LICENCE AGREEMENT





               (1) UNIVERSITY COLLEGE CARDIFF CONSULTANTS LIMITED


                              (2) BIOENVISION INC.


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     THIS AGREEMENT is made the 21 day of June 1999 BETWEEN:

(1)  UNIVERSITY COLLEGE CARDIFF CONSULTANTS LIMITED a company incorporated under
     the laws of England and Wales (company  number  1477909)  whose  registered
     office is at P0 Box 497, 56 Park Place, Cardiff CFI 3XR ("UC3"); and

(2)  BIOENVISION INC., a Delaware  corporation with its main office at Trafalgar
     House, 11 Waterloo Place, London SW1Y 4AU ("BIOENVISION")

WHEREAS:

(A)  UC3 is the sole proprietor of the Applications.

(B)  UC3  has  the  exclusive   worldwide  right  to  license  the  use  of  the
     Applications.

(C)  UC3 is the proprietor of the Know-how.

(D)  Further   research  and   development   work  on  the  application  of  the
     Applications  and  Know-how  in the  Field  of Use  and the  production  of
     Licensed Products is required.

(E)  Such further research and development is the  responsibility of BIOENVISION
     and includes the Project.

(F)  BIOENVISION  wishes to take a licence under the  Applications and a licence
     under the Know-how and UC3 has agreed to grant such licences on and subject
     to the terms and conditions set out below.

IT IS AGREED as follows:

1.   Definitions and Interpretation

     In this Agreement, the recitals and the Schedules hereto:

1.1  the  following  words and  expressions  shall have the  following  meanings
     unless the context otherwise requires:

     "Applications"              the patent  applications short particulars of
                                 which  are set out in the  Schedule  and also
                                 one   patent    application   to   be   filed
                                 immediately after execution of this Agreement
                                 by  UC3  on  each  of  the   subjects  of  i)
                                 1,2-diphenylethanes and  1,3-diphenylpropanes
                                 and derivatives and ii) benzyl  tetralins and
                                 derivatives, together with


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                                 any  patent  applications  claiming  priority
                                 therefrom anywhere in the Territory;  and any
                                 patents granted  pursuant  thereto or divided
                                 out  therefrom  anywhere in the Territory and
                                 any extensions or renewals thereof including,
                                 without       limitation,       supplementary
                                 certificates of protection;

     "Approved Sub-Licensee"     any person to whom a  sub-licence  is granted
                                 by   BIOENVISION   in  accordance   with  the
                                 provisions of clause 2.3 below;

     "Cardiff University         the University of Wales, Cardiff of PO Box 923,
                                 Cardiff CFl 3TE, UK;

     "Compound"                  any chemical  compound  falling within one or
                                 more  claims of the  Patents (or any of them)
                                 and/or   utilising   or   incorporating   the
                                 Know-how;

     "Commencement Date"         the date of  countersignature of this Licence
                                 Agreement;

     "Field of Use"              cancer therapy in humans and animals;

     "Improvements"              all and any results of the  Project  together
                                 with all and any Intellectual Property Rights
                                 therein or relating  thereto and  assigned to
                                 UC3 by Cardiff University;

     "Improvement Patents"       any patent  applications  filed by UC3 in the
                                 Territory  in  respect  of  any  Improvements
                                 together   with   any   patent   applications
                                 claiming priority  therefrom  anywhere in the
                                 Territory;  and any patents granted  pursuant
                                 thereto or divided out therefrom  anywhere in
                                 the Territory and any  extensions or renewals
                                 thereof   including,    without   limitation,
                                 supplementary certificates of protection;

     "Intellectual  Property
      Rights"                    all  and  any  rights  in or  to  inventions,
                                 patents,   trademarks,   registered  designs,
                                 applications for any of the foregoing and the
                                 right  to apply  therefor  in any part of the
                                 world;    copyrights,     database    rights,
                                 topography  rights,   design  rights,   trade
                                 names,   get-up,   rights   to   confidential
                                 information,  know-how;  any rights under


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                                 licences  or  consents  in  relation  to  the
                                 foregoing,  and  any  similar  or  equivalent
                                 rights arising and/or subsisting  anywhere in
                                 the world;

     "Know-how"                  all  technical,   industrial  and  commercial
                                 information  and  techniques  relating to the
                                 application of the  Applications in the Field
                                 of Use in whatever form and on whatever media
                                 stored  which UC3 is free to disclose  and to
                                 licence;

     "Licensed Products"         Products    designed,    developed,    and/or
                                 manufactured for use in the Field of Use;

