**Exhibit 10.42**

RESEARCH AGREEMENT

FOR INVESTIGATOR SPONSORED CLINICAL TRIAL

This Research Agreement(“Agreement”) dated as of and effective the 11th day of August, 2006 is made by and between

BIOENVISION Limited,whose trading office is 10 Lochside Place, Edinburgh Park, Edinburgh EH12 9RGUK, (“BIOENVISION”)

And

Cardiff University, whoseadministrative offices are at 30-36 Newport Road, Cardiff, CF24 ODE,(“Sponsor”)

WHEREAS,

a)                                      BIOENVISIONhas agreed, without any involvement in the initiation or conduct of theSponsor’s clinical trial to provide financial support for the followingClinical Trial entitled:

AML 16 ClinicalTrial:  “A PHASE II/III TRIAL FOR OLDERPATIENTS WITHACUTE MYELOID LEUKAEMIA AND HIGH RISK MYELODYSPLASTCSYNDROME: Intensive Arm” (up to 400 patients enrolled)(Trial Reference ISRCTN 11036523)

b)                                     TheClinical Trial is being initiated by the Sponsor and is to be conducted underthe supervision of the Chief Investigator, Professor Alan Burnett, at theDepartment of Haematology, Cardiff University and in addition participatinghospitals, who may participate according to the conditions agreed with theSponsor.

c)                                      ThisAgreement sets forth the obligations of Chief Investigator and Sponsor as wellas the nature of BIOENVISION’S obligations.

NOW, THEREFORE, based onthe foregoing premises and the mutual covenants and agreements contained hereinand other consideration the receipt and sufficiency of which is herebyacknowledged, the parties hereto hereby agree as follows:

1.                                       GENERAL

a)                                      Forthe avoidance of doubt the Sponsor agrees that BIOENVISION is neither thesponsor nor co-sponsor of the Clinical Trial nor, during the term of thisAgreement or otherwise, shall BIOENVISION be deemed to be the sponsor orco-sponsor of the Clinical Trial for any purpose whatsoever.

b)                                     Subjectto the provisions set out below at Clause 1, it is recognised that the Sponsorintends to invite other hospitals, institutions or investigators to participatein this Clinical Trial under the leadership of the Sponsor and ChiefInvestigator, it is set out herewith that whatever relationship this doesrequire between the Sponsor and these sites or investigators, it does not andshall not establish any contractual relationship or other contractual liabilityor contractual obligation of any nature whatsoever, in each case, betweenBIOENVISION and these sites and/or investigators.  Further, the adding of these sites orinvestigators by the Sponsor shall not affect any of the Sponsor’s obligationsas the Sponsor of the Clinical Trial, which need to be fulfilled for theClinical Trial as a whole, independent of the number of participating sites orinvestigators.  The Sponsor isresponsible for ensuring that any such participating sites and investigatorscomply and act consistently with the Sponsor’s obligations and with the rightsof BIOENVISION which are set out in this Agreement.

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c)                                      TheSponsor makes no representation or warranty and Bioenvision expresslyindemnifies and waives all claims against the Sponsor arising out of or inconnection with any claims relating to the stability, safety, or toxicity ofthe Medicinal Product developed, formulated, packaged or manufactured inaccordance with its provision under this Agreement for the Clinical Trial.

d)                                     Bioenvisionassumes all risk or loss or claims in respect of the use of the MedicinalProduct save where the Sponsor has been negligent and/or indemnifies theSponsor in respect of such loss or damage and Bioenvision further warrants thatthe use of the Medicinal Product will not infringe any patents or any otherproprietary rights and will indemnify the Sponsor in respect of any claimsrelating to such warranty.

e)                                      TheSponsor will indemnify Bioenvision against claims arising as a result ofclinical negligence and/or negligent harm to Clinical Trial Subjects under itsduty of care during the conduct of the Clinical Trial pursuant to thisAgreement.

