LICENSE AGREEMENT

                                     BETWEEN

                          BUKWANG PHARM. IND. CO., LTD.

                                       AND

                         TRIANGLE PHARMACEUTICALS, INC.

*** Certain confidential portions of this Exhibit were omitted by means of
blackout of the text (the "Mark"). This Exhibit has been filed separately with
the Secretary of the Commission without the Mark pursuant to the Company's
Application Requesting Confidential Treatment under Rule 24b-2 under the
Securities Exchange Act.
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                                TABLE OF CONTENTS

ARTICLE 1.   DEFINITIONS.....................................................2

ARTICLE 2.   LICENSES........................................................9

ARTICLE 3.   LICENSE FEE, ROYALTIES, AND MILESTONE PAYMENTS.................12

ARTICLE 4.   REPORTS AND ACCOUNTING.........................................18

ARTICLE 5.   PAYMENTS.......................................................21

ARTICLE 6.   DEVELOPMENT PROGRAM............................................23

ARTICLE 7.   JOINT PROJECT COMMITTEE........................................27

ARTICLE 8.   PATENT PROSECUTION.............................................29

ARTICLE 9.   INFRINGEMENT...................................................33

ARTICLE 10.  TRANSFER OF KNOW-HOW; TECHNICAL ASSISTANCE.....................35

ARTICLE 11.  WARRANTIES AND REPRESENTATIONS; LIMITATION OF LIABILITY; AND
             DISCLAIMERS....................................................37

ARTICLE 12.  INDEMNIFICATION................................................41

ARTICLE 13.  CONFIDENTIALITY................................................43

ARTICLE 14.  CONDITIONS PRECEDENT...........................................45

ARTICLE 15.  TERM AND TERMINATION...........................................45

ARTICLE 16.  ASSIGNMENT.....................................................48

ARTICLE 17.  REGISTRATION OF LICENSE........................................49
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ARTICLE 18.  NOTIFICATION AND AUTHORIZATION UNDER DRUG PRICE
             COMPETITION AND PATENT TERM RESTORATION ACT....................49

ARTICLE 19.  DISPUTE RESOLUTION AND ARBITRATION.............................51

ARTICLE 20.  GENERAL PROVISIONS.............................................53
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      THIS LICENSE AGREEMENT is made and entered into as of this 27th day of
February 1998, by and between BUKWANG PHARM. IND. CO., LTD., with its principal
offices at 398-1, Daebang-Dong, Dongjak-Ku, Seoul 156-020, Korea (hereinafter
referred to as "Bukwang"), and TRIANGLE PHARMACEUTICALS, INC., with principal
offices located at 4 University Place, 4611 University Drive, Durham, NC 27707
(hereinafter referred to as "Triangle").

                                   WITNESSETH:

      WHEREAS, Bukwang has evidenced the in vitro and in vivo activity of an
L-nucleoside compound known generically as "L-FMAU";

      WHEREAS, L-FMAU is covered by patents and patent applications filed in
various countries throughout the world;

      WHEREAS, Bukwang, has entered into a License Agreement, dated December 28,
1995, as amended effective September 1, 1997 and December 1, 1997 (the "Primary
License Agreement") with Yale University ("Yale") and University of Georgia
Research Foundation, Inc. ("UGARF"; Yale and UGARF are hereinafter referred to
as the "Primary Licensors"), a copy of which Primary License Agreement is
attached hereto as Exhibit A, pursuant to which Bukwang has obtained an
exclusive worldwide license under the Primary Licensors' patents and patent
applications and has acquired the right to grant licenses under such patents and
patent applications;

      WHEREAS, Bukwang possesses certain technology and know-how relating to
L-FMAU and has the right to grant licenses in respect of such technology and
know-how; and

      WHEREAS, Triangle desires to obtain an exclusive license under such
patents, patent applications, technology and know-how;


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      NOW, THEREFORE, in consideration of the premises and the covenants herein
contained, the parties agree as follows:

                             ARTICLE 1. DEFINITIONS

      The following terms as used herein, when written with an initial capital
letter, shall have the meanings ascribed to them below:

      1.1 "Acquisition Cost" shall mean the actual invoiced price paid by a
party to any non-Affiliate third party for acquiring any item (e.g., a Compound
or other active ingredient), including but not limited to, shipping and handling
costs and customs duties incurred and paid by such party in connection with the
acquisition of such item.

      1.2 "Affiliate" shall mean any corporation or non-corporate business
entity which controls, is controlled by, or is under common control with a party
to this Agreement. A corporation or non-corporate business entity shall be
regarded as in control of another corporation if it owns, or directly or
indirectly controls, at least fifty (50%) percent of the voting stock of the
other corporation, or (a) in the absence of the ownership of at least fifty
(50%) percent of the voting stock of a corporation or (b) in the case of a
non-corporate business entity, or non-profit corporation, if it possesses,
directly or indirectly, the power to direct or cause the direction of the
management and policies of such corporation or non-corporate business entity, as
applicable.

      1.3 "Agreement" or "License Agreement" shall mean this Agreement,
including all Exhibits attached to this Agreement.

      1.4 "Bukwang Know-How" shall mean all inventions, discoveries, trade
secrets, information, experience, data, formulas, procedures and results which
are useful for the development and registration of the Compounds or the Licensed
Products and the development, registration, manufacturing, using or selling of
the Licensed Products which are rightfully held by Bukwang as of the Effective
Date (including, but not limited to, any of the foregoing items licensed to
Bukwang under the Primary License 


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Agreement), or which are not Joint Know-How or Joint Inventions and are
developed or acquired by Bukwang during the period beginning on the Effective
Date and ending upon termination or expiration of this Agreement pursuant to
Article 15 including, but not limited to, all manufacturing and synthesis
know-how.

      1.5 "Bukwang Patents" shall mean all patents and patent applications in
the Territory owned or controlled by Bukwang or under which Bukwang has a right
to practice with the right to extend such right to practice to Triangle
(including, but not limited to, all patents and patent applications licensed to
Bukwang under the Primary License Agreement) which contain claims the rights to
which are useful for the development, registration, manufacturing, using or
selling of the Compounds or Licensed Products which are filed prior to or during
the term of this Agreement in the United States or any foreign jurisdiction in
the Territory, including any addition, continuation, continuation-in-part or
division thereof or any substitute application thereof; any patent issued with
respect to such patent application, any reissue, extension or patent term
extension of any such patent, and any confirmation patent or registration patent
or patent of addition based on any such patent; and any other United States and
foreign patent or inventor's certificate with regard thereto. Bukwang Patents
shall include but not be limited to those listed in Exhibit B attached hereto.

      1.6 "Bulk Drug Substance" shall mean the Compound in bulk form which, if
appropriately formulated and finished, would be suitable for preclinical or
clinical use.

      1.7 "Compounds" shall mean the compound known as L-FMAU, with the chemical
name 2'-fluoro-5-methyl-(beta)-L-arabinofuranosyluracil, including any salts and
esters thereof.

      1.8 "Development Program" shall mean the research and development program
described in Article 6 of this Agreement.

      1.9 "Dollars" shall mean United States dollars.

      1.10 "EBV" shall mean Epstein-Barr virus.


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      1.11 "Effective Date" shall mean the later of (a) the date first written
above and (b) the date, if any, that the condition set forth in Article 14 shall
have been satisfied or, if applicable, waived.

      1.12 "FDA" shall mean the United States Food and Drug Administration or
any successor entity.

      1.13 "Field" shall mean all human antiviral applications and uses.

      1.14 "HBV" shall mean hepatitis B virus.

      1.15 "IND" shall mean an Investigational New Drug Application or its
domestic equivalent.

      1.16 "Indemnitees" shall mean (a) in the case of the indemnity set forth
in Section 12.1, Bukwang, its Affiliates, the Primary Licensors and the
directors, officers and employees of any of the foregoing; (b) in the case of
the indemnity set forth in Section 12.2, Triangle, its Affiliates and
sublicensees, and their directors, officers and employees; and (c) in the case
of the Indemnitees referenced in Section 12.3, the parties identified in
Subsections 1.16(a) and 1.16(b) above, as applicable.

      1.17 "Joint Inventions" shall mean any inventions related to the Compounds
or the Licensed Products, whether patented or not, which are jointly made during
the period beginning on the Effective Date and ending two (2) years after
termination or expiration of this Agreement pursuant to Article 15 by at least
one (1) Bukwang employee or person contractually required to assign or license
patent rights covering such inventions to Bukwang and at least one (1) Triangle
employee or person contractually required to assign or license patent rights
covering such inventions to Triangle.

      1.18 "Joint Know-How" shall mean all inventions, discoveries, trade
secrets, information, data, formulas, procedures and results which are useful
for the development, registration, manufacturing, using or selling of the
Compounds or the Licensed Products which are developed jointly by at least one
(1) Bukwang employee or person 


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contractually required to assign or license such data and know-how to Bukwang
and at least one (1) Triangle employee or person contractually required to
assign or license such data or know-how to Triangle, during the period beginning
on the Effective Date and ending two (2) years after termination or expiration
of this Agreement pursuant to Article 15. All Joint Know-How shall be owned
jointly by the parties hereto. Triangle shall have the exclusive right to use
such Joint Know-How in the Territory, unless the license granted pursuant to
Section 2.1 is terminated in a given country or countries of the Territory by
Bukwang pursuant to Section 6.3 or 15.2 or by Triangle pursuant to Section 15.3,
in which case, Bukwang shall have a non-exclusive right to use the Joint
Know-How in such country or countries. Bukwang shall have the exclusive right to
use such Joint Know-How outside the Territory.

      1.19 "Joint Project Committee" shall mean the committee described in
Article 7 hereof.

      1.20 "Licensed Product(s)" shall mean any Compound or any pharmaceutical
product containing one or more Compounds as an active ingredient, alone or in
combination with other active ingredients.

      1.21 "Manufacturing Cost," in respect of a particular item (e.g., a
Compound or other active ingredient), shall mean the costs of direct labor
(including allocable employee benefits and employment taxes), direct material,
direct energy, direct utilities and other charges incurred directly by a party
in the manufacture by it of such item and, without duplication, normal
production overhead (i.e., indirect labor, utilities, maintenance, depreciation
of the manufacturing equipment and facilities and other allocable overhead of
the manufacturing facility), all determined in accordance with U.S. GAAP.

      1.22 "NDA" shall mean a New Drug Application or its domestic equivalent.

      1.23 "Net Sales" of Licensed Products which contain as their active
ingredients only one or more Compounds shall mean the gross sales price of such
Licensed Products 


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billed by Triangle, its Affiliates or sublicensees to independent customers
including any consideration received, directly or indirectly, from such
customers in respect of the sale, distribution or transfer of Licensed Products,
less (a) normal and customary trade, quantity and cash discounts, all rebates
(including those paid to third party payors), sales, use, or other similar
taxes, and all transportation, insurance and handling charges; and (b) all
credits and allowances granted to such independent customers on account of
returns or retroactive price reductions in lieu of returns, whether during the
specific royalty period or not, all determined in accordance with U.S. GAAP. In
the event that Triangle or its Affiliates or sublicensees distribute any
Licensed Products to a third party for non-monetary consideration (e.g., barter
or exchange), such distribution shall be considered a sale for accounting and
royalty purposes. Net Sales for any such distributions shall be determined on a
country-by-country basis and shall be the average price of "arm's length" sales
by Triangle or its Affiliates or sublicensees in such country in the Territory
during the royalty period in which such sale occurs or, if no such "arm's
length" sales occurred in such country in the Territory during such royalty
period, during the last royalty period in which such "arm's length" sales
occurred. If no "arm's length" sales have occurred in a particular country in
the Territory, Net Sales for any such distributions in such country in the
Territory, shall be the average price of "arm's length" sales in all countries
in the Territory during such royalty period.

      1.24 "Net Sales" of Licensed Products which contain as their active
ingredients both or one or more Compounds and other compounds (a "Combination
Product") shall mean the gross sales price of such Combination Product billed by
Triangle, its Affiliates or sublicensees to independent customers, including any
consideration received, directly or indirectly, from such customers in respect
of the sale, distribution or transfer of Licensed Products, less all the
allowances, adjustments, reductions, discounts, taxes, duties, rebates and other
items referred to in Section 1.23 multiplied by a fraction, the numerator of
which shall be the billing party's Acquisition Cost or Manufacturing Cost, 


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as applicable, for all Compounds included in such Licensed Product and the
denominator of which shall be the billing party's Acquisition Cost or
Manufacturing Cost, as applicable, for all active ingredients contained in such
Licensed Product, all determined in accordance with U.S. GAAP. In the event that
Triangle or its Affiliates or sublicensees distribute any Licensed Products to a
third party for non-monetary consideration (e.g., barter or exchange), such
distribution shall be considered a sale for accounting and royalty purposes. Net
Sales for any such distributions shall be determined on a country-by-country
basis and shall be the average price of "arm's length" sales by Triangle or its
Affiliates or sublicensees in such country in the Territory during the royalty
period in which such sale occurs or, if no such "arm's length" sales occurred in
such country in the Territory during such royalty period, during the last
royalty period in which such "arm's length" sales occurred. If no "arm's length"
sales have occurred in a particular country in the Territory, Net Sales for any
such distributions in such country in the Territory, shall be the average price
of "arm's length" sales in all countries in the Territory during such royalty
period.

      1.25 "Phase II Completion Date" shall mean sixty (60) days after the
completion of statistical analyses of the final results of those Phase II
clinical studies which Triangle considers reasonably necessary for purposes of
inclusion in an NDA for a Licensed Product for HBV. As used in the preceding
sentence, "Phase II clinical trials" shall mean those well-controlled clinical
trials sponsored by Triangle, the primary objective of which (as reasonably
determined by Triangle) is to ascertain additional data regarding the safety and
tolerance of a Licensed Product and preliminary data regarding such Licensed
Product's antiviral effects against HBV.

