Agreement Execution Date Idenix GSK
      DEFINITIONS
  Affiliate provided
 AIDS




---



##### 



ANDA
 Annual Net Sales
 Business Day
 Calendar Quarter
 Calendar Year
 CFR
 cGMP
 Co-Labeling Right
 Co-Labeling Patent Rights
 Combination Product Sole Compound
Product Double
Combination Product Triple Combination Product
 2




---



##### 



Commercially Reasonable Efforts
 Confidential Information Disclosing Party
 Receiving Party
     3




---



##### 



Control Controlled
 Cover Covered Covering
 Develop Developing Development
 DOJ
 Effective Date
 EMEA
 Exploit Exploitation
 FDA
 Field
 First Commercial Sale
 FTC
 Fully Allocated Cost of Goods
 4




---



##### 



Generic Competition provided
 Generic Product
 GSK Invention
 HBV
 HCV
 HIV
 HSR Act
 HSR Clearance Date provided however
 Idenix Entities
 Idenix Indemnitees
 Idenix IP
 Idenix Invention
 5




---



##### 



Idenix Know-How provided however
 Idenix Patent Rights Exhibit
A provided however
 IDX899
 
 IDX989
 
 6




---



##### 



IND
 Information
 Intellectual Property Rights
 Joint IP
 Joint Invention
 Joint Know-How
 Joint Patent Rights
 Know-How
 Knowledge Known
 La Colla Agreement
 Law
 Licensed Compound Exhibit A,
 7




---



##### 



Major Market
 Measured COGS
 Measured Net Sales
 MHLW
 NDA MAA
 Net Sales Seller
      8




---



##### 



provided
      Novartis
 Novartis Protected Entities
 Novartis Waiver Exhibit B
 NNRTI
 Party Parties
 Patent Rights
 9




---



##### 



Person
 Phase II Clinical Trial
 Phase III Clinical Trial
 Prior Confidentiality Agreements February 2008 CDA June 2008 CDA
 Product provided however
 Professor La Colla
 Regulatory Approval
 Regulatory Authority
 Regulatory Documentation
 Royalty Term
 10




---



##### 



Stock Purchase Agreement Exhibit C
 Sublicensee
 Successful Completion Schedule 5.2(a)
 Territory
 Third Party
 University
 University Agreements
 University Amendment Exhibit D
 U.S.C.
 Valid Claim
 Other Defined Terms
 11




---



##### 



Definition
    
    Section1974 Convention
    
    14.7AAI
    
    5.3(a)(iii)Agreement
    
    PreambleAuditor
    
    5.9Bankruptcy Code
    
    14.4Breaching Party
    
    12.2(b)Challenge
    
    12.2(d)Combination Product Net Sales
    
    5.3(b)(i)Committee
    
    4.5(a)Development Plan
    
    4.3Disclosing Party
    
    1.14Execution Date
    
    PreambleExecutive Officer
    
    14.8February 2008 CDA
    
    1.70GSK
    
    PreambleGSK Indemnitees
    
    8.2GSK IP
    
    12.3(a)(iii)Hatch-Waxman Act
    
    6.6Idenix
    
    PreambleInitial Materials
    
    3.2(a)Inventions
    
    6.1IP Committee
    
    4.5(a)JSC
    
    4.5(a)June 2008 CDA
    
    1.70
 12




---



##### 



Definition
    
    SectionLosses
    
    8.1MAA
    
    1.59MTA
    
    3.2(a)Non-Breaching Party
    
    12.2(b)Paragraph IV Certification
    
    6.3(a)Patent Term Extensions
    
    6.5(a)Phase IIb Clinical Trial
    
    Schedule 5.2(a)Product Trademarks
    
    2.2Receiving Party
    
    1.14Seller
    
    1.60Severed Clause
    
    14.10SPC
    
    6.5(a)Specifications
    
    3.2Term
    
    12.1
 Construction
      13




---



##### 



LICENSES AND ASSIGNMENTS
 License
 Grants
 Sublicenses provided
 Trademark Product
Trademarks provided
 Exclusivity
 Retained Rights
 14




---



##### 



TECHNOLOGY AND MATERIALS TRANSFER
 Technology Transfer to GSK
 Materials Transfer to GSK
 MTA Initial Materials). Exhibit E Specifications
  15