f)                                        TheSponsor shall only be liable to Bioenvision in respect to the Results providedto Bioenvision to the extent that the Sponsor has been negligent or is inwilful default in respect of the Results and/or is in deliberate breach of theterms and conditions of this Agreement.

g)                                     NeitherParty shall be liable to the other for any loss of profit, business,reputation, contracts, revenues or anticipated savings for any special,indirect or consequential damage or any nature which arises directly orindirectly out of or in connection with this Agreement.

h)                                     Subjectto the foregoing provisions of this Clause 1, Bioenvision shall indemnify andhold the Sponsor free and harmless from any and all claims, demands, liability,losses, actions or causes of actions, or any fines or penalties, and any andall expenses associated therewith (including, without limiting the generalityof the foregoing, defence costs and reasonable out-of-pocket attorney’s fees),arising out of or in connection with, are the result of, or are otherwiserelated to:

### any act or omission of Bioenvision;

### the promotion, distribution, use, misuse or sale of the MedicinalProduct (including, without limiting the generality of the foregoing, anyclaims, express, implied or statutory, made as to the efficacy or safetythereof);

### any Drug Product Labelling or packaging;

### Bioenvision’s compliance or non-compliance with any applicablegovernmental, local governmental, or regulatory authority laws or regulations;

### any failure of Bioenvision to perform, in whole or in part, any of itsobligations hereunder, or

### Bioenvision’s manufacture or handling of the Medicinal Drug, or anyacts or omissions of Bioenvision in respect thereof.

2.                                       RESPONSIBILITIESRELATED TO THE CLINICAL TRIAL.  In Consideration of BIOENVISION providingcertain financial support set forth in this Agreement, the Sponsor agrees toassume the following obligations:

a)                                      Toprovide BIOENVISION with the Protocol which has been developed by the ChiefInvestigator (and any and all amendments, modifications, supplements thereto orrestatements thereof), used or to be used in the Clinical Trial and the writtenapproval of the same by the Central Office for Research Ethics Committees(“COREC”).

b)                                     Topermit Bioenvision to review the design of the CRFs (Case Record Forms) for theClinical Trial.

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c)                                      Tofurnish BIOENVISION with a copy of all correspondence with the COREC and/or theoffices of domestic or foreign regulatory agencies within five (5) businessdays of receipt or transmittal by or the Sponsor;

d)                                     Tonotify BIOENVISION immediately of any action by the COREC altering their reviewor approval of the Clinical Trial;

e)                                      Topromptly notify BIOENVISION of any problems or potential concerns involvingrisk to human subjects;

f)                                        Tofurnish BIOENVISION with a monthly summary status report of the researchperformed under the Clinical Trial in a format to be agreed between BIOENVISIONand the Chief Investigator.  The contentof this interim report is subject to the provisions of the Data Protection Act1998;

g)                                     Tofurnish BIOENVISION with a complete report of the research performed underintensive arm of the Clinical Trial along with a publishable manuscript (the“Clinical Trial Report”) within 90 days of the completion of the ClinicalTrial.  The complete report will bestructured in a format to be discussed and agreed between BIOENVISION and theChief Investigator.  BIOENVISION herebyrecognises that the Chief Investigator has the right of first publicationwithin the 60 day period immediately following the delivery of the ClinicalTrial Report to BIOENVISION.  The Sponsorshall retain all Intellectual Property Rights in respect of the Results of theClinical Trial save to the extent that the provisions of clause 6(a) and/or6(c) apply;

h)                                     Tonotify BIOENVISION immediately of any changes in the status of the ChiefInvestigator or the Sponsor’s status at the site(s); provided, however, thatany such change in status shall be notified to BIOENVISION in writing.

i)                                         Tonot use BIOENVISION’S name in any advertising or other communication concerningthis Clinical Trial other than with the prior written consent of BIOENVISION inits sole discretion;

j)                                         Toconduct the Clinical Trial in accordance with the Protocol attached hereto as AppendixA; provided, however that any change to the Protocol shall be notified toBIOENVISION in writing and that BIOENVISION shall acknowledge receipt of anysuch notification.

