CO-DEVELOPMENT AGREEMENT

THIS AGREEMENT (the  "Agreement") is entered into and effective this .... day of
 ......1998,  the same  date  affixed  hereto  by the  party  last  signing  this
Agreement, by and between Orion Pharmaceuticals Ltd ("Orion")  of............and
Bioenvision,  Inc  ("Bioenvision")  of Trafalgar  House,  11 Waterloo  Place, St
James's, London SW1Y 4AU

                                   WITNESSETH

WHEREAS,  Orion has rights in patents and technical  information relating to the
development  and uses of DNA vectors and related  technologies  [Technology(s)];
and

WHEREAS,  Bioenvision  recognizes  that Orion owns  inventions and  intellectual
property useful in the conduct of Bioenvision's business; and

WHEREAS,  Bioenvision  recognizes  that its anticipated  business  activity will
encompass the practice of technology that requires a license under patents owned
by Orion; and

WHEREAS, Bioenvision wishes to acquire certain rights to practice the inventions
of such patents and technical information; and

WHEREAS the parties have signed a "Terms for Co-Development Agreement" set forth
in Appendix I, to enter into this Agreement, and

NOW THEREFORE,  in  consideration  of the mutual  covenants herein contained and
intending to be legally bound thereby, the parties agree as follows:

                                 1. DEFINITIONS

As usual herein the following terms shall have the meanings set forth below:

A. Co-Development Program means the joint development of the Technology by
Bioenvision and Orion.

B. Field  means,  and is limited to, the practice of the Patent,  Invention  and
Technical  information  licensed  hereunder  for use in human and animal  health
applications.

C. Net Sale  Price  means the gross  amount  recognized  by  Bioenvision  or its
affiliates for the sale of a Product(s) through normal distribution channels (as
determined by generally accepted accounting  principles),  less any discounts or
deductions  for value added taxes  incurred and not recovered by  Bioenvision or
the equivalent in Great Britain or elsewhere in the Territory.


D.  Invention  means  patented  and  unpatented,  patentable  and  unpatentable,
proprietary  technology  ("Technology") related to DNA vectors for the treatment
of  liver   insufficiency,   with  particular  reference  to  the  treatment  of
hypoalbuminaemia,  developed  by or on behalf of Orion,  that is (i)  related to
human and animal health


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applications  of the Technology or (ii) necessary for the practice of Technology
for human and  animal  health  applications  as  disclosed  and  claimed  in the
Patent(s).

E. Improvement means those  unencumbered  technology  advances in the Technology
made by or on behalf of Orion during the term of this  Agreement that are either
within the scope of and would constitute an infringement of the Patent claims or
use Technical  Information and are within the Field. Orion shall be obligated to
include  within the  licenses  granted only those Orion  improvements  developed
during the first three (3) years from the effective date of the Agreement  which
would  be  reasonably  deemed  necessary  for  Bioenvision's   practice  of  the
Technology,  and without which such practice would constitute an infringement of
Orion's rights,  unless such grant is not possible due to Orion's obligations to
a third party. Notwithstanding the limitation of Orion's obligation set forth in
the previous  sentence,  all Improvements  developed under projects  funded,  in
whole or in part,  by  Bioenvision  will be included in the licenses  granted in
this Agreement.  In the event tat a conflicting  obligation  prevents Orion from
including an Improvement within the grant of license, Orion shall use reasonable
efforts to assist  Bioenvision to obtain rights from the appropriate third party
or parties.

F Licensed Technology means the Patent,  Improvement,  and Technical Information
relating  to  human  and  animal  health   applications  of  the  Technology  or
Product(s).

G. Patent means the patents and/or patent applications, covering the Technology,
Product(s),  Invention or  Improvement  as defined  above,  patents to be issued
pursuant  thereto,  and all divisionals,  continuations,  continuations-in-part,
reissues,  substitutions,  and extensions  thereof,  and any patent issuing on a
patent  application  filed after the Effective Date of this  Agreement  which is
included in the grant of license  hereunder and any foreign  counterparts of the
foregoing.

H. Product  means a product,  service,  test,  or  information  which is sold or
provided for a fee and but for the license  granted herein would infringe one or
more claims of a Patent, or was discovered, developed, approved, manufactured or
marketed using an Invention, Improvement or Technical Information.

I.   Technical   Information   means   unencumbered   published  or  unpublished
confidential  and  proprietary   information  in  the  nature  of  research  and
development  information,  knowledge  and  technical  data,  together with trade
secrets  relating to the Technology,  including any inventions in the possession
of and  belonging  solely  to Orion on or  prior to the  Effective  Date of this
Agreement and which Orion has the  obligation to include in this  Agreement,  or
which comes into the possession of Bioenvision during the term of this Agreement
and which is  generated  as a  consequence  of access to  technical  information
provided by Orion.  Orion shall include herein only that  Technical  Information
which is  reasonably  necessary for  Bioenvision's  practice of the Invention or
without which such practice would  constitute an infringement of Orion's rights.
Technical  Information includes only the above information which is developed by
or on behalf of Orion, or is generated  pursuant to research funded, in whole or
in part, by Bioenvision.