---



##### 



Other Assistance
 DEVELOPMENT AND COMMERCIALIZATION
 Responsibility
 Compliance with Laws
 16




---



##### 



Diligence
 Exhibit F Development Plan
 provided however
 provided however
 Reporting
   17




---



##### 



Committees
 Structure JSC IP Committee Committee provided however
 JSC Responsibilities
  18




---



##### 



IP Committee Responsibilities
 Committee Administration
 19




---



##### 



Committee Meetings
 Termination of Committees
 PAYMENTS
 Initial Payments
 Milestone Payments
 Development Milestones
 Milestone Event:
    
    Milestone Payment:(i) Successful Completion of development
of the first formulation of a Licensed
Compound
    
    [**] U.S. Dollars (US $[**])(ii) Successful Completion of development
of the first fixed dose combination
formulation of a Licensed Compound
    
    [**] U.S. Dollars (US $[**])(iii) Successful Completion of a segment
II reproductive toxicity study
    
    [**] U.S. Dollars (US $[**])
 20




---



##### 



Milestone Event:
    
    Milestone Payment:(iv) Successful Completion of a six (6)
month rodent chronic toxicology study
    
    [**] U.S. Dollars (US $[**])(v) Successful Completion of a chronic
toxicology non-rodent study of at least nine
(9) months
    
    [**] U.S. Dollars (US $[**])(vi) Successful Completion of a
carcinogenicity program in at least one (1)
rodent species
    
    [**] U.S. Dollars (US $[**])(vii) First patient dosed in first Phase II
Clinical Trial studying chronic dosing (24 
48 weeks) in combination with other ARTs in
HIV-infected patients as defined in the
Development Plan
    
    [**] U.S. Dollars (US $[**])(viii) First patient dosed in Phase III
Clinical Trial of a Product for HIV
    
    [**] U.S. Dollars (US $[**])(ix) Acceptance for review by the FDA of an
NDA for first Product for HIV
    
    [**] U.S. Dollars (US $[**])(x) Acceptance for review by EMEA of an NDA
for first Product for HIV
    
    [**] U.S. Dollars (US $[**])(xi) Acceptance for review by MHLW of an NDA
for first Product for HIV
    
    [**] U.S. Dollars (US $[**])(xii) Receipt of Regulatory Approval from
the FDA for first Product for HIV
    
    [**] U.S. Dollars (US $[**])(xiii) First Commercial Sale of the first
Product for HIV in the first of one (1) of
the following countries: [**].
    
    [**] U.S. Dollars (US $[**])(xiv) Receipt of Regulatory Approval from
the MHLW for first Product for HIV
    
    [**] U.S. Dollars (US $[**])
 Sales Milestones
 21




---



##### 



Milestone Event:
    
    Milestone Payment:(i) Annual Net Sales greater than [**] U.S.
Dollars (US $[**])
    
    [**] U.S. Dollars (US $[**])(ii) Annual Net Sales greater than [**]
U.S. Dollars (US $[**])
    
    [**] U.S. Dollars (US $[**])(iii) Annual Net Sales greater than [**]
U.S. Dollars (US $[**])
    
    [**] U.S. Dollars (US $[**])
 Overlapping Milestones provided however
 Royalties
 Base Rate
  22




---



##### 



Annual Net Sales Tiers:
    
    Royalty Rate:The portion of Annual Net Sales which is less than or equal
to [**] U.S. Dollars (US $[**])
    
    [**]%The portion of Annual Net Sales which is greater than [**]
U.S. Dollars (US $[**]), but less than or equal to [**] U.S.
Dollars (US $[**])
    
    [**]%The portion of Annual Net Sales which is greater than [**]
U.S. Dollars (US $[**]), but less than or equal to [**] U.S.
Dollars (US $[**])
    
    [**]%The portion of Annual Net Sales which is greater than [**]
U.S. Dollars (US $[**])
    
    [**]%
   AAI Schedule 5.3(a) provided however
 Calculation of Royalty Payments for Combination Products
 Combination Product Net Sales
  23




---



##### 



provided however
  24




---



##### 



Royalty Term provided however
 Royalty Stacking provided
 Generic Competition
 No Discounting in Exchange for In-Kind Consideration
 Existing Third Party Agreements
 25