     "Net Receipts"              in the case of any sub-licence by BIOENVISION
                                 to an Approved  Sub-Licensee  at arm's length
                                 the total sums payable to BIOENVISION  for or
                                 in   connection   with  the   grant  of  such
                                 sub-licence   in  whatever   form   including
                                 without  limitation  lump  sum  payments  and
                                 royalties     after    the    deduction    of
                                 BIOENVISION's    reasonable    legal    costs
                                 necessarily  incurred in connection  with the
                                 preparation,  negotiation  and  execution  of
                                 such   sub-licences.   In  the  case  of  any
                                 sub-licences   by   BIOENVISION  to  Approved
                                 Sub-Licensees  other than at arm's length the
                                 sum  equivalent  to  the  sums  for  which  a
                                 sub-licence  at arm's  length would have been
                                 granted less  BIOENVISION's  reasonable legal
                                 costs referred to above;

     "Net Sales Value"           in the  case of sales  at  arm's  length  the
                                 invoiced price of each Licensed  Product sold
                                 by  BIOENVISION  after the  deduction  of any
                                 reasonable  discounts  and  rebates  actually
                                 granted  and any  credits  actually  given by
                                 BIOENVISION for returned  Licensed  Products.
                                 In all other cases (including but not limited
                                 to commercial  uses of the Licensed  Products
                                 which are not  invoiced by  BIOENVISION)  the
                                 sum  equivalent to the invoiced  price of the
                                 Licensed  Products  at  which a sale at arm's
                                 length   would   have   been  made  less  the
                                 deductions referred to above:

     "Patents"                   together the Applications and any Improvement
                                 Patents;



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     "Products"                  together  Compounds and any medical  products
                                 comprising one or more Compounds as an active
                                 ingredient; and each a Product,

     "Project"                   the Research  Agreement of even date herewith
                                 between  BIOENVISION and  Cardiff  University
                                 for the  provision by Cardiff  University  of
                                 research  and  development  services  on  and
                                 subject to the terms and  conditions  therein
                                 contained;

     "Term"                      the period during which this  Agreement is in
                                 force in  accordance  with the  provisions of
                                 clause 14.1 below;

     "Territory"                 the  Field  of Use  anywhere  in  the  world,
                                 including   countries   where  there  are  no
                                 Patents;

     "Year"                      each  calendar  year  during the Term or part
                                 thereof  in the  case of the  first  and last
                                 calendar years of the Term;

1.2  words and expressions  (including  words and expressions  defined in clause
     1.1  above) in the  singular  shall  include  the  plural  and vice  versa;
     references to a "party" or the "parties"  shall mean a party or the parties
     to this  Agreement;  words importing any gender shall include every gender;
     references  to a person  shall  include  bodies  corporate,  unincorporated
     associations, partnerships, trusts and individuals;

1.3  headings  are for  convenience  only and shall not affect the  construction
     interpretation  or of this  Agreement;  references  to  sub-clauses  are to
     sub-clauses of the clause in which the reference  appears and references to
     clauses are to clauses of this Agreement;

1.4  the recitals and the  Schedules to this  Agreement  shall form part of this
     Agreement as if set out in the body of this  Agreement  and  references  to
     this Agreement shall include the recitals and the Schedules;

1.5  references to sales of Licensed  Products shall include all sales and other
     disposals of or dealings  with the Licensed  Products by or on behalf of or
     with the consent of BIOENVISION.

2.   Licence

2.1  In consideration of and conditional upon BIOENVISION:


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     (a)  meeting is obligations under clauses 6 and 8 below; and

     (b)  paying to UC3 is costs and expenses  pursuant to clauses 6 and 8.2 (d)
          below  (save to the extent of any notice  given  under  clause 8.2 (e)
          below); and

     (c)  performing its other obligations hereunder

     UC3 hereby grants to BIOENVISION with effect from the Commencement Date and
     during the Term and subject  always to the  provisions  of clauses 2.3, 2.4
     and 2.5 below:

     (i)  an exclusive licence under the Applications; and

     (ii) a non-exclusive licence under the Know-how

     to develop,  manufacture, use, sell, offer for sale or otherwise deal in or
     with Licensed  Products in the  Territory  together with the right to grant
     sub-licences  thereunder  to Approved  Sub-Licensees  on and subject to the
     terms and conditions herein contained.

2.2  Nothing contained in this Agreement shall be interpreted or construed as in
     any way granting any rights or  permission  to  BIOENVISION  to utilise the
     Patents,  the Know-how,  the Improvements  and/or the Compounds or any part
     thereof  and/or to  manufacture,  use,  sell or  otherwise  deal in or with
     Products for any purpose or application other than in the Field of Use.