      1.26 "Phase III Completion Date" shall mean sixty (60) days after the
completion of statistical analyses of the final results of those Phase III
clinical studies which Triangle considers reasonably necessary for inclusion in
an NDA for a Licensed Product for HBV. As used in the preceding sentence, "Phase
III clinical trials" shall 


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mean those well-controlled clinical trials sponsored by Triangle the primary
objective of which (as reasonably determined by Triangle) is to ascertain
definitive safety data and efficacy data regarding such Licensed Product's
antiviral effects against HBV sufficient to support an NDA.

      1.27 "Registration" shall mean, in relation to any Licensed Product, such
approvals by the regulatory authorities in a given country (including pricing
approvals, if any) as may be legally required before such Licensed Product may
be commercialized or sold in such country.

      1.28 "Territory" shall mean the entire world, excluding Korea. 

      1.29 "Toxicity Study Completion Date" shall mean thirty (30) days after
completion of statistical analyses of the results of the second toxicity study
referred to in Section 6.1.

      1.30 "Triangle Know-How" shall mean all inventions, discoveries, trade
secrets, information, experience, data, formulas, procedures and results arising
solely out of the Development Program or the manufacture, use or sale of the
Licensed Products which are useful for development, registration, manufacturing,
using or selling of the Compounds or the Licensed Products which are rightfully
held by Triangle as of the Effective Date, or which are not Joint Know-How or
Joint Inventions and are developed or acquired by Triangle during the period
beginning on the Effective Date and ending upon termination or expiration of
this Agreement pursuant to Article 15.

      1.31 "Triangle Patents" shall mean all patents and patent applications
owned or controlled by Triangle or under which Triangle has a right to practice
with the right to extend such right to practice to Bukwang which contain claims
the rights to which are useful for the development, registration, manufacturing,
using or selling of the Compounds or the Licensed Products, including any
addition, continuation, continuation-in-part or division thereof or any
substitute application thereof; any patent issued with respect to such patent
application, any reissue, extension or patent term extension of any


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such patent, and any confirmation patent or registration patent or patent of
addition based on any such patent; and any other United States and foreign
patent or inventor's certificate with regard thereto.

      1.32 "U.S. GAAP" shall mean generally accepted accounting principles in
the United States, consistently applied.

      1.33 "Valid Claim" shall mean an issued or granted claim of any issued and
unexpired patent included among the Bukwang Patents, which has not been held
unenforceable, unpatentable or invalid by a decision of a court or governmental
body of competent jurisdiction, which is unappealable or unappealed within the
time allowed for appeal, which has not been rendered unenforceable through
disclaimer or otherwise or which has not been lost through an interference or
opposition proceeding.

                               ARTICLE 2. LICENSES

      2.1 License Under Bukwang Patents and Bukwang Know-How.

            Bukwang hereby grants Triangle the exclusive right and license to
practice the Bukwang Patents and the Bukwang Know-How to make, have made, use,
import, offer for sale, sell and have sold Licensed Products (including, but not
limited to, Bulk Drug Substance) in the Territory during the term of this
Agreement.

      2.2 Extension to Affiliates. Triangle shall have the right to extend its
rights under the license granted in Section 2.1 to one or more of its
Affiliates, provided, that Triangle (a) gives Bukwang at least thirty (30) days'
prior written notice of such extension and (b) shall remain responsible for such
Affiliate's compliance with all obligations under this Agreement which apply to
such Affiliate.

      2.3 Sublicenses. Triangle may grant sublicenses to non-Affiliate third
parties without any consent; provided, however, that in the event that Triangle
proposes to grant a sublicense to a prospective non-Affiliate sublicensee ***

                                     ***

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          ***          , then Triangle must first obtain the prior consent of
Bukwang and the Primary Licensors, which consent shall not be unreasonably
withheld or delayed. No sublicense granted by Triangle shall relieve it of any
obligation hereunder. With respect to any sublicense for which Bukwang's consent
is not required pursuant to the immediately preceding sentence, Triangle shall
provide Bukwang with notice of its intention to grant a sublicense at least
fifteen (15) days prior to entering into the applicable sublicense agreement.
Triangle shall promptly provide Bukwang with a copy of any executed sublicense
agreement.

      2.4 License Under Triangle Patents and Triangle Know-How. Triangle hereby
grants Bukwang a non-exclusive right and license to practice the Triangle
Patents and Triangle Know-How to make, have made, use, import, offer for sale,
sell and have sold Licensed Products, with a right to sublicense, outside the
Territory and, in the event Triangle's license granted under Section 2.1 is
terminated in a given country of the Territory (other than by expiration or by
Triangle pursuant to Section 15.2 of this Agreement), in such country from and
after the date of termination. The license granted pursuant to this Section 2.4
shall be royalty free.

      2.5 Covenant Not to Sue. Each party granting a license agrees that during
the term of this Agreement, neither it nor any of its Affiliates, will assert
against the other party (a "licensed party") or its Affiliates or sublicensees
any patent not included in the Bukwang Patents or Triangle Patents, as
applicable, that is or might be infringed by reason of such licensed party's or
its Affiliates' or sublicensees' exercise of the license granted to it
hereunder.

      2.6 Right of First Discussion. If, at any time during the term hereof,
Bukwang (a) acquires rights in respect of human uses or applications of L-FMAU
outside the Field (a "Non-Field Use") and (b) decides to license any rights
relating to such Non-Field Use, it shall give prompt notice thereof to Triangle.
Such notice shall include a description of the rights which Bukwang wishes to
license, together with all data and information in


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Bukwang's possession relating to the applicable Non-Field Use. Thereafter,
Triangle shall have thirty (30) days to notify Bukwang whether Triangle is
interested in commencing negotiations to obtain a license to such rights (the
"Non-Field License"). If Triangle does not give such notice within such thirty
(30) day period, Bukwang shall be entitled to commence negotiations with a third
party in respect of the Non-Field License. If Triangle gives such notice within
such thirty (30) days, the parties shall commence good faith negotiations in an
effort to reach agreement on the terms of the Non-Field License. If such
negotiations do not result in the execution of the Non-Field License, Bukwang
agrees that, for a period of twelve (12) months after cessation of such
negotiations, it will not offer the Non-Field License to a third party
containing financial terms more favorable than those last offered to Triangle
during such negotiations without first offering the Non-Field License to
Triangle on the same terms. In such event, Triangle shall have thirty (30) days
to accept the Non-Field License containing such more favorable financial terms
and if it fails to do so, it shall have no further rights to such Non-Field Use.

      2.7 Retained License. Triangle acknowledges that, pursuant to paragraph
2.2 of the Primary License Agreement, the Primary Licensors have retained on
their behalf and on the behalf of any of their research collaborators a
royalty-free right and license to make and use Licensed Products and to practice
the Licensed Technology (as defined therein) for research and educational
purposes only.

      2.8 United States Government Rights. Triangle acknowledges that the
Bukwang Patents, Bukwang Know-How, or portions thereof were developed with
financial or other assistance through grants or contracts funded by the United
States government. Triangle acknowledges that in accordance with Public Law
96-517, other applicable statutes, regulations and Executive Orders now in
existence or as may be amended or subsequently enacted, the United States
government has certain rights in the Bukwang Patents and Bukwang Know-How.
Triangle shall take all reasonable actions


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necessary to enable the Primary Licensors to satisfy their obligations of which
Triangle is aware under any federal law relating to the Bukwang Patents or
Bukwang Know-How. If at any time during the term of this Agreement, the United
States government should take action which terminates the Primary License
Agreement or requires that the Primary License Agreement be terminated, Triangle
acknowledges that upon such termination, this Agreement will automatically
terminate. In such event, Triangle shall not have any right to the return of any
payments of any kind made by it to Bukwang prior to the date of termination,
other than any overpayment of earned royalties as determined by any audit
conducted pursuant to Section 4.2.

      2.9 No Implied License. The license and rights granted in this Agreement
to Triangle shall not be construed to confer any rights upon Triangle by
implication, estoppel or otherwise as to any technology, know-how or any other
intellectual property not specifically identified as Bukwang Patents or Bukwang
Know-How.

            ARTICLE 3. LICENSE FEE, ROYALTIES, AND MILESTONE PAYMENTS

      3.1 License Fee. As partial consideration for entering into this
Agreement, Triangle agrees to pay Bukwang a license fee of $6,000,000, payable
within ten (10) days after the Effective Date.

      3.2 Milestone Payments.

            (a) Triangle shall pay Bukwang a milestone payment ("Milestone
Payment") in the amount specified below no later than *** after the occurrence
of the corresponding event designated below (except as otherwise specified in
Subsection 3.2(e)), unless Triangle has given Bukwang notice of termination of
this Agreement in the entire Territory prior to such due date.


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            Milestone                                              Milestone
            ---------                                              ---------
                                                                    Payment
                                                                    -------

               ***                                                     ***

Marketing Milestone Payments (in accordance with 
  Subsection 3.2(b))                                              $30,000,000
                                                                  -----------

Total Milestone Payments                                          $62,500,000

            (b) On each *** in Net Sales (up to a cumulative total of *** in Net
Sales within the Territory) a Marketing Milestone Payment of *** will be due (up
to an aggregate of $30,000,000), as reflected in clause (vii) of the Subsection
3.2(a). Upon payment of the final *** in respect of the first *** in cumulative
Net Sales within the Territory, the Marketing Milestone Payment obligations will
terminate. Each Marketing Milestone Payment will be due at the same time the
royalty report covering the royalty period in which such incremental *** in Net
Sales is due.

            (c) The *** total reflects the additional Milestone Payments which
will be due upon ***. The Milestone Payment due upon ***

            (d) All Milestone Payments described in clauses (i), (ii), and (iii)
of Subsection 3.2(a) will be *** against earned royalties payable to Bukwang.
Such credit may be applied during each royalty period (up to a maximum of *** of
royalties payable for such royalty period) until *** of such Milestone Payments
have been credited.

      (e) In the event Bukwang terminates this Agreement pursuant to Section 6.3
or 15.2 or Triangle terminates this Agreement with respect to the entire
Territory pursuant to Section 15.3, any *** Milestone Payment due pursuant to
clause (vii) of Subsection 3.2(a) shall be ***. By 


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way of example only, if Triangle terminates the Agreement in the entire
Territory and, at the time of termination *** , Triangle would owe Bukwang a
final *** Milestone Payment of ***

      3.3 Earned Royalties; Duration and Reduction.

            (a)   Triangle shall pay Bukwang a royalty equal to fourteen percent
                  (14%) of the Net Sales of Licensed Products sold in the
                  Territory by Triangle and its Affiliates and sublicensees for
                  the periods and subject to the reductions set forth in this
                  Agreement.

            (b)   Royalties shall be paid in respect of Licensed Products in a
                  given country for a period of ten (10) years after the initial
                  commercial introduction of a Licensed Product in such country.
                  After such ten (10) year period in a given country, royalties
                  shall be paid in respect of a given Licensed Product in such
                  country only so long as the manufacture, use, offer for sale,
                  sale or importation of such Licensed Product in such country
                  would, in the absence of this license, infringe a Valid Claim.

            (c)   If at any time during such ten (10) year period, (I) a third
                  party or third parties commence selling a therapeutic product
                  in a country of the Territory in which no Valid Claims exist
                  and (ii) such product contains any Compound ("unlicensed unit
                  sales") and (iii) such unlicensed unit sales for any royalty
                  period amount to *** or more of Triangle's unit sales of such
                  Licensed Product in such country in such royalty period,
                  determined in accordance with Subsection 3.3(d) below, then
                  Triangle's royalty obligation in such country with respect to
                  such Licensed Product shall


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                  be reduced by *** of the royalty otherwise payable commencing
                  with the royalty period next succeeding the royalty period in
                  which such *** threshold was initially exceeded and shall
                  resume with the royalty period next succeeding the first
                  royalty period in which such *** threshold is no longer
                  exceeded.

            (d)   For purposes of this Section 3.3, (i) "unlicensed unit sales"
                  and "Triangle unit sales" shall be deemed to mean the grams of
                  Compounds contained in the third party product (irrespective
                  of dosage form) or the Licensed Product (irrespective of
                  dosage form), respectively, as reflected on the label of each
                  such unit; and (ii) unlicensed unit sales shall be determined
                  by the sales reports of IMS America Ltd. Of Plymouth Meeting,
                  Pennsylvania ("IMS") or any successor to IMS or any other
                  independent marketing auditing firm selected by Triangle or
                  its Affiliates or sublicensees and reasonably acceptable to
                  Bukwang. If Triangle is entitled to a royalty reduction based
                  on unlicensed unit sales pursuant to Subsection 3.3(b) for any
                  royalty period, it or its Affiliates or sublicensees shall
                  submit the sales report of IMS or such other independent firm,
                  as applicable, for the relevant royalty period to Bukwang,
                  together with Triangle's or its Affiliates' or sublicensees'
                  sales report for the relevant royalty period. Such sales
                  reports for each royalty period in which Triangle is entitled
                  to such royalty reduction shall be submitted with the royalty
                  report for such royalty period submitted pursuant to Section
                  4.1. 

      3.4 Annual Minimum Royalties. In the event that, during the third full
calendar year following the year during which the FDA Registration for an HBV
indication is granted for a Licensed Product or any calendar year thereafter for
as long as 

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royalty obligations exist *** , Triangle's total annual royalty payments
(without giving effect to any credits taken pursuant to Subsection 3.2 (d)) to
Bukwang pursuant to Section 3.3 above are less than the annual minimum amount
set forth opposite such year below (the "Annual Minimum"), Triangle shall make a
payment to Bukwang together with the royalty report for the fourth quarter of
such year required in Section 4.1 of this Agreement equal to the difference
between such Annual Minimum and the royalties paid to Bukwang for the preceding
year pursuant to Section 3.3 above:

                  Calendar Year                             Annual Minimum
                  -------------                             --------------

                                       ***

As used in this Section 3.4, *** .