---



##### 



Reports and Payments
 Tax Withholding
 26




---



##### 



Blocked Payments
 Late Payments The Wall Street Journal provided , however
 Financial Records
 Audit Right
 Auditor
 27




---



##### 



Invoices
 th
 Licensed Compounds or Products for Other Indications
 Development Milestones, Sales Milestones and Royalties for Licensed Compounds Other
Than IDX899 provided however
 28




---



##### 



provided, further
 INTELLECTUAL PROPERTY PROTECTION
 Ownership of Inventions Inventions
 Prosecution and Maintenance of Idenix Patent Rights and Joint Patent Rights
   provided however
   Enforcement of Idenix Patent Rights and Joint Patent Rights
 Notice
 29




---



##### 



Paragraph IV Certification
 Infringement
 provided that
   provided that
 Patent Rights Certifications and Infringement Suits
 30




---



##### 



provided that
 No Admissions
 Claimed Infringement provided however
 Patent Term Extensions
 SPC Patent Term Extensions
   31




---



##### 



Patent Rights Listings and Regulatory Data Protection Hatch-Waxman
Act  provided however
 CONFIDENTIAL INFORMATION
 Non-Use and Non-Disclosure of Confidential Information
 Permitted Disclosures
  provided
 provided
 32




---



##### 



Scientific Publications; Clinical Trial Registry
 provided
 provided
 33




---



##### 



Publicity
 Exhibit G
  provided
 provided
  provided
  INDEMNIFICATION
 Indemnification by GSK Losses
 34




---



##### 



provided however
 Indemnification by Idenix GSK
Indemnitees provided however
 Allocation
 35




---



##### 



INSURANCE
  WARRANTIES AND COVENANTS
 Mutual Warranties
       36




---



##### 



Additional Idenix Warranties
 Exhibit A
 Exhibit A
       37




---



##### 



38




---



##### 



Idenix Covenants
 Disclaimer
 LIMITATION OF LIABILITY
  39




---



##### 



TERMINATION
 Term Term provided however
 Termination
 Termination For Convenience
 Termination For Material Breach Non-Breaching
Party Breaching Party
 Termination for Bankruptcy
 Termination for Patent Challenge Challenge provided Challenge
 Effects Of Termination
  40




---



##### 



GSK IP provided however
 provided
    41




---



##### 



mutatis mutandis
   mutatis mutandis
 provided however
 42




---



##### 



provided however
 HSR
 HSR Filing
 Cooperation
 provided however
  Termination Due to Passage of Time
 43




---



##### 



provided however
 MISCELLANEOUS
 Effectiveness of the Agreement
 Assignment provided
 Force Majeure
 Section 365(n) of the Bankruptcy Code Bankruptcy Code
 44




---



##### 



Notices
  
  
  
  
 45




---



##### 



Relationship of the Parties
 Governing Law 1974 Convention
 Dispute Resolution
 provided however
  Executive Officer
  46




---



##### 



Injunctive Relief
 Severability Severed Clause
 Entire Agreement provided however provided further
 Amendment and Waiver
 No Implied Waivers
 Export Compliance
 47




---



##### 



Counterparts and Facsimile Signatures
 Performance by Affiliates
 [Remainder of Page Intentionally Left Blank]
 48




---



##### 



Idenix PHARMACEUTICALS, Inc.By:
    /s/ Jean-Pierre Sommadossi, Ph.D.Name:
    Jean-Pierre Sommadossi, Ph.D.Title:
    Chairman and CEOSMITHKLINE BEECHAM Corporation d/b/A 
GlaxosmithklineBy:
    /s/ William J. MosherName:
    William J. MosherTitle:
    Vice President and Secretary




---



##### 








---



##### 



HIV WAIVER AND CONSENT
 Idenix US Idenix Cayman Idenix Novartis
 INTRODUCTION
 Novartis Licence Agreement
     IN CONSIDERATION
 Definitions
 Patent Rights




---



##### 



Affiliate control
 Co-Labeling Right
 Entity
 Idenix Entities
 IDX899
 
 IDX989
 3




---



##### 



Novartis Protected Entities
 Possible Licensees
 Terms Sheet
 Transaction
 Waived Compounds
 Waived Compound Intellectual Property
 4