2.3  BIOENVISION shall have the right to grant  sub-licences  hereunder PROVIDED
     THAT:

     (a)  all sub-licences shall be expressly restricted to the Field of Use;

     (b)  all such sub-licences shall determine when and to the same extent that
          this Agreement determines howsoever arising;

     (c)  all  sub-licences  shall be at arm's  length  terms  unless  otherwise
          agreed in writing by UG3;

     (d)  BIOENVISION  shall  provide UC3 with the name,  registered  office and
          trading address of any sub-licensee  prior to such  sub-licence  being
          granted;  and

     (e)  UC3 shall be provided by  BIOENVISION  with a copy of any  sub-licence
          within thirty (30) days of such sub-licence being entered into.

2.4  If at any time during the Term either:


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     (a)  BIOENVISION  Is  to  make  payment  to  UC3  in  accordance  with  the
          provisions of clause 8.2 (d) below in respect of any Patents; or

     (b)  BIOENVISION  determines its payment  obligations  under clause 8.2 (d)
          below in accordance with the provisions of clause 8.2 (e) below

     UC3 shall in its sole discretion have the option to terminate BIOENVISION's
     licence pursuant to clause 2.1 above in that part of the Territory to which
     the relevant costs and/or expenses relate immediately on giving BIOENVISION
     written notice.

2.5  Nothing  contained  in this  Agreement  or in  clause  2.1  above  shall be
     interpreted or construed as in any way  precluding or  restricting  Cardiff
     University  and UC3 from  undertaking  or continuing  with any research and
     development work in the Territory utilising the Patents, the Know-how,  the
     Improvements and/or any Compounds.

3.   Disclosure of Know-how

     As soon as reasonably practicable following execution of this Agreement UC3
     shall to the extent that:

     (a)  it has not already done so; and

     (b)  such Know-how is reasonably  necessary for BIOENVISION to exercise its
          rights granted hereunder

     disclose to BIOENVISION the Know-how.

4.   Improvements

4.1  UC3 shall disclose to BIOENVISION  any  Improvements  as soon as reasonably
     practicable  but,  in any  event,  no more than one (1) month from the date
     that UC3 is made aware of such Improvements.


4.2  UC3  grants to  BIOENVISION  with  effect  from the date of  disclosure  to
     BIOENVISION of the Improvements (if any) and during the Term on and subject
     to the terms and conditions contained herein an exclusive licence under the
     Improvements  (if  any)  to  use  such  Improvements  in  the  development,
     manufacture,  use,  sale and offer  for sale of  Licensed  Products  in the
     Territory  together  with the right  subject  always to the  provisions  of
     clause 2.3 above to grant sub-licences thereunder to Approved Sub-Licenses.

5.   Confidential Information

5.1  For the purposes of this clause 5 "Confidential Information" shall mean all
     information of a confidential  nature whether oral or written comprising or
     relating to:


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     (a)  the Compounds;

     (b)  the Products;

     (c)  the Licensed Products;

     (d)  the terms of this Agreement;

     (e)  the Patents;

     (f)  the Know-how;

     (g)  the Improvements; and

     (h)  any  other  information  of a  confidential  nature  relating  to  the
          business of either party

     disclosed or made  available by either party to the other party pursuant to
     the  terms of this  Agreement  whether  prior to the  Commencement  Date or
     subsequent thereto.

5.2  Subject to the  provisions  of clauses 5.3, 5.4 and 5.5 below neither party
     (the "Recipient") shall in respect of Confidential Information belonging to
     and provided or disclosed by the other party (the "Disclosing Party"):

     (a)  disclose  such  Confidential  Information  or any part  thereof to any
          person;

     (b)  use such  Confidential  Information or any part thereof otherwise than
          in accordance with and for the purposes of this Agreement;

     (c)  copy such  Confidential  Information or any part thereof other than to
          the  extent  necessary  to  exercise  its  rights  or to  perform  its
          obligations under this Agreement.

5.3  The  Recipient  shall be  permitted  to disclose  Confidential  Information
     belonging  to  the  Disclosing  Party  (and  all or any  part  thereof)  in
     confidence to those of its  professional  advisers,  officers and employees
     who need to know the same in order to perform  their  duties in  connection
     herewith or, in the case of  professional  advisers,  to provide  advice in
     respect hereof.

5.4  BIOENVISION  shall  be  permitted  to  disclose  Confidential   Information
     belonging in UC3 (and all or any part thereof):

     (a)  to customers who purchase Licensed Products to the extent necessary to
          enable such customers to use the Licensed Products;


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     (b)  in  confidence  to  Approved  Sub-Licensees  on  the  same  terms  and
          conditions as are contained in this clause 5;

     (c)  in  confidence  to  approved  financial   institutions  and  potential
          investors  in   BIOENVISION,   to  the  extent   necessary  to  enable
          BIOIENVISION to attract investment;

     (d)  to such  governmental  agencies,  bodies  and/or  other  organisations
          anywhere in the  Territory  as may be necessary in order to apply for,
          obtain and/or  maintain in force any medical  and/or any  governmental
          approvals,  licences  and/or  consents  as may  from  time  to time be
          required  in  connection  with the  manufacture,  use  and/or  sale of
          Licensed Products in the Territory;

     (e)  in  confidence  to potential  Approved  Sub-Licensees  but only to the
          extent strictly  necessary to enable such persons to evaluate  whether
          in the case of potential  Approved  Sub-Licensees  they wish to become
          Approved Sub-Licensees or in the case of potential investors they wish
          to invest in BIOENVISION.

