<PAGE>

                                                                   EXHIBIT 10.21

                  *** CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS
                  DOCUMENT (INDICATED BY ASTERISKS) HAS BEEN OMITTED AND FILED
                  SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION
                  PURSUANT TO A REQUEST FOR CONFIDENTIAL TREATMENT UNDER 17
                  C.F.R. SECTIONS 200.80(B)(4), 200.83 AND 230.406.

                                    AGREEMENT

         This Agreement is made effective December 20, 2002 (the "Effective
Date"), by and among ICN Pharmaceuticals, Inc., a Delaware corporation, with
offices at 3300 Hyland Avenue, Costa Mesa, California 92626 ("ICN"), Ribapharm
Inc., a Delaware corporation with offices at 3300 Hyland Avenue, Costa Mesa,
California 92626 ("Ribapharm"), Devron Averett, an individual residing at
[...***...] ("Averett"), and Anadys Pharmaceuticals, Inc., a Delaware
corporation, with offices at 9050 Camino Santa Fe, San Diego, California 92121
("Anadys"), with ICN and Ribapharm being collectively referred to herein from
time to time as "Licensors", and ICN, Ribapharm, Averett and Anadys being
collectively referred to herein from time to time as the "Parties".

                                   WITNESSETH

         WHEREAS ICN and Averett entered into a letter agreement effective
January 22, 1999 (the "1999 Letter Agreement"), wherein ICN licensed various
intellectual property rights to Averett, a true and correct copy of which is
attached hereto as Exhibit A;

         WHEREAS ICN and Averett entered into a license agreement effective
October 11, 1999 (the "1999 License Agreement"), wherein ICN licensed various
intellectual property and compound rights to Averett, a true and correct copy of
which is attached hereto as Exhibit B;

         WHEREAS in March 2000, Averett (i) sublicensed to Anadys, formerly
known as Scriptgen Pharmaceuticals, Inc., all of his rights arising from the
1999 Letter Agreement and 1999 License Agreement and (ii) granted to Anadys a
power of attorney; a true and correct copy of such sublicense agreement is
attached hereto as Exhibit C.

         WHEREAS ICN has transferred certain of the relevant intellectual
property rights to Ribapharm in 2002; and

         WHEREAS a dispute exists among the Parties as to whether the "1999
License Agreement" supercedes the "1999 Letter Agreement", and additional
disputes have arisen among the Parties with respect to their various rights and
obligations under the 1999 Letter and 1999 License Agreements (the "Dispute").

         NOW THEREFORE the Parties have agreed to a full and final settlement of
the Dispute under the terms and conditions set forth below.

                                    AGREEMENT

         In consideration of the above, and the mutual covenants set forth in
this Agreement, and other good and valuable consideration received by the
Parties, the Parties agree as follows.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

<PAGE>

         1. Definitions and Interpretation

         1.1.     "Active Metabolite" means any chemical entity, whose detection
                  and structure are demonstrable to the satisfaction of
                  reviewers at either the US FDA or the Journal of Medicinal
                  Chemistry, that is derived from a Compound after
                  administration of a Compound to humans, provided that such
                  derived chemical entity both retains specific biological
                  activity in an assay in which the compound is active and is
                  produced in sufficient quantity in humans after administration
                  of a Compound to humans such that the arithmetic result of the
                  biological activity of the active metabolite multiplied by the
                  levels achieved in human plasma is at least [...***...]
                  percent ([...***...]%) of the result of a similar arithmetic
                  operation applied to a Compound or Prodrug. Furthermore, a
                  derived chemical entity is an Active Metabolite only if it
                  retains [...***...] of the structural integrity (atoms and
                  their covalent bonds) of the Compound.

         1.2.     "Compounds" means the following:

                  [...***...] (ICN Registry Number [...***...]);

                                  [...***...]

                  [...***...] (ICN Registry Number [...***...]);

                                  [...***...]

                  [...***...] (ICN Registry Number [...***... ]);

                                  [...***...]

                  [...***...] (ICN Registry Number [...***...]);

                                    [...***...]

                  [...***...] (ICN Registry Number [...***...])

                                  [...***...]

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     2 of 23

<PAGE>

                  and/or

                  [...***...] (ICN Registry Number [...***...]

                                    [...***...].

While not explicitly shown, the Compounds include their naturally occurring
[...***...].

(In the event of a discrepancy between the name listed and the chemical
structure, the structure controls.)

         1.3      "Inactive Metabolite" means any chemical entity, whose
                  detection and structure are demonstrable to the satisfaction
                  of reviewers at either the US FDA or the Journal of Medicinal
                  Chemistry, that is derived from a Compound after
                  administration of a Compound to humans, provided that such
                  derived chemical entity is neither an Active Metabolite nor a
                  Prodrug.

         1.4      "Anadys Prosecuted Applications" means those patent
                  applications that are to be prosecuted by or at the direction
                  of Anadys to secure formal patent protection with respect to
                  any of the Intellectual Property Rights, including reissues,
                  extensions, divisionals, continuations, continuations-in-part,
                  and/or any other applications claiming priority to the same.
                  Among other things, Exhibit D-1, which is incorporated herein,
                  identifies currently existing applications deemed to be Anadys
                  Prosecuted Applications, which applications are identified in
                  Exhibit D-1 as being prosecuted by Anadys. For ease of
                  reference, Exhibit D-1 also identifies additional applications
                  and patents which Anadys has only a license to under the terms
                  of this Agreement, which applications and patents are
                  identified in Exhibit D-1 as being prosecuted by Licensors. In
                  addition, Anadys shall be able to prosecute additional claims
                  within the Anadys Prosecuted Applications to both (i)
                  intellectual property created or owned solely by Anadys and
                  (ii) intellectual property deriving from the subject matter
                  disclosed in PCT applications US [...***...] and US
                  [...***...], and corresponding and subsequent US and foreign
                  applications and patents, including reissues, extensions,
                  divisionals, continuations, continuations-in-part, and/or any
                  other applications claiming priority to the same. Subject to
                  the provisions of this Agreement, Licensors own all rights in
                  all Anadys Prosecuted Applications and applications claiming
                  priority to the Anadys Prosecuted Applications.

         1.5      "Licensor Prosecuted Applications" means those patent
                  applications that are to be prosecuted by or at the direction
                  of ICN or Ribapharm to secure formal patent protection with
                  respect to subject matter disclosed in PCT

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     3 of 23

<PAGE>

                  applications US [...***...] and US [...***...], and
                  corresponding and subsequent US and foreign applications and
                  patents, including reissues, extensions, divisionals,
                  continuations, continuations-in-part, and/or any other
                  applications claiming priority to the same. Exhibit D-2, which
                  is incorporated herein, identifies applications deemed to be
                  Licensor Prosecuted Applications. Licensor owns all rights in
                  all Licensor Prosecuted Applications subject to the provisions
                  of this Agreement.

         1.6      "Intellectual Property Rights" means the rights ICN or
                  Ribapharm owns now, and/or during the term of this Agreement
                  that were disclosed in any of US Patents [...***...] and
                  [...***...], PCT applications [...***...] and [...***...], and
                  corresponding, priority and subsequent US and foreign
                  applications and patents, with respect to a) any of the
                  Compounds, b) all Prodrugs and Metabolites of such Compounds,
                  and c) all methods of using the Compounds, Prodrugs and/or
                  Metabolites.