---



##### 



Waiver and Consent
      Representations. Warranties. Covenants and Indemnity
     Novartis Retained Rights
 5




---



##### 



Confidentiality
 Governing Law
 Entire Agreement
  6




---



##### 



EXECUTION
 IDENIX PHARMACEUTICALS. INC.By:
    /s/ John WeidenbruchName:
    John WeidenbruchTitle:
    Executive Vice Presidential and General CounselIDENIX (CAYMAN) LIMITEDBy:
    /s/ Jean-Pierre SommadossiName:
    Jean-Pierre Sommadossi, Ph.D.Title:
    DirectorNOVARTIS PHARMA AGBy:
    /s/ Neil JohnstonName:
    Neil JohnstonTitle:
    Head of Finance, Global Business Development & LicensingBy:
    /s/ P.A. HoName:
    P.A. HoTitle:
    Senior Legal Counsel 7




---



##### 



SCHEDULE 1
 TypeRelated/Idenix Ref. No.
    
    Country
    
    Serial No.
    
    Filed
    
    Title
   8




---



##### 



SCHEDULE 2
 Possible Licensees
 1.
    
    GlaxoSmithKline plc.
 [END OF SCHEDULE]
 9




---



##### 



[to be attached]




---



##### 



AMENDMENT AGREEMENT
  IDENIX PHARMACEUTICALS, INC.,
  IDENIX SARL,
  SmithKline Beecham Corporation doing business as GLAXOSMITHKLINE,
  UN1VERSITA DEGLI STUDI DI CAGLIARI,
  PROF. PAOLO LA COLLA, -
  A)
    
    on 4 January 1999, the University and Idenix SARL, this last on behalf and for the benefit of
Idenix, entered into an agreement entitled Co-operative Antiviral Research Activity
Agreement (hereinafter referred to as the Co-operative Agreement) aimed at performing a
joint research activity in the antiviral substances field;B)
    
    in accordance with the Co-operative Agreement, on 14 December 2000, the University and Idenix
entered into a license agreement (hereinafter the License Agreement) according to which the
University grants to Idenix the exclusive license for the exploitation, whether direct or
indirect, of the results obtained and that will be obtained from the performance of the joint
research activity under the Co-operative Agreement;




---



##### 



C)
    
    the above mentioned Co-operative Agreement and License Agreement (together, the Original
Agreements) have been initially amended on 10 April 2002 (the April 10, 2002 Amendment);D)
    
    the Original Agreements, as so amended, have been afterwards amended with the deed
undersigned by the parties on 8 May 2003, also in consideration of the transactions at that
time pending between Idenix and Novartis Pharma AG for the acquisition, by this last, of the
majority of the shareholding of Idenix (the amendments indicated in this point have become
effective on 8 May 2003, following to the occurred execution of a Development, License and
Commercialization Agreement and of a Manufacturing and Supply Agreement by and among
Idenix, Idenix (Cayman) Limited and Novartis) (together, the Novartis Agreements); the deed
undersigned by the parties on 8 May 2003 provided, in favour of Novartis, the right to cure
possible breaches of the Original Agreements by Idenix;E)
    
    the parties further amended the Original Agreements, as previously amended, on 30 June 2004
(the June 30, 2004 Letter Amendment) and on 24 October 2005 (the October 24, 2005
Amendment). The Original Agreements, as amended through and including the April 10, 2002
Amendment, the June 30, 2004 Amendment, and the October 24, 2005 Amendment shall be
collectively defined the Cagliari Agreements, provided that the Cagliari Agreements do not
include the Novartis Agreements;F)
    
    on 30 June 2004 the University and Prof. La Colla executed an agreement (the June 30, 2004
Assignment Agreement) called assignment of the intellectual property rights deriving from
the execution of the Co-operative Antiviral Research Activity Agreement;G)
    
    on 22 December 2006 the parties have extended the validity of the Co-operative Agreement up
to 22 January 2011 (the December 22, 2006 Amendment);H)
    
    on 03 December, 2008 Idenix and Prof. Paolo La Colla executed an agreement (hereinafter
[**] Agreement, which is attached herewith under Enclosure B);I)
    