      3.5 Accrual of Royalties. No royalty shall be payable on a Licensed
Product made, sold, or used for tests or development purposes, or distributed as
samples. No royalties shall be payable on sales among Triangle, its Affiliates
and sublicensees, but royalties shall be payable on subsequent sales by
Triangle, its Affiliates or sublicensees to a third party. No multiple royalty
shall be payable because the manufacture, use, offer for sale, sale or import of
a Licensed Product is covered by more than one Valid Claim or by at least one
Valid Claim and the Bukwang Know-How.

      3.6 Third Party Royalties. If Triangle, its Affiliates or sublicensees
determine, after consultation with Bukwang, but at Triangle's sole discretion,
that it or they may be required to pay royalties and other amounts to any third
party because the manufacture, use, offer for sale, sale or importation of a
Licensed Product infringes or may infringe any patent or other intellectual
property rights of such third party in one or more countries (collectively, the
" Third Party Royalties"), Triangle, its Affiliates or sublicensees may 

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                                       16
<PAGE>

deduct the Third Party Royalties it or they pay to such third party from earned
royalties and Milestone Payments thereafter due to Bukwang. Triangle may credit
*** of any Third Party Royalties up to *** of Net Sales of Licensed Products and
*** of the amount of any Third Party Royalties in excess of *** of Net Sales of
Licensed Products. In no event shall the royalties due on Net Sales of Licensed
Products in any royalty period or any Milestone Payment be thereby reduced on
account of any reduction pursuant to this Section 3.6 by more than *** of the
amount which would have been otherwise payable.

      3.7 Compulsory Licenses. Should a compulsory license be granted to any
third party in any country of the Territory to make, have made, use, import,
offer for sale or sell Licensed Products, the royalty rate payable hereunder for
sales of the Licensed Products by Triangle in such country shall be adjusted to
match any lower royalty rate granted to the third party for such country.

      3.8 Reduction in Royalty Due to Invalid Claims. In the event that
applicable claims of all patents or patent applications included within the
Bukwang Patents under which Triangle is selling or actively developing a
Licensed Product shall be held invalid or not infringed by the Licensed Products
Triangle is selling or actively developing by a court of competent jurisdiction
in a given country of the Territory, whether or not there is a conflicting
decision by another court of competent jurisdiction in such country, Triangle
may reduce all royalty payments on its, its Affiliates' or its sublicensees'
sales of such Licensed Product covered by such claims by *** and, if it does so,
shall deposit the reduced portion of such royalty payments in an
interest-bearing escrow account until such judgment is finally reversed by an
unappealed or unappealable decision of a court of competent jurisdiction of
higher dignity in such country or is otherwise unappealable or is unappealed
within the time allowed therefor, except that, in those instances, if any, in
which Triangle has patent prosecution responsibility in respect 

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                                       17
<PAGE>

of such patents and patent applications, if such judgment becomes unappealable
due to the inaction of Triangle or its Affiliates or sublicensees such judgment
will be deemed to have been reversed. If such judgment is finally reversed by an
unappealable decree of a court of competent jurisdiction of higher dignity in
such country, or is deemed reversed as provided herein, the former royalty
payments shall be resumed and the royalty payments not theretofore made and
interest earned thereon shall become due and payable to Bukwang. If such
judgment is not reversed, deemed reversed, is unappealed or becomes
unappealable, as aforesaid, Triangle shall be entitled to all sums in such
escrow account. Triangle will include an accounting of any escrow account
established pursuant to this Section 3.8 in each royalty report submitted to
Bukwang pursuant to Article 4.

      3.9 Limitation on Royalty Reduction. Any provision of this Agreement to
the contrary notwithstanding, in no event will earned royalties paid to Bukwang
be less than *** of Net Sales of Licensed Products for any royalty period during
the term hereof.

                        ARTICLE 4. REPORTS AND ACCOUNTING

      4.1 Royalty Reports and Records.

            (a) During the term of this Agreement commencing with the commercial
introduction of the first Licensed Product, Triangle shall furnish, or cause to
be furnished to Bukwang, written reports governing each of Triangle's fiscal
quarters showing:

            (i) the gross sales of all Licensed Products sold by Triangle, its
Affiliates and sublicensees during the reporting period, together with the
calculations of Net Sales in accordance with Sections 1.23 and 1.24; and

            (ii) the royalties payable in Dollars, which shall have accrued
hereunder in respect of such Net Sales; and

            (iii) the exchange rates used, if any, in determining the amount of

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                                       18
<PAGE>

Dollars; and

            (iv) any withholding taxes required to be made from such royalties.

            (b) With respect to sales of the Licensed Product invoiced in
Dollars, the gross sales, Net Sales, and royalties payable shall be expressed in
Dollars. With respect to sales of the Licensed Product invoiced in a currency
other than Dollars, the gross sales, Net Sales, and royalties payable shall be
expressed in the domestic currency of the party making the sale together with
the Dollar equivalent of the royalty payable, calculated using the simple
average of the exchange rates published in the Wall Street Journal on the last
day of each month during the reporting period. If any Triangle Affiliate or
sublicensee makes any sales invoiced in a currency other than its domestic
currency, the gross sales and Net Sales shall be converted to its domestic
currency in accordance with the Affiliate's or sublicensee's normal accounting
practices. Triangle or its Affiliate or sublicensee making any royalty payment
shall furnish to Bukwang appropriate evidence of payment of any tax or other
amount deducted from any royalty payment.

            (c) Reports shall be made on a quarterly basis. Quarterly reports
shall be due within *** of the close of every Triangle fiscal quarter and shall
be prepared in accordance with U.S. GAAP. Triangle shall keep accurate records
in sufficient detail to enable royalties and other payments payable hereunder to
be determined. Triangle shall be responsible for all royalties and late payments
that are due to Bukwang that have not been paid by Triangle's Affiliates and
sublicensees. Triangle's Affiliates and sublicensees shall have, and shall be
notified by Triangle that they have, the option of making any royalty payment
directly to Bukwang.

      4.2 Right to Audit. Bukwang (or the Primary Licensors on Bukwang's behalf
if authorized in writing to Triangle by Bukwang and provided they agree to be
bound by the provisions of Sections 4.2 and 4.3) shall have the right, upon
prior notice to Triangle, 

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                                       19
<PAGE>

not more than once in each Triangle fiscal year nor more than once in respect of
any fiscal year, through an independent certified public accountant selected by
Bukwang or the Primary Licensors, as applicable, and acceptable to Triangle,
which acceptance shall not be unreasonably refused, to have access during normal
business hours to those records of Triangle as may be reasonably necessary to
verify the accuracy of the royalty reports required to be furnished by Triangle
pursuant to Section 4.1 of the Agreement. Such accountant may report only the
accuracy or inaccuracy of the royalty reports furnished by Triangle and, in the
event they are determined to be inaccurate, the corrections in the amounts which
need to be made to such reports. Triangle shall include in any sublicenses
granted pursuant to this Agreement a provision requiring the sublicensee to keep
and maintain records of sales made pursuant to such sublicense in accordance
with U.S. GAAP and to grant access to such records by Bukwang's or the Primary
Licensors' independent certified public accountant, as applicable, under the
same terms that Bukwang has access to Triangle's records. If such independent
certified public accountant's report shows any underpayment of royalties by
Triangle its Affiliates or sublicensees, within thirty (30) days after
Triangle's receipt of such report, Triangle shall remit or shall cause its
sublicensees to remit to Bukwang:

            (a) the amount of such underpayment; and

            (b) if such underpayment exceeds *** percent of the total royalties
owed for the fiscal year then being reviewed, the reasonably necessary fees and
expenses of such independent certified public accountant performing the audit.
Otherwise, Bukwang's accountant's fees and expenses shall be borne by Bukwang.
Any overpayment of royalties shall be fully creditable against future royalties
payable in any subsequent royalty periods or if this Agreement terminates or
expires before such overpayment in fully credited, Bukwang agrees to refund the
uncredited portion of such overpayment within *** after receipt of the final
royalty payment hereunder. 

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<PAGE>

Upon the expiration of *** following the end of any fiscal year, the calculation
of royalties payable with respect to such fiscal year shall be binding and
conclusive on Bukwang and Triangle, unless an audit for such fiscal year is
initiated before expiration of such *** . Triangle shall retain, and shall cause
its Affiliates and sublicensees to retain, those records required to be
maintained pursuant to this Section 4.2 in respect of each fiscal year for a
period of *** after the end of such fiscal year.

      4.3 Confidentiality of Records. All information subject to review under
this Article 4 shall be confidential. Except where otherwise required by law,
Bukwang and its accountant shall retain all such information in confidence.

                               ARTICLE 5. PAYMENTS

      5.1 Payments and Due Dates. (a) Except as otherwise provided herein,
royalties and other amounts payable to Bukwang as a result of activities
occurring during the period covered by each royalty report provided for under
Article 4 of this Agreement shall be due and payable on the date such royalty
report is due. Payments of royalties and other amounts in whole or in part may
be made in advance of such due date. Bukwang and Triangle agree that unless
otherwise directed by Bukwang in writing, subject, however, to the last sentence
of this Subsection 5.1(a), Triangle will remit all royalties and other amounts
due pursuant to Article 3 of this Agreement in the following percentages (or, if
different, in the percentages then in effect under the Primary License
Agreement) to Bukwang and each of the Primary Licensors:

                                            Percentage Allocation

     Type of Payment (Section)         UGARF        Yale       Bukwang

License Fee (Section 3.1)              ***          ***         ***

Milestone Payments (Section 3.2)       ***          ***         ***

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<PAGE>

Earned Royalties (Section 3.3)         ***          ***         ***

Annual Minimum Royalties (Section 3.4) ***          ***         ***

Bukwang agrees that payment by Triangle of any amounts due pursuant to Article 3
to Bukwang, UGARF and Yale in the percentages set forth above shall be deemed to
a payment to Bukwang. Bukwang further agrees that in the event royalties payable
hereunder for a given royalty period are less than *** of the Net Sales of
Licensed Products during such royalty period, Triangle may make such adjustments
in the applicable percentages set forth above as are necessary to ensure that
the sum of the royalties paid to UGARF and YALE is not less than *** of the Net
Sales of Licensed Products for such royalty period. Bukwang shall have the
option to have Triangle make all payments described in this Subsection 5.1(a)
directly to Bukwang upon thirty (30) days' prior written notice and, if it
exercises such option, may, thereafter, elect to have Triangle make payments as
aforesaid to Bukwang, UGARF and Yale upon thirty (30) days' prior written
notice. Bukwang may not change its election more than once during each fiscal
year unless such change is required in order for Bukwang to comply with
applicable laws and regulations. In the event this License Agreement becomes a
direct license among Triangle and the Primary Licensors pursuant to paragraph
2.5 of the Primary License Agreement, all payments made pursuant to this
Subsection 5.1(a) will be made by Triangle to the Primary Licensors in the
percentages then in effect under the Primary License Agreement and to Bukwang as
provided in Subsection 5.1(b) below.

            (b) Any provision of this Agreement to the contrary notwithstanding,
any royalties on Net Sales of Licensed Products due pursuant to this Agreement
which would not constitute Licensed Products as defined in the Primary License
Agreement shall be payable solely to Bukwang. Bukwang shall notify Triangle of
any instances to which this Subsection 5.1(b) applies and, thereafter, Triangle
shall remit royalties on such sales as 

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<PAGE>

provided in this Subsection 5.1(b).

            (c) All payments to Bukwang shall be made by wire transfer to an
account of Bukwang designated by Bukwang from time to time; provided, however,
that in the event that Bukwang fails to designate such account, Triangle or its
Affiliates and sublicensees may remit payment to Bukwang to the address
applicable for the receipt of notices hereunder; provided, further, that any
notice by Bukwang of such account or change in such account, shall not be
effective until fifteen (15) days after receipt thereof by Triangle. Unless
otherwise agreed, all payments to Yale and UGARF shall be made as specified in
paragraph 5.1 of the Primary License Agreement.

      5.2 Currency Restrictions. Except as hereinafter provided in this Section
5.2, all royalties and other amounts shall be paid in Dollars. If, at any time,
legal restrictions prevent the prompt remittance of part of or all royalties
with respect to any country in the Territory where Licensed Products are sold,
Triangle or its sublicensee shall have the right and option to make such
payments by depositing the amount thereof in local currency to Bukwang's
accounts in a bank or depository in such country.

      5.3 Overdue Payments. In the event any payment due hereunder is not made
when due, the payment shall accrue interest (beginning on the date such payment
is due) calculated at the rate of *** and such payment when made shall be
accompanied by all interest so accrued. The remittance of such interest shall
not foreclose Bukwang from exercising any other rights it may have pursuant to
this Agreement because such payment is late.

                         ARTICLE 6. DEVELOPMENT PROGRAM

      6.1 Development Program. Subject to Bukwang's timely performance of its
obligations hereunder, and in complete fulfillment of Triangle's diligence
obligations hereunder and any such obligations implied by law, Triangle will
undertake, or, if applicable, will cause its Affiliates and sublicensees to
undertake, the development

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                                       23
<PAGE>

activities described in this Article 6. Triangle shall, at its expense, use its
*** (a) to conduct a development program (the "Development Program") relating to
the use of the Licensed Product for HBV and (b) if the results of the
Development Program so justify, to seek Registration for such Licensed Product
in the United States. As part of the Development Program, Triangle shall be
responsible for conducting 3-month toxicity studies in two species of animals
pursuant to protocols which it develops or approves, as applicable. Triangle
shall commence both toxicity studies as promptly as practicable *** after it
obtains Bulk Drug Substance of a quality and in such quantities reasonably
necessary to perform such toxicity studies. Bukwang shall promptly reimburse
Triangle for *** of the out-of-pocket costs (excluding all drug costs, which
shall be the responsibility of Triangle) incurred by Triangle in conducting such
toxicity studies, subject to reasonable substantiation by Triangle of such
out-of-pocket costs. The Development Program shall be mutually discussed by the
parties hereto at the meetings of the Joint Project Committee held pursuant to
Article 7 and shall take into consideration studies and experiments carried out,
or to be carried out by, Bukwang and its licensees, if any, outside the
Territory, but the activities within the Territory comprising the Development
Program shall be determined at Triangle's sole discretion. Anything in this
Agreement to the contrary notwithstanding, Triangle shall be entitled to
exercise prudent and justifiable business judgment in meeting its ***
obligations hereunder. For purposes of this Article 6, *** .