         1.7      "Metabolite" means a chemical entity that is an Active
                  Metabolite and/or a Phosphorylated Metabolite, but expressly
                  excludes the following compounds:[...***...], [...***...],
                  [...***...], [...***...], and [...***...] and any other
                  compounds that Licensors have commercialized or are actively
                  pursuing in human clinical trials pursuant to an
                  Investigational New Drug Application that has been filed with
                  the United States Food and Drug Administration or equivalent
                  filing with an equivalent foreign body at the time a
                  Metabolite is identified pursuant to Section 2.3.

         1.8      "Net Sales" means, in relation to a Product, the gross amount
                  received by Anadys, and its respective sublicensees from third
                  parties that are not affiliates or sublicensees of the selling
                  party (unless such affiliate or sublicensees is the end user
                  of such Product, in which case the amount billed therefor
                  shall be deemed to be the amount that would have been billed
                  to a third party in an arm's-length transaction) for sales of
                  Products to third parties, less the following items, as
                  allocable to such Product (if not previously deducted from the
                  amount invoiced): (a) trade discounts, credits or allowances;
                  (b) credits or allowances additionally granted upon returns,
                  rejections or recalls (except where any such recall arises out
                  of Anadys' or its sublicensee's gross negligence, willful
                  misconduct or fraud); (c) freight, shipping and insurance
                  charges; (d) taxes, duties or other governmental tariffs
                  (other than income taxes); and (e) government mandated
                  rebates. With regard to a Product that is comprised as part of
                  one or more Products and in part of one or more other active
                  ingredients that are not Products (a "Combination Product"),
                  Net Sales shall be determined by multiplying Net Sales of such
                  Combination Product (calculated in accordance with the
                  preceding sentence) by the fraction A/A+B, in which A is the
                  fair market value of the Product included in the Combination
                  Product, and B is the fair market value of the other active
                  ingredient(s) included in the Combination Product.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     4 of 23

<PAGE>

         1.9      "[...***...]" means a chemical entity related to a Compound by
                  incorporation into a Compound of a [...***...] at the
                  [...***...]- or [...***...] - position, or a
                  [...***...],[...***...] or [...***...] at the [...***...] -
                  position.

         1.10     "Prodrug" means any chemical entity that upon or after
                  administration to a human is transformed into a Compound,
                  wherein said Compound and/or its metabolites are substantially
                  the only pharmaceutically active metabolic products.

         1.11     "Product" means any human or animal pharmaceutical product
                  containing, in whole or as a component, one or more of the
                  Compounds, a Prodrug, or a Metabolite.

         1.12     In this Agreement, unless the context requires otherwise: the
                  singular includes the plural and vice versa; words denoting
                  persons include corporations, partnerships and other legal
                  persons; a reference to a specified section, paragraph or
                  schedule is a reference to that specified section, paragraph
                  or schedule of this Agreement; the article and section
                  headings are for convenience only and do not affect the
                  interpretation of this Agreement; "including" means including
                  without limitation; and a reference to a Party includes its
                  successors and permitted assigns.

2.       Grant

         2.1      Licensors hereby grant to Anadys an exclusive (even as to
                  Licensors), worldwide license to Intellectual Property Rights,
                  with the right to sublicense, to develop, make, have made,
                  market, import, export, distribute, use, offer for sale, sell,
                  or have sold any of the Compounds, Prodrugs, and/or
                  Metabolites. For clarity, the license grant in this Section
                  2.1 includes, without limitation, rights to the Intellectual
                  Property Rights disclosed in any of the patents or
                  applications listed in Exhibits D-1 or D-2. Simultaneously
                  with the execution of this Agreement, Licensors shall execute
                  an assignment to Anadys of all US and foreign patents
                  corresponding to US Patent [...***...], US Patent [...***...],
                  US Patent [...***...] and US Patent Application No.
                  [...***...], which assignment is attached as Exhibit E to this
                  Agreement. Licensors also grant Anadys a paid-up, irrevocable,
                  non-exclusive, worldwide license to Licensor technical
                  information related to the Compounds, but only for technical
                  information in existence as of the Execution Date of this
                  Agreement.

         2.2      During the term of this Agreement, Licensors agree not to sue,
                  threaten to sue, or otherwise object to, Anadys, its
                  sublicensees, assigns or others receiving any of Anadys'
                  rights herein, under any existing or future Licensor patents
                  with respect to developing, making, having made, marketing,
                  importing, exporting, distributing, using, offering for sale,
                  selling or having sold any of the Compounds, Prodrugs, and/or

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     5 of 23

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                  Metabolites, unless Anadys, its sublicensees, assigns or
                  others receiving rights herein, sell a Combination Product (as
                  defined in Section 1.8) which includes as a component of such
                  Combination Product a proprietary compound owned or acquired
                  by Licensors and not licensed herein.

         2.3      During the term of this Agreement, Licensors agree not to sue,
                  threaten to sue, or otherwise object to, Anadys, its
                  sublicenses, assigns or others receiving any of Anadys' rights
                  herein, under any existing or future Licensor patents with
                  respect to the formation, presence or activity of an Inactive
                  Metabolite resulting from the administration of a Compound,
                  Prodrug and/or Metabolite to a human. Prior to the
                  determination of whether a metabolite is an Active Metabolite
                  or an Inactive Metabolite, Anadys shall be free to synthesize
                  and characterize all metabolites for the purpose of full
                  structural characterization and determination of activity. If,
                  after completion of the studies permitted pursuant to the
                  immediately preceding sentence, it is determined that a
                  metabolite is an Inactive Metabolite, then Anadys' rights with
                  respect to such Inactive Metabolite shall be limited to those
                  contained in this Section 2.3. If at any time a metabolite is
                  determined to meet the criteria for an Active Metabolite as
                  set forth in Section 1.1, Anadys will promptly notify
                  Licensors of such determination and such metabolite will be
                  deemed a Metabolite for the duration of this Agreement and all
                  the rights to Metabolites as set forth in this Agreement will
                  apply; provided, however, that if, within thirty (30) days of
                  receiving such notification from Anadys, Licensors can show
                  that as of the date of receiving the notification from Anadys,
                  the identified metabolite has been commercialized by Licensors
                  or is being actively pursued in human clinical trials by
                  Licensors pursuant to an Investigational New Drug Application
                  that has been filed with the United States Food and Drug
                  Administration or equivalent filing with an equivalent foreign
                  body, then such metabolite will be treated as an Inactive
                  Metabolite with Anadys' rights restricted to the freedom to
                  operate considerations in this Section 2.3. Once a
                  determination is made that a metabolite is an Inactive
                  Metabolite, Anadys' rights with respect to Inactive
                  Metabolites are limited to the context of administration of
                  the Compound to a human and the freedom to operate
                  considerations in this Section 2.3.

 3.      Royalty

         3.1      Anadys will pay a royalty to Licensors based on Net Sales of
                  all Products, computed on a country by country basis, as
                  follows. The royalty shall be [...***...] percent
                  ([...***...]%) of the Net Sales for those Products containing
                  a Compound, and shall be [...***...] percent ([...***...]%) of
                  the Net Sales for those Products containing a Prodrug or
                  Metabolite. Only a single royalty shall be paid on sales of
                  Product no matter how many patents licensed under the
                  Intellectual Property Rights contain claims encompassing
                  Product. In any event, the royalty payments due for each

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     6 of 23

<PAGE>

                  Product in each country shall terminate upon the expiration of
                  the last patent within the Intellectual Property Rights in
                  that country having a claim reading on the Product.

         3.2      Royalties shall be remitted to Ribapharm quarterly, no later
                  than sixty (60) days following the end of each calendar
                  quarter, and shall be calculated according to then-applicable
                  United States Generally Accepted Accounting Standards
                  ("GAAP").