    Idenix is currently carrying on negotiations with GSK in order to define an agreement
relating to the granting of exclusive licenses to non-nucleoside reverse transcriptase
inhibitor compounds owned and/or controlled by Idenix and namely:
 (i)
    
    an exclusive license, from Idenix to GSK, of the [**] patents covering
inventions developed within the Co-operative Agreement and listed in Enclosure A to
this agreement, including future patents related to the family of patents or compounds
mentioned under such Enclosure A;(ii)
    
    an exclusive license, from Idenix to GSK, of the [**] patents listed
in Enclosure B to this agreement and as the subject of the [**] Agreement,
including future patents related to the family of patents or compounds mentioned under
such Enclosure B; (collectively the GSK Agreement);
 12




---



##### 



J)
    
    art. 2.2 of the Licence Agreement allows Idenix (formerly Novirio) to grant sublicenses
under the license granted pursuant to Section 2.1 above to parties with whom Novirio or its
Affiliates has agreed to jointly develop or commercialize Licensed Products;K)
    
    in the light of the negotiations currently pending between Idenix and GSK;
 (i)
    
    Idenix, Idenix SARL and the University hereby execute this amendment to the
License Agreement and the Co-operative Agreement (to the extent that this latter refers
to the licence granted by the University under art. 9.1 to Idenix) which shall be
effective only if and when Idenix and GSK shall have executed the agreement mentioned
under previous recital (I) and;(ii)
    
    Idenix and Prof. La Colla hereby execute an amendment to the [**]
Agreement which shall be effective only if and when Idenix and GSK shall have executed
the agreement mentioned under previous recital (I),
   1)
    
    The recitals and the Enclosures to this agreement shall represent an integral and substantial
part of this agreement (hereinafter the Amendment).2)
    
    This Amendment shall represent an amendment to the License Agreement (as amended), the
Co-operative Agreement (as amended) and to the [**] Agreement and shall become
automatically effective among the parties hereof, if and when Idenix and GSK shall have
executed the agreement mentioned under previous recital I, upon the Effective Date.3a)
    
    In relation to the provision mentioned under art. 2.2 of the License Agreement and article
9.1 of the Co-operative Agreement, the University hereby acknowledges and accepts that
 (i)
    
    Idenix is permitted to sublicense to GSK the patents, arising under the
Co-operative Agreement and the License Agreement, listed in Enclosure A, including
future patents related to the family of patents or compounds mentioned under such
Enclosure A, for development or commercialization of the Licensed Products;(ii)
    
    such sublicense shall no longer be conditioned upon an agreement between Idenix
(formerly Novirio) or its Affiliates and GSK to jointly develop or commercialize
Licensed Products, and GSK shall be entitled to develop and commercialize Licensed
Products solely and on its own behalf in accordance with the License Agreement;(iii)
    
    GSK is, in its turn, permitted to sublicense the patents mentioned under the
Enclosure A, including future patents related to the family of patents or
 13




---



##### 



compounds mentioned under such Enclosure A, to its affiliates or to third parties,
solely in accordance with the agreement to be executed between Idenix and GSK,
provided that, for purposes of this art. 3a) affiliates shall mean any
corporation, company, partnership, joint venture and/or firm that controls, is
controlled by, or is under common control with GSK.
 3b)
    
    Idenix may disclose to GSK as required under the agreement between GSK and Idenix
confidential information (as identified in art. 6 of the Co-operative Agreement) owned by the
University of Cagliari it being understood that GSK may make further limited disclosures as
permitted under the agreement between GSK and Idenix.3c)
    
    Idenix will license to GSK the [**] patents which represent the subject matter of
the [**] Agreement (Enclosure B, including future patents related to the family of
patents or compounds mentioned under such Enclosure B).4a)
    
    As of, and thereafter the Effective Date, should Idenix be in breach of one or more of the
obligations mentioned under the License Agreement or the Co-operative Agreement and either
Idenix or Novartis not cure such breach within the 3 months and 15 days term (Idenix Cure
Term) granted pursuant to the amendment to the License Agreement or the Co-operative
Agreement mentioned under recital D) to this Amendment, GSK shall have the right to cure such
breach within 15 days (Grace Term) after expiration of the Idenix Cure Term provided that,
if GSK cures the breach within the Grace Term, GSK shall then have the right, without the need
for any further action by Idenix, to partially succeed to Idenix in the License Agreement with
sole reference to the patents mentioned within the Enclosure A to this Amendment and to future
patents related to the family of patents or compounds mentioned under such Enclosure A, or the
Co-operative Agreement (to the sole extent it refers to the license granted by the University
to Idenix pursuant to art. 9.1 of the same Co-operative Agreement), thereby assuming the
rights and obligations of Idenix under such agreement, provided that
 (i)
    