      6.2 Fulfillment.

            (a) Subject to the foregoing provisions of this Article 6,
Triangle's *** obligations set forth in this Article 6 shall be deemed to have
been satisfied if 

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<PAGE>

Triangle:

            (i) files what it reasonably believes to be a complete NDA for a
Licensed Product for HBV with the FDA within *** after the Effective Date;
provided, however, said *** period shall be subject to up to *** extensions
of *** , at Triangle's election, by payment to Bukwang of a sum of *** for each
*** extensions and *** for each *** extensions; and

            (ii) commercially introduces, or causes its Affiliates or
sublicensees to commercially introduce, such Licensed Product in the United
States within *** after FDA Registration of such Licensed Product, if otherwise
commercially feasible.

            (b) Triangle agrees to use its *** to give Bukwang at least ten (10)
days' notice prior to the exercise of any extension pursuant to Subsection 6.2
(a). Extension payments under Subsection 6.2(a) shall be made within the first
ten (10) days of each such extension period. Notwithstanding any provision of
Subsection 6.2(a) to the contrary: (i) in the event that Triangle is unable to
obtain Bulk Drug Substance of a quality and in such quantities reasonably
necessary to perform the toxicity studies referred in Section 6.1 within ***
after the Effective Date, the *** period referred to in Subsection 6.2(a) shall
be adjusted by that period in excess of such *** period that expires before
Triangle obtains such Bulk Drug Substance; provided, however, that the period of
the extension prescribed in this clause (i) of this Subsection 6.2(b) shall, in
no event, exceed *** ; and (ii) such *** period shall also be adjusted
appropriately (x) to account for any delay by Bukwang in the transfer of Bukwang
Know-How beyond the period specified in Section 10.1 and (y) in the event the
FDA requires that toxicity studies other than those described in Section 6.1 be
performed prior to the commencement of clinical trials in the U.S.

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                                       25
<PAGE>

      6.3 Bukwang Remedies.

            (a) In the event Triangle fails to meet any diligence requirements
set forth in Subsection 6.2(a), and does not demonstrate to Bukwang's reasonable
satisfaction that, despite Triangle's *** , the failure to meet the diligence
requirement was delayed due to reasons beyond Triangle's reasonable control,
Bukwang shall have the option, as its sole and exclusive remedy, to terminate
the Agreement in the entire Territory. The remedy set forth in this Section 6.3
shall be Bukwang's sole and exclusive remedy.

            (b) Prior to exercising any rights under this Section 6.3, Bukwang
shall give Triangle thirty (30) days' notice and shall meet with Triangle, at
Triangle's request and expense, during such thirty (30) day period, to discuss
any disagreements about whether Triangle has complied with the applicable
diligence requirements of this Article 6. Upon expiration of such thirty (30)
day period, Bukwang shall have the right in its sole discretion to proceed with
the exercise of all rights and remedies provided for herein unless the
applicable diligence requirement is fulfilled during such thirty (30) day
period.

      6.4 Clinical Utility Diligence Obligation. Triangle acknowledges that
viral resistance may limit the clinical utility and commercial potential of the
Compounds. In the conduct of the Development Program, Triangle shall use its ***
to conduct preclinical and clinical studies of the Compounds in combination with
other anti-HBV drugs or drug candidates in order to determine *** . Triangle
shall conduct preclinical combination studies with at least *** and shall use
its *** to conduct clinical combination studies with as many other drugs or drug
candidates as it deems

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                                       26
<PAGE>

appropriate to determine the optimal combinations or sequence of combinations
necessary to provide maximum efficacy against HBV and enhance the clinical
utility and commercial potential of the Compounds. Such combination studies may
include *** and, because the outcome of such combination studies cannot be
predicted with certainty, these studies may include other drugs or drug
candidates being developed by Triangle or third parties which because of various
factors are ultimately determined not to be additive to, or synergistic with,
the Compounds.

                       ARTICLE 7. JOINT PROJECT COMMITTEE

      7.1 Appointment of Coordinators. As soon as practicable after the
Effective Date, Bukwang and Triangle shall each appoint an authorized
representative (a "Coordinator"). Each such party shall provide notice to the
other as to the identity of the individual so appointed. Each Coordinator shall
be responsible for communications, other than legal notices, between the parties
with respect to the subject matter of this Agreement. Each party may replace its
Coordinator at any time for any or no reason by providing written notice to the
other party.

      7.2 Joint Project Committee. The Coordinators shall establish the Joint
Project Committee consisting of representatives of Triangle and Bukwang. The
Joint Project Committee will consist of at least three (3) persons from each of
Triangle and Bukwang, such persons having significant responsibility for the
development and/or marketing of the Licensed Product. The Joint Project
Committee will meet from time to time at mutually agreeable times via
teleconference or in-person, but no less than semi-annually during the term of
the Agreement. The Coordinators shall set the agenda for each meeting, and each
Coordinator shall determine which regular members of Joint Project Committee and
other representatives of such Coordinator's party shall attend in light of the
agenda. Each party shall bear its own costs incurred in connection with

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                                       27
<PAGE>

participation in the Joint Project Committee.

      7.3 Objective of the Joint Project Committee. The primary objective of the
Joint Project Committee will be to facilitate the expeditious Registration of a
Licensed Product in the U.S. by Triangle and in Korea by Bukwang by, inter alia:

            (a) facilitating the exchange of data and study results between the
parties;

            (b) providing a forum for protocol and development plan review; and

            (c) coordinating the developmental efforts of the parties so as to
avoid duplication and inconsistency of such efforts.

      Each party agrees to give due consideration to any input received from the
other party at such Joint Project Committee meetings; provided, however, that
all final decisions relating to the development of Licensed Products in the
Territory will be made by Triangle and all final decisions relating to the
development of Licensed Products in Korea will be made by Bukwang; provided,
further, that Bukwang will give due consideration to input from Triangle as to
the design of clinical trial protocols from Phase I to Phase III in Korea and
will give Triangle's scientists access to the results of such clinical trials.

      7.4 Exchange of Study Results. Each party shall submit a report detailing
the results of each non-clinical and clinical study which it performs to the
other party within thirty (30) days after completion of the final statistical
analyses of the results of such study. In addition, each party will provide the
other party with *** progress reports summarizing its activities in respect of
the development of Licensed Products during the relevant semi-annual period.
Such reports shall cover the *** and shall be due on or before *** .

      7.5 Publications. Each party reserves the right to publish or publicly
present

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<PAGE>

the results of its own development activities in respect of the Licensed
Products (the "Results"). The party proposing to publish or publicly present the
Results (the "publishing party") will, however, submit a draft of any proposed
manuscript, abstract, speech, transparencies, presentation materials and press
releases to the other party (the "non-publishing party") for comments at least
fifteen (15) days prior to submission for publication or oral presentation,
except, in the case of press releases, where applicable law, in the reasonable
opinion of the publishing party, requires such press release to be issued within
time constraints which would make such review impractical. The non-publishing
party shall notify the publishing party in writing within fifteen (15) days of
receipt of such draft whether such draft contains Information (as hereinafter
defined) of the non-publishing party which it considers to be confidential under
the provisions of Article 13 hereof, or information that if published would have
an adverse effect on a patent application for which the non-publishing party has
initial patent prosecution responsibility pursuant to Article 8 of this
Agreement. In the latter case, the non-publishing party shall have the right to
request a delay and the publishing party shall delay such publication for a
period not exceeding sixty (60) days. In any such notification, the
non-publishing party shall indicate with specificity its suggestions regarding
the manner and degree to which the publishing party may disclose such
information. The publishing party shall have the final authority to determine
the scope and content of any publication, provided that such authority shall be
exercised with reasonable regard for the interests of the non-publishing party,
except that no publication will contain any Information disclosed by the
non-publishing party to the publishing party without the non-publishing party's
prior written permission. Each party shall cause its Affiliates, licensees or
sublicensees, as the case may be, to comply with the requirements of this
Section 7.5 with respect to any of their proposed publications.

                          ARTICLE 8. PATENT PROSECUTION


                                       29
<PAGE>

8.1 Title to Inventions. Each party shall have and retain sole title in
inventions, whether or not patentable, made by it or on its behalf (as by its
employees or agents) in the course of work performed under this Agreement. 

8.2 Bukwang Patents. (a) During the period ending *** after the Effective Date,
Bukwang shall, in consultation with Triangle, file, prosecute and maintain all
patent applications and patents included in the Bukwang Patents which Bukwang
owns, if any, at its sole expense. At the end of such *** period, Triangle shall
assume responsibility for filing, prosecution and maintenance of the Bukwang
Patents owned by Bukwang, if any, at Triangle's expense. Bukwang and its patent
counsel will cooperate fully with Triangle and its patent counsel to effect an
orderly transfer of such prosecution and maintenance responsibilities.

            (b) With respect to any Bukwang Patents licensed to it pursuant to
the Primary License Agreement in the Territory, Triangle shall have those rights
relating to the prosecution and maintenance of such Bukwang Patents as are set
forth in Article 7 of the Primary License Agreement.

            (c) Except as otherwise expressly set forth in the first sentence of
Subsection 8.2(a), Triangle agrees to reimburse the Primary Licensors or
Bukwang, as applicable, for all external fees, costs and expenses incurred by
them in filing, prosecuting and maintaining the Bukwang Patents in the
Territory. Invoices, including reasonable substantiation thereof, shall be
submitted once in respect of each fiscal quarter as promptly as practicable
after the end of such quarter. Payments shall be due net thirty (30) days from
the date of invoice. If Triangle fails to reimburse Bukwang or the Primary
Licensors, as applicable, for any undisputed patent prosecution expenses
respecting any patent application or issued patent included in the Bukwang
Patents within the time allowed therefor, upon at least thirty (30) days' prior
notice to Triangle, Bukwang or the Primary Licensors, as applicable, may remove
such patent application or issued patent

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<PAGE>

from the Bukwang Patents and Bukwang or the Primary Licensors shall be free, at
its or their election, to abandon or maintain the prosecution of such patent
application or issued patent or grant rights to such patent application or
issued patent to third parties.

            (d) Triangle reserves the right to terminate its obligations
pursuant to this Section 8.2 with respect to any patent application or patent
included in the Bukwang Patents in any country or countries upon at least ***
prior written notice to Bukwang and the Primary Licensors. After the date
specified in such notice on which Triangle's obligation to pay further expenses
terminates, such patent application or patent, as the case may be, shall no
longer be included in the Bukwang Patents in those countries in which Triangle
has exercised its rights to terminate such obligations.

      8.3 Triangle Inventions. Triangle shall, in consultation with Bukwang,
file such patent applications regarding any of the Triangle Patents owned or
controlled by Triangle, and thereafter shall diligently and in the exercise of
its discretion in a manner reasonably consistent with the goals and expectations
of the parties hereunder, giving due and reasonable consideration to Bukwang's
position, prosecute and maintain in force the resulting Triangle Patents, all at
Triangle's expense. Triangle shall enable Bukwang to directly contact and confer
with Triangle's patent counsel, at Bukwang's expense, with respect to the
prosecution of any patent applications constituting part of the Triangle Patents
and shall use its reasonable efforts to amend, correct or refile any patent or
patent application included in the Triangle Patents to include claims reasonably
requested by Bukwang. The territorial scope of such filings shall be the subject
of specific discussion between the parties. If for any reason Triangle declines
to file a patent application or, having filed, declines to prosecute or maintain
any of the Triangle Patents in any country, Bukwang may so file, prosecute or
maintain in Triangle's name and at Bukwang's expense in such country, in which
event, Triangle shall, at Bukwang's request and expense, provide all reasonable
assistance.

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      8.4 Joint Inventions. With respect to Joint Inventions: (a) all patent
applications and patents with respect thereto shall be jointly owned by Bukwang
and Triangle; (b) Triangle and its sublicensees and assignees shall be free to
use such patent applications and patents in the Territory and Bukwang and its
licensees and assignees shall be free to use such patent applications and
patents outside the Territory, in each event, without payment of royalty or
accounting therefor; (c) each party agrees to consult with the other party and
to give due and reasonable consideration to the other party's position in
determining the territorial scope of patent filings within the Territory (in the
case of Triangle) and outside the Territory (in the case of Bukwang), and the
prosecution and maintenance of resulting patent rights based on Joint
Inventions; and (d) Triangle shall have the sole right and discretion to file
any patent application and prosecute and maintain any resulting patent rights on
Joint Inventions, in which event, Bukwang shall, at Triangle's request, provide
all reasonable assistance and shall promptly reimburse Triangle with *** of the
out-of-pocket expenses so incurred by Triangle.

      8.5 Further Obligations.

            (a) Except as otherwise provided in Articles 9 and 18, each party's
responsibilities for patent prosecution activities pursuant to this Article 8
shall also include all ex parte and inter partes activities relating to the
relevant patent applications and patents, including all interference, opposition
and observation proceedings before any patent offices and litigation to
determine the validity, enforceability, allowability or subsistence of such
patent applications and patents. Each party agrees to give due consideration to
the other party's position with respect to any such patent prosecution
activities (which term, as used herein, shall include without limitation, any
inter partes activities of the type described in the first sentence of this
Subsection 8.5 (a)). In the event a party fails to initiate or pursue any patent
prosecution activities for which it is responsible, or having commenced such
patent prosecution activities, declines to pursue 

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                                       32
<PAGE>

such patent prosecution activities, the other party may initiate, pursue or
assume such patent prosecution activities, at its sole expense.