J. Territory means worldwide..

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                      2. LICENSE AND CO-DEVELOPMENT PROGRAM


A. The  parties  to this  Agreement  hereby  agree  to  jointly  co-develop  the
Technology  according to the terms of this Agreement which supersedes the "Heads
of Terms for a  Co-Development  Agreement" set forth in Appendix I and all other
written or verbal agreements,  express or implied, between Orion and Bioenvision
relating to co-development of the Technology.

B.  Orion  hereby  grants  to  Bioenvision,  to the  extent of the Field for the
Territory,  an exclusive  license to make,  have made, use and sell  Product(s),
provided  Bioenvision sells Product(s) under existing Orion trade-marks or under
new  trade-mark(s) to be agreed by both parties and the terms of clause 6H shall
apply to such new trademark(s).

C. The exclusive  license set forth herein shall remain exclusive for so long as
Bioenvision  meets the payments and other  obligations  set forth with regard to
the development and  commercialization  of the Licensed Technology or a Product.
If such  conditions are not met,  Orion,  in its sole  discretion,  may elect to
terminate  the  Co-Development  Agreement  or take  whatever  actions  it  deems
necessary.

D. The licence shall continue in force until expiry of the last patent for which
the product is covered,  this term to include new patents applied for during the
course of this Agreement. This term shall also continue in force until such time
as Bioenvision ceases to use any trade-mark belonging to Orion.

                        3. TECHNICAL INFORMATION LICENSE

A. To the extent it is able to do so, Orion hereby grants to Bioenvision, to the
extent of the Field for the Territory, an exclusive license to use the Technical
Information necessary to practice the Technology such that Bioenvision may make,
have made,  use and sell  Product(s),  including  disclosures  of the  Technical
Information  as needed  to obtain  patent  rights  or  authorization  to sell or
manufacture Products or services in the Field within any political  jurisdiction
requiring such disclosure.

B. The exclusive  license set forth herein shall remain exclusive for so long as
Bioenvision  meets the payments and other  obligations set forth with regard .to
the development and  commercialization  of the Licensed Technology or a Product.
If such  conditions  are not  met,  Orion in its sole  discretion  may  elect to
terminate  the  Co-Development  Agreement  or  take  whatever  action  it  deems
necessary

C. (1) Orion  shall make  efforts to make  available  to  Bioenvision  Technical
Information in Orion's  possession  related to the Technology that Orion has the
obligation to disclose under this Agreement.  Bioenvision  shall not disclose to
third  parties any Technical  Information  furnished by Orion during the term of
this Agreement, or any time thereafter,  provided,  however, that disclosure may
be made of any such  Technical  Information  at any  time:  (i) with the prior
written  consent of Orion,  or (ii) to the extent  necessary,  to  Bioenvision's
sublicensees  and purchasers of Bioenvision's  Product(s) or services,  or (iii)
after the same shall have  entered  into the public  domain  through no fault of
Bioenvision or Bioenvision's  subsidiaries.  Disclosure of Technical Information
is permitted without a prior written consent of



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Orion to the extent required by statute,  rule or regulation of a governing body
during  the  course  of  Bioenvision's  normal  business  practices,  or in  the
application or prosecution of an application for patent rights, or in connection
with  securing  financing  for  the  development  or  commercialization  of  the
Technology or a Product.  Bioenvision  shall inform Orion of any such disclosure
and use its best efforts to protect its  confidentiality  under such disclosure.
Any combination of Technical  Information  shall not be considered in the public
domain merely because  individual  elements thereof are in the public domain. To
the extent that any such  Technical  Information  is disclosed to  Bioenvision's
sublicensees  and  purchasers  of  Bioenvision's  Product(s)  or  services,  the
agreements  contained  in this  Section  shall  be made by  Bioenvision  under a
confidentiality agreement to apply to and be made binding upon all such parties.

(2) The  fact  that  some or all of the  Technical  Information  becomes  public
knowledge  shall not affect the financial  obligations  for use of the Technical
Information licensed under this Agreement if such Technical Information was used
or usable in the discovery, development,  manufacture, or approval for sale of a
Product within the Field.

               4. LICENSE FEE AND RESEARCH AND DEVELOPMENT FUNDING

A. Bioenvision shall pay the costs of any further pre-clinical  development work
deemed necessary prior to commencing clinical trials, and this shall include the
development  of the  Product  for  other  therapeutic  applications,  the use of
different  formulations and preparations of the Product.  The pre-clinical costs
not to exceed $1.5 million, unless agreed to buy both parties.

B. Bioenvision shall pay the costs of clinical trials of the Product.  The costs
of such development will not exceed $4 million (four million U.S. dollars).