k)                                      Tosubmit promptly all changes in the Protocol for BIOENVISION’S review.  The Sponsor also agrees to notify BIOENVISIONimmediately if any subject in this Clinical Trial is simultaneously enrolled inanother Clinical Trial;

l)                                         Tonotify BIOENVISION of any “serious” adverse event possibly related toCLOFARABINE, within 24 hours of receiving notification of such an event.  For purposes of this requirement, under ICHguidelines (ICH E2A Directive 2001/20) “serious” means any adverse event(s)which are:

#### associated with the patient’s death;

#### associated with inpatient hospitalisation orprolonged hospitalisation of the patient;

#### life-threatening to the patient;

#### associated with severe or permanentdisability/incapacity;

#### associated with cancer, or a congenitalanomaly; or

#### significant for any other reason.

The Sponsor agrees to make available to BIOENVISION,promptly, and within reporting guidelines for serious adverse events, thecompleted SAE Form and any and all such records as may be reasonably 

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necessary and pertinent to investigate an adverseevent, including, without limitation, any such adverse event which may beassociated with use of a BIOENVISION drug during the Clinical Trial;

m)                                   Tocomply with all laws, regulations or standards applicable to the Clinical Trial,including, but not limited to, obligations for safety reporting, and any otherrequirements reporting to regulatory authorities, informed consent, ethicalreview board requirements, obtaining and documenting regulatory authorisationsand CTAs and EUDRACT documentation prior to the commencement of the ClinicalTrial, archiving and retention of records, and all other applicable principlesof Good Clinical Practice; and

n)                                     Tomaintain records, and to instruct participating centres to do likewise, of thereceipt, storage and administration or dispensing of CLOFARABINE, identifying(but not necessarily by name) each patient to whom the drug is administered ordispensed, and to make these records available to BIOENVISION at any timerequested.

o)                                     TheSponsor shall be responsible for compliance with all laws and regulationsapplicable to any destruction or disposition of CLOFARABINE at the Sponsor’ssite and/or at the site of any other institution participating in the ClinicalTrial.

p)                                     Toprovide BIOENVISION with a copy of the Clinical Trial Monitoring Plan, prior tothe commencement of the Clinical Trial, and to further provide BIOENVISION witha copy of the record of monitoring visits and source data verification witheach and every summary status and complete report of the research, as detailedin clause 2(f) and 2(g) of this Agreement.

3.                                       CONSIDERATIONAND PAYMENTS.

a)                                      Contingenton the Sponsor’s compliance with the obligations set forth herein, BIOENVISIONshall provide the Sponsor with an initial Clinical Trial set up payment of[****] and further payments based on the provision of summary status reports asset out in paragraph 2(f) and as detailed in Appendix B.  The final payment will be due on delivery ofthe final Clinical Trial Report and publishable manuscript provided for inclause 2(g), in each case, as more fully described in the Financial SupportSchedule attached hereto as Appendix B.

b)                                     BIOENVISION’Spayment obligations set forth in clause 3(a) and Appendix B attached hereto arecontingent upon Sponsor’s obligation to reimburse BIOENVISION for the costassociated with the supply of clofarabine, as detailed in the Financial SupportSchedule attached hereto as Appendix B.

c)                                      Allpayments by BIOENVISION under this clause 3 shall be made within thirty (30)days of the end of the month in which the Sponsor’s invoice (notification ofmeeting the respective milestone as set in the Financial Support Schedule (AppendixB)) is received.  Each invoice shallset forth in reasonable detail the status of the Clinical Trial or relevantClinical Trial report, as applicable, and the description and amount due.  Matters in dispute shall be payable uponmutual resolution of such disputes.  The Sponsorshall be prepared to follow up with any and all such supporting documentationreasonably requested by BIOENVISION.

All payments by Sponsorto BIOENVISION shall be made within sixty (60) days of the end of the month inwhich BIOENVISION’S Invoice is delivered.