            (b) In conducting its patent prosecution activities under this
Agreement, each party may use patent attorneys selected by it in its own
discretion. In addition to the other obligations set forth in this Article 8,
each party undertakes to keep the other party throughout the term of this
Agreement regularly informed of the status and progress of the patent
prosecution activities it undertakes under this Agreement including, but not
limited to, supplying the other, upon reasonable request and at reasonable
intervals, with all correspondence with the United States, Japan and European
patent office counterparts with respect to the United States, Japan and European
patents and patent applications. To the extent that a party has not previously
done so, or promptly upon request by the other party in order to assist such
other party in connection with any of its activities or the exercise of any of
its rights pursuant to Articles 8 and 9, such party shall provide the other
party with such additional relevant documentation which such other party may
reasonably request relating to such patent applications and patents in the
Bukwang Patents, Triangle Patents or those relating to Joint Inventions, as
applicable, including but not limited to, copies thereof and access to
laboratory notebooks, other supporting data and relevant employees. If a party
decides to abandon or allow to lapse any patent application or patent or not to
initiate or any other patent prosecution activity for which it has patent
prosecution responsibility pursuant to this Article 8, it shall give the other
party notice thereof in a sufficiently timely manner so as to enable such other
party to determine whether to assume patent prosecution activity in connection
therewith. Each party shall use its *** to give such notice at least sixty (60)
days before any abandonment, lapse or any other relevant deadline.

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                                       33
<PAGE>

                             ARTICLE 9. INFRINGEMENT

            9.1 Third Party Infringement. If Triangle or Bukwang becomes aware
of any activity that it believes represents a substantial infringement of a
Valid Claim or patents relating to Joint Inventions, the party obtaining such
knowledge shall promptly advise the other of all relevant facts and
circumstances pertaining to the potential infringement.

            9.2 Triangle's Rights Against Third Party Infringers.

                  (a) Except to the extent otherwise provided in paragraph 8.1
of the Primary License Agreement in respect of those Bukwang Patents licensed to
Bukwang thereunder, Triangle shall have the first right to enforce or have
enforced, at no expense to Bukwang, any Bukwang Patents or patent rights
relating to Joint Inventions against infringement by third parties and shall be
entitled to retain recovery from such enforcement as prescribed by this
Subsection 9.2(a). Upon Triangle's undertaking to pay all expenditures
reasonably incurred by Bukwang, Bukwang shall reasonably cooperate in any such
enforcement and, as necessary, join as a party therein. After first deducting
its costs and expenses incurred in respect of enforcement (to the extent not
otherwise awarded by settlement or a court), Triangle shall pay royalties
(calculated per Section 3.3) on the balance of any monetary recovery. In the
event that Triangle does not file suit against or commence settlement
negotiations with a substantial infringer of the Bukwang Patents or patent
rights relating to Joint Inventions within six (6) months after receipt of a
written demand from Bukwang that Triangle bring suit, then the parties will
consult with one another in an effort to determine whether a reasonably prudent
licensee would institute litigation to enforce the patent in question in light
of all relevant business and economic factors (including, but not limited to,
the projected cost of such litigation, the likelihood of success on the merits,
the probable amount of any damage award, the prospects for satisfaction of any
judgment against the alleged infringer, the possibility of


                                       34
<PAGE>

counterclaims against Triangle and Bukwang, the diversion of Triangle's human
and economic resources, the impact of any possible adverse outcome on Triangle
and the effect any publicity might have on Triangle's and Bukwang's respective
reputations and goodwill). If the parties cannot agree, the determination will
be made by a mutually and reasonably acceptable third party consultant. If after
such process, it is determined that a suit should be filed and Triangle does not
file suit or commence settlement negotiations forthwith against the substantial
infringer, then Bukwang shall have the right to enforce any patent licensed
hereunder on behalf of itself and Triangle (with Bukwang retaining all
recoveries from such enforcement).

                  (b) In the event Triangle commences a suit pursuant to
Subsection 9.2(a), Triangle may deposit up to *** of any royalties and Milestone
Payments which are otherwise payable to Bukwang during the pendency of such suit
in an interest-bearing escrow account. Upon final resolution of such suit,
Triangle shall provide Bukwang with an accounting of the amounts escrowed and
Triangle's expenses incurred in such infringement suit. Triangle shall be
entitled to offset any expenses which Triangle fails to recoup in such suit
against the escrowed amounts. Any escrowed amounts (and interest thereon) in
excess of Triangle's unrecouped expenses shall be promptly paid to Bukwang and
the Primary Licensors pursuant to Section 5.1.

             ARTICLE 10. TRANSFER OF KNOW-HOW; TECHNICAL ASSISTANCE

      10.1 Transfer by Bukwang. Within *** following the Effective Date and as
far as it has not previously done so, Bukwang shall supply Triangle with all
Bukwang Know-How. With respect to any Bukwang Know-How developed by Bukwang
during the term of this Agreement, such disclosure will be made at least on a
quarterly basis or sooner, if practicable.

      10.2 Technical Assistance.

            (a) Bukwang shall, upon request by Triangle, provide Triangle with

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                                       35
<PAGE>

reasonable cooperation and assistance, consistent with the other provisions
hereof, in connection with the transfer of Bukwang Know-How. Such assistance may
include, but is not limited to, development of the formulations of the Licensed
Products; procurement of supplies and raw materials; initial developmental and
production batch manufacturing runs; process, specification and analytical
methodology design and improvement; and, in general, such other assistance as
may contribute to the efficient application by Triangle of the Bukwang Know-How.
In this regard, Bukwang agrees to make appropriate employees of Bukwang
reasonably available to assist Triangle, and Bukwang agrees to provide
reasonable numbers of appropriate Triangle personnel with access during normal
business hours to the appropriate personnel and operations of Bukwang for such
periods of time as may be reasonable in order to familiarize Triangle personnel
with the Bukwang Know-How as applied by Bukwang. At Triangle's reasonable
request, such assistance shall be furnished at Triangle's or its subcontractors'
or sublicensees' facilities in the Territory, subject to a mutually agreed upon
schedule. Such technical assistance shall include but not be limited to the
following:

            (i) Bukwang shall: (A) provide Triangle with access to any and all
Drug Master File(s) or counterparts thereof in any countries of the Territory
("DMF") of Bukwang relating to the manufacture of Bulk Drug Substance existing
as of the Effective Date; (B) provide Triangle with letters of authorization to
the FDA and other applicable government authorities in other countries of the
Territory to refer to Bukwang's DMF's; and (C) reasonably cooperate with
Triangle in obtaining access to and letters of authorization to refer to the
DMF's of Bukwang's subcontractors which are, or will be, supplying any Bulk Drug
Substance; and

            (ii) Within *** after the Effective Date, Bukwang shall provide
Triangle with copies of all documentation in Bukwang's possession, including all
correspondence between Bukwang and its subcontractors, regarding the manufacture
of 

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                                       36
<PAGE>

the Bulk Drug Substance which would be necessary or useful to assist Triangle in
the commercial production of Bulk Drug Substance or to support Registration of
the Licensed Products.

            (b) During the period prior to the *** anniversary of the Effective
Date, (i) Bukwang shall provide up to *** man-days of such technical assistance
during each year of such period at Bukwang's sole expense and (ii) subsequent to
such *** man-days of technical assistance, Bukwang shall provide such additional
technical assistance as may be reasonably requested by Triangle, provided, that
all reasonable out-of-pocket travel costs and expenses incurred by Bukwang in
rendering technical assistance pursuant to this Section 10.2 in excess of such
*** man-days per year shall be reimbursed to Bukwang by Triangle and, in
addition, Triangle will pay Bukwang a consultancy fee in an amount to be
negotiated by the parties hereto in good faith (but not to exceed the
consultancy fee, if any, then being charged by Bukwang to third parties) for
each consultancy day in excess of *** man-days spent by personnel of Bukwang in
rendering technical assistance to Triangle. Technical assistance furnished
pursuant to this Section 10.2 shall continue only until the *** anniversary of
the Effective Date of this Agreement.

            (c) In the event Bukwang supplies any Bulk Drug Substance to
Triangle, Triangle will reimburse Bukwang for its Manufacturing Cost or
Acquisition Cost therefor, subject, however, to reasonable substantiation
thereof.

            (d) Triangle shall be responsible for arranging for the synthesis of
adequate quantities of Licensed Products for all clinical, non-clinical and
commercial purposes in the Territory to fulfill its obligations hereunder.

      10.3 Transfer by Triangle. With respect to any Triangle Know-How developed
by Triangle during the term of this Agreement, Triangle shall supply Bukwang
with such Triangle Know-How on at least a quarterly basis or sooner, if
practicable.

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<PAGE>

      10.4 Language of Disclosures. All disclosures pursuant to this Agreement
will be in English.

            ARTICLE 11. WARRANTIES AND REPRESENTATIONS; LIMITATION OF
                           LIABILITY; AND DISCLAIMERS

      11.1 Warranties and Representations of Bukwang. Bukwang warrants and
represents the following as of the date hereof:

            (a) It possesses the necessary rights to enter into this License
Agreement;

            (b) Exhibit A is a true, complete and accurate copy of the Primary
License Agreement

            (c) Exhibit B is a complete list of all patents and patent
applications included in the Bukwang Patents as of the Effective Date;

            (d) it is not aware of any material facts which it has not disclosed
to Triangle regarding the manufacture, use or sale of any Licensed Product or
the practice of any inventions included in the Bukwang Patents or the use of the
Bukwang Know-How by Triangle (except, potentially, details regarding the Bukwang
Know-How to be provided under Article 10), including without limitation any
material facts regarding the possibility that such manufacture, use, sale or
practice might infringe any third party's know-how, patent rights or other
intellectual property in the Territory;

            (e) it is aware of no third party using or infringing all or any of
the Bukwang Patents in derogation of the rights granted pursuant to this
Agreement;

            (f) it is aware of no third party claim to any rights in the Bukwang
Patents or the Bukwang Know-How;

            (g) it is aware of no pending interference or opposition proceeding
or litigation or any communication which threatens an interference or opposition
proceeding or litigation before any patent and trademark office, court, or any
other governmental 


                                       38
<PAGE>

entity or court in any jurisdiction in regard to the Bukwang Patents; and

            (h) the Primary License Agreement is in full force and effect and
Bukwang will: (i) use its best efforts to fulfill all of its obligations under
the Primary License Agreement, including, but not limited to any due diligence
obligations outside the Territory set forth therein; (ii) take no action or fail
to take any action which will cause it to be in breach of any provision of the
Primary License Agreement; (iii) immediately notify Triangle in the event that
Bukwang receives written notice from the Primary Licensors (or their successors)
that Bukwang is in default under the Primary License Agreement or that the
Primary Licensors (or their successors) have terminated or intend to terminate
the Primary License Agreement; and (iv) not amend the Primary License Agreement
in a manner which adversely affects Triangle's rights and obligations hereunder.

      11.2 Warranties and Representations by Triangle. Triangle represents and
warrants that it has or will obtain, the skill and expertise in the technical
areas relating to the Bukwang Patents and Bukwang Know-How to make or have made
an evaluation of the capabilities, safety, utility and commercial application of
the Bukwang Patents and the Bukwang Know-How.

      11.3 Warranties and Representations of Each Party. Each party hereto
warrants and represents to: (a) the other that it is free to enter into this
Agreement (including the receipt of all corporate authorizations) and to carry
out all of the provisions hereof, including, its grant to the other of the
licenses described in Article 2; (b) to its knowledge, there is no failure to
comply with, no violation of or any default under, any law, permit or court
order applicable to it which might have a material adverse effect on its ability
to execute, deliver and perform this Agreement or on its ability to consummate
the transactions contemplated hereby; and (c) it shall comply with laws and
regulations relating to the performance of its obligations or the exercise of
its rights hereunder including, in the case of Triangle, those relating to the
manufacture, processing, 


                                       39
<PAGE>

producing, use, sale, or distribution of Licensed Products; and that it shall
not take any action which would cause it or the other party to violate such laws
and regulations.

      11.4 Disclaimer and Limitation of Warranties. Bukwang makes no warranty as
to validity of the Bukwang Patents licensed hereunder and, except as expressly
stated in Section 11.1, makes no representation whatsoever with regard to the
scope of the Bukwang Patents or Bukwang Know-How, or that the Bukwang Patents or
Bukwang Know-How may be exploited by Triangle or its Affiliates or sublicensees
without infringing intellectual property rights of third parties.

EXCEPT AS OTHERWISE SET FORTH IN SECTION 11.1 ABOVE, BUKWANG MAKES NO
REPRESENTATION OR WARRANTY OF ANY KIND WITH RESPECT TO THE BUKWANG PATENTS OR
BUKWANG KNOW-HOW AND EXPRESSLY DISCLAIMS ANY WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE AND ANY OTHER IMPLIED WARRANTIES WITH RESPECT
TO THE CAPABILITIES, SAFETY, UTILITY, OR COMMERCIAL APPLICATION OF BUKWANG
PATENTS OR BUKWANG KNOW-HOW.

      11.5 Limitation of Liability.

            (a) Neither Bukwang nor the Primary Licensors shall be liable to
Triangle or Triangle's Affiliates, sublicensees or any of its or their customers
for any special, incidental or consequential damages resulting from defects in
the testing, labeling, manufacture or other application of the Licensed Products
manufactured, tested or sold pursuant to this Agreement.

            (b) Any provision of this Agreement to the contrary notwithstanding,
Bukwang shall not be liable to Triangle, its Affiliates or sublicensees for any
damage that any party may suffer as a result of any third party actions for
patent infringement or for any other claims against Triangle, its Affiliates or
sublicensees in connection with their use of Bukwang Patents or Bukwang
Know-How; provided, however, that the foregoing


                                       40
<PAGE>

limitation shall in no way affect or otherwise limit any remedies which Triangle
or its Affiliates or sublicensees may have against Bukwang as a result of
Bukwang's breach of any of its warranties and representations set forth in
Article 11 hereof.