B.   Bioenvision  shall  issue  to  Orion  100,000  shares  of  common  stock of
     Bioenvision  Group,  Inc.  within  60  days of the  Effective  Date of this
     Agreement.

C.   Orion shall issue to Bioenvision  shares of common stock  equivalent to 20%
     of the total stock of Orion,  within 60 days of the Effective  Date of this
     Agreement

D Bioenvision shall pay the cost of prosecuting,  filing and maintaining patents
and defending revocation proceedings on patents and patent applications,  on the
Product within the Territory.



                                 5. ACQUISITION

     Acquisition  of the  Licensed  Technology  is meant in its  broadest  sense
including assignment,  transfer, sublicense, merger, joint venture and so on and
so forth.


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A. If all or part of the rights granted to  Bioenvision  are acquired by a third
party all current or future payments  derived by Bioenvision  from the transfer,
whether in cash,  shares,  property or any other form of payment,  including but
not limited to up-front  payments,  milestone  payments  and  royalties  will be
divided equally between Orion and Bioenvision, after repayment to Bioenvision of
all development costs incurred by Bioenvision.

                               6. ROYALTY PAYMENTS

A.  Bioenvision  shall  have  exclusive  rights to  market  the  Product  in the
Territory under the following  terms:  For the Patent and Technical  Information
licenses granted herein,  Bioenvision shall pay to Orion a royalty of 10% of the
Net Sale Price of all Product(s) sold to an unaffiliated third party,  likely to
be a distributor or wholesaler,  but not limited to such,  where  Bioenvision is
responsible for the marketing of the Product.

B. If the Product  incorporates  inventions,  patents, or technical  information
that is necessary for the successful  commercialization  of the Product and that
is obtained  from sources  other than Orion,  the Parties  agree to negotiate in
good faith a new royalty  rate to reflect the  contribution  of such third party
inventions, patents, or technical information, but in no event shall the royalty
rate be reduced by more than 50%.

C.  If this  Agreement  is for  any  reason  terminated  before  all the  earned
royalties herein provided for have been paid,  Bioenvision shall immediately pay
to Orion any remaining  unpaid  balance of earned  royalties even though the due
date provided in Article 8 has not been reached.

D. If Bioenvision  shall sell the rights to the  Technology in combination  with
the sale, acquisition,  merger or disposition of Bioenvision, Inc., Bioenvision,
Orion  and the third  party(ies)  shall  negotiate  in good  faith the  specific
details  for such sale of rights,  subject to the  approval of Orion which shall
not be unreasonably withheld.

E.  After  expiry  of the last  patent a  royalty  of 5% of net sale  price  for
products sold directly by Bioenvision shall be payable if Bioenvision  continues
to use any or all trade-marks  currently owned by Orion, or other  trade-mark(s)
used by Bioenvision as defined in clause 2B

                                 7. SUBLICENSING

A.  Bioenvision  shall  have  the  right  to  sublicense  in the  Field  for the
Territory.

B. Bioenvision will keep Orion routinely  updated on progress of discussions and
negotiations with potential sub-licensees.  Orion shall have the right to review
the form of  sublicenses to be granted  hereunder  prior to the execution of the
same by Bioenvision. Bioenvision agrees that sublicense agreements shall conform
in all material respects to the terms and conditions of this Agreement. If Orion
has not objected within thirty (30) days of receiving the form of such agreement
describing the material  terms,  Bioenvision  may proceed to negotiate and grant
sublicenses  without  further  review by Orion if the form of the sublicense has
not materially


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changed.  Bioenvision  shall provide Orion with a copy of each sublicense within
thirty  (30) days of  execution,  and shall not grant to its  sub-licensees  any
Orion rights not conveyed by this Agreement.

C. If this Agreement is terminated for any reason,  except breach of contract by
Orion, any sublicense shall automatically  transfer to Orion, unless sublicensee
is in breach or  default of  sublicense,  and remain in full force and effect so
long  as the  sublicensees  performs  the  obligations  of the  sublicense,  and
Bioenvision  will execute such  documents as may be requested by Orion to attest
to the  transfer  to Orion of all  sublicense  rights,  including  the  right to
receive future payments.

                            8.  PAYMENTS AND REPORTS

A. Payments owed to Orion shall be payable within thirty (30) days of receipt by
Bioenvision  except as stated  otherwise  elsewhere in this Agreement and except
for royalties and profit-sharing compensation as a result of direct marketing of
Product by Bioenvision.

B. Royalties and  profit-sharing  compensation owed to Orion as a consequence of
direct  marketing  of  Product  by  Bioenvision  shall be due for each  calendar
quarter beginning with the first calendar quarter in which sales occur and shall
be payable to Orion within  forty-five  (45) days  following the last day of the
applicable  calendar  quarter.  All payments from  Bioenvision to Orion shall be
made in Pounds Sterling (pounds) by bank credit transfer to Orion at the address
designated in writing by Orion from time-to-time.

