the 1993 Agreement (but specifically
excluding the grantback provisions of such sentence), IGEN's diagnostic rights
in the Pro Gen technology shall continue to be retained in IGEN. At the request
of Company, IGEN shall do all things reasonably necessary to confirm Company's
full ownership of ProGen.

                                  ARTICLE III

                         Representations and Warranties

      Section 3.1 Wohlstadter's Representations and Warranties. Samuel
Wohlstadter represents and warrants to IGEN that: (a) he has approved this
Agreement in his capacity as a


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stockholder and chief executive officer of the Company; (b) there are currently
no negotiations or discussions concerning Major Financing for the Company from
third-party sources; and (c) all consents, filings, notices, approvals and
authorizations of or with (i) any court, governmental agency or body or any self
regulatory authorities, or (ii) any other person or entity, in each case to the
extent required for the execution, delivery and performance by Wohlstadter of
this Agreement, have been obtained or made and are in full force and effect.

      Section 3.2 Company's Representations and Warranties. The Company
represents and warrants to IGEN that (a) the Company is duly organized, validly
existing and in good standing under the laws of the jurisdiction of its
formation; (b) the Company has all necessary right, power and authority to
execute and deliver this Agreement, this Agreement has been duly and validly
authorized, executed and delivered by the Company and is a valid and binding
agreement, enforceable against the Company in accordance with its terms, and the
Company has full right, power and authority to perform its obligations under
this Agreement; (c) all necessary consents, approvals and authorizations of all
government authorities and other persons required to be obtained by the Company
in connection with execution, delivery and performance of this Agreement have
been obtained; and (d) the execution and delivery of this Agreement, the
performance of the Company's obligations hereunder (i) do not conflict with or
violate any requirement of applicable laws or regulations and (ii) do not and
will not conflict with, violate or breach or constitute a default or require any
consent under, any contractual obligations of the Company.

      Section 3.3 IGEN's Representations and Warranties. IGEN represents and
warrants to Company that (a) IGEN is duly organized, validly existing and in
good standing under the laws of the jurisdiction of its formation; (b) IGEN has
all necessary right, power and authority to execute and deliver this Agreement,
this Agreement has been duly and validly authorized, executed and delivered by
IGEN and is a valid and binding agreement, enforceable against IGEN in
accordance with its terms, and IGEN has full right, power and authority to
perform its obligations under this Agreement; (c) all necessary consents,
approvals and authorizations of all government authorities and other persons
required to be obtained by IGEN in connection with execution, delivery and
performance of this Agreement have been obtained; and (d) the execution and
delivery of this Agreement, the performance of IGEN's obligations hereunder (i)
do not conflict with or violate any requirement of applicable laws or
regulations and (ii) do not and will not conflict with, violate or breach or
constitute a default or require any consent under, any contractual obligations
of IGEN.

                                   ARTICLE IV

                             Closing and Termination

      Section 4.1 Conditions Precedent.

      (a) The obligations of IGEN to consummate the Transaction are subject to
(i) there not being in effect any injunction or other order issued by a court of
competent jurisdiction restraining or prohibiting the consummation of the
Transaction and (ii) the representations and warranties of Samuel Wohlstadter
and the Company being true and correct as of the Effective Date and as of the
Closing as if made at the Closing.


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      (b) The obligations of the Company to consummate the Transaction are
subject to (i) there not being in effect any injunction or other order issued by
a court of competent jurisdiction restraining or prohibiting the consummation of
the Transaction and (ii) the representations and warranties of IGEN being true
and correct as of the Effective Date and as of the Closing as if made at the
Closing.

      (c) The obligations of each party to consummate each of the transactions
are subject to (i) the parties obtaining the consent of Roche Holding Ltd. to
this Agreement and to the Equity Right Purchase and License Amendment Agreement
dated as of the date hereof between IGEN and Proteinix, Inc. (the "Proteinix
Agreement"), and (ii) the parties to the Proteinix Agreement having entered into
the sublicense agreements contemplated therein.