         3.3      Anadys shall pay a minimum annual royalty (a "Minimum Annual
                  Royalty") of [...***...] United States Dollars (US
                  $[...***...]) for calendar year [...***...], [...***...]
                  United States Dollars (US $[...***...]) for calendar year
                  2007, and [...***...] United States Dollars (US $[...***...])
                  for each calendar year thereafter through [...***...].

                  3.3.1    The Minimum Annual Royalty shall be due and payable
                           in advance, on or before the first day of December of
                           the preceding year, (the "Due Date"), and will be
                           credited as an advance payment of royalties which may
                           accrue during the applicable calendar year.

                  3.3.2    In no event shall a Minimum Annual Royalty payment be
                           carried over as a pre-payment of royalties for any
                           subsequent year, nor shall any minimum royalty
                           payment be refunded in whole or in part.

                  3.3.3    In the event that Anadys fail to make any minimum
                           annual royalty within ninety (90) days following any
                           Due Date, all of the Granted Rights shall
                           automatically revert back to Licensors. Any such
                           result is subject to the cure provision of subsection
                           6.3.

         3.4      All applicable taxes relating to the sale of Products are the
                  responsibility of Anadys, its sublicensee, and assignees, and
                  shall not be charged to or against Licensors.

         4.       Special Duties and Responsibilities of Licensors

         4.1      At their own expense, Licensors will execute the documents
                  which constitute Powers of Attorney attached to this Agreement
                  as Exhibits F and letters to foreign associates, and will
                  comply with and honor the terms of such documents.

         4.2      To assist Anadys in prosecuting the Anadys Prosecuted
                  Applications, Licensors will offset the actual out-of-pocket
                  costs of Anadys' expenses in prosecuting the Anadys Prosecuted
                  Applications up to a maximum of [...***...] United States
                  Dollars (US $[...***...]). Licensors agree to pay such
                  expenses within thirty (30) days of receiving written invoices
                  from Anadys indicating such costs.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     7 of 23

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         4.3      At all times during the Term of this Agreement, Licensors will
                  fully cooperate with Anadys in the prosecution of all the
                  Anadys Prosecuted Applications, including, but not limited to,
                  promptly signing all declarations, powers of attorney, and
                  other papers needed to be executed to further the prosecution
                  of such applications.

         4.4      Within sixty (60) days, after receiving written notice from
                  Anadys that an Anadys Prosecuted Application has been issued
                  as a patent in a country, and after establishing in good faith
                  that (a) the claims of such patent do not extend beyond the
                  Intellectual Property Rights, and that (b) an assignment to
                  Anadys will not adversely affect the prosecution of any of
                  Licensor Prosecuted Applications, Licensors will execute an
                  assignment assigning such patent to Anadys. Such an assignment
                  is voided ab initio if the assigned patent subjects any of
                  Licensor or Anadys Prosecuted Applications to any rejections
                  that may be overcome by showing the co-ownership of the
                  assigned patent and the rejected application, provided, in no
                  event shall an assignment be voided more than four (4) years
                  after its execution. Licensors or Anadys shall notify the
                  other in writing if the assignment is voided, and will provide
                  written documentation establishing that the co-ownership is
                  necessary. If an assignment is voided pursuant to this
                  subsection 4.4, Anadys shall retain an exclusive worldwide
                  license to the affected Anadys or Licensor Prosecuted
                  Application as set forth in subsection 2.1. In the event of
                  any dispute between the Parties under this subsection 4.4, the
                  Parties agree to submit such a dispute to an independent
                  patent attorney mutually selected by the Parties, and the
                  decision of the patent attorney shall be binding.

         4.5      For the first Product proposed to be commercialized for each
                  of the Compounds (or its Prodrugs or Metabolites), Licensors
                  shall make milestone payments to Anadys as follows:

                  4.5.1    [...***...] United States Dollars (US $[...***...])
                           upon filing of an Investigational New Drug
                           Application with the United States Food and Drug
                           Administration (the "FDA") for the proposed Product;

                  4.5.2    [...***...] United States Dollars (US $[...***...])
                           upon regulatory approval to initiate Phase 2 studies
                           of the proposed Product;

                  4.5.3    [...***...] United States Dollars (US $[...***...])
                           upon regulatory approval to initiate Phase 3 studies
                           of the proposed Product; and

                  4.5.4    [...***...] United States Dollars (US $[...***...])
                           each for the first two proposed Products and
                           [...***...] United States Dollars (US $[...***...])
                           for each proposed Product thereafter, upon regulatory
                           approval by the FDA for commercial sale of the
                           proposed Product.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     8 of 23

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                  4.5.5    Such payments shall be due and payable upon written
                           notification to Licensors by Anadys or their duly
                           authorized agents, of the occurrence of the
                           triggering event.

         4.6      Failure by Licensors to make any milestone payment within
                  ninety (90) days of such written notification shall
                  automatically result in a fully paid-up, worldwide,
                  irrevocable, exclusive license to Anadys and their
                  sublicensees for the corresponding Product. Any such result is
                  subject to the cure provision of subsection 6.3.

         4.7      Licensors shall be jointly and severally liable for all
                  Licensor obligations under this Agreement.

5.       Special Duties and Responsibilities of Anadys and Averett

         5.1      At all times during the Term of this Agreement, Anadys and
                  Averett will fully cooperate with Licensors in the prosecution
                  of all the Licensor Prosecuted Applications, including, but
                  not limited to, promptly signing all declarations, powers of
                  attorney, and other papers needed to be executed to further
                  the prosecution of such applications.

         5.2      Anadys shall use commercially reasonable efforts to
                  commercialize the Compounds, Prodrugs, and/or Metabolites.

         5.3      Anadys shall ensure that no Products will be marketed using
                  the names ICN(R) or Ribapharm(TM) without written permission
                  of the respective owner.

6.       Term and Termination

         6.1      The Term of this Agreement shall be effective on a country by
                  country basis from the Effective Date set forth above until
                  the last patent within the Intellectual Property Rights
                  claiming any of the Compounds, Prodrugs, or Metabolites shall
                  expire in that country, and shall continue in full force and
                  effect, unless terminated earlier according to the provisions
                  hereof.

         6.2      Anadys may terminate this Agreement upon sixty (60) days
                  written notice to Licensors, with or without cause, as to any
                  of the Compounds, their Prodrugs or Metabolites of such
                  Compounds, without further obligation on their part with
                  respect to same except as to accrued hold harmless rights and
                  accrued but unpaid royalties, by assigning back to Licensors
                  all right, title, and interest that Anadys, its sublicensees,
                  and assigns had previously obtained herein with respect to
                  such Compounds, Prodrugs and Metabolites, and in such instance
                  Anadys, its sublicensees, and assigns would thereupon also be
                  relieved of their royalty obligations with respect to such
                  Compounds, Prodrugs and Metabolites.