C. In the event that  Bioenvision  is prevented from making any payment to Orion
under  this  Agreement  by virtue of  restrictions  on  currency  conversion  or
repatriation under the statutes,  laws, codes or governmental regulations of the
country from which the payment is to be made,  then such payments may be paid by
depositing  them in the currency in which  accrued to Orion's  account in a bank
acceptable  to Orion in the country  whose  currency is  involved.  If the local
currency cannot be converted or remitted to Orion within twelve (12) months from
the initial deposit,  Bioenvision  shall pay Orion the equivalent of such amount
at the initially  computed  conversion rate (including any interest earnings) in
Pounds  Sterling  (pounds),  and the local  currency  shall be transferred to an
account in a bank acceptable to Bioenvision in that country.

D. Payments to Orion  hereunder shall be deemed paid as of the day on which they
are received at the address designated.  Any part of a payment which is not paid
on or before  the date when due shall  accrue  interest  thereon  from such date
until the date of its payment in full at two (2) percentage  points over the per
annum  interest  rate  published as the "Prime Rate" in The Wall Street  Journal
(Eastern  Edition),  but in no event  shall such rate  exceed the  maximum  rate
permitted by applicable law.

E. Bioenvision  shall deliver to Orion within forty-five (45) days after the end
of each calendar quarter a report,  certified by the chief financial officer (or
equivalent) of Bioenvision,  setting forth in reasonable  detail the calculation
of Orion  payments  made  during  the  quarter  and for each  calendar  quarter,
including gross sales, value added


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taxes,  number of units  sold,  unit price and the like on a  country-by-country
basis by Bioenvision, sublicensees, joint ventures and their affiliates.

F. The  Bioenvision  report to Orion  shall be  supported  by and  based  upon a
similar  financial  report or, if permitted,  a copy from each  sublicensee  and
other commercialization entity(ies).

G.  The  parties  will  promptly  share  all  information  generated  under  the
Co-Development Program pursuant to the confidentiality  provisions of Article 21
and with particular respect to the pre-clinical studies and clinical trials.

                                   9. RECORDS

Bioenvision  shall keep accurate  records of all operations  affecting  payments
hereunder,  and shall permit Orion or its duly  authorized  agent to inspect all
such records and to make copies of or extracts from such. records during regular
business hours throughout the term of this Agreement and for a reasonable period
of not less than  three  (3)  years  thereafter.  The fees  charged  for a Orion
authorized  audit shall be paid by Orion;  provided,  however,  that if an audit
discloses an underpayment by Bioenvision of more than five percent (5%) for such
audited period,  Bioenvision  shall pay the reasonable fees and expenses charged
by the firm conducting the audit.

                   10. OWNERSHIP OF THE TECHNOLOGY, TECHNICAL
                          INFORMATION AND IMPROVEMENTS

A. Orion and  Bioenvision  shall each retain full  ownership  of their  existing
intellectual  property rights including rights in the process of being protected
and rights conceived but not yet reduced to practice as of the effective date of
this Agreement.

B. All  Improvements by Orion developed  under projects  funded,  in whole or in
part,  by  Bioenvision  shall be owned by Orion  and  shall be  included  in the
licenses granted in this Agreement.  In the event that a conflicting  obligation
prevents Orion from including  such an  Improvement,  Orion shall use reasonable
efforts to assist  Bioenvision to obtain rights from the appropriate third party
or parties.

C. All  Improvements  by Orion made  during  the first  three (3) years from the
effective  date of the Agreement and not developed  under  projects  funded,  in
whole or in part,  by  Bioenvision,  shall  be  owned  by  Orion  and if  deemed
reasonably necessary for Bioenvision  practice of the Technology,  without which
such practice  would  constitute an  infringement  of Orion's  rights,  shall be
included to the extent  necessary,  as decided solely by Orion,  in the licenses
granted in this  Agreement,  unless  inclusion  is not  possible  due to Orion's
obligations  to a  third  party.  In the  event  that a  conflicting  obligation
prevents Orion from including  such an  Improvement,  Orion shall use reasonable
efforts to assist  Bioenvision to obtain rights from the appropriate third party
or parties.

D.  Bioenvision  shall have the first right of negotiation to a license or other
commercial  arrangement  to any  Orion  intellectual  property  developed  under
projects funded, in whole or in part, by Bioenvision,  which does not constitute
an Improvement.


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                               11.  PATENT PROSECUTION

A. Orion  shall  file,  prosecute  and  maintain  all of the Patent that are the
property of Orion as of the date of this Agreement.

B.  Bioenvision  shall  bear  all  patenting  expenses  related  to the  filing,
prosecution or maintenance of all Patent and Improvement  licensed  hereunder in
whole or in part.

C. Orion shall furnish  Bioenvision  with copies of all allowed claims when such
claims  are  allowed  in the  Field  and in the  Territory  for all  Patent  and
Improvement licensed hereunder.