5.5  The obligations as to  confidentiality  contained in clause 5.1 above shall
     not apply to any Confidential Information:

     (a)  which  is in the  public  domain  at the date of  disclosure  or which
          subsequently enters the public domain through no act or failure to act
          on the part of the Recipient,  its professional advisers,  officers or
          employees or on the part of Approved  Sub-Licensees or its officers or
          employees; or

     (b)  which was lawfully and properly in the  possession of the Recipient at
          the date of disclosure; or

     (c)  which the Recipient  subsequently obtains otherwise than in confidence
          from a person  in good  faith  who did not  derive  the  same  whether
          directly or indirectly in confidence from the Disclosing Party or from
          any  person  to  whom  the  Disclosing  Party  disclosed  the  same in
          confidence; or

     (d)  the  disclosure of which is required by any  applicable  law or by any
          supervisory or regulatory body to whose rules the Recipient is subject
          or with whose rules it is necessary for the Recipient to comply.

5.6  The  provisions of this clause 5 shall survive the expiry or termination of
     this Agreement howsoever arising.

6.   Consideration

6.1  In  part  consideration  of  the  licence  and  rights  hereby  granted  to
     BIOENVISION, BIOENVISION undertakes to pay to UC3:


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     (a)  royalties  calculated at a rate of five per cent (5%) of the Net Sales
          Value of each Licensed  Product sold by or on behalf of BIOENVISION in
          the Territory each Year during the Term; and

     (b)  royalties  calculated  at a rate of: thirty five per cent (35%) of Net
          Receipts from sub-licences  granted by BIOENVISION and relating to the
          grant  and  exercise  of such  sub-licences  and/or  sale of  Licensed
          Products in the Territory.

6.2  All sums to be paid to UC3 hereunder  shall be paid in pounds  sterling and
     shall  be  exclusive  of  value  added  tax  which  shall  be  payable  (if
     applicable) in addition by BIOENVISION and where  applicable  shall be paid
     at the rate of exchange in force at Barclays Bank plc, PO Box 522, Northway
     House, Ty Glas Avenue,  Llanishen,  Cardiff CF4 5ZY on the date for payment
     thereof (or if such date is not a day when the banks are open for  business
     the next  business  day when the banks are so open)  PROVIDED  ALWAYS  THAT
     where any  payment is made after the date  provided  for herein  conversion
     shall be made at UC3's  option at the rate of  exchange in force on the day
     payment is in fact made if this is more favourable to UC3.

6.3  BIOENVISION shall and shall procure that all Approved  Sub-Licensees  shall
     during  the Term  and for a period  of six (6)  years  thereafter  maintain
     complete  and  accurate   records  of  all  matters   connected   with  the
     manufacture,  use and sale and other  disposal of Licensed  Products in the
     Territory  showing  separately  in the case of  BIOENVISION  the  number of
     sub-licences  granted  and in the  case of both  BIOENVISION  and  Approved
     Sub-Licensees,  the quantity of all Licensed Products  manufactured,  used,
     sold or  otherwise  disposed of in the  Territory  showing the Net Receipts
     and/or Net Sales Values therefor (as applicable).

6.4  BIOENVISION  shall  submit to UC3 within  thirty  (30) days after March 31,
     June 30,  September 30 and  December 31 in each Year a report  showing on a
     country by country basis:

     (a)  the Net Receipts  received by  BIOENVISION  in the preceding  calendar
          quarter; and

     (b)  the total number of Licensed  Products  manufactured,  used,  sold and
          otherwise disposed of by BIOENVISION in the preceding calendar quarter
          and the Net Sales Values therefor.

6.5  At the time of delivery  of each such  report  pursuant to clause 6.4 above
     BIOENVISION shall pay to UC3 the full amount of all sums due and payable to
     UC3 in respect of that  calendar  quarter  pursuant  to the  provisions  of
     clause 6.1 above.