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         6.3      If any Party fails to perform any of its material obligations
                  under this Agreement, the non-defaulting Parties may give
                  written notice of the default to the defaulting Party. Unless
                  such default is cured within sixty (60) days after such
                  notice, the non-defaulting Party may give a final written
                  notice of the default to the defaulting Party. If the default
                  is not cured within thirty (30) days after such final notice,
                  the Agreement may be terminated. Notwithstanding the
                  foregoing, to the extent a material breach of this Agreement
                  relates to one or more Compounds, Metabolites, Prodrugs, or
                  Products, but not all Compounds, Metabolites, Prodrugs or
                  Products, then any termination of this Agreement in accordance
                  with this Section 6.3 shall apply solely to the affected
                  Compound(s), Metabolite(s), Prodrug(s) or Product(s) only, and
                  in such case this Agreement will remain in full force and
                  effect with respect to the Compounds, Metabolites, Prodrugs or
                  Products that are not terminated. If this Agreement is
                  terminated by Anadys under this Section 6.3 for the willful
                  breach by Licensors of Section 4.1, 4.2, 4.3 or 4.4, then the
                  financial obligations of Anadys and its sublicensees under
                  this Agreement with respect to the Compound, Metabolite,
                  Prodrug affected by such breach shall be extinguished and
                  Anadys shall have a fully paid-up, worldwide, irrevocable,
                  exclusive license to (a) such Compound, Prodrug, and/or
                  Metabolite, and (b) to the Intellectual Property Rights
                  associated therewith.

         6.4      In the event that this Agreement is terminated or rejected by
                  a Party or its receiver or trustee under applicable bankruptcy
                  laws due to such Party's bankruptcy, then all rights and
                  licenses granted under or pursuant to this Agreement by such
                  Party are, and shall otherwise be deemed, for purposes of
                  Section 365(n) of the Bankruptcy Code and any similar law or
                  regulation in any other country, licenses or rights to
                  "intellectual property" as defined under Section 101(52) of
                  the Bankruptcy Code. The Parties agree that all Intellectual
                  Property Rights licensed hereunder, including without
                  limitation, any patents or patent applications in any country
                  of a Party covered by the license grants under this Agreement
                  are part of the definition of "intellectual property" under
                  the Bankruptcy Code or any similar law or regulation in any
                  other country.

         6.5      All provisions of this Agreement required to interpret and
                  enforce the Parties' rights and obligations under this
                  Agreement also will survive to the extent required for the
                  full observation and performance of this Agreement by the
                  Parties. The termination or expiration of this Agreement for
                  any reason shall be without prejudice to any rights that shall
                  have accrued to the benefit of any other Party under this
                  Agreement prior to such termination or expiration, including,
                  but not limited to, injunctive relief, and any damages arising
                  from any breach hereunder.

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7.       Records and Record Keeping

         7.1      Beginning the calendar quarter following execution of this
                  Agreement, Anadys shall submit written quarterly reports to
                  Ribapharm notifying Licensors of (i) any Prodrugs or
                  Metabolites that have been identified in the preceding quarter
                  and (ii) summarizing what trials and non-clinical work is
                  being conducted in an effort to bring Products to market. Upon
                  receipt of the first regulatory approval for any of the
                  Products, Anadys shall submit royalty reports with each
                  quarterly payment, setting forth the quantity and net selling
                  price of each Product sold in that quarter and the date of
                  such sale, and the total amount of royalties being paid for
                  that quarter.

         7.2      Anadys will keep and shall require its sublicensees and
                  assignees to keep, full, accurate and complete books and
                  records (together with supporting documentation) as are
                  necessary to establish compliance with the terms and
                  conditions of this Agreement. Such records shall be maintained
                  for a period of at least five (5) years from the end of the
                  reporting period to which they relate.

         7.3      During the term of this Agreement with at least thirty (30)
                  days' prior written notice to Anadys, Licensors have the right
                  to have a duly authorized independent agent or representative
                  of its selection audit, inspect, and verify all books,
                  records, and supporting documentation relating to the
                  royalties contemplated herein, whether kept by Anadys, its
                  sublicensees, assignees or others receiving any of Anadys'
                  rights herein, at a place mutually agreed upon by the Parties
                  involved during regular business hours. Such audit shall be
                  for the purpose of verifying compliance with the terms and
                  conditions of this Agreement, including verification of
                  reports and payments made hereunder. Other information
                  disclosed during such audit shall be considered confidential
                  to the audited Party and shall not be revealed to Licensors by
                  their agent or representative other than as required under the
                  audit provisions of this subsection 7.3.

         7.4      Should Licensors or their representatives determine that a
                  royalty deficiency exists, such deficiency shall become
                  immediately due and owing, and shall be subject to interest at
                  a rate equal to the lesser of: [...***...] of the sum of the
                  then current US annual prime rate and [...***...] percent
                  ([...***...]%) per month, or the maximum interest rate allowed
                  by law. Said interest shall accrue and be calculated from the
                  date the corresponding royalty was originally due. In the
                  event an audit shall disclose a royalty deficiency of greater
                  than [...***...] percent ([...***...]%), the costs of such
                  audit shall be borne by Anadys.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

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8.       Licensing, Sublicensing and Assigning

         8.1      Anadys shall ensure that all of their sublicensees, assignees,
                  and others receiving any of Anadys' rights herein ("Other
                  Parties") are subject to the same royalties, duties and
                  responsibilities, and other obligations required of Anadys
                  herein, as though each such entity had been a party to this
                  Agreement. This Agreement binds all such Other Parties.

         8.2      This Agreement shall be attached as an Exhibit to any such
                  agreement ("Other Party Agreement") under which all Other
                  Parties receive any of any of Anadys' rights herein. Anadys
                  shall have the right to redact the financial terms from this
                  Agreement prior to attaching it as an Exhibit.

         8.3      Within 30 days of the execution or modification of any Other
                  Party Agreement, Anadys shall furnish Licensors with a true
                  and complete copy of same.

         8.4      Any Party may assign any of its rights or obligations under
                  this Agreement, provided, however, that such assignment shall
                  not relieve the assigning party or its assigns of the
                  responsibilities for performance under this Agreement. Each
                  assigning party shall provide written notice to the other
                  Parties of any assignment within thirty (30) days.

         8.5      For purposes of this Agreement, the Parties are not joint
                  venturers, partners, principal and agent, master and servant
                  or employer and employee. With respect to the subject matter
                  of this Agreement, the Parties have no power to bind or
                  obligate each other in any manner, other than as expressly set
                  forth in this Agreement. A change of this relationship,
                  however, is not precluded by this Agreement.

9.       Patent Application and Maintenance

         9.1      Licensors are responsible for prosecution fees and costs with
                  respect to all Licensor Prosecuted Applications.

         9.2      Licensors covenant and agree that they will not, prior to
                  [...***...], intentionally abandon any Licensor Prosecuted
                  Application (including by virtue of issuance of any patents)
                  for which a continuation or divisional application has not
                  been filed unless they give Anadys at least one hundred twenty
                  (120) days prior written notice (unless such period of advance
                  notice is not possible due to no fault of Licensors' or their
                  counsel, in which case the maximum possible notice under such
                  shorter period shall be provided) of such intended abandonment
                  or issuance; provided, however, that the unavoidable
                  abandonment of a Licensor Prosecuted Application will not be
                  deemed a breach of this Section 9.2 so long as Licensors
                  actively pursue any revival possibilities; and provided
                  further, that if Anadys at its sole discretion no longer needs
                  access to a particular Licensor Prosecuted Application, Anadys
                  shall give notice of

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     12 of 23

<PAGE>

                  such fact to Licensors and as of the date of Licensors'
                  receipt of such notice, such Licensor Prosecuted Application
                  shall no longer remain subject to this Section 9.2. For
                  purposes of this Section 9.2, "intentionally abandon" shall
                  include, without limitation, Licensors' or Licensors'
                  counsel's failure to respond to a notification of an upcoming
                  abandonment or the failure to take action which leads to an
                  abandonment.