    the License Agreement or the Co-operative agreement will not terminate in case
Idenix or GSK demonstrate that the obligations have been contracted or proven the fault
was a case of force majeure or the same is demonstrated by GSK within the Grace Term;(ii)
    
    the University of Cagliari shall provide written notice to GSK by registered
mail (in addition to Idenix and Novartis) of any breach or default under the License
Agreement or the Co-operative Agreement and with any related correspondence that is
delivered to Idenix and at the same time that of delivery to Idenix.
 4b)
    
    As of, and thereafter the Effective Date, should Idenix be in breach of one or more of the
obligations mentioned under the [**] Agreement, Idenix shall have the right to cure
such breach within 3 months after reception of a registered letter sent by Prof La Colla to
Idenix and GSK detailing the reasons for such complaint, provided that, should the breach be
cured by Idenix, the [**] Agreement shall remain between Idenix and Prof. La Colla.
Should the breach not be cured within such 3 months term, the agreement shall remain in force
for a further 30 days term starting from the expiration of
 14




---



##### 



the 3 months period during which GSK shall still have the right to cure such breach in lieu
of Idenix, provided that if GSK cures the breach within such 30 days term, GSK shall then
have the right, without the need for any further action by Idenix to succeed to Idenix in
the [**] Agreement, thereby assuming the rights and obligations of Idenix under
such [**] Agreement.5)
    
    It is understood that, should the agreement between Idenix and GSK state the right of Idenix
to receive any up-front payment, milestone or other fixed amount (Fixed Amount) related to
such agreement and pertaining to both the [**] patents and the [**] patents
licensed by Idenix to GSK, the University and Professor La Colla shall, with specific
reference to such Fixed Amount, receive from Idenix only the percentage provided under the
Cagliari Agreements, provided that Prof. La Colla shall not be entitled also to the
percentages provided under the [**] Agreement in relation to the Fixed Amount. For
purposes of clarity, it is understood by the parties that if Idenix and GSK enter into the
agreement referenced herein and a payment is made by GSK to Idenix at the time of licensing
both the [**] patents and the [**] patents, only one payment will be made to
the University and Professor LaColla in relation to the [**] patents and the
[**] patents. If future milestone or royalty payments are made based on a specific
patent family, the respective agreement shall govern any such payment to be made to the
University and Professor La Colla.6)
    
    The provisions of article 8.2 of the Co-operative Agreement and article 5.1 of the License
Agreement are hereby expressly amended to permit GSK to file, prosecute and maintain patents
licensed to GSK by Idenix and mentioned under Enclosure A (including future patents related to
the family of patents or compounds mentioned under such Enclosure A) in lieu of Idenixs first
right to file, prosecute and maintain such patents, provided that the relevant expenses shall
be borne by Idenix or by GSK as may be agreed between these last two entities and the
University of Cagliari hereby permits and acknowledges such actions by GSK. It is understood
that, with reference to the patents listed under Enclosure A, such filing, prosecution and
maintenance shall be performed in the name and on behalf of Idenix and of University of
Cagliari.7)
    
    Consistently with the amendment of article 5.1 of the License Agreement above, GSK or any of
its affiliates or permitted sublicensees shall be permitted to exercise Idenix right to
institute an action against a third party for infringement of the patents licensed to GSK by
Idenix, including those mentioned under Enclosure A as Idenix designee and as may be agreed
between Idenix and GSK.8)
    
    To this aim, with the signature of the present document, the parties acknowledge that as of
the execution date, no breaches of the License Agreement and of the [**] Agreements
have occurred.9)
    
    It is understood that, without limitation to the rights granted to GSK according to previous
art. 4a) and 4b), the University of Cagliari and Prof. La Colla expressly permit,
respectively, the assignment of the License Agreement, the Co-operative Agreement and of the
[**] Agreement by Idenix to GSK.
 