6.6  All  sums  due to UC3  hereunder  shall  be  paid  free  and  clear  of all
     deductions  or  withholdings  whatsoever  save  that  BIOENVISION  shall be
     entitled to deduct and to


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     pay over to the  relevant  revenue  authorities  such  taxes and  duties as
     BIOENVISION  is required by law to deduct on remittance of such payments to
     UC3.  BIOENVISION  shall provide UC3 with such documentary  evidence as UC3
     may reasonably  require regarding the amounts so deducted and such evidence
     of payment to such revenue  authorities as UC3 may  reasonably  require for
     the purposes of seeking to recover such taxes (or any part  thereof)  under
     any applicable  legislation or to enable the appropriate  provisions of any
     double tax agreement to operate in respect of any such payments.

6.7  Without  prejudice  to any  other  rights or  remedies  to which UC3 may be
     entitled  whether  hereunder  or at law,  UC3 shall be  entitled  to charge
     interest  at the rate of two per cent (2%) above the base  lending  rate of
     Barclays  Bank plc from time to time in force on all overdue  sums owing to
     UC3 hereunder (before as well as after judgement).

6.8  BIOENVISION shall and shall procure that all Approved  Sub-Licensees  shall
     whenever  required by UC3 allow an independent  accountant  upon reasonable
     notice and during  normal  business  hours to verify  the  accuracy  of the
     reports  required to be furnished  under the provisions of clause 6.4 above
     by  inspecting   and  taking  copies  of   BIOENVISION   and  any  Approved
     Sub-Licensee's  records and accounts  PROVIDED  ALWAYS THAT such inspection
     shall not take place  more than once in every two (2)  years.  The costs of
     any such inspection  shall be borne by UC3 unless an underpayment of monies
     due to UC3  hereunder of more than five percent (5%) is found in which case
     all costs incurred shall be borne by BIOENVISION or if already  incurred by
     UC3  reimbursed by BIOENVISION  immediately  upon written demand by UC3 for
     payment of the same.

7.   Obligations of UC3

     Subject  always to the  provisions  of clause 8 below UC3 shall  during the
     Term:

     (a)  diligently  prosecute to grant the patent  Applications  listed in the
          Schedule;

     (b)  maintain in force any granted patents included within the Patents;

     (c)  use its reasonable efforts to amend any patent  Applications listed in
          the Schedule and /or any other patent  Applications  contained  within
          the Patents to include any additional claims  reasonably  requested by
          BIOENVISION; and

     (d)  keep BIOENVISION  regularly informed of the status and progress of the
          patent   Application   included  in  the  Schedule  and  discuss  with
          BIOENVISION   the  content  of  any  and  all   amendments  to  patent
          Applications before submission.

8.   Obligations of BIOENVISION


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8.1  BIOENVISION  shall use its best  efforts to  commercialise  the  Compounds.
     Specifically,  in the first instance  BIOENVISION shall undertake  clinical
     development of Compounds or Licensed Products for the purposes of preparing
     such Compounds or Licensed  Products for market.  BIOENVISION shall use its
     best efforts to commence  Phase 1 clinical  trials of one or more Compounds
     within four (4) years of execution of this Agreement.

8.2  During the Term BIOENVISION shall:

     (a)  be  responsible  for  obtaining  and  maintaining  in  force  all such
          licences,  consents and  approvals  of any  government  or  regulatory
          authority  in the  Territory  as may be required  from time to time in
          connection  with  the   manufacture,   use,  sale,   import,   export,
          advertisement,  storage or use of  Licensed  Products  anywhere in the
          Territory;

     (b)  attend  meetings  with UC3 at  regular  intervals  and in any event at
          least twice in any Year to discuss  without  limitation  BIOENVISION's
          development  and  exploitation  of the  Patents,  the Know-how and the
          Licensed Products in the Territory;

     (c)  not act as agent of UC3 and not give any indication  that it is acting
          otherwise than as a principal and not make any  representation or give
          any warranty on behalf of UC3;

     (d)  subject  always to the  provisions  of  clauses  8.2 (e) and 8.3 below
          within  thirty (30) days of receipt of an invoice  from UC3 in respect
          thereof, reimburse UC3 for all costs and expenses incurred by UC3 in:

          (i)       prosecuting to grant the patent  Applications  listed in the
                    Schedule and any other patent Applications  contained within
                    the Patents from time to time; and/or

          (ii)      maintaining in force any granted patents included within the
                    Patents; and/or

          (iii)     amending  any  patent  Applications  listed in the  Schedule
                    and/or any other patent  Applications  contained  within the
                    Patents  to  include  any   additional   claims   reasonably
                    requested by BIOENVISION;

     (e)  BIOENVISION  shall be  entitled at any time on giving to UC3 three (3)
          months notice in writing to determine its payment obligations pursuant
          to clause 8.2 (d) above in respect of any or all of the Patents within
          any part of the Territory.

8.3  If at any time  during  the Term UC3  grants to any  person a  licence  and
     sub-licence under the Patents and Know-how in a field of use other than the
     Field of Use, UC3


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     and BIOENVISION  shall  re-negotiate  the level of costs and expenses to be
     borne by BIOENVISION pursuant to the provisions of clause 8.2 (d) above.