BIOENVISION’s paymentwill be made to:

AML 16 BioenvisionAccount

RACD FinanceDepartment

Cardiff University

30-36 Newport Road

Cardiff

CF24 ODE

**** Material omittedpursuant to a request for confidential treatment under Rule 24b-2 of theExchange Act of 1934.  Material filedseparately with the Securities and Exchange Commission.

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Or in such other nameand/ or address as provided after BIOENVISION’S receipt of prior written noticeof such change.

Sponsor’s payments willbe made to:

BioenvisionLimited

10 Lochside Place

Edinburgh Park

Edinburgh

EH12 9RG

Attention: Accounts Department

Or in such other nameand/ or address as provided after Sponsor’s receipt of prior written notice ofsuch change.

4.                                       CLINICALTRIAL DRUG SUPPLY AND DELIVERY.  Contingent on the Sponsors compliance withthe obligations set forth herein and with the terms set forth in the FinancialSupport Schedule (Appendix B), the parties hereby agree as follows:

a)                                      TheSponsor will notify BIOENVISION of the specific needs for each shipment ofclofarabine during the conduct of the Clinical Trial.  Each request will-be activated by electroniccommunication from the Trial Office in the Clinical Trials Unit, University ofBirmingham identifying the principal investigator and site in addition todetailing the patient trial number, quantity, named pharmacist and fulldelivery invoice address.

b)                                     TheSponsor must provide BIOENVISION with a copy of the Sponsor’s COREC approval,and the EC approval of each participating site, prior to BIOENVISION shipmentof clofarabine.

c)                                      Bioenvisionwill be responsible for the labelling of the Clinical Trial drug in compliancewith the European Directive 2001/20/EC, (Volume 4 Good Manufacturing Practices,Annexe 13, Manufacture of investigational medicinal products).

5.                                       PUBLICATION.

a)                                      Uponcompletion of each Clinical Trial, and any prior publication of multi-centredata, or when the Clinical Trial data are adequate (in Sponsor’s andBIOENVISION’ s reasonable judgement), the Sponsor will prepare the dataderiving from the Clinical Trial for publication.  In so far as any publication relates toclofarabine such data will be submitted to BIOENVISION for review and commentprior to publication.  In order to ensurethat BIOENVISION will be able to make comments and suggestions where pertinent,material for public dissemination will be submitted to BIOENVISION for reviewat least thirty (30) days prior to submission for publication, publicdissemination, or review by a publication committee.

b)                                     Duringthe period for review of a proposed publication referred to in clause (a)above, BIOENVISION shall be entitled to make a reasoned request to the Sponsorthat publication be delayed for a period of up to six (6) months from the dateof first submission to BIOENVISION in order to enable BIOENVISION to take stepsto protect its proprietary information. The Sponsor shall not unreasonably withhold consent to such a request.

c)                                      Inthe event that any such Publication does not relate to clofarabine then thePublication shall be provided to BIOENVISION for information purposes only.

# 6.                                       INTELLECTUALPROPERTY

a)                                      TheSponsor will disclose and promptly assign to BIOENVISION in writing anyimprovements, inventions or discoveries relating to clofarabine, whether or notpatentable, including without limitation any and all reformulations ofclofarabine, generated by the Sponsor or one of its agents, employees orrepresentatives, or arising from the activities or discoveries, whether or notpatentable, generated or arising from the activities under this 

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Agreement relating toclofarabine conceived and/or reduced to practice during the term of thisAgreement relating to clofarabine which are conceived or reduced to practice bythe Sponsor, any co-sponsor of this Clinical Trial and/or any employee orrepresentative of the Sponsor or such co-sponsor or the Clinical Trial (the“Intellectual Property Rights”).