D. Orion shall provide  Bioenvision with draft copies of all  correspondence and
filings and related prosecution documents on the Patent and Improvement licensed
hereunder and Bioenvision  shall promptly  provide  comments,  if any, to Orion.
Orion  shall  confer  with  Bioenvision,  and make  reasonable  efforts to adopt
Bioenvision's   suggestions   regarding   prosecution   tactics  and   strategy.
Notwithstanding  the foregoing,  Orion shall have the right to take such actions
as are reasonably necessary, in its good faith judgement, to preserve all rights
under the Patent and Improvement throughout the Territory. As soon as practical,
subsequent  to the  filing of any  prosecution  document,  Orion  shall  provide
Bioenvision  with a copy  of  such  document.  In  addition,  Orion  shall  copy
Bioenvision with any official office action and Orion responses and submissions.
Bioenvision  shall bear the  expenses of the  activities  noted in this  Article
11.E.

E. Orion will inform  Bioenvision at least sixty (60) days prior to any decision
having  as  a  result  the  failure  to  file,  or  the  abandonment  of  Patent
applications or failure to maintain a Patent,  Patents and Improvements licensed
hereunder  so that  Bioenvision  may take  over and  maintain  such  Patent  and
Improvements in force.

F. Provided that Orion has been informed by Bioenvision at least sixty (60) days
in advance,  in the event that Bioenvision decides not to pay patenting expenses
in any jurisdiction, Orion may elect to maintain such Patent and Improvements in
force and terminate  Bioenvision's  licenses  granted as for the jurisdiction in
which Bioenvision abandoned or failed to file or maintain such Patent rights.

                         12. INFRINGEMENT BY TIRED PARTY

A. Either party shall notify the other party of any suspected  infringement by a
third party of the Patent in the Field and the  Territory,  and each party shall
inform the other of any evidence of such infringement(s).

B. Bioenvision shall have the first right to institute suit for  infringement(s)
in the Field and  Territory  so long as this  Agreement  remains  exclusive.  At
Bioenvision's   expense,  Orion  will  reasonably  assist  Bioenvision  in  such
prosecutions  if so  requested  by  Bioenvision,  and will lend its name to such
actions if  requested by  Bioenvision  or required by law.  Notwithstanding  the
foregoing  Orion shall have the right to  participate  and be represented in any
such prosecutions by its own counsel at its own expense.


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C.  If  Orion  notifies   Bioenvision  of  its  desire  to  institute  suit  for
infringement(s)  and  Bioenvision  fails to  exercise  its first  right to do so
within  ninety (90) days of such  notice,  then Orion may,  at its own  expense,
bring suit or take any other appropriate action. At Orion's expense, Bioenvision
will reasonably  assist Orion in such prosecutions if so requested by Orion, and
will lend its name to such  actions if  requested  by Orion or  required by law.
Notwithstanding  the foregoing  Bioenvision  shall have the right to participate
and be  represented  in any  such  prosecutions  by its own  counsel  at its own
expense.

D. No  settlement of any  suspected  infringement(s),  whether or not a suit has
been  instituted,  may be entered  into without the express  written  consent of
Bioenvision and Orion.

E. Any  amounts  recovered  pursuant  to an  infringement  suit,  settlement  or
otherwise  shall be retained by and be the  property of the party  bringing  the
action. In the event Bioenvision receives any monies or other consideration from
a third party as a result of  Bioenvision's exercise of its rights  under this
Agreement,  Bioenvision shall first be reimbursed for expenses incurred and paid
for, Orion shall then receive a portion of the remainder in accordance  with the
applicable  provision(s)  of Article 6 as  applied  to all such  monies or other
considerations  whether  such  monies or other  considerations  are  denoted  as
"royalties," "damages," "releases" from prior acts, or any other designation.

F. If  Bioenvision  fails to  exercise  its first  right to  institute  suit for
infringement(s) and Orion elects not to institute suit, then Orion shall provide
Bioenvision  with at least sixty (60) days notice of its  intention to terminate
Bioenvision's   licenses  granted  in  those   jurisdictions   affected  by  the
infringement or to take any other action it sees fit in its best judgement.

                           13. REVOCATION PROCEEDINGS

A. In the event either party becomes aware of the  institution  by a third party
of any proceedings for the revocation of any Patent,  patents or Improvements in
any country in the Territory licensed hereunder to Bioenvision, such party shall
notify the other party promptly.  Bioenvision  shall defend any such proceedings
at its own expense, in its own name.

B. Orion shall have the right to participate in such  revocation  proceedings at
Bioenvision's  expense,  and will lend its name to such proceedings if requested
by Bioenvision or required by law.  Sublicensees of Bioenvision  shall also have
the right to participate in such revocation proceedings.

C. Settlement of any revocation  proceedings shall be subject to the approval of
Orion; such approval shall not be unreasonably withheld.

                     14. INFRINGEMENT OF THIRD PARTY RIGHTS

A. Orion will reasonably assist Bioenvision to defend or settle such third party
claim if so requested and at the expense of Bioenvision.