 15




---



##### 



Idenix Pharmaceuticals, Inc.By:
    
    /s/ John F. Weidenbruch

Name: John F. Weidenbruch, Esq.Title: Executive Vice President/General Counsel
 21 January 2009

Date
 16




---



##### 



Idenix SARIBy:
    
    /s/ Jean-Pierre Sommadossi

Name: Jean-Pierre SommadossiTitle: Gerant
 21 January 2009

Date
 17




---



##### 



SmithKline Beecham Corporation Doing business as GLAXOSMITHKLINEBy:
    
    /s/ William J. Mosher

Name: William J. MosherTitle: Vice President & Secretary
 Date
 18




---



##### 



Università degli Studi di CagliariBy:
    
    /s/ Prof. Adolfo Lai

Name: Prof. Adolfo LaiTitle:
 8 Gen. 2009

Date
 Certifico io Ufficiale Rogante Sostituto
dellUniversità degli Studi di Cagliari che la firma,
apposta in mia presenza dal Prof. Adolfo Lai nuto a Ottana il 28.07.1943,
Pro Rettore dellUniversità di Cagliari e della cui identità personale sono certo, è autentica
LUfficiale Rogante Sostituto
Dr. Achile Filiberto Putzu/s/ Dr. Achile Filiberto Putzu
    SEAL 19




---



##### 



Prof. Paolo La CollaBy:
    
    /s/ Paolo La Colla

Name: Prof. Paolo La CollaTitle:
 8 Gen. 2009

Date
 Certifico io Ufficiale Rogante
Sostituto dellUniversità degli Studi di Cagliari che la firma, apposta in mia presenza dal Prof. Paolo La Colla, nato a La Maddalena il 14.08.1944, Professore Orinario presso
lUniversità di Cagliari e della cui identità personale sono certo, è autentica
LUfficiale Rogante Sostituto
Dr. Achile Filiberto Putzu/s/ Dr. Achile Filiberto Putzu
    SEAL 20




---



##### 



ENCLOSURE A
  TypeRelated/Idenix Ref. No.
    
    Country
    
    Serial No.
    
    Filed
    
    Title
   21




---



##### 



ENCLOSURE B
  TypeRelated/Idenix Ref. No.
    
    Country
    
    Serial No.
    
    Filed
    
    Title
   22




---



##### 



IDX899 APIRegulatorySpecificationsANALYSIS
    
    METHOD(1)
    
    Acceptance Criteria
   23




---



##### 



ANALYSIS
    
    METHOD(1)
    
    SPECIFICATIONS




---



##### 



25




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##### 



IDENIX PHARMACEUTICALS AND GLAXOSMITHKLINE SIGN WORLDWIDE LICENSE
AGREEMENT FOR IDX899, A NOVEL NNRTI FOR THE TREATMENT OF HIV
 Cambridge, MA and London, UK  February 6, 2009
     About IXD899
 10 ®
 26




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About Idenix
 www.idenix.com.
 GlaxoSmithKline www.gsk.com
 Idenix Pharmaceuticals Forward-looking Statements
   Idenix Pharmaceuticals Contacts:
 
 27




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GlaxoSmithKline Contacts:
 UK Media enquiries:
    
    Philip Thomson
    
    (020) 8047 5502Alice Hunt
    
    (020) 8047 5502David Outhwaite
    
    (020) 8047 5502Stephen Rea
    
    (020) 8047 5502US Media enquiries:
    
    Nancy Pekarek
    
    (919) 483 2839Mary Anne Rhyne
    
    (919) 483 2839Kevin Colgan
    
    (919) 483 2839Sarah Alspach
    
    (215) 751 7709European
Analyst/Investor enquiries:
    
    David Mawdsley
    
    (020) 8047 5564Sally Ferguson
    
    (020) 8047 5543Gary Davies
    
    (020) 8047 5503US Analyst/ Investor enquiries:
    
    Tom Curry
    
    (215) 751 5419Jen Hill
    
    (215) 751 7002
  28




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Schedule 3.2(a)
 Drug Substance Availability
  Batch #
    
    [**]
    
    [**]
    
    [**]Supplier
    
    [**]
    
    [**]
    
    [**]DOM
    
    [**]
    
    [**]
    
    [**]Size
    
    [**]
    
    [**]
    
    [**]Use
    
    [**]
    