         9.3      Subject to subsection 4.2, Anadys is responsible for
                  prosecution fees and costs with respect to all Anadys
                  Prosecuted Applications.

         9.4      Anadys has no obligation to pursue or maintain any of the
                  Anadys Prosecuted Applications.

         9.5      Both Licensors and Anadys shall promptly notify the other, in
                  writing, upon the issuance of any patent issued from the
                  Anadys Prosecuted Applications or Licensor Prosecuted
                  Applications claiming Intellectual Property Rights or claiming
                  priority to PCT applications US[...***...], or US [...***...]
                  or US provisional applications [...***...], [...***...],
                  [...***...] or [...***...] and promptly upon receiving any
                  notice of allowance related to the foregoing.

10.      Infringement

         10.1     None of the Parties has any obligation to enforce any patents
                  issuing under the Intellectual Property Rights. However, if
                  called upon by another Party to assist in a legal action
                  against an alleged infringer, each of the Parties will assist
                  to the best of its abilities, provided that it is compensated
                  for reasonable out-of-pocket expenses on an ongoing basis for
                  such assistance.

         10.2     In the event that a Party does take legal action against an
                  alleged infringer of any of the Intellectual Property Rights
                  at its own expense, then such acting Party is under no
                  obligation to distribute any awards that may arise from such
                  legal action to the other Parties.

11.      Validity and Enforceability

         11.1     Anadys and Averett agree that they will not challenge directly
                  or indirectly the validity or enforceability of any patents
                  issued from Licensor Prosecuted Applications of which patents
                  Averett is an assignor.

         11.2     Licensors agree that they will not challenge directly or
                  indirectly the validity or enforceability of any patents
                  issued from Anadys Prosecuted Applications of which patents
                  Licensor is an assignor.

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     13 of 23

<PAGE>

         11.3     The parties agree that the failure of either party to satisfy
                  its obligations set forth in any of Sections 4.1, 4.3, 4.4,
                  5.1, 5.3 and 14.13, will subject the non-breaching party to
                  immediate and irreparable harm that will leave the
                  non-breaching party without an adequate remedy at law, and
                  entitle the non-breaching party to immediate injunctive relief
                  in a court of law to compel the breaching party to comply with
                  its obligations under paragraphs 4.1, 4.3, 4.4, 5.1, 5.3 and
                  14.13, as well as such further relief as may be granted by a
                  court of competent jurisdiction.

12.      Representations And Warranties

         12.1     Licensors (as well as their employees and agents) make no
                  representation or warranty as to the patentability of the
                  Intellectual Property Rights.

         12.2     Licensors and Anadys (as well as their employees and agents)
                  make no representation or warranty with respect to any aspect
                  of the drafting, prosecution, or content of the Licensor
                  Prosecuted Applications, the Anadys Prosecuted Applications,
                  or any patents maturing from any such applications, except
                  that Licensors represent and warrant that to their best
                  knowledge they have fully disclosed all existing issued
                  patents related to Intellectual Property Rights, all existing
                  Anadys Prosecuted Applications and all existing Licensor
                  Prosecuted Applications to Anadys. Should Licensors become
                  aware of any other existing patents and applications related
                  to Intellectual Property Rights, Licensors will promptly
                  disclose them to the Anadys and provide to Anadys copies of
                  such patents and applications.

         12.3     Licensors represent and warrant that they own the Intellectual
                  Property Rights and that they have full right and power to
                  grant the licenses and assignments contained herein. Licensors
                  represent and warrant that to their best knowledge their
                  rights to the listed patent applications and patents set forth
                  in Exhibits D-1, D-2 and E are unencumbered by any liens,
                  security interests, or other rights or claims of any third
                  party, and that no other person or entity has or shall have
                  any claim of ownership, except as defined by this Agreement.
                  Licensors also represent and warrant that to their best
                  knowledge they have not assigned or transferred Intellectual
                  Property Rights to any third party, except as provided for
                  under this Agreement, and they know of no fact that does or
                  could materially adversely affect the rights granted to Anadys
                  under this Agreement.

         12.4     LICENSORS AND ANADYS (AS WELL AS THEIR EMPLOYEES AND AGENTS)
                  MAKE NO WARRANTIES, EXPRESS OR IMPLIED, OF MERCHANTABILITY OR
                  FITNESS FOR A PARTICULAR PURPOSE OF ANY SUBJECT MATTER HEREIN
                  OR DEFINED BY THE CLAIMS OF ANY OF THE LICENSOR PROSECUTED

                                     14 of 23

<PAGE>

                  APPLICATIONS, THE ANADYS PROSECUTED APPLICATIONS, OR ANY
                  PATENTS MATURING FROM ANY SUCH APPLICATIONS.

         12.5     Anadys shall not indemnify, but will hold harmless Licensors,
                  their employees, agents, consultants and representatives, from
                  and against all liability, demands, damages, expenses, and
                  losses, including, but not limited to, death, personal injury,
                  illness, or property damage in connection with or arising out
                  of the design, manufacture, distribution, or use by Anadys,
                  its sublicensees, assignees, or others receiving any of
                  Anadys' rights herein, of any Product or materials or other
                  products of processes developed in connection with or arising
                  out of any of Anadys' rights herein.

         12.6     Each of the Parties warrants that it has all requisite legal
                  and (where appropriate) corporate power and authority to carry
                  on its business and to perform its obligations under this
                  Agreement. Each Party warrants that it has taken all action
                  necessary for the execution and delivery of this Agreement and
                  the performance of its obligations under this Agreement. Each
                  of the corporate entities warrants that the person(s)
                  executing this Agreement on its behalf has all necessary
                  corporate powers and have been duly authorized to execute and
                  deliver this Agreement on its behalf.

13.      Release

         13.1     Except for the liabilities and obligations arising out of this
                  Agreement, the Licensors, for themselves and to the full
                  extent that execution of this Agreement renders it legally
                  possible, for each of their predecessors, successors,
                  partners, assigns, parents, subsidiaries, divisions, officers,
                  employees, directors, shareholders, and agents, release and
                  forever discharge Anadys and Averett, and each of their
                  respective predecessors, successors, assigns, agents,
                  affiliates, representatives, heirs, parents, subsidiaries,
                  divisions, officers, employees, directors, shareholders, and
                  attorneys from any and all claims, demands, debts,
                  liabilities, obligations, damages, accounts, actions, and
                  causes of action of every kind in law, equity, or otherwise,
                  and every other thing whatsoever, whether known or unknown,
                  suspected or unsuspected, certain or speculative, which each
                  Licensor ever had, or now has, against Anadys or Averett,
                  existing as of the Effective Date of this Agreement or which
                  may have at any time prior to the Effective Date hereof come
                  into existence or which may in the future arise out of any
                  acts or omissions of Anadys or Averett taken at any time prior
                  to Effective Date hereof, including, without limitation, any
                  and all claims, demands, debts, liabilities, obligations,
                  damages, accounts, actions, and causes of action known or
                  suspected that relate in any manner to the Dispute.