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B Orion shall have the right to participate and be represented in any such claim
by a third party by its own counsel.

C. No  settlement  of any third  party  claim may be entered  into  without  the
express written consent of Orion.

D. In the event,  by way of  counterclaim  or  otherwise,  either  party or both
parties  recover any damages or other sums in any action,  suit,  or  proceeding
involving a claim by a third party,  or in  settlement  thereof,  such  recovery
shall be applied and shared as mutually agreed.

                               15. REPRESENTATIONS

A. Orion represents that it has the right to grant all of the rights herein.

B. Orion is unaware of any claims  asserted  against  Orion by any third parties
with respect to Patent  infringement or any other type of liability  relevant to
licensing of the Inventions,  which have not been disclosed to Bioenvision as of
the Effective Date of this Agreement.

C. Orion  represents that it has full power,  authority and legal right to enter
into this contemplated Agreement and to consummate the transactions contemplated
therein.

D. Bioenvision  represents that it has full power,  authority and legal right to
enter  into this  contemplated  Agreement  and to  consummate  the  transactions
contemplated therein.

E.  Bioenvision  shall  accept  liability to the extent of the Field and for the
Territory for or on account of any injury, loss or damage, of any kind or nature
sustained by, or any damage assessed or asserted against, or any other liability
incurred by or imposed upon either party arising out of or in connection with or
resulting from (i) the production, use or sale of any Product(s) or (ii) the use
of any  technical  information,  techniques,  or  practices  disclosed by either
party, or (iii) any advertising or other promotional  activities with respect to
any of the foregoing. If a sublicense is granted by Bioenvision to a third party
that third party shall accept all  liability  for any injury,  loss or damage as
defined above.

                                16.   INDEMNIFICATION

     Bioenvision hereby agrees to indemnify,  hold harmless and defend liability
to the  extent  of the  Field  and for the  Territory  Orion  and its  officers,
directors,  representatives,  agents and employees  from and against any and all
demands,  claims,  suits or actions  of any  character  presented  or brought on
account of any injuries,  losses or damages  sustained by any person or property
in  consequence  of (i)  any  act or  omission  of  Bioenvision  or its  agents,
employees or  subcontractors,  or (ii) any  liability,  except for any injuries,
losses or  damages  that  specifically  result  from the  negligence  or willful
misconduct of Orion. The foregoing indemnity shall include but


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not be limited to court costs, attorneys' fees, costs of investigation and costs
of defense associated with such demands, claims, suits or actions. The foregoing
indemnity shall apply only to the extent of the Field and in the Territory.

                                  17. INSURANCE

     Bioenvision shall maintain,  during the term of this Agreement,  reasonable
amounts  of  comprehensive  general  liability  insurance,   including  products
liability insurance, with reputable and financially secure insurance carriers to
cover the activities of Bioenvision and its affiliates.  Such insurance shall be
written to cover  claims  incurred,  discovered,  manifested,  or made during or
beyond the expiration or  termination  of this Agreement  during the period that
any product,  process,  or service,  relating to, or developed pursuant to, this
Agreement  is being  commercially  distributed  or sold by  Bioenvision  or by a
sublicensee,  affiliate or agent of  Bioenvision.  Bioenvision  shall furnish to
Orion a certificate of insurance evidencing such coverage and periodically, upon
request, provide evidence that the coverage is still in effect.

                            18. TERM AND TERMINATION

A. This  Agreement  shall  commence on the  Effective  Date and,  unless  sooner
terminated under this Article 18, shall expire upon the later of: (i) expiration
of the last to expire of all Patent(s),  Improvement(s),  and Patent(s) licensed
under  this  Agreement  including  any  extensions  thereof  and any  periods of
exclusivity  granted by regulatory  agencies or other governmental  bodies; (ii)
Bioenvision  is no  longer  due  any  payments  from  Sublicensee(s);  or  (iii)
Bioenvision is no longer directly marketing a Product.

B. The  payment  obligations  under the  licenses  granted  to  Bioenvision  for
Licensed Patents and Technical Information shall continue throughout the term as
defined in this Agreement but would be subject to good faith renegotiations upon
the  expiration  of the last to  expire  of the  Licensed  Patents,  or upon the
abandonment of the last to be abandoned of any patent applications if no patents
have been  issued,  whichever  is the later,  unless  this  Agreement  is sooner
terminated. Such good faith renegotiations shall take into account on a country-
by-country  or regional  basis but not be limited  to: (i) Product  competition;
(ii) utilization,  incorporation and value of Technical Information; (iii) value
of Technical  Information if no longer  confidential  or proprietary  through no
fault of Bioenvision, its Sublicensee(s),  contractors,  financiers or any other
Bioenvision  agent(s)  or  purchasers  of Product or services  having  access to
Technical  Information;  (iv) the applicable contract or patent law or (v) prior
payment commitments.