8.4  BIOENVISION shall and shall procure that all Approved  Sub-Licensees shall,
     to the extent reasonably practicable:

     (a)  mark the  packaging  for all  Licensed  Products  with the  applicable
          patent application number in the relevant country in the Territory or,
          where patents have been granted in respect of the Licensed Products in
          such countries, the relevant patent number; and

     (b)  include a statement in a form approved by UC3 making it clear that the
          Licensed Products are manufactured under licence from UC3.

9.   Intellectual Property Rights

     The Improvements and all Intellectual Property Rights in or relating to the
     manufacture and use of Compounds, the Know-how and the Patents shall belong
     to UC3  absolutely  and save as  expressly  provided  herein  no  rights or
     licences in respect thereof are or shall be granted to BIOENVISION.

10.  Infringement of Patents and/or Licensed Know-how

10.1 Each party shall immediately  inform the other party of any infringement of
     the Patents,  Improvements,  Know-how and/or any part thereof by any person
     which comes to its attention during the Term.

10.2 BIOENVISION  shall at the  request and expense of UC3 take or join with UC3
     in taking  all such  action as UC3 may in its sole  discretion  decide  and
     require for the purpose of protecting the Patents,  Improvements,  Know-how
     and/or any part thereof.

10.3 Nothing  contained in this clause 10 shall be  interpreted  or construed as
     imposing any  obligation on UC3 to take any action or  proceedings  against
     any  person  who   infringes   or  is  alleged  to  infringe  the  Patents,
     Improvements,  Know-how or any part thereof. If UC3 decides not to take any
     action for  infringement  BIOENVISION  shall be  entitled  to do so and UC3
     shall  SUBJECT  ALWAYS to  BIOENVISION  agreeing  to  indemnify  UC3 to its
     reasonable satisfaction in respect of any costs, damages, expenses or other
     loss  incurred  or  suffered  by UC3 in any such  action at the request and
     expense of BIOENVISION join with BIOENVISION in any such action and provide
     such  assistance  in connection  therewith as  BIOENVISION  may  reasonably
     require.

11.  UC3 Warranties and Limitations of Liability

11.1 UC3 warrants that:


<PAGE>


     (a)  it has the  right to  enter  into  this  Agreement  and to  grant  the
          licenses hereby granted;

     (b)  so far as UC3 is  aware  not  having  made an  exhaustive  search  the
          practice in the Field of Use of any of the inventions  included in the
          Applications  does not  infringe any  person's  Intellectual  Property
          Rights;

     (c)  UC3 has no notice of any  reason  why any of the  patent  Applications
          listed in the Schedule should not proceed to grant.

11.2 Save  as  set  out  in  clause  11.1  above  UC3  makes  no  warranties  or
     representations whether express or implied regarding the Patents, Know-how,
     the Improvements,  Licensed Products and/or the adequacy or accuracy of the
     Know-how and/or the Patents and in particular (without limitation) UC3 does
     not warrant nor provide any representation that the manufacture, use and/or
     sale of Licensed  Products and/or use of the Patents and/or Know-how and/or
     Improvements  will not infringe any person's  Intellectual  Property Rights
     and all or any warranties or representations  implied by law or statute are
     hereby expressly excluded.

12.  BIOENVISION Warranty

     BIOENVISION warrants that it has the right to enter into this Agreement and
     to perform its obligations hereunder.

13.  Indemnity

13.1 UC3 shall not be responsible for and  BIOENVISION  shall indemnify and hold
     UC3 harmless from and against all or any loss, costs, claims,  proceedings,
     expenses  (including  without limitation legal costs) and damages howsoever
     suffered or incurred by UC3 as a result of or in connection with the use by
     BIOENVISION  and/or  any  Approved  Sub-Licensees  of  the  Patents  and/or
     Know-how and/or Improvements  including without limitation any manufacture,
     use and/or sale of Licensed Products.

13.2 The  indemnity  contained in clause 13.1 above shall not apply to any loss,
     costs,  claims,  proceedings,  expenses and damages to the extent that they
     are  suffered or incurred by UC3 as a result of any breach by UC3 of any of
     the provisions of this Agreement on its part to be performed.

14.  Term and Termination

14.1 This Agreement shall be deemed to have come into force on the  Commencement
     Date and unless  earlier  determined in accordance  with the  provisions of
     clause 2.4 above and clauses 14.2, 14.3, 14.4, 14.5 and/or 18.3 below shall
     continue  until  expiry of the last of the  Patents to expire or if none of
     the patent Applications contained within the Patents proceed to grant until
     the tenth (10th) anniversary date of the Commencement Date.