b)                                     Anyother rights in any improvements, inventions or discoveries includingintellectual property rights (other than the “Intellectual Property Rights”defined in clause 6(a) above), whether or not patentable, generated by theSponsor or one of its agents, employees or representatives, or arising from theactivities or discoveries, whether or not patentable, generated or arising fromthe activities under this Agreement conceived and/or reduced to practice duringthe term of this Agreement which are conceived or reduced to practice by theSponsor, any co-sponsor of this Clinical Trial and/or any employee orrepresentative of the Sponsor or such co-sponsor or the Clinical Trial (the“Sponsor Intellectual Property Rights”) shall belong with the Sponsor.

c)                                      AnyIntellectual Property Rights concerning the use of clofarabine shall be thesole and exclusive property of BIOENVISION, regardless of the source of anysuch improvement, invention, reformulation or discoveries, and, during the termof this Agreement or thereafter, as applicable, the Sponsor agrees to promptlyassign or cause to be assigned all right, title and interest in and to suchIntellectual Property Rights to BIOENVISION.

d)                                     BIOENVISION’Sobligation to make final payment for the final Clinical Trial Report set forthin clause 3(a) above shall be contingent upon its having received any and allsuch Intellectual Property Rights from the Sponsor and/or Chief Investigator.

7.                                       Termand Termination.  The term of this Agreement shall expire uponcompletion of the Clinical Trial; provided, however, that

a)                                      EitherBIOENVISION or the Sponsor (the “Terminating Party”) may terminate thisAgreement with immediate effect at any time if the other Party (the “DefaultingParty”) is (i) in breach of any of the Defaulting Party’s obligations hereunderand fails to remedy such breach where it is capable of remedy within 28 days ofa written notice from the Terminating Party specifying the breach and requiringits remedy; or (ii) declared insolvent or has an administrator or receiverappointed over all or any part of its assets or ceases or threatens to cease tocarry on its business.

b)                                     AParty may terminate this Agreement immediately on notice to the other Partywith immediate effect if it is reasonably of the opinion that the ClinicalTrial should cease in the interests of the health of Clinical Trial Patientsinvolved in the Clinical Trial as advised by the Clinical Trial independentData and Ethics Monitoring Committee.

c)                                      BIOENVISIONmay terminate this Agreement on notice to the Sponsor if Professor Alan Burnettis no longer able (for whatever reason) to act as Chief Investigator and noreplacement mutually acceptable to BIOENVISION and the Sponsor can be found.

d)                                     IfBIOENVISION terminates this Agreement for any reason pursuant to clause 8(a)above, BIOENVISION agrees that it shall confer with the Sponsor and use itsbest endeavours to minimise any inconvenience or harm to Clinical TrialPatients caused by the premature termination of the Clinical Trial.

e)                                      Ifthis Agreement or this Clinical Trial is terminated for any reason prior tocompletion of the Clinical Trial or BIOENVISION’s receipt of a final ClinicalTrial report, the Sponsor shall

### immediately return to BIOENVISION or dispose of (as instructed byBIOENVISION) all unused clofarabine and other supplies previously supplied byBIOENVISION to the Sponsor’s site and instruct participating sites to dolikewise.

### promptly provide BIOENVISION with an itemised statement of work performedas of the date of termination consistent with the Financial Support Schedule(Appendix B); and

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### promptly refund to BIOENVISION the amount, if any, by which BIOENVISIONpayment(s) under this Agreement exceed BIOENVISION obligation.

# 8.                                       AGREEMENTAND MODIFICATION

a)                                      ThisAgreement including its Appendices contains the entire understanding betweenthe Parties and supersedes all other understandings and/or agreements betweenthe parties, whether written or oral, prior to the date hereof between theParties relating to the Clinical Trial or the other subject matter of thisAgreement.

b)                                     BIOENVISIONreserves the right to modify and re-negotiate the terms of this agreement underthe following conditions:

### if it is determined by BIOENVISION thataspects of the Clinical Trial conducted within the terms of this Agreementwould be suitable for use as part of a regulatory strategy for clofarabine,BIOENVISION reserves the right to negotiate a new contract with The Sponsorwhich would constitute a separate Agreement.