      11.6 Insurance. Without limiting Triangle's indemnity obligations under
Article 12, Triangle shall maintain throughout the term of this Agreement, and
shall use its *** to maintain for a reasonable period of time thereafter, a
commercial, general liability insurance policy, written by a reputable insurance
company authorized to do business in the United States, which:

            (a) insures Indemnitees for all claims, damages, and actions
mentioned in Section 12.1 of this Agreement;

            (b) includes a contractual endorsement providing coverage for all
liability arising out of bodily injury and property damage;

            (c) requires the insurance carrier to provide Bukwang with no less
than thirty (30) days' written notice of any change in the terms or coverage of
the policy or its cancellation; and

            (d) provides the Indemnitees with product liability coverage in an
amount no less than *** per occurrence for bodily injury and *** per occurrence
for property damage, subject to a reasonable aggregate amount. 

Triangle shall provide Bukwang with certificates of insurance evidencing the
above insurance coverage.

                           ARTICLE 12. INDEMNIFICATION

      12.1 Triangle's Indemnification. Subject to compliance by the Indemnitees
with the provisions set forth in Section 12.3, Triangle shall defend, indemnify,
and hold harmless the Indemnitees, from and against any and all claims, demands,
losses, liabilities, expenses, and damages including investigative costs, court
costs and

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                                       41
<PAGE>

reasonable attorneys' fees (collectively, the "Liabilities") which Indemnitees
may suffer, pay, or incur as a result of or in connection with: (a) any and all
personal injury (including death) and property damage caused or contributed to,
in whole or in part, by manufacture, testing, design, use, sale, or labeling of
any Licensed Products or the practice of the Bukwang Patents or Bukwang Know-How
by Triangle or Triangle's Affiliates or sublicensees, excluding any Liabilities
arising as a result of Bukwang's or, if applicable, its subcontractor's
negligence, intentional misconduct or breach of contract in supplying Bulk Drug
Substance (it being acknowledged by Triangle that neither Bukwang nor any
Bukwang subcontractor currently intends to supply any Bulk Drug Substance to
Triangle and in the event Triangle acquires any Bulk Drug Substance from *** ,
such acquisition will be pursuant to a direct contract); and (b) any breach by
Triangle of its representations, warranties and covenants contained in this
Agreement. Triangle's obligations under this Article shall survive the
expiration or termination of this Agreement for any reason.

      12.2 Bukwang's Indemnification. Subject to compliance by the Indemnitees
with the provisions set forth in Section 12.3, Bukwang shall indemnify and hold
the Indemnitees harmless from and against any and all Liabilities which
Indemnitees may suffer, pay or incur as a result of or in connection with: (a)
any breach by Bukwang of any of its representations, warranties and covenants
set forth in this Agreement; and (b) any claims or suits asserted or commenced
by the Primary Licensors regarding any royalty payments made by Triangle to
Bukwang pursuant to Subsection 5.1(b) of this Agreement. Bukwang's obligations
under this Article shall survive expiration or termination of this Agreement for
any reason.

      12.3 Indemnification Procedures. Any Indemnitee which intends to claim
indemnification under this Article shall, promptly after becoming aware thereof,
notify the party from whom it is seeking indemnification (the "Indemnitor") in
writing of any 

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<PAGE>

matter in respect of which the Indemnitee or any of its employees intend to
claim such indemnification. The Indemnitee shall permit, and shall cause its
employees to permit, the Indemnitor, at its discretion, to settle any such
matter and agrees to the complete control of such defense or settlement by the
Indemnitor; provided, however, that such settlement does not adversely affect
the Indemnitee's rights hereunder or impose any obligations on the Indemnitee in
addition to those set forth herein in order for it to exercise such rights. No
such matter shall be settled by such Indemnitee without the prior written
consent of the Indemnitor and neither the Indemnitor nor the Indemnitee shall be
responsible for any legal fees or other costs incurred other than as provided
herein. The Indemnitee and its employees shall cooperate fully with the
Indemnitor and its legal representatives in the investigation and defense of any
matter covered by the applicable indemnification. The Indemnitee shall have the
right, but not the obligation, to be represented by counsel of its own selection
and expense.

                           ARTICLE 13. CONFIDENTIALITY

      13.1 Treatment of Confidential Information. Except as otherwise provided
hereunder, during the term of this Agreement and for a period of *** thereafter:

            (a) Triangle and its Affiliates and sublicensees shall retain in
confidence and use only for purposes of this Agreement, any written information
and data supplied by or on behalf of Bukwang under this Agreement and the
Restricted Disclosure and Testing Agreement, dated October 27, 1997, between
Bukwang and Triangle (the "Confidentiality Agreement"); and

            (b) Bukwang shall retain in confidence and use only for purposes of
this Agreement any written information and data supplied by or on behalf of
Triangle to Bukwang under this Agreement.

      For purposes of this Agreement, all such information and data which a
party is 

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                                       43
<PAGE>

obligated to retain in confidence shall be called "Information."

      13.2 Right to Disclose. To the extent that it is reasonably necessary to
fulfill its obligations or exercise its rights under this Agreement, or any
rights which survive termination or expiration hereof, each party may disclose
Information to its Affiliates, sublicensees (actual or prospective),
consultants, outside contractors, actual or prospective investors, and clinical
investigators on condition that such entities or persons agree in writing:

            (a) to keep the Information confidential for a period of at least
*** from the date of disclosure by such party to the same extent as such party
is required to keep the Information confidential; and

            (b) to use the Information only for those purposes for which the
disclosing party is authorized to use the Information.

      Each party or its Affiliates or sublicensees, as applicable, may disclose
Information to the government or other regulatory authorities to the extent that
such disclosure (i) is necessary for the prosecution and enforcement of patents,
or authorizations to conduct preclinical or clinical trials to commercially
market Licensed Products, provided such party is then otherwise entitled to
engage in such activities in accordance with the provisions of this Agreement,
or (ii) is legally required.

      13.3 Release from Restrictions. The obligation not to disclose or use
Information shall not apply to any part of such Information that:

            (a) is or becomes patented (but the existence of a patent shall only
permit disclosure and not, unless otherwise provided hereunder, use), published
or otherwise part of the public domain, other than by unauthorized acts of the
party obligated not to disclose such Information (for purposes of this Article
13 the "receiving party") or its Affiliates or sublicensees in contravention of
this Agreement; or

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                                       44
<PAGE>

            (b) is disclosed to the receiving party or its Affiliates or
sublicensees by a third party provided that such Information was not obtained by
such third party directly or indirectly from the other party to this Agreement;
or

            (c) prior to disclosure under the Confidentiality Agreement or this
Agreement, as the case may be, was already in the possession of the receiving
party, its Affiliates or sublicensees, provided that such Information was not
obtained directly or indirectly from the other party to this Agreement; or

            (d) results from research and development by the receiving party or
its Affiliates or sublicensees, independent of disclosures from the other party
to this Agreement, provided that the persons developing such information have
not had exposure to the information received from the other party to this
Agreement; or

            (e) is required by law to be disclosed by the receiving party,
provided that in the case of disclosure in connection with any litigation, the
receiving party uses reasonable efforts to notify the other party immediately
upon learning of such requirement in order to give the other party reasonable
opportunity to oppose such requirement; or

            (f) Triangle and Bukwang agree in writing may be disclosed.

                        ARTICLE 14. CONDITIONS PRECEDENT

            This Agreement will not become effective until the Primary Licensors
and Bukwang shall have properly executed and delivered an Amendment to the
Primary License Agreement to Triangle in the form and substance attached hereto
as Exhibit C. In the event the condition set forth in this Article 14 has not
been satisfied within thirty (30) days from the date set forth at the beginning
of this Agreement, Triangle may terminate this Agreement by giving Bukwang ten
(10) days' prior notice.

                        ARTICLE 15. TERM AND TERMINATION

      15.1 Term. Unless sooner terminated as otherwise provided in this
Agreement,


                                       45
<PAGE>

the term of this Agreement shall commence on the Effective Date and shall
continue in full force and effect until the expiration of Triangle's obligations
to pay royalties hereunder.

      15.2 Termination by Default.

            (a) If either party defaults in the performance of, or fails to be
in compliance with, any material agreement, condition or covenant of this
Agreement, including, as to Triangle, the provisions of Section 16.2 hereof, the
non-defaulting party may terminate this Agreement with respect to the defaulting
party if such default or noncompliance shall not have been remedied, or, in the
event the default or non-compliance cannot be remedied within such period,
reasonable steps shall not have been initiated to remedy the same, within ***
after receipt by the defaulting party of a written notice thereof from the
non-defaulting party.

            (b) In the event that: (i) any proceeding is commenced by or against
a party seeking relief under any bankruptcy, insolvency or similar law and if
such proceeding is involuntary, it remains undismissed for *** ; or a party, by
action or answer, approves of, consents to or acquiesces in such proceeding or
admits the material allegations of or defaults in answering a petition filed in
such proceeding; or (ii) a receiver, liquidator, assignee, custodian or trustee
(or similar official) is appointed for a party in respect of any substantial
part of its assets or for purposes of the winding-up or liquidation of its
business and such appointment remains unstayed and in effect for a period of ***
; or (iii) a party makes an assignment for the benefit of creditors; then, in
any such event, such party shall be deemed in default for purposes of this
Section 15.2.

      15.3 Termination by Triangle. Triangle shall have the right to terminate
this Agreement in the entire Territory or one or more countries of the Territory
(without affecting this Agreement in the remaining countries of the Territory),
by giving Bukwang sixty (60) days' prior written notice thereof.

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<PAGE>

      15.4 Obligations Upon Termination. If this Agreement is terminated as a
result of Triangle's breach pursuant to Section 15.2, or is terminated in whole
or in part by Bukwang in accordance with Section 6.3 or by Triangle in
accordance with Section 15.3, then: (a) in the case of termination in the entire
Territory, Triangle shall use, and shall cause its Affiliates and sublicensees
to use, its and their *** to return, or at Bukwang's direction, destroy all
data, writings and other documents and tangible materials supplied to Triangle
by Bukwang properly organized and to provide Bukwang with reasonable transition
assistance, and upon Bukwang's request, Triangle shall sell any Licensed Product
in its possession to Bukwang at Triangle's Acquisition Cost or Manufacturing
Cost therefor, as applicable; and (b) with respect to those countries with
respect to which termination occurs, Triangle shall provide Bukwang with full
and complete copies of all toxicity, efficacy, and other data generated by
Triangle or Triangle's Affiliates, and sublicensees, in the course of Triangle's
efforts to develop Licensed Products or to obtain governmental approval for the
sale of Licensed Products, including but not limited to any regulatory filings
with any government agency in such countries. Bukwang shall be authorized to
cross-reference any such regulatory filings made by Triangle, its Affiliates and
sublicensees in the countries in which termination occurs where permitted by
law. Bukwang shall be entitled to provide information pertaining to the Triangle
Patents, Triangle Know-How and Joint Know-How to any third party with a bona
fide interest in licensing such technology in the countries in which termination
occurs. Such data shall be provided on a confidential basis; provided, however,
that if such third party concludes a license with Bukwang, such third party
shall be free to use such data for all purposes, including to obtain government
approvals to sell any product containing any Compound in such countries.

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<PAGE>

      15.5 Effect of Termination. In the event of any expiration or termination
pursuant to this Article 15, neither party shall have any remaining rights or
obligations under this Agreement other than as provided below:

            (a) Bukwang will have the right to receive all payments accrued
prior to the effective date of termination;

            (b) termination or expiration of this Agreement for any reason shall
have no effect on the parties' obligations under Articles 9, 12 and 13 or their
respective rights in Joint Know-How set forth in Section 1.18;

            (c) upon expiration of Triangle's royalty obligations under this
Agreement in a given country, Triangle shall have a perpetual, fully paid-up,
non-exclusive license to use the Bukwang Know-How in such country;

            (d) termination of this Agreement by Bukwang pursuant to Section 6.3
or 15.2 or by Triangle pursuant to Section 15.3, shall have no effect on the
rights and obligations of the parties under Section 15.4; and

            (e) the parties' shall retain any other remedies for breach of this
Agreement they may otherwise have.

      15.6 Default by Triangles' Affiliates and Sublicensees. For purposes of
this Article 15, any breach or default of the provisions of this Agreement by
Triangle's Affiliates or sublicensees shall be deemed to be breach of this
Agreement by Triangle, and Triangle shall be liable to Bukwang for such breach
or default to the same extent as if such breach or default had been made
directly by Triangle.

                             ARTICLE 16. ASSIGNMENT

      16.1 Assignment by Either Party. Neither party shall assign this Agreement
or any part thereof without the prior written consent of the other party, which
consent shall not be unreasonably withheld or delayed. Each party may, however,
without such consent, assign or sell its rights under this Agreement (a) in
connection with the sale or


                                       48
<PAGE>

transfer of all or substantially all of its pharmaceutical business to a third
party; (b) in the event of a merger or consolidation with a third party; or (c)
to an Affiliate. No assignment shall relieve any party of responsibility for the
performance of any accrued obligation which such party has under this Agreement.
Any assignment shall be contingent upon the assignee assuming in writing all of
the obligations of its assignor under this Agreement.

      16.2 ***. Subsequent to any assignment by Triangle pursuant Subsection
16.1(a) or (b) above, ***. Bukwang shall so inform Triangle in writing
specifying with reasonable particularity the basis for such determination. If
Triangle disagrees with Bukwang regarding Bukwang's determination, Triangle
shall so inform Bukwang in writing within thirty (30) days after receipt of such
written notice and this issue shall be determined pursuant to the provisions set
forth in Section 19.2. If the arbitrator(s) determine that *** . Triangle shall
have *** from the date it receives written notice of the arbitration result ***
that is not easily curable within such *** period, Triangle shall have an
additional reasonable period of time to effect such cure (which additional
period shall in no event exceed *** ). If Triangle does not send written notice
of Bukwang within such thirty (30) day period disagreeing with Bukwang's
position on the matter, Triangle shall have *** from the date of its receipt of
Bukwang's written notice *** that is not reasonably curable within such ***
period, Triangle shall have an additional reasonable period of time to effect
such cure (which

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                                       49
<PAGE>

additional period shall in no event exceed *** ).