C.  Bioenvision  may terminate  this Agreement at any time upon ninety (90) days
written  notice to Orion and upon  payment of all amounts due Orion  through the
effective date of the termination.

D. Upon termination of this Agreement,  neither party shall be released from any
obligation  that  matured  prior  to the  effective  date of  such  termination.
Bioenvision and any sublicensee may,  however,  after the effective date of such
termination,  sell all Products in inventory provided that Bioenvision shall pay
to Orion the royalties and


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profit-sharing  thereon as  required  by Article 6 hereof and submit the reports
required by Article 8 hereof

E.  Except as  provided  in above,  if either  party  shall be in default of any
obligation  hereunder,  the other party may terminate  this  Agreement by giving
Notice of  Termination  by Certified or  Registered  Mail to the party at fault,
specifying  the  basis for  termination.  If within  sixty  (60) days  after the
receipt of such Notice of  Termination,  the party in default  shall  remedy the
condition  forming the basis for  termination  such Notice of Termination  shall
cease to be operative, and this Agreement shall continue in full force.

F. Orion shall have the right to terminate this  Agreement if Bioenvision  shall
cease to carry out its business as related to the Product(s), become bankrupt or
insolvent,  apply for or consent to the  appointment  of a trustee,  receiver or
liquidator of its assets or seek relief under any law for the aid of debtors.

G. Bioenvision shall inform Orion of its intention to file a voluntary  petition
in  bankruptcy  or of  another's  intention to file an  involuntary  petition in
bankruptcy  to be  received  at least  thirty  (30) days prior to filing  such a
petition.

H. Notwithstanding  anything else in this Agreement to the contrary, the parties
agree  that  Bioenvision's  obligation  to  pay  Orion  any  payments  or  other
consideration  accrued  but  unpaid  prior  to  termination  shall  survive  the
termination of this Agreement.

                   19. CONFIDENTIALITY; PUBLICATION; PUBLICITY

A. In fulfilling their obligations under this Agreement,  it may be desirable or
necessary  for  the  parties  to  disclose  to  one  another  certain  of  their
Confidential  Information.   In  the  event  of  receipt  of  such  Confidential
Information,  the  receiving  party  agrees  to  preserve  such  information  as
confidential  and not to  disclose  it to third  parties  or to use it except in
connection  with this  Agreement  during  the term of this  Agreement  and for a
period of five (5) years following its  termination.  The foregoing  obligations
shall not apply to any information that:

     1. is now in the public domain or becomes generally available to the public
     through no fault of the receiving party;

     2. is already known to, or in the possession of, the receiving party as can
     be demonstrated by documentary evidence;

     3. is disclosed to the  receiving  party on a  non-confidential  basis by a
     third party having the right to make such disclosure; or

     4. is independently developed by the receiving party as can be demonstrated
     by documentary evidence.

     In addition,  to the extent reasonably  necessary to fulfil its obligations
or  exercise  its  rights  under  this   Agreement  (i)  a  party  may  disclose
Confidential Information to its Affiliates, Sub-licensees,  consultants, outside
contractors, research

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investigators and clinical  investigators,  on a need-to-know basis on condition
that  such  persons  or  entities  agree to be bound by the  provisions  of this
Agreement,  (ii) a  party  or  its  Affiliates  or  Sub-licensees  may  disclose
Confidential  Information to governmental or other regulatory authorities to the
extent  that such  disclosure  is  reasonably  necessary  to obtain  patents  or
regulatory   authorizations,   provided  the  disclosing   party  shall  request
confidential  treatment  thereof,  and (iii) a party may  disclose  Confidential
Information  as required by  applicable  law,  regulation  or judicial  process,
provided  that such party  shall give the other party (x) prior  written  notice
thereof, (y) adequate opportunity to object to any such disclosure or to request
confidential treatment thereof, and (z) shall take all steps reasonably possible
to minimize the disclosure to that level mandated by law.

B. (i) If either  party  desires  to  publish  or  present  the  results  of the
Co-Development  Program,  the  publishing/presenting  party  shall  provide  the
non-publishing/non-presenting  party a copy of the  manuscript  of any  proposed
publication or presentation. The non-publishing/non-presenting  party shall then
have thirty (30) days to review and comment on the  manuscript or  presentation,
and the publishing/presenting  party agrees to delete any information identified
by the non-publishing/non-presenting  party as its Trade Secrets or Confidential
Information.

     (ii) In the event the non-publishing/non-presenting party determines that a
Patent application covering information contained in the proposed publication or
presentation   should  be  filed,   the  party   proposing  the  publication  or
presentation  shall delay such  publication or presentation for up to sixty (60)
days  after the thirty  (30) days  outlined  in clause  B(i) above to allow such
filing to be made.

C. Each party shall provide the other party with the prior opportunity to review
and approve any press releases or similar public  announcements  concerning this
Agreement  or  clinical,  regulatory  and  commercial  developments  related  to
Products as soon as  practicable,  but in no event later than 24 hours before an
announcement is made.  Bioenvision  shall not use the name of Orion or otherwise
refer to any organization  related to Orion, except with the written approval of
Orion, such approval not to be unreasonably withheld.