<PAGE>


14.2 Either  party shall be entitled to  terminate  this  Agreement on three (3)
     calendar months written notice to the other party

14.3 UC3 shall be entitled to terminate  this  Agreement  immediately on written
     notice to BIOENVISION if:

     (a)  at any time later than four (4) years after the date of  execution  of
          this  Licence  Agreement  BIOENVISION  fails to  demonstrate  to UC3's
          satisfaction  that  BIOENVISION  has complied  with the  provisions of
          clause 8.1 above or

     (b)  BIOENVISION challenges or assists any person to challenge the validity
          of the Patents and/or the Know-how or any part thereof.

14.4 Without prejudice to any other right or remedy either party may immediately
     by notice in writing to the other party  terminate  this  Agreement  at any
     time if:

     (a)  the other party shall commit a breach of any of the provisions of this
          Agreement  and shall  not  within  thirty  (30) days of notice of such
          breach  remedy the same (if capable of remedy).  For the  avoidance of
          doubt and without  prejudice  to the  provisions  of clause 14.3 above
          failure to  achieve  any  milestone  by the date set out  therefor  in
          clause 8.1 shall not be  considered to be a breach by  BIOENVISION  of
          the provisions of this Agreement; or

     (b)  the other party has a petition  for  winding-up  presented  against it
          and/or a  petition  presented  against  it for the  appointment  of an
          administrator  of its  undertaking  or an  application  for an interim
          order under Part VIII of the Insolvency Act 1986 or if the other party
          has an administrator,  receiver or administrative  receiver  appointed
          over any of its assets or  undertaking  or if the other party resolves
          to or goes into voluntary  liquidation (other than for the purposes of
          a bona fide reconstruction or amalgamation of a solvent company) or if
          the other party proposes or makes any voluntary  arrangement  with its
          creditors  or if the other party ceases to carry on business or if the
          other party is unable to pay its debts  within the meaning of Sections
          123 or 236 of the  Insolvency  Act 1986 or upon the  happening  of any
          equivalent event under the laws of any relevant jurisdiction.

14.5 BIOENVISION shall be entitled to terminate its rights in any country within
     the  Territory  at the end of any Year on giving  not less  than  three (3)
     months notice in writing to UC3 such notice to expire at the end of a Year.

15.  Effects of Expiry and Termination

15.1 In the  event of the  expiry of this  Agreement  by  effluxion  of time and
     PROVIDED  ALWAYS  that  where  such  expiry  occurs  upon the tenth  (10th)
     anniversary of the  Commencement  Date the Know-how and/or any Improvements
     do not at that date


<PAGE>


     remain  secret  and  substantial   BIOENVISION  shall  be  entitled  to  an
     irrevocable,  royalty free,  non-exclusive  licence to use the Know-how and
     the Improvements in the development,  manufacture,  use, sale and offer for
     sale of Licensed Products in the Territory together with the right to grant
     sub-licences thereunder.

15.2 In the event of termination of this Agreement pursuant to the provisions of
     clause 2.4, 14.2, 14.3, sub-clauses 14.4 (a) or (b) or clause 14.5 above or
     clause 18.3 below all rights and licences  hereunder  shall  cease.  In the
     event of  BIOENVISION  exercising its rights to terminate its rights in any
     country  within the Territory in accordance  with the  provisions of clause
     14.5 above but not the entire  Agreement all rights and licences in respect
     of such country shall cease.

15.3 Nothing in this  Agreement  shall be  construed as  preventing  BIOENVISION
     after termination of this Agreement from developing,  manufacturing, using,
     selling,  offering for sale or otherwise  dealing with Licensed Products in
     countries where no patents granted pursuant to the Patents are in force but
     only if and to the extent that the Licensed Products do not:

     (a)  utilise or  incorporate  any Know-how  and/or  Improvements  which are
          secret  and not in the public  domain or are in the public  domain but
          only as a result  of a  breach  by  BIOENVISION  and/or  any  Approved
          Sub-Licensee  and/or  any of its  employees  or  agents  of any of its
          confidentiality obligations hereunder or under any sub-licence.

15.4 BIOENVISION  shall within  thirty (30) days of the date of  termination  or
     expiry of this Agreement  howsoever  arising render to UC3 a written report
     in the form  referred  to in clause 6.4 above in  respect  of the  calendar
     quarter  or part  thereof  up to and  including  the said date of expiry or
     termination  and shall at the same  time pay to UC3 the full  amount of all
     sums due and payable  pursuant to clause 6 above in respect of all Licensed
     Products sold by  BIOENVISION  and/or Net Receipts  received by BIOENVISION
     during the calendar  quarter or part thereof up to and  including  the said
     date of expiry or  termination.  Subsequent to  termination of this Licence
     Agreement  BIOENVISION  shall pay to UC3  royalties  as defined in clause 6
     above on Licensed Products manufactured but unsold at the effective date of
     termination.