                       ARTICLE 17. REGISTRATION OF LICENSE

Triangle, at its expense, may register the license granted under this Agreement
in any country of the Territory where the use, sale or manufacture of a Licensed
Product in such country would be covered by a Valid Claim. Upon request by
Triangle, Bukwang agrees promptly to execute any "short form" licenses submitted
to it by Triangle reasonably necessary in order to effect the foregoing
registration in such country.

           ARTICLE 18. NOTIFICATION AND AUTHORIZATION UNDER DRUG PRICE
                  COMPETITION AND PATENT TERM RESTORATION ACT

      18.1 Notices Relating to the Act. Bukwang shall use its best efforts to
cause the Primary Licensors to notify Triangle of (a) the issuance of each U.S.
patent included among the Bukwang Patents, giving the date of issue and patent
number for each such patent; and (b) each notice pertaining to any patent
included among the Bukwang Patents which the Primary Licensors receive as patent
owners pursuant to the Drug Price Competition and Patent Term Restoration Act of
1984 (hereinafter the "Act"), including but not necessarily limited to notices
pursuant to ss.ss.101 and 103 of the Act from persons who have filed an
abbreviated NDA ("ANDA") or a "paper" NDA. Such notices shall be given promptly,
but in any event within ten (10) days of notice of each such patent's date of
issue or receipt of each such notice pursuant to the Act, whichever is
applicable.

      18.2 Authorization Relating to Patent Term Extension. Bukwang hereby
authorizes Triangle and will use its best efforts to obtain the Primary
Licensors' authorization for Triangle (a) to include in any NDA for a Licensed
Product, as Triangle may deem appropriate under the Act, a list of patents
included among the Bukwang Patents that relate to such Licensed Product and such
other information as Triangle in its reasonable discretion believes is
appropriate to be filed pursuant to the Act; (b) to 

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                                       50
<PAGE>

commence suit for any infringement of the Bukwang Patents under ss. 271(e) (2)
of Title 35 of the United States Code occasioned by the submission by a third
party of an IND or a paper NDA for a Licensed Product pursuant to ss.ss.101 or
103 of the Act; and (c) in consultation with Bukwang and the Primary Licensors,
to exercise any rights that may be exercisable by Bukwang or the Primary
Licensors, as applicable, as patent owners under the Act to apply for an
extension of the term of any patent included among the Bukwang Patents. In the
event that applicable law in any other country of the Territory hereafter
provides for the extension of the term of any patent included among the Bukwang
Patents in such country, upon request by Triangle, Bukwang shall authorize
Triangle and shall use its best efforts to obtain the Primary Licensors'
authorization for Triangle or, if requested by Triangle, its sublicensees, to
apply for such extension, in consultation with Bukwang and the Primary
Licensors. Bukwang agrees to cooperate and shall use its best efforts to cause
the Primary Licensors to cooperate with Triangle or its sublicensees, as
applicable, in the exercise of the authorizations granted herein or which may be
granted pursuant to this Section 18.2 and will execute such documents and take
such additional action and use its best efforts to cause the Primary Licensors
to execute such documents and to take such additional actions as Triangle may
reasonably request in connection therewith, including, if necessary, permitting
itself and using its best efforts to permit the Primary Licensors to permit
themselves to be joined as proper parties in any suit for infringement brought
by Triangle under subsection (b) above. Triangle shall bear the costs and
expenses, including but not limited to attorneys' fees, of any suit for
infringement brought by Triangle under subsection (b) above.

                 ARTICLE 19. DISPUTE RESOLUTION AND ARBITRATION

      19.1 Initial Resolution. In the case of any disputes between the parties
arising from this Agreement, and in case this Agreement does not provide a
solution for how to resolve such disputes, the parties shall discuss and
negotiate in good faith a solution acceptable to both parties and in the spirit
of this Agreement. If after negotiating in good


                                       51
<PAGE>

faith pursuant to the foregoing sentence, the parties fail to reach agreement
within thirty (30) days, then the President of Bukwang and the Chief Executive
Officer or Chief Operating Officer of Triangle shall discuss in good faith an
appropriate resolution to the dispute. If these executives fail, after good
faith discussions not to exceed thirty (30) days, to reach an amicable agreement
then the parties shall submit to binding arbitration pursuant to Section 19.2
("Arbitration"). The date of submission of the matter to substrate shall be the
"Dispute Date".

      19.2 Arbitration. The following provisions shall govern any arbitration
pursuant to this Agreement.

            (a) Arbitration shall be conducted in accordance with the Rules of
the American Arbitration Association. In the event of any conflict between the
Rules and this Section, the provisions of this Section shall govern. The
Arbitration shall be conducted in ***.

            (b) The Arbitration shall be heard by a panel of three arbitrators
(each an "Arbitrator"). Triangle and Bukwang shall each select one Arbitrator.
Such Arbitrators shall be attorneys, licensed to practice law in the State of
Georgia, actively engaged in the full-time practice of law for a period of no
less than seven (7) years. Such Arbitrators shall not be affiliated, directly or
indirectly, with the parties or the attorneys representing the parties in the
Arbitration and shall not have any prior involvement in the matter. In the event
that either party fails within fifteen (15) days after the Dispute Date (i) to
select an Arbitrator who, to its knowledge, meets the requirements set forth in
this subsection (b) and (ii) to notify the other party of the selection, the
other party will then have the right to select such Arbitrator. The third
Arbitrator shall be selected by mutual agreement of the parties from a list of
neutral arbitrators compiled by the American Arbitration Association 

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                                       52
<PAGE>

for the parties. Such Arbitrator shall be an attorney, licensed to practice law
in the State of Georgia, actively engaged in the full time practice of law for a
period of no less than ten (10) years. The third Arbitrator shall not have any
prior or current relationship, direct or indirect, with any party to this
Agreement. If the parties to the Arbitration are unable to agree upon the third
Arbitrator within fifteen (15) days from the Dispute Date, the appointment of
the third Arbitrator shall be made as expeditiously as possible and in
compliance with this Section 19.2 by the two Arbitrators selected by the
parties. If those Arbitrators cannot agree on the third Arbitrator within ten
(10) days, then the third Arbitrator shall be designated by the American
Arbitration Association or the appropriate designated representative thereof
upon the written request of any party with simultaneous notice of such request
to the other party to the Arbitration. The third Arbitrator shall preside over
the panel of Arbitrators and the Arbitration.

            (c) The Arbitrators shall apply the substantive laws of the *** to
the validity, construction and interpretation of this Agreement as is applicable
to contracts made wholly performable within the state.

            (d) The Arbitration shall be resolved no later than sixty (60) days
from the date of acceptance by the third Arbitrator of his or her appointment
unless otherwise agreed to by the parties to the Arbitration.

            (e) Each party shall bear the expenses and costs of the Arbitrator
selected by the party. The third Arbitrator shall be compensated for services
rendered at the prevailing hourly rate of compensation and reimbursed for any
expenses incurred in

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                                       53
<PAGE>

connection with rendering such services. The non-prevailing party shall bear the
costs and expenses of compensation and reimbursement for the third Arbitrator.

            (f) The decision of the Arbitrators shall be rendered in writing and
shall be final and binding and may be enforced at the request of either party to
the Arbitration in the United States District Court for the Northern District of
Georgia or any court of the State Georgia having competent jurisdiction. Such
decision may not be appealed except upon a claim of bad faith or fraud by the
Arbitrators.

            (g) This Article 19 shall not apply to issues relating to the
validity, construction or effect of the Bukwang Patents. In the event that, in
any Arbitration, any issue arises concerning the validity, construction or
effect of any of the Bukwang Patents, the Arbitrators shall assume the validity
of all claims as set forth in such Bukwang Patents. Matters, controversies or
disputes concerning the Licensed Patents shall be resolved in any court having
jurisdiction thereof or in any other manner mutually agreed to by the parties.

                         ARTICLE 20. GENERAL PROVISIONS

      20.1 Export Controls. Bukwang acknowledges that Triangle is subject to
United States laws and regulations controlling the export of technical data,
biological materials, chemical compositions and other commodities and that
Triangle's obligations under this Agreement are contingent upon compliance with
applicable United States export laws and regulations. The transfer of technical
data, biological materials, chemical compositions and commodities may require a
license from the cognizant agency of the United States government or written
assurances by Bukwang that Bukwang shall not export data or commodities to
certain foreign countries without the prior approval of certain United States
agencies, or as otherwise prescribed by applicable law or regulation. 


                                       54
<PAGE>

Triangle neither represents that an export license shall not be required nor
that, if required, such export license shall issue.

      20.2 Independent Contractors. It is understood and agreed that the parties
hereto are independent contractors and are engaged in the operation of their own
respective businesses, and neither party hereto is to be considered the agent of
the other party for any purpose whatsoever, and neither party shall have any
authority to enter into any contracts or assume any obligations for the other
party nor make any warranties or representations on behalf of that other party.

      20.3 Patent Marking. Triangle shall mark Licensed Products sold in the
United States with United States patent numbers. Licensed Products manufactured
or sold in other countries shall be marked in compliance with the intellectual
property laws in force in such countries. The foregoing obligations shall be
subject to size and space limitations. If Bukwang believes that a Licensed
Product should be marked with the number of a Bukwang Patent, Bukwang shall
provide written notice to Triangle which identifies the patent number and the
Licensed Product on which it should appear. It shall also be Bukwang's
responsibility to inform Triangle in writing when marking with a Bukwang Patent
number should be discontinued. To the extent that Triangle complies with
Bukwang's instructions, Bukwang shall indemnify and hold Triangle harmless for
any liability, claim or action for false patent marking or non-marking.

      20.4 Publicity. The parties agree to issue mutual press releases
concerning their entry into this Agreement, with the content of such releases to
be approved (which consent shall not be unreasonably withheld or delayed) in
advance by the parties. In all other respects, except as required by law,
neither party shall use the name of the other party in any publicity release
without the prior written permission of such other party, which shall not be
unreasonably withheld. The other party shall have a reasonable opportunity to
review and comment on any such proposed publicity release. Except as required by
law, neither party shall publicly disclose the terms of this Agreement or issue


                                       55
<PAGE>

any publicity release with regard thereto unless expressly authorized to do so
by the other party which authorization shall be agreed upon.

      20.5 Governing Law. This Agreement and all amendments, modifications,
alterations, or supplements hereto, and the rights of the parties hereunder,
shall be construed under and governed by the laws of the *** , exclusive of its
conflicts of laws principles.

      20.6 Entire Agreement. This Agreement, together with the Exhibits attached
hereto, constitutes the entire agreement between Bukwang and Triangle with
respect to the subject matter hereof and shall not be modified, amended or
terminated, except as herein provided or except by another agreement in writing
executed by the parties hereto. Upon the Effective Date, the Confidentiality
Agreement shall terminate.

      20.7 Interpretation. Except (a) as otherwise provided in the Primary
License Agreement and (b) for any amendment to the Primary License Agreement to
the extent such amendment would adversely affect the rights and obligations of
Triangle hereunder (unless Triangle has given prior written consent thereto in
writing), in the event of any conflict between the terms hereof and the terms of
the Primary License Agreement, the terms of the Primary License Agreement shall
control.

      20.8 Waiver. No provision of this Agreement may be waived except by a
writing signed by the party entitled to the benefit thereof, and no such waiver
of any provision hereof in one instance shall constitute a waiver of any other
provision or of such provision in any other instance. No omission, delay or
failure on the part of any party hereto in exercising any rights hereunder will
constitute a waiver of such rights or of any other rights hereunder.

      20.9 Severability. All rights and restrictions contained herein may be
exercised and shall be applicable and binding only to the extent that they do
not violate any applicable laws and are intended to be limited to the extent
necessary so that they will not

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                                       56
<PAGE>

render this Agreement illegal, invalid or unenforceable. If any provision or
portion of any provision of this Agreement, not essential to the commercial
purpose of this Agreement, shall be held to be illegal, invalid or unenforceable
by a court of competent jurisdiction, it is the intention of the parties that
the remaining provisions or portions thereof shall constitute their agreement
with respect to the subject matter hereof, and all such remaining provisions, or
portions thereof, shall remain in full force and effect. To the extent legally
permissible, any illegal, invalid or unenforceable provision of this Agreement
shall be replaced by a valid provision which shall implement the commercial
purpose of the illegal, invalid, or unenforceable provision. In the event that
any provision essential to the commercial purpose of this Agreement is held to
be illegal, invalid or unenforceable and cannot be replaced by a valid provision
which will implement the commercial purpose of this Agreement, this Agreement
and the rights granted herein shall terminate.

      20.10 Force Majeure.

            (a) Any delays in, or failure of performance of, any party to this
Agreement, shall not constitute a default hereunder, or give rise to any claim
for damages, if and to the extent caused by occurrences beyond the control of
the party affected, including, but not limited to, acts of God, strikes or other
concerted acts of workmen, civil disturbances, fires, floods, explosions, riots,
war, rebellion, sabotage, acts of governmental authority or failure of
governmental authority to issue licenses or approvals which may be required
("Force Majeure").

            (b) The party asserting the Force Majeure shall promptly notify the
other party of the event constituting Force Majeure and of all relevant details
of the occurrence and where appropriate an estimate of how long such Force
Majeure event shall continue.

            (c) If such Force Majeure event continues thereafter and in any
event, the parties shall consult with each other in order to find a fair
solution and shall use all reasonable endeavors to minimize the consequences of
such Force Majeure.