      Section 4.2 Closing. Subject to the closing conditions set forth in
Section 4.1 , the closing of the Transaction (the "Closing") shall take place at
the offices of IGEN no later than two business days before the transfer of
assets from IGEN to BioVeris Corporation ("BioVeris") pursuant to the
restructuring agreement between IGEN and Bio Veris (the "Bio Veris Restructuring
Date"). At the Closing: (a) IGEN will sell, transfer and deliver the Equity
Right to the Company, represented by an instrument acknowledging the termination
of the Equity Right; and (b) the Company shall pay IGEN the Purchase Price for
the Equity Right by wire transfer of immediately available funds to be paid to
such account designated by IGEN in writing to the Company at least one (1)
business day prior to the Closing.

      Section 4.3 Termination. This Agreement shall terminate without liability
to any party if the Closing shall not have occurred on or prior to the later of
(i) the date that is thirty (30) days after the BioVeris Restructuring Date (or,
if such date is not a business day, the following business day) and (ii) March
31, 2004, provided that such termination shall not relieve any party from
obligation for any breach or misrepresentation prior to termination.

                                   ARTICLE V

                                 Mutual Release

      Section 5.1 Release by the Company. Effective upon the Closing, the
Company, on its own behalf and on behalf of its stockholders, officers,
employees, directors, agents, representatives, attorneys, predecessors,
successors, and assigns, hereby fully and finally releases, acquits, and forever
discharges, IGEN together with its stockholders, officers, employees, directors,
agents, representatives, attorneys, predecessors, successors, and assigns, from
any and all claims and obligations under the 1993 Agreement, and agrees that it
will not prosecute or pursue any and all claims or actions it may now have or
may have in the future with respect to any activities being conducted up to the
date of this Agreement by IGEN that were directly or indirectly conducted in
conjunction with the Company License.

      Section 5.2 Release by IGEN. Effective upon the Closing, IGEN, on its own
behalf and on behalf of its stockholders, officers, employees, directors,
agents, representatives, attorneys, predecessors, successors, and assigns,
hereby fully and finally releases, acquits, and forever discharges the Company,
together with its stockholders, officers, employees, directors, agents,
representatives, attorneys, predecessors, successors, and assigns, from any and
all claims and


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obligations under the 1993 Agreement, and agrees that it will not prosecute or
pursue any and all claims or actions it may now have or may have in the future
with respect to any activities being conducted up to the date of this Agreement
by the Company that were directly or indirectly conducted in conjunction with
the IGEN License.

                                   ARTICLE VI

                            Miscellaneous Provisions

      Section 6.1 Expenses. Each of the parties hereto shall pay its own
expenses incurred in connection with this Agreement.

      Section 6.2 Further Actions. At any time or times from and after the
Closing, any party shall, at the request of another party, execute and deliver
any further instruments and documents and take all such further action as such
other may reasonably request in order to evidence or effect the consummation of
the Transaction.

      Section 6.3 Filings. Any party to this Agreement may make any filings that
are required by law or by obligations pursuant to any listing agreement with any
national securities exchange as a result of the Transaction.

      Section 6.4 Survival. All representations, warranties, covenants and
agreements made by IGEN, the Company or Wohlstadter in this Agreement shall
survive the Closing.

      Section 6.5 Notices. All notices, requests, consents, approvals,
agreements, authorizations, acknowledgments, and other communications required
or permitted among the parties shall be in writing and shall be deemed given
when (a) sent by registered or certified mail, return receipt requested, postage
prepaid, (b) sent via a reputable overnight courier service, or (c) sent by
facsimile transmission, in each case properly addressed in accordance with the
address specified below.