    [**]
    
    [**]Form
    
    [**]
    
    [**]
    
    [**]




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Schedule 5.2(a)
 Successful Completion
 Successful Completion Definition for CorrespondingDevelopment Milestone
    
    Milestone EventSuccessful Completion of development
of a commercially viable formulation
    
    Achieved upon the first patient
dosed in the first Phase IIb
Clinical Trial using a once-daily
solid oral dosage formulation
developed and approved by GSK for
its physical properties. Phase
IIb Clinical Trial means a Phase
II Clinical Trial to determine
initial efficacy and dose range
finding.Successful Completion of a Segment
II reproductive toxicity study
    
    Segment II reproductive toxicity
study that demonstrates no direct
teratogenic effects.Successful Completion of 6-month
rodent chronic toxicology study.
    
    Safety findings support dosing
beyond 6 months at therapeutically
and commercially relevant doses so
that both FDA and applicable
European Union (EU) health
authorities authorize initiation of
a Phase IIb Clinical Trial with
IDX-899 and agree that data support
the initiation of a Phase III
Clinical Trial with IDX-899.Successful Completion of at least
9-month non-rodent chronic
toxicology study.
    
    Safety findings support dosing
beyond 9 months at therapeutically
and commercially relevant doses in
NNRTI treatment-experienced
patients so that both FDA and
applicable EU health authorities
authorize initiation of a Phase IIb
Clinical Trial with IDX-899.Successful Completion of 24-month
carcinogenicity studies in at least
one (1) rodent species.
    
    Carcinogenicity program supports
registration without additional
studies per both FDA and EMEA
agreementSuccessful Completion of development
of a commercially viable fixed dose
combination formulation
    
    Development of a once daily tablet
[**] that is shown to be
bioequivalent to individual
products (80%  125% per FDA
definition of bioequivalence) as
determined from a pivotal
bioequivalence study as determined
by the Development Plan in Exhibit
F.
 30




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Schedule 5.3(a)
 UNAIDS Accelerating Access Initiative Countries
 Country
    
    
    
    
    
    Country1
    
    Angola
    
    
    32
    
    
    Malawi2
    
    Bangladesh
    
    
    33
    
    
    Maldives3
    
    Benin
    
    
    34
    
    
    Mali4
    
    Bhutan
    
    
    35
    
    
    Mauritania5
    
    Botswana
    
    
    36
    
    
    Mauritius6
    
    Burkina Faso
    
    
    37
    
    
    Mozambique7
    
    Burundi
    
    
    38
    
    
    Myanmar8
    
    Cambodia
    
    
    39
    
    
    Namibia9
    
    Cameroon
    
    
    40
    
    
    Nepal10
    
    Cape Verde
    
    
    41
    
    
    Niger11
    
    Central Africa Rep.
    
    
    42
    
    
    Nigeria12
    
    Chad
    
    
    43
    
    
    Rwanda13
    
    Comoros
    
    
    44
    
    
    Samoa14
    
    Congo
    
    
    45
    
    
    Sao Tome & Principe15
    
    Côte dIvoire
    
    
    46
    
    
    Senegal16
    
    Djibouti
    
    
    47
    
    
    Seychelles17
    
    DR Congo (Zaire)
    
    
    48
    
    
    Sierra Leone18
    
    Equatorial Guinea
    
    
    49
    
    
    Solomon Islands19
    
    Eritrea
    
    
    50
    
    
    Somalia20
    
    Ethiopia
    
    
    51
    
    
    South Africa21
    
    Gabon
    
    
    52
    
    
    Sudan22
    
    Gambia
    
    
    53
    
    
    Swaziland23
    
    Ghana
    
    
    54
    
    
    Tanzania24
    
    Guinea
    
    
    55
    
    
    Togo25
    
    Guinea Bissau
    
    
    56
    
    
    Tuvalu26
    
    Haiti
    
    
    57
    
    
    Uganda27
    
    Kenya
    
    
    58
    
    
    Vanuatu28
    
    Kiribati
    
    
    59
    
    
    Yemen29
    
    Lao Peoples DR
    
    
    60
    
    
    Zambia30
    
    Lesotho
    
    
    61
    
    
    Zimbabwe31
    
    Liberia




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Schedule 10.2
 Disclosure Schedule