         13.2     Except for the liabilities and obligations arising out of this
                  Agreement, Anadys, for itself and to the full extent that
                  execution of this Agreement

                                     15 of 23

<PAGE>

                  renders it legally possible, for its predecessors, successors,
                  partners, assigns, parents, subsidiaries, divisions, officers,
                  employees, directors, shareholders, and agents, release and
                  forever discharge Licensors herein, and each of their
                  respective predecessors, successors, assigns, agents,
                  affiliates, representatives, heirs, parents, subsidiaries,
                  divisions, officers, employees, directors, shareholders, and
                  attorneys from any and all claims, demands, debts,
                  liabilities, obligations, damages, accounts, actions, and
                  causes of action of every kind in law, equity, or otherwise,
                  and every other thing whatsoever, whether known or unknown,
                  suspected or unsuspected, certain or speculative, which Anadys
                  ever had, or now has, against Licensors, existing as of the
                  Effective Date of this Agreement or which may have at any time
                  prior to the Effective Date hereof come into existence or
                  which may in the future arise out of any actions or omissions
                  of Licensors taken at any time prior to the Effective Date
                  hereof, including, without limitation, any and all claims,
                  demands, debts, liabilities, obligations, damages, accounts,
                  actions, and causes of action know or suspected that relate in
                  any manner to the Dispute.

         13.3     Except for the liabilities and obligations arising out of this
                  Agreement, Averett, for himself and to the full extent that
                  execution of this Agreement renders it legally possible, for
                  each of his predecessors, successors, partners, assigns,
                  parents, subsidiaries, divisions, officers, employees,
                  directors, shareholders, and agents, releases and forever
                  discharges Licensors herein, and each of their respective
                  predecessors, successors, assigns, agents, affiliates,
                  representatives, heirs, parents, subsidiaries, divisions,
                  officers, employees, directors, shareholders, and attorneys
                  from any and all claims, demands, debts, liabilities,
                  obligations, damages, accounts, actions, and causes of action
                  of every kind in law, equity, or otherwise, and every other
                  thing whatsoever, whether known or unknown, suspected or
                  unsuspected, certain or speculative, which Averett ever had,
                  or now has, against Licensors, existing as of the Effective
                  Date of this Agreement or which may have at any time prior to
                  the Effective Date hereof come into existence or which may in
                  the future arise out of any actions or omissions of Licensors
                  taken at any time prior to the Effective Date hereof,
                  including, without limitation, any and all claims, demands,
                  debts, liabilities, obligations, damages, accounts, actions,
                  and causes of action know or suspected that relate in any
                  manner to the Dispute.

         13.4     Each of the Parties hereto acknowledges that it is aware of,
                  has read, has had explained to it by its attorneys,
                  understands and expressly waives any and all rights it has or
                  may have under California Civil Code Section 1542 and every
                  like provision in any foreign jurisdiction. Section 1542
                  provides as follows:

                           "A general release does not extend to
                           claims which the creditor does not know or
                           suspect to exist in his favor at the time
                           of executing the release, which if

                                     16 of 23

<PAGE>

                           known by him must have materially affected
                           his settlement with the debtor."

         13.5     Each of the Parties hereto acknowledges that it may later
                  discover facts different from or in addition to those which it
                  knows or believes to be true with respect to these released
                  claims, and it agrees that, in such event, this Agreement
                  shall nevertheless remain effective in all respects,
                  notwithstanding such different or additional facts or the
                  discovery of those facts, except as to facts represented,
                  warranted, and/or covenanted under this Agreement.

14.      General

         14.1     This Agreement may not be altered or otherwise amended except
                  by an instrument in writing signed by each of the Parties;
                  provided, however, that an alteration or amendment to this
                  Agreement shall not require Averett's signature unless
                  Averett's rights hereunder are prejudiced by such amendment.

         14.2     None of the Parties herein may waive or release any of its
                  rights under this Agreement except if the same be in writing.
                  The failure of any Party to assert a right hereunder or to
                  insist upon compliance with any term or condition of this
                  Agreement shall not constitute a waiver of that right or
                  excuse a similar subsequent failure to perform any such term
                  by any of the other Parties.

         14.3     The failure or omission by a Party in the performance of any
                  obligation under this Agreement will not be deemed a breach of
                  this Agreement or create any liability if it arises from any
                  cause or causes beyond the control of the Party, such as
                  strikes, riots, war, acts of God, invasion, fire, explosion,
                  floods, delay of carrier, shortage or failure in the supply of
                  materials, energy shortage and acts of government or
                  governmental agencies or instrumentalities. If due to such an
                  event a Party is delayed or hindered in or prevented from the
                  performance of its duties or doing acts required under the
                  terms of this Agreement, the performance of such act will be
                  excused for the period of the delay not to exceed ninety (90)
                  days. A Party subject to such an excusable delay will take all
                  reasonable steps to resolve any condition forming the basis of
                  the delay.

         14.4     All notices, consents, requests, waivers and other
                  communications in connection with this Agreement: must be in
                  writing, signed by an authorized officer of the sender, and
                  sent by personal delivery, fax (with confirmation copy),
                  internationally recognized courier, or certified or registered
                  mail, postage prepaid (airmail where applicable); will be
                  deemed to be given when actually received; and must be sent to
                  the receiving Party at the address or fax number, as
                  applicable, set forth

                                     17 of 23

<PAGE>

                  below, or any replacement address or fax number notified to
                  the sender by notice actually received by the sender.

                  above, or any replacement address or fax number notified to
                  the sender by notice actually received by the sender.

         If to Devron Averett:
                  Devron Averett, Ph.D.
                  [...***...]

         If to Anadys:
                  Anadys Pharmaceuticals, Inc.
                  9050 Camino Santa Fe
                  San Diego, CA 92121
                  Attn: Michael Kamdar, Vice President, Corporate Development

         With copy to:
                  Elizabeth E. Reed,
                  Senior Director, Legal Affairs

         If to ICN Pharmaceuticals:
                           3300 Hyland Avenue
                           Costa Mesa, CA 92626
                           Attn: Harry Roosje, VP Legal

         If to Ribapharm, Inc:
                           3300 Hyland Avenue
                           Costa Mesa, CA 92626,
                           Attn: Roger Loomis, General Counsel

         14.5     Except as expressly provided otherwise in this Agreement, all
                  legal and other costs and expenses incurred in connection with
                  the negotiation and entering into of this Agreement and the
                  transactions contemplated by this Agreement will be paid by
                  the Party incurring such costs or expenses. Notwithstanding
                  the foregoing, a Party prevailing in a litigation shall be
                  entitled to recover attorney's fees and costs as a result of
                  the successful enforcement of the terms of this Agreement.

         14.6     Except as expressly provided elsewhere in this Agreement, each
                  Party will at its expense promptly execute and deliver any
                  further instruments and documents and take any further action
                  as the other Party may reasonably request in order to give
                  effect to the transactions contemplated by this Agreement.

         14.7     The Parties have participated jointly in the negotiation and
                  drafting of this Agreement. If a question of intent or
                  interpretation arises, this Agreement will be construed as if
                  drafted jointly by the Parties and no presumption or

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     18 of 23

<PAGE>

                  burden of proof will arise favoring or disfavoring a party
                  because of the authorship of any provision of this Agreement.

         14.8     The Exhibits identified in this Agreement are incorporated by
                  reference and made a part of this Agreement.

         14.9     The provisions of this Agreement are severable, and in the
                  event that any provision of this Agreement is determined to be
                  invalid or unenforceable under any controlling body of law,
                  such determination shall not in any way affect the validity or
                  enforceability of the remaining portions of this Agreement.

         14.10    This Agreement and the exhibits hereto contains the entire
                  agreement between the Parties related to the subject matter
                  herein, and all prior negotiations, representations,
                  agreements, and understandings are merged into, extinguished
                  by, and completely expressed by this Agreement and the
                  exhibits hereto. This Agreement supercedes the 1999 License
                  Agreement and the 1999 Letter Agreement.

         14.11    This Agreement will be governed by and construed in accordance
                  with the laws of the State of California.