### if clofarabine is approved by the EMeA forthe treatment of first line Acute Myeloid Leukaemia, BIOENVISION reserves theright to review and re-negotiate the entire Agreement, subject to providing noless than three (3) months prior written notice to the Sponsor.

9.                                       GENERALPROVISIONS:

a)                                      IndependentContractors.  In conducting this ClinicalTrial, the Sponsor will not be acting as an agent, partner, or employee ofBIOENVISION and will not have any authority to, nor will the Sponsor, makeagreements with third- parties that are binding upon BIOENVISION in any manneror nature whatsoever.

b)                                     Notices.  Unless otherwise agreed to in this Agreement,any notice, request or other communication required to be given pursuant to theprovisions of this Agreement shall be in writing and shall be deemed to begiven when delivered in person or five business days after being deposited inthe mail, postage prepaid, certified, return receipt requested, or two businessdays after being deposited with an internationally recognised overnightcourier, return receipt requested, or one business day after being faxed, tothe parties addressed as follows:

If to the Sponsor:

Geraint Jones

Director ofResearch and Commercial Division

Cardiff University

30-36 Newport Road

Cardiff

CF24 ODE

In respect of Serious Adverse Events:

Alan K Burnett MD

Department ofHaematology

Cardiff University

Heath Park,Cardiff

CF14 4XN

If to BIOENVISION:

Hugh Griffith

BioenvisionLimited

10 Lochside Place

Edinburgh

EH12 9RG

Fax:  0131 2483300

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With a copy to:

David Luci

Bioenvision, Inc

345 Park Avenue

41st Floor

New York 10154

USA

c)                                      GoverningLaw; Jurisdiction.  This Agreement shallbe governed by and construed in accordance with the internal laws of Englandand Wales.  Each party to this Agreementagrees to be bound by the jurisdiction of the courts located in London, Englandin connection with any dispute arising under this Agreement.

d)                                     Counterparts.  This Agreement may be signed in one or morecounterparts, each of which shall be deemed an original as against either partywhose signature appears thereon, but all of which together shall constitute oneand the same instrument.

e)                                      Survivalof Obligations.  In the event of thetermination of this Agreement, all obligations of the parties hereto existingprior to termination shall remain the obligation of each such party untildischarged.  All confidentialityobligations shall survive any such termination for a period of ten (10) yearsthereafter.

f)                                        Authority;No conflicts.  The Sponsor represents andwarrants to BIOENVISION that The Sponsor has full power and authority to enterinto this Agreement and entering into this Agreement does not conflict with anyother obligation of the Sponsor and/or Chief Investigator.  The Sponsor agrees to assure that any and allother centres to be included in the Clinical Trial(s) shall have the power andauthority to participate in the Clinical Trial(s) prior to allowing suchparticipation in the Clinical Trial(s).

# 10.                                 CONFIDENTIALITY:

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a)                                      EachParty further agrees to take reasonable and appropriate measures to safeguardConfidential Information received from the other from theft, loss or negligentdisclosure to others and to limit access to Confidential Information to thoseof its officers, directors and employees who reasonably require such access inorder to accomplish performance of this Agreement.  Each Party shall take all reasonableprecautions in dealing with The Project Description and with any informationdocuments and papers provided to it by the other Party so as to prevent anyunauthorised person from having access to The Project Description, information,documents or papers or to any report on or records of any tests carried out.

b)                                     Therestrictions contained in this Clause shall continue to apply after the terminationor expiration of this Agreement.

c)                                      Theprovision of Clause 10a) shall not apply to the whole or any part of theConfidential Information that;

### i)                                         Islawfully obtained free of any duty of confidentiality otherwise than directlyor indirectly from the other Party;

### ii)                                      Isknown to the receiving Party at the time of disclosure without breach of thisAgreement by the receiving Party

### iii)                                   wasalready in the possession of the Party receiving such information and whichthey can show from written records other than as a result of a breach of thisAgreement;

### iv)                                  Isin the public domain without out or other than as a result of a breach of thisAgreement by the receiving Party;