      If to IGEN, to:

      IGEN International, Inc.
      16020 Industrial Drive
      Gaithersburg, MD 20877
      Attention:  General Counsel

      If to the Company, to:

      Wellstat Therapeutics Corporation
      930 Clopper Road
      Gaithersburg, MD 20878
      Attention:  Legal Department


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or such other address as the person to whom notice is to be given may have
previously furnished to the others in writing in the manner set forth above
(provided that notice of any change of address shall be effective only upon
receipt thereof).

      Section 6.6 Amendment; Entire Agreement. This Agreement may not be
modified, amended, altered or supplemented except upon the execution and
delivery of a written agreement executed by the parties hereto. This Agreement
constitutes the entire agreement between the parties with respect to the subject
matter hereof, and supersedes an previous arrangements with respect to the
subject matter hereof, whether written or oral.

      Section 6.7 Specific Performance. Each of the parties acknowledges and
agrees that the other party would be damaged irreparably in the event any of the
provisions of this Agreement are not performed in accordance with their specific
terms or otherwise are breached. Accordingly, each of the parties agrees that
the other party shall be entitled to an injunction or injunctions to prevent
breaches of the provisions of this Agreement and to enforce specifically this
Agreement and the terms and provisions hereof in any action instituted in any
court of the United States or any state thereof having jurisdiction over the
parties and the matter, in addition to any other remedy to which they may be
entitled, at law or in equity.

      Section 6.8 Assignment. No party may assign any of its rights or
obligations under this Agreement without the prior written consent of the other
parties, and any such attempted assignment without the prior written consent of
the other parties shall be null and void except that IGEN may assign this
Agreement to BioVeris, Inc. pursuant to that certain Restructuring Agreement
between IGEN and BioVeris, Inc. (f/k/a IGEN Integrated Healthcare LLC). After
any assignment of this Agreement by IGEN to BioVeris, Inc, IGEN shall have no
further rights or obligations under or related to this Agreement. This Agreement
shall be binding on, and inure to the benefit of, the parties and their
respective successors and permitted assigns.

      Section 6.9 Severability. Wherever possible, each provision hereof shall
be interpreted in such manner as to be effective and valid under applicable law,
but in case any one or more of the provisions contained herein shall, for any
reason, be held to be invalid, illegal or unenforceable in any respect, such
invalidity, illegality or unenforceability shall not affect any other provisions
of this Agreement, and this Agreement shall be construed as if such invalid,
illegal or unenforceable provision or provisions had never been contained herein
unless the deletion of such provisions or provisions would result in such a
material change as to cause completion of the transactions contemplated hereby
to be unreasonable.

      Section 6.10 Counterparts. This Agreement may be executed in two or more
counterparts, each of which will be deemed to be an original but all of which
together will constitute one and the same instrument.

      Section 6.11 Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of Delaware, without regard
to the laws that may be applicable under conflicts of laws principles.


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                            {Signature Page Follows}


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      IN WITNESS WHEREOF, this Agreement has been duly executed and delivered by
the parties hereto on the date first written above.

                                          IGEN International, Inc.



                                          By: /s/ RICHARD MASSEY
                                             --------------------------
                                             Name:
                                             Title:


                                          Wellstat Therapeutics Corporation

                                          By: /s/ SAMUEL WOHLSTADTER
                                             --------------------------
                                              Name:
                                              Title:


      The undersigned has executed the foregoing Agreement solely for the
purpose of acknowledging and agreeing to the representations and warranties set
forth in Section 3.1 thereof.


                                          /s/ SAMUEL WOHLSTADTER
                                          ----------------------------
                                          Samuel Wohlstadter


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                                   EXHIBIT "A"


                               ISSUED U.S. PATENT

                                    6,258,360

and all continuations, divisionals, continuations-in-part, substitutions,
reissues, reexaminations, renewals, extensions, confirmation patents,
registration patents, patents of addition, and foreign counterparts of any of
the above, as well as patents and patent applications that claim priority to a
priority application of one or more of the above.


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