         14.12    This Agreement may be executed in any number of counterparts
                  and by facsimile, each of which will be deemed to be an
                  original and all of which together will constitute one and the
                  same agreement.

         14.13    The Parties agree that the material terms of this Agreement
                  will be considered confidential information of the Parties.
                  Notwithstanding the foregoing, each Party shall have the right
                  to disclose the material terms of this Agreement (a) in
                  confidence to any bona fide potential investor, investment
                  banker, acquirer, merger partner or other potential financial
                  partner, and where reasonably practicable, shall obtain an
                  adequate agreement of confidentiality consistent with the
                  terms of this Agreement; (b) to exercise its rights under this
                  Agreement and in connection with regulatory filings or to
                  comply with applicable laws or regulations or valid court
                  orders; and/or (c) to record assignment documents.
                  Notwithstanding the foregoing, in the event a Party is
                  required to make a disclosure of the material terms of this
                  Agreement pursuant to (b) above, it will give reasonable
                  advance written notice to the other Party of such disclosure
                  and endeavor in good faith to secure confidential treatment of
                  such information or a protective order related to such
                  information. In any event, the Parties agree to take all
                  reasonable action to avoid disclosure of the material terms of
                  this Agreement. The parties also agree that the reports and
                  disclosures made under Section 2.3 and Section 7.1 shall be
                  deemed "Confidential Information" and shall be subject to the
                  terms of the Confidentiality and Non-Disclosure Agreement
                  dated as of the date hereof by and between the Parties and
                  attached hereto as Exhibit G.

                                     19 of 23

<PAGE>

         14.14    The obligations of the parties under Sections 5.3, 11.1, 11.2,
                  12.5, 13 and 14.13 shall survive the termination of this
                  Agreement.

         In Witness whereof, the Parties have caused this Agreement to be
signed, effective as of the Effective Date set forth above.

ICN PHARMACEUTICALS, INC.

By: ____________________________
    Harry Roosje
    V.P. Legal

RIBAPHARM INC.

By: ____________________________
    Johnson Lau, MD, Ph.D.
    Chief Executive Officer

DEVRON AVERETT

__________________________

ANADYS PHARMACEUTICALS, INC.

By: _____________________________________
       Kleanthis G. Xanthopoulos, Ph.D.
       President and CEO

            [SIGNATURE PAGE TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                     20 of 23

<PAGE>

                                   EXHIBIT A

         Letter Agreement between Devron R. Averett, Ph.D. and ICN
Pharmaceuticals, Inc. dated January 22, 1999.

                                  [...***...]

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     21 of 23

<PAGE>

                                    EXHIBIT B

         License Agreement between Devron R. Averett, Ph.D. and ICN
Pharmaceuticals, Inc. dated October 11, 1999.

                                  [...***...]

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     22 of 23

<PAGE>

                                    EXHIBIT C

         Sublicense Agreement between Devron R. Averett, Ph.D. and Scriptgen
Pharmaceuticals, Inc. dated March 1, 2000.

                                  [...***...]

                                             ***CONFIDENTIAL TREATMENT REQUESTED

                                     23 of 23

<PAGE>

                                   EXHIBIT D-1

                ANADYS PROSECUTED AND OTHER LICENSED APPLICATIONS

<Table>
<Caption>
   COUNTRY
RUTAN & TUCKER                                                                                                         PROSECUTED
 DOCKET NO.           APPL. NO.            TITLE                      INVENTOR                          STATUS             BY
--------------        ---------            -----                      --------                          ------         -----------
<S>                  <C>                 <C>                          <C>                               <C>            <C>

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Allowed           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

</Table>

                                             ***CONFIDENTIAL TREATMENT REQUESTED


              [EXHIBIT D-1 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 1 of 5

<PAGE>



<Table>
<Caption>
   COUNTRY
RUTAN & TUCKER                                                                                                         PROSECUTED
 DOCKET NO.           APPL. NO.            TITLE                      INVENTOR                          STATUS             BY
--------------        ---------            -----                      --------                          ------         -----------
<S>                  <C>                 <C>                          <C>                               <C>            <C>
[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys
</Table>

                                             ***CONFIDENTIAL TREATMENT REQUESTED


              [EXHIBIT D-1 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 2 of 5

<PAGE>


<Table>
<Caption>
   COUNTRY
RUTAN & TUCKER                                                                                                         PROSECUTED
 DOCKET NO.           APPL. NO.            TITLE                      INVENTOR                          STATUS             BY
--------------        ---------            -----                      --------                          ------         -----------
<S>                  <C>                 <C>                          <C>                               <C>            <C>
[...***...]          [...***...]         [...***...]                  [...***...]                       Abandoned         Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys
</Table>

                                             ***CONFIDENTIAL TREATMENT REQUESTED


              [EXHIBIT D-1 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 3 of 5

<PAGE>


<Table>
<Caption>
   COUNTRY
RUTAN & TUCKER                                                                                                         PROSECUTED
 DOCKET NO.           APPL. NO.            TITLE                      INVENTOR                          STATUS             BY
--------------        ---------            -----                      --------                          ------         -----------
<S>                  <C>                 <C>                          <C>                               <C>            <C>
[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Anadys

[...***...]          [...***...]         [...***...]                  [...***...]                       Issued/6,479,463  Licensors


</Table>

                                             ***CONFIDENTIAL TREATMENT REQUESTED


              [EXHIBIT D-1 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 4 of 5

<PAGE>


<Table>
<Caption>
   COUNTRY
RUTAN & TUCKER                                                                                                         PROSECUTED
 DOCKET NO.           APPL. NO.            TITLE                      INVENTOR                          STATUS             BY
--------------        ---------            -----                      --------                          ------         -----------
<S>                  <C>                 <C>                          <C>                               <C>            <C>

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Licensors

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Licensors

[...***...]          [...***...]         [...***...]                  [...***...]                       Issued[...***...] Licensors

[...***...]          [...***...]         [...***...]                  [...***...]                       Pending           Licensors

[...***...]          [...***...]         [...***...]                  [...***...]                       Issued[...***...] Licensors

[...***...]          [...***...]         [...***...]                  [...***...]                       Issued[...***...] Licensors

</Table>




                                             ***CONFIDENTIAL TREATMENT REQUESTED


              [EXHIBIT D-1 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 5 of 5
<PAGE>

                                   EXHIBIT D-2

                              LICENSOR PATENTS AND
                               PATENT APPLICATIONS

<TABLE>
<CAPTION>
       COUNTRY
RUTAN & TUCKER DOCKET
         NO.                  APPL. NO.       TITLE             INVENTOR                 STATUS
<S>                          <C>            <C>                <C>                 <C>
     [...***...]             [...***...]    [...***...]        [...***...]         Issued/[...***...]
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Issued/[...***...]
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Issued/[...***...]
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
     [...***...]             [...***...]    [...***...]        [...***...]         Pending
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

              [EXHIBIT D-2 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 1 of 3

<PAGE>

<TABLE>
<S>                     <C>            <C>                <C>          <C>
[...***...]             [...***...]    [...***...]        [...***...]  Allowed
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Issued/[...***...]
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Issued/[...***...]
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Issued/[...***...]
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Issued/[...***...]
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Issued/[...***...]
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
[...***...]             [...***...]    [...***...]        [...***...]  Pending
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

              [EXHIBIT D-2 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                   Page 2 of 3

<PAGE>

<TABLE>
<S>              <C>              <C>              <C>                  <C>
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Issued/[...***...]
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Issued/[...***...]
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Superceded
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Issued/[...***...]
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Pending
[...***...]      [...***...]      [...***...]      [...***...]          Issued/[...***...]
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