### v)                                     isnecessarily disclosed pursuant to a statutory obligation or is legally requiredto be disclosed to a regulatory agency or pursuant to an order of a court ofcompetent jurisdiction, provided that where permissible the disclosing Party begiven an opportunity to seek protective order and following any such disclosurethe Confidential Information shall remain Confidential Information for thepurposes of this Agreement and shall remain to be dealt with according to theprovisions of this Agreement;

### vi)                                  isdisclosed with prior written consent of the other Party;

### vii)                               isdiscovered or developed independently by the receiving Party in activities notrelated to the performance of this Agreement;

### viii)                            isnecessarily disclosed by a Party, by virtue of its status as a public authorityin terms of the Freedom of Information Act (England) 2000 subject at all timesto the provisions of Clause s.41 and s.43 thereof.  In the event of any notice being received byeither Party pursuant to this FOI Act 2000, then the Party receiving suchnotice shall immediately notify the other Party prior to disclosing anyConfidential Information under this Agreement. The Parties hereby agree that all and any Confidential Information underthis Agreement is exempt information pursuant to s 41 and s. 43 of the FOI Act2000 and shall be exempt form disclosure to any third party

d)                                     EachParty further agrees to return to the other Party, upon request, all copies ofConfidential Information, except for one record copy which may, upon writtennotice to the other Party, be retained in confidence for archive purposes only.

e)                                      Thereceiving Party agrees to notify the disclosing Party promptly of the date of,and the circumstances involved in, the loss or unauthorised disclosure of anyConfidential Information belonging to such Party.

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f)                                        Theconfidentiality and non-use obligations imposed by this clause shall continuein force for 10 years following termination or expiration of this Agreement.

IN WITNESS WHEREOF, eachparty has caused This Agreement to be signed by its duly authorised officer asof the day and year written below.

Signed for an on behalfof Cardiff UniversityOn [30th] day of August 2006.
| /s/ Kathy Pittard Davies |                                                                                                                      | Witness: | /s/ Chris Shaw |
|--------------------------|---------------------------------------------------------------------------------------------------------------------------|----------|----------------|
|                     |                                                                                                                      |     |
| Name:                    |                                                                                                                      |     | Name:          | Chris Shaw |
|                     | Dr. Kathy  Pittard Davies  Deputy Director and Head of Research Policy   and Management  Research and Commercial Division |     | Address:       | RACD, 30-36 Newport Road, Cardiff |

 

Signed for an on behalfof Bioenvision LimitedOn [ 11] day of August 2006.
| /s/ Hugh Griffith |          | Witness: | /s/ Moira Adamson |
|-------------------|---------------|----------|-------------------|
|              |          |     |
| Name:             | Hugh Griffith |     | Name:             | Moira Adamson |
|              |          |     |              |   |
|              |          |     | Address:          | 10 Lochside Place, Edinburgh |

 

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APPENDIX APROTOCOL

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APPENDIX BFINANCIAL SUPPORT SCHEDULE