15.5 The expiry or  termination of this  Agreement  howsoever  arising shall not
     release either party from any  obligations  arising  hereunder prior to the
     date of termination.

15.6 The  provisions  of clauses 5, 6, 9,  11.2,  13, 16, 18 and this  clause 15
     shall  survive  the  expiry  or  termination  of this  Agreement  howsoever
     arising.

15.7 References in clauses 15.3,  15.4,  15.5 and 15.6 above to  termination  of
     this  Agreement  shall be deemed to include  termination  of  BIOENVISION's
     rights and licences in any country within the Territory.

16   Notices


<PAGE>


     Any notice required or authorised to be given hereunder shall be in writing
     and  served  personally  or  sent by post  or  facsimile  addressed  to the
     relevant party as follows:

     UC3                         PO Box 497
                                 56 Park Place
                                 Cardiff
                                 CF1 3XR

     For the attention of:       Dr. Nick Bourne

     Facsimile Number:           01222 874189

     BIOENVISION                 Trafalgar House
                                 11 Waterloo Place
                                 London SW1Y 4AU

     For the attention of:       Mr. Chris Wood
     Facsimile Number:           0171 8397570


     or to such other  address or  facsimile  number as may from time to time be
     notified to the other party hereto in writing for this purpose.  Any notice
     served personally shall be deemed to have been given upon such service. Any
     notice  sent by post shall be deemed to have been served two (2) days after
     the same shall have been posted and any notice sent by  facsimile  shall be
     deemed to have been served upon transmission and in proving such service it
     shall be  sufficient  to prove that the letter or  facsimile  was  properly
     addressed and as the case may be posted or transmitted.

17.  Assignment

     BIOENVISION  shall  be  entitled  to  assign  any or all of its  rights  or
     obligations arising hereunder to any person subject always to:

     (a)  the  assignee   entering  into  a  novation  of  this  Agreement  with
          BIOENVISION and UC3 in such form as UC3 shall reasonably require; and

     (b)  BIOENVISION reimbursing UC3 for all costs and expenses incurred by UC3
          in connection with any such novation; and

     (c)  all payments due to UC3 prior to the effective date of such assignment
          having been paid in full.

18.  Miscellaneous


<PAGE>


18.1 Any  reasonable  forbearance  or  delay  on the  part of  either  party  in
     enforcing the provisions of this  Agreement or any of its rights  hereunder
     shall not be construed as a waiver of such  provisions or any of its rights
     thereafter to enforce the same.

18.2 This  Agreement  embodies the entire  understanding  of the parties  hereto
     relating to the subject matter hereof and  supersedes all  representations,
     understandings,  documents and agreements  made or exchanged by the parties
     prior to the date hereof.

18.3 If either  party  shall by reason of  events or  circumstances  beyond  its
     control including without limitation acts of God,  political  intervention,
     fire, flood, legislation or industrial dispute be prevented from or delayed
     in performing its  obligations  hereunder and shall promptly give notice of
     such event or  circumstance  to the other  party the  parties'  obligations
     hereunder  shall from the date of such notice and without  prejudice to any
     rights or remedies  accrued or arising prior to such date be suspended.  If
     such event shall  continue for a period of more than three (3)  consecutive
     calendar  months either party shall be entitled to terminate this Agreement
     in which  event the  provisions  of clause 15 above  shall  apply.  Nothing
     contained  in this  clause  18.3  shall  be  interpreted  or  construed  as
     releasing   BIOENVISION  from  its  obligation  to  pay  the  royalties  in
     accordance with the provisions of clause 6 above.

18.4 The parties shall execute such further  documents and do all such things as
     may be necessary to carry the  provisions of this Agreement into full force
     and effect.

18.5 This  Agreement  shall be  governed  by and  construed  in all  respects in
     accordance with the laws of England and Wales.

18.6 This  Agreement  may be  executed  in  duplicate  each of which shall be an
     original and shall constitute one and the same instrument.

IN WITNESS  whereof the parties hereto have caused this Agreement to be executed
the day and year first before written.


<PAGE>


                                  THE SCHEDULE


                               Patent Applications


Country                          Application Number              Date of Filing

UK





<PAGE>


     SIGNED by  /s/ N.B. Bourne
                                Dr. NB Bourne, Director
     duly authorised representative
     for and on behalf of
     UNIVERSITY COLLEGE CARDIFF
     CONSULTANTS LIMITED





     SIGNED by  /s/ [ILLEGIBLE]
                                 Dr. [ILLEGIBLE]
     duly authorised representative
     for and on behalf of
     BIOENVISION INC.