              [EXHIBIT D-2 TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 3 of 3

<PAGE>

                                   ASSIGNMENT

         WHEREAS, ICN Pharmaceuticals, Inc., a Delaware corporation, with
offices at 3300 Hyland Avenue, Costa Mesa, California 92626 ("ICN"), and
Ribapharm Inc., a Delaware corporation with offices at 3300 Hyland Avenue, Costa
Mesa, California 92626 ("Ribapharm"), with ICN and Ribapharm being collectively
referred to herein from time to time as "Assignors," own the rights to the
patents and patent applications listed in Schedule A;

         AND WHEREAS, Anadys Pharmaceuticals, Inc., a Delaware corporation, with
offices at 9050 Camino Santa Fe, San Diego, California 92121 ("Anadys"), Anadys
being referred to herein from time to time as "Assignee," is desirous of
acquiring the entire right, title and interest in and to said patents and patent
applications listed in Schedule A;

         NOW THEREFORE, to all whom it may concern, be it known that pursuant to
the Agreement dated December 20, 2002, Assignors have sold, assigned, and
transferred, and by these presents do sell, assign and transfer unto said
Assignee, its successors or assigns, the entire right, title and interest in and
to all inventions and improvements claimed in all patents listed in Schedule A,
and in and to all renewals thereof, which may be granted therefrom, and all
extensions of such patents, which assignment is subject to Section 4.4 of the
Agreement; and Assignors do hereby authorize and request the Commissioner of
Patents and Trademarks to issue any and all United States Letters Patent for the
aforesaid inventions and improvements to the Assignee as the assignee of the
entire right, title and interest in and to the same, for the use of the
Assignee, its successors and assigns;

                  AND, in accordance with the Agreement signed on December 20,
2002, Assignors do hereby agree that we and our executors and legal
representatives will make, execute and deliver any and all other instruments in
writing including any and all further application papers, affidavits,
assignments and other documents, and will testify in all legal proceedings and
generally do all things which may be necessary or desirable more effectually to
secure to and vest in said Assignee, its successors or assigns the entire

<PAGE>

right, title and interest in and to the patents, rights, titles, benefits,
privileges and advantages hereby sold, assigned and conveyed, or intended so to
be;

                  AND, furthermore Assignor covenants and agrees with said
Assignee, its successors and assigns, that no assignment, grant, mortgage,
license or other agreement affecting the rights and property herein conveyed has
been made to others by Assignors and that full right to convey the same as
herein expressed is legally possessed.

                  IN TESTIMONY WHEREOF, I have hereunto set my hand this ______
day of ___________________, 2002.

ICN PHARMACEUTICALS, INC.

By: __________________________
    Harry Roosje
    V.P. Legal

RIBAPHARM INC.

By: __________________________
    Johnson Lau, MD, Ph.D.
    Chief Executive Officer

<PAGE>

                            SCHEDULE A TO ASSIGNMENT

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
  COUNTRY                    APPL. NO.                  TITLE                INVENTOR           PATENT NO.
----------------------------------------------------------------------------------------------------------
<S>                        <C>                       <C>                    <C>                <C>
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

        [SCHEDULE A TO EXHIBIT E OF THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 1 of 4

<PAGE>

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
  COUNTRY                    APPL. NO.                  TITLE                INVENTOR           PATENT NO.
----------------------------------------------------------------------------------------------------------
<S>                        <C>                       <C>                    <C>                <C>
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
</TABLE>

                                           ***CONFIDENTIAL TREATMENT REQUESTED

        [SCHEDULE A TO EXHIBIT E OF THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 2 of 4

<PAGE>

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
  COUNTRY                    APPL. NO.                  TITLE                INVENTOR           PATENT NO.
----------------------------------------------------------------------------------------------------------
<S>                        <C>                       <C>                    <C>                <C>
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

        [SCHEDULE A TO EXHIBIT E OF THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 3 of 4

<PAGE>

<TABLE>
<CAPTION>
----------------------------------------------------------------------------------------------------------
  COUNTRY                    APPL. NO.                  TITLE                INVENTOR           PATENT NO.
----------------------------------------------------------------------------------------------------------
<S>                        <C>                       <C>                    <C>                <C>
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
[...***...]                [...***...]               [...***...]            [...***...]        [...***...]

----------------------------------------------------------------------------------------------------------
</TABLE>

                                             ***CONFIDENTIAL TREATMENT REQUESTED

        [SCHEDULE A TO EXHIBIT E OF THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 4 of 4
<PAGE>

                                    EXHIBIT F

                    UNITED STATES PATENT AND TRADEMARK OFFICE

<TABLE>
<S>               <C>             <C>                     <C>
Applicant:        [...***...]     Examiner:               [...***...]
Serial No.:       [...***...]     Group Art Unit:         1623
Filed:            [...***...]     Docket No.:             [...***...]
Title:            [...***...]
</TABLE>

                      REVOCATION AND NEW POWER OF ATTORNEY

Commissioner for Patents
Washington, D.C. 20231

Dear Sir:

         The undersigned assignee of record hereby revokes any existing Powers
of Attorney and appoints Merchant & Gould, P.C. as attorneys and/or patent
agents with the full power to represent the applicant in connection with the
above-identified application.

         Please direct all correspondence to [...***...], MERCHANT & GOULD P.C.,
P.O. Box 2903, Minneapolis, MN 55402-0903, telephone [...***...] and list This
application to the Merchant & Gould Customer No. 23552.

                                                 ICN PHARMACEUTICALS, INC.

Date:______________________                      By: ___________________________
                                                     Harry Roosje
                                                     V.P. Legal

                                                 RIBAPHARM INC.

Date:______________________                      By: ___________________________
                                                     Johnson Lau, MD, Ph.D.
                                                     Chief Executive Officer

                                             ***CONFIDENTIAL TREATMENT REQUESTED

               [EXHIBIT F TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 1 of 2

<PAGE>

                    UNITED STATES PATENT AND TRADEMARK OFFICE

<TABLE>
<S>               <C>                <C>                   <C>
Applicant:        [...***...]        Examiner:             [...***...]
Serial No.:       [...***...]        Group Art Unit:       1623
Filed:            [...***...]        Docket No.:           [...***...]
Title:            [...***...]
</TABLE>

                      REVOCATION AND NEW POWER OF ATTORNEY

Commissioner for Patents
Washington, D.C. 20231

Dear Sir:

         The undersigned assignee of record hereby revokes any existing Powers
of Attorney and appoints Merchant & Gould, P.C. as attorneys and/or patent
agents with the full power to represent the applicant in connection with the
above-identified application.

         Please direct all correspondence to [...***...], MERCHANT & GOULD P.C.,
P.O. Box 2903, Minneapolis, MN 55402-0903, telephone [...***...] and list This
application to the Merchant & Gould Customer No. 23552.

                                               ICN PHARMACEUTICALS, INC.

Date:______________________                    By: _____________________________
                                                   Harry Roosje
                                                   V.P. Legal

                                               RIBAPHARM INC.

Date:______________________                    By: _____________________________
                                                   Johnson Lau, MD, Ph.D.
                                                   Chief Executive Officer

                                             ***CONFIDENTIAL TREATMENT REQUESTED

               [EXHIBIT F TO THE AGREEMENT DATED DECEMBER 20, 2002
               BY AND BETWEEN ICN, RIBAPHARM, ANADYS AND AVERETT]

                                  Page 2 of 2