In accordance with theResearch Agreement and contingent on the Sponsors compliance with theobligations set forth herein and those referenced in Clause 2 and 3 of theaforementioned Research Agreement, and depending on completion of theMILESTONES BIOENVISION shall provide financial support totaling [****] asdetailed below.
| Payment   Number | ** ** | **Milestone**                                                                                | ** ** | **Amount** |
|------------------|------------|----------------------------------------------------------------------------------------------|------------|------------|
| 1                |       | Upon signature of contract                                                                   |       | [****]     |
| 2                |       | Upon completion of clofarabine dosing of 25 patients  and receipt of monthly status reports  |       | [****]     |
| 3                |       | Upon completion of clofarabine dosing of 50 patients  and receipt of monthly status reports  |       | [****]     |
| 4                |       | Upon completion of clofarabine dosing of 75 patients  and receipt of monthly status reports  |       | [****]     |
| 5                |       | Upon completion of clofarabine dosing of 100  patients and receipt of monthly status reports |       | [****]     |
| 6                |       | Upon completion of clofarabine dosing of 125  patients and receipt of monthly status reports |       | [****]     |
| 7                |       | Upon completion of clofarabine dosing of 150  patients and receipt of monthly status reports |       | [****]     |
| 8                |       | Upon completion of clofarabine dosing of 175  patients and receipt of monthly status reports |       | [****]     |
| 9                |       | Upon completion of clofarabine dosing of 200  patients and receipt of monthly status reports |       | [****]     |
| 10               |       | Upon completion of clofarabine dosing of 225  patients and receipt of monthly status reports |       | [****]     |
| 11               |       | Upon completion of clofarabine dosing of 250  patients and receipt of monthly status reports |       | [****]     |
| 12               |       | Upon completion of clofarabine dosing of 275  patients and receipt of monthly status reports |       | [****]     |
| 13               |       | Upon completion of clofarabine dosing of 300  patients and receipt of monthly status reports |       | [****]     |
| 14               |       | Upon completion of clofarabine dosing of 325  patients and receipt of monthly status reports |       | [****]     |
| 15               |       | Upon completion of clofarabine dosing of 350  patients and receipt of monthly status reports |       | [****]     |
| 16               |       | Upon completion of clofarabine dosing of 375  patients and receipt of monthly status reports |       | [****]     |
| 17               |       | Upon completion of clofarabine dosing of 400  patients and receipt of final study report     |       | [****]     |
| **TOTAL**        | ** ** | ** **                                                                                   | ** ** | **[****]** |

 

BIOENVISION’s paymentobligations set forth in clause 3 of this Research Agreement and this AppendixB are contingent upon The Sponsor’s promptly providing clinical data from theClinical Trial to BIOENVISION.

Sponsor shall payBIOENVISION for the cost associated with the supply of clofarabine [****].

BIOENVISION shall havethe right to offset amounts due and owing to Sponsor against amounts due andowing by Sponsor to BIOENVISION under this Agreement.

**** Material omittedpursuant to a request for confidential treatment under Rule 24b-2 of theExchange Act of 1934.  Material filedseparately with the Securities and Exchange Commission.

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APPENDIX C

Sponsor acknowledges itis acquiring drug supply of clofarabine solely and exclusively to properlycompare and contrast treatment regimens of compounds known or considered to beactive agents in the adult AML disease indication in performance of theinvestigator sponsored clinical study known as AML-16.

Sponsor furtheracknowledges it will acquire drug supply of clofarabine at prevailing marketrates to conduct the AML-16 clinical study regardless of Bioenvision’s decisionto either acquire or not acquire the clinical data generated by AML-16 (andrelated interim and final study reports generated by Sponsor) and that acomparison of compounds to treat adult AML would be incomplete withoutinclusion of clofarabine in this multi-arm clinical study.

IN WITNESS WHEREOF, theparties have caused this Appendix C to Research Agreement to be executed bytheir duly authorised officer, as of the 30th day of August 2006.
| BIOENVISION LIMITED |                                                                                |
|---------------------|-------------------------------------------------------------------------------------|
|                |                                                                                |
|                |                                                                                |
| By:                 |   /s/ Hugh Griffith                                                            |   |   |
|                |                                                                                |
|                | Name:                                                                               | Hugh Griffith |   |
|                |                                                                                |
|                | Title:                                                                              | C.O.O. |   |
|                |                                                                                |
|                |                                                                                |
| CARDIFF  UNIVERSITY |                                                                                |
|                |                                                                                |
|                |                                                                                |
| By:                 |   /s/ Kathy Pittard Davies                                                     |   |   |
|                |                                                                                |
|                | Name: Dr.  Kathy Pittard Davies                                                |   |
|                |                                                                                |   |
|                | Title:   Deputy Director and Head of  Research Policy and Management |
|                | Research and Commercial Division                                                    |
|                     |                                                                                     |  |  |  |  |  |  |

 

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