                             20. DISPUTE RESOLUTION

A. The parties  shall  attempt to resolve  through  good faith  discussions  any
dispute which arises under this  Agreement.  Any dispute may, at the election of
either party, be referred to the chief executive officers, or the equivalent, of
each party.  If they are unable to resolve the dispute,  within thirty (30) days
after  delivery of written  notice of the  dispute  from one party to the other,
either  party may seek to resolve it by referring  the matter to an  appropriate
arbitration service with experience in the field relevant to the dispute.

                                21. ASSIGNABILITY

A. Orion or  Bioenvision  shall not assign any rights under this  Agreement  not
specifically  transferable  by its terms without  prior  written  consent of the
other party

                                   22. REFORM


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A. The parties  agree that if any part,  form,  or provision  of this  Agreement
shall be found  illegal  or in  conflict  with any valid  controlling  law,  the
validity of the remaining provisions shall not be affected thereby.

B. In the event the legality of any provision of this  Agreement is brought into
question  because  of a decision  by a court of  competent  jurisdiction  of any
country  in  which  this  Agreement   applies,   Orion,  by  written  notice  to
Bioenvision,  may revise the  provision in question or may delete it entirely so
as to comply with the decision of the said court.

                           23.  WAIVER AND ALTERATION

A. The failure of either party to insist, in any one or more instances, upon the
performance  of any of the terms,  covenants or conditions of this Agreement and
to  exercise  any  right  hereunder,  shall  not be  construed  as a  waiver  or
relinquishment of the future performance of any such term, covenant or condition
or the future  exercise of such right,  but the  obligations  of the other party
with respect to such future performance shall continue in full force and effect.

B. A provision of this Agreement may be altered only by a writing signed by both
parties.

                                   24. MARKING

A.  Bioenvision  shall  place in a  conspicuous  location  on any product or its
packaging,  which is made or sold under any Patent coming within this Agreement,
a patent notice in accordance  with the laws  concerning the marking of patented
articles.

B. Bioenvision shall include a marking provision similar to Paragraph A above in
every sublicense granted pursuant to Article 7 above.

                               25. IMPLEMENTATION

Each party shall execute any instruments  reasonably believed by the other party
to be necessary to implement the provisions of this Agreement.

                                26. GOVERNING LAW

This  Agreement  shall be deemed to have been entered into and shall be governed
by, construed and enforced in accordance with laws of England and in the English
language,  and any  action  brought  to  enforce  any  provision  or  obligation
hereunder  shall be brought in a court of competent  jurisdiction  in the United
Kingdom.

                                  27. HEADINGS

The headings of the articles, sections and paragraphs used in this Agreement are
included  for  convenience  only  and  are  not  to be  used  in  construing  or
interpreting this Agreement.

                             28. PARTIES INDEPENDENT


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In making and performing  this  Agreement,  the parties act and shall act at all
times as independent  entities and nothing  contained in this Agreement shall be
construed or implied to create an agency,  partnership  or employer and employee
relationship  between  Bioenvision and Orion.  Except as  specifically  provided
herein,  at no time shall either party make  commitments or incur any charges or
expenses for or in the name of the other party.

                                29. COUNTERPARTS

This Agreement  shall become binding when any one or more  counterparts  hereof,
individually or taken together, shall bear the signatures of each of the parties
hereto.  This Agreement may be executed in any number of  counterparts,  each of
which shall be an  original as against  either  party  whose  signature  appears
thereon,  but all of  which  together  shall  constitute  but  one and the  same
instrument.

                                30. FORCE MAJEURE

The  parties  shall  not  be  responsible  for  failure  to  perform  any of the
obligations  imposed by this  Agreement  (except an  obligation  to pay  money),
provided  the failure is not due to  negligence  and  provided  such  failure is
caused by fire, storms,  floods,  strikes,  lockouts,  accidents,  war, riots or
civil commotions, inability to obtain railroad cars or raw materials, embargoes,
any State or Federal regulation, law, or restriction,  seizure or acquisition of
the  Technology or the Product(s) by the Government of the United Kingdom or the
United States of America or of any state,  or of any agency thereof or by reason
of any compliance  with a demand or request for such Product for any purpose for
national  defense,  or any other  cause or  contingency  beyond  the  reasonable
control of said party  (whether  or not of the same kind or nature as the causes
or contingencies above enumerated) shall not subject the party so failing to any
liability to the other.


                                  31. EXECUTION

     IN WITNESS WHEREOF the parties have caused this Agreement to be executed by
their duly  authorized  officers on the  respective  dates and at the respective
places hereinafter set forth.


BIOENVISION:                              ORION:


By: _______________________________       By: _________________________________


Position: _________________________       Position: ___________________________


Date: _____________________________       Date: _______________________________




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