                                       57
<PAGE>

      20.11 Counterparts. This Agreement may be executed in one or more
counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

      20.12 Notices. All notices, statements, and reports required to be given
under this Agreement shall be in writing and shall be deemed to have been given
upon delivery in person or, when deposited (a) in the mail in the country of
residence of the party giving the notice, registered or certified postage
prepaid or (b) with a professional courier service (e.g., FedEx or UPS), and
addressed as follows:

      To Bukwang:       Bukwang Pharm. IND. Co., Ltd
                        398-1 Daebang-Dong-Dongjak-Ku
                        Seoul 156-020
                        Korea
                        Attn: Sung-Koo Lee, Managing Director
                        Fax: 02-816-2792

      With a copy to:   Robert Finch, Esq.
                        Arnall, Golden & Gregory, LLP
                        2800 One Atlantic Center
                        1201 W. Peachtree St.
                        Atlanta, Georgia 30309  USA
                        Fax:  (404) 873-8617

      To Triangle:      Triangle Pharmaceuticals, Inc.
                        4 University Place, 4611 University Drive
                        Durham, NC 27707, U.S.A.
                        Attn: Chris A. Rallis, Vice President Business
                              Development, General Counsel
                        Fax:  (919) 493-5925

Any party hereto may change the address to which notices to such party are to be
sent by giving notice to the other party at the address and in the manner
provided above. Any notice may be given, in addition to the manner set forth
above, by telex, facsimile or cable, provided that the party giving such notice
obtains acknowledgment by telex, facsimile or cable that such notice has been
received by the party to be notified. Notices 


                                       58
<PAGE>

made in this manner shall be deemed to have been given when such acknowledgment
has been transmitted. Any provision of this Section 20.12 to the contrary
notwithstanding, any notice to Bukwang shall be effective if given as to Bukwang
prescribed above by Triangle, despite any failure to deliver copies as
prescribed above.


                                       59
<PAGE>

      IN WITNESS WHEREOF, Bukwang and Triangle have caused this Agreement to be
signed by their duly authorized representatives, under seal, as of the day and
year indicated above.

                              BUKWANG PHARM. IND. CO., LTD.


                              By: /s/ Illegible
                                 ------------------------------------

                              Title: 
                                     ----------------------------------

                              TRIANGLE PHARMACEUTICALS, INC.


                              By: /s/ David N. Barry
                                 ------------------------------------

                              Title:  Chairman & CEO
                                     ----------------------------------

                 [SIGNATURE PAGE FOR BUKWANG LICENSE AGREEMENT]
<PAGE>

                                    EXHIBIT A

                                LICENSE AGREEMENT

                                     between

                 UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC.

                              YALE UNIVERSITY, AND

                          BUKWANG PHARM. IND. CO., LTD.
<PAGE>

                                TABLE OF CONTENTS

                                                                          Page
                                                                          ----

      ARTICLE 1.  DEFINITIONS..............................................  2

      ARTICLE 2.  GRANT OF LICENSE.........................................  4

      ARTICLE 3.  DILIGENCE AND COMMERCIALIZATION..........................  6

      ARTICLE 4.  CONSIDERATION FOR LICENSE................................  7

      ARTICLE 5.  REPORTS AND PAYMENTS.....................................  9

      ARTICLE 6.  RECORDS.................................................. 11

      ARTICLE 7.  PATENT PROSECUTION....................................... 12

      ARTICLE 8.  ABATEMENT OF INFRINGEMENT................................ 14

      ARTICLE 9.  DISCLOSURE OF INFORMATION AND CONFIDENTIALITY............ 15

      ARTICLE 10. REPRESENTATIONS, MERCHANTABILITY AND EXCLUSION OF
                  WARRANTIES............................................... 17

      ARTICLE 11. DAMAGES, INDEMNIFICATION AND INSURANCE................... 18

      ARTICLE 12. TERM AND TERMINATION..................................... 20

      ARTICLE 13. ASSIGNMENT............................................... 23

      ARTICLE 14. MISCELLANEOUS............................................ 23

      ARTICLE 15. NOTICES.................................................. 26

      EXHIBIT A   LICENSED PATENTS......................................... 28

      EXHIBIT B   LICENSEE'S DEVELOPMENT PLAN.............................. 29
<PAGE>

      THIS LICENSE AGREEMENT is dated the 28th day of December, 1995, by and
among the UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC., a nonprofit Georgia
corporation with offices located in Boyd Graduate Studies Research Center, The
University of Georgia, Athena, Georgia 30602 (hereinafter "UGARF"), and YALE
UNIVERSITY (hereinafter "YALE"), located in New Haven, Connecticut, and BUKWANG
PHARM. IND. CO. LTD., a Korean corporation with headquarters located at 398-1
Daebang-Dong, Dongjak-ku, Seoul 156-020, Republic of Korea (hereinafter
"BUKWANG").

                                   WITNESSETH

      WHEREAS, Dr. Chung K. Chu, during the course of his employment at The
University of Georgia, and Dr. Yung-chi Cheng, during the course of his
employment at YALE, developed certain inventions as more fully defined herein;
and

      WHEREAS, UGARF is the assignee of all right, title, and interest in
inventions developed by employees of The University of Georgia and is
responsible for the protection and commercial development of such inventions;
and

      WHEREAS, UGARF and YALE want to have the inventions further developed and
made available for commercial use by the public; and

      WHEREAS, BUKWANG represents that it has the necessary expertise and
resources to fully develop and commercialize the inventions; and

      WHEREAS, UGARF and YALE wish to grant BUKWANG such a license in accordance
with the terms and conditions of this Agreement.
<PAGE>

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

                             ARTICLE 1. DEFINITIONS

      The following terms are as used herein shall have the following meaning:

      1.1 "Affiliates" shall mean any corporation, partnership or other business
entity which is directly or indirectly controlled by BUKWANG or any entity which
directly or indirectly controls BUKWANG. "Controls" as used herein means owns
directly or indirectly at least thirty percent (30%) of the voting shares.

      1.2 "Agreement" or "License Agreement" shall mean this Agreement,
including all Exhibits attached to this Agreement.

      1.3 "BUKWANG's Development Plan" shall mean the development plan
reproduced as EXHIBIT B of this Agreement.

      1.4 "Field of Use" shall mean the treatment of viral infections. 

      1.5 "Indemnitees" shall mean UGARF, UGARF's officers and directors, UGA,
UGA's employees, YALE, YALE's officers and directors, the Inventors, and their
heirs, executors, administrators, and legal representatives.

      1.6 "Inventors" shall mean Dr. Yung-chi Cheng and Dr. Chung K. Chu.

      1.7 "License Agreement Year" shall mean and include each twelve-month
period, beginning with the Operative Date, during the term of this Agreement.

      1.8 "Licensed Patents" shall mean the patent applications and patents
identified in EXHIBIT A hereof, together with all divisionals, continuations,
reissues, reexaminations and foreign counterparts of such applications or
patents.


                                       2
<PAGE>

      1.9 "Licensed Product(s)" shall mean any process, service, or product, the
manufacture, use, or sale of which is covered by a Valid Claim or incorporates
or uses any Licensed Technology.

      1.10 "Licensed Technology" shall mean all designs, technical information,
know-how, knowledge, data, specifications, test results and other information,
whether or not patented, which are known to the Inventors, except such
technology already existing in the public domain or such technology already
known to BUKWANG, on the date of this Agreement, and which are useful for the
development, commercialization, manufacture, use or sale of any Licensed
Product.

      1.11 "Licensed Territory" shall mean the world.

      1.12 "LICENSOR" shall mean UGARF and YALE, jointly.

      1.13 "Net Selling Price" of Licensed Products shall mean the total
invoiced price paid to BUKWANG or its Affiliates by a purchaser of a Licensed
Product less the following discounts: a) customary trade, quantity and cash
discounts actually allowed and taken; b) credits actually given for rejected or
returned Licensed Products; c) freight and insurance costs, if separately
itemized on the invoice paid by the customer; and d) excise taxes and customs
duties included in the invoiced amount. Where a Sale is deemed consummated by a
gift, use, or other disposition of Licensed Products for other than a selling
price stated in cash, the term "Net Selling Price" shall mean the average gross
selling price billed by BUKWANG for the same quantity of Sales of Licensed
Products during the three (3) month period immediately preceding such Sale,
without reduction of any kind.

      1.14 "Operative Date" of this Agreement shall mean the date on which
LICENSOR receives notification from the United States Government of its approval
of the grant of rights made to BUKWANG hereunder.

      1.15 "Sale" or "Sold" shall mean the sale, transfer, exchange or other
disposition of Licensed 


                                       3
<PAGE>

Products whether by gift or otherwise, by BUKWANG, its Affiliates or any other
person authorized by


                                       4
<PAGE>

BUKWANG. For the purposes of this Agreement, the following activities shall not
be deemed as Sale: (a) the provision of Licensed Products, prior to the approval
of Licensed Products in a country and pursuant to a requirement issued by the
appropriate governmental agency in that country, for consumption by or
administration to persons for humanitarian purposes or compassionate use, (b)
the provision of Licensed Products for use in clinical trials, or (c) the
provision of samples of Licensed Products without charge by BUKWANG for
promotional purposes. Sales of Licensed Products shall be deemed consummated
upon the first to occur of: (a) receipt of payment from the purchaser; (b)
delivery of Licensed Products to the purchaser or a common carrier; (c) release
of Licensed Products from consignment; (d) if deemed Sold by use, when first put
to such use; or (e) if otherwise transferred, exchanged, or disposed of whether
by gift or otherwise when such transfer, exchange, gift, or other disposition
occurs.

      1.16 "UGA" shall mean The University of Georgia.

      1.17 "Valid Claim" shall mean a claim included among the Licensed Patents
so long as such claim shall not have been irrevocably abandoned or held invalid
in an unappealable decision of a court or other authority of competent
jurisdiction.

                           ARTICLE 2. GRANT OF LICENSE

      2.1 License. LICENSOR hereby grants BUKWANG an exclusive right and license
under the Licensed Patents to make, have made, use, and Sell Licensed Products
and to practice Licensed Technology for the Field of Use in the Licensed
Territory during the term of this Agreement.

      2.2 Retained License. LICENSOR retains on behalf of UGARF, YALE and UGA
and any research collaborators, a royalty-free right and license to make and use
Licensed Products and to practice Licensed Technology for research and
educational purposes only.


                                       5
<PAGE>

      2.3 No Implied License. The license and right granted in this Agreement
shall not be construed to confer any rights upon BUKWANG by implication,
estoppel, or otherwise as to any technology not specifically identified in this
Agreement as Licensed Patents or Licensed Technology.

      2.4 United States Government Rights. The Licensed Patents, Licensed
Technology, or portions thereof were developed with financial or other
assistance through grants or contracts funded by the United States government.
BUKWANG acknowledges that in accordance with Public Law 96-517 and other
statutes, regulations, and Executive Orders as now exist or may be amended or
enacted, the United States government has certain rights in the Licensed Patents
and Licensed Technology. BUKWANG shall take all reasonable actions necessary to
enable LICENSOR to satisfy its obligations under any federal law relating to the
Licensed Patents or Licensed Technology. BUKWANG acknowledges that LICENSOR must
obtain a waiver from the United States government, pursuant to United States
Code of Federal Regulations, Section 37.401.14(i), to enable LICENSOR to grant
the rights and license hereunder. LICENSOR has requested such a waiver, but if
this Agreement is executed prior to the granting of said waiver, BUKWANG agrees
that this Agreement will automatically terminate if the request for waiver is
denied. LICENSOR shall notify BUKWANG within ten (10) days of receipt of notice
of denial of said waiver from the United States government. If at any time
during the term of this Agreement, the United States government should take
action which renders it impossible or impractical for LICENSOR to grant the
rights and license granted herein to BUKWANG under this Agreement or otherwise
perform LICENSOR's obligations, LICENSOR or BUKWANG may terminate this Agreement
immediately by notice to the other party. BUKWANG shall not have any right to
the return of any payments of any kind made by it to LICENSOR prior to the date
of termination.

      2.5 Republic of Korea Government Approval. It will be necessary for the
Fair Trade 


                                       6
<PAGE>

Committee in Economic Planning Ministry of the Republic of Korea to approve this
Agreement. If this Agreement is executed prior to the granting of such approval,
LICENSOR agrees that this Agreement shall 


                                       7
<PAGE>

automatically terminate if approval is denied. BUKWANG shall not have any right
to the return of any payments of any kind made by it to LICENSOR prior to the
date of termination.

                   ARTICLE 3. DILIGENCE AND COMMERCIALIZATION

      3.1 Diligence and Commercialization. BUKWANG shall use its *** throughout
the term of this Agreement to diligently pursue BUKWANG's Development Plan and
to bring Licensed Products to market through a thorough, rigorous, and diligent
program for exploitation of the rights and license herein granted to BUKWANG and
to create, supply, and service in the Licensed Territory as extensive a market
as possible. In no instance shall BUKWANG's *** be less than efforts customary
in the pharmaceutical industry.

      3.2 Lack of Diligence. If LICENSOR concludes that BUKWANG is not diligent
in developing and Selling Licensed Products pursuant to paragraph 3.1 for any
reason other than a) the withholding by a regulatory agency of marketing
approval despite BUKWANG's diligent effort to obtain such approval; or b)
unanticipated technical or scientific problems which have been reported to
LICENSOR in writing; or c) other causes beyond the reasonable control of
BUKWANG; then LICENSOR may, at its sole discretion, terminate this Agreement
pursuant to paragraph 12.4 hereof.

      3.3 No Competing Products. BUKWANG agrees that it will not concurrently
develop a compound or composition with the same mode or mechanism of action as
compound(s) or composition(s) covered by the Licensed Patents. BUKWANG shall
provide, on a semi-annual basis, a certified statement from a corporate officer
of BUKWANG that BUKWANG is not concurrently developing a competing compound or
composition with the same mode or mechanism of action as compound(s) or
composition(s) covered by the Licensed Patents. In the event that BUKWANG
undertakes the concurrent development


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    Confidential Treatment and filed separately with the Commission.


                                       8
<PAGE>

of such a competing product or does not provide certification as stipulated in
this paragraph, LICENSOR shall have the right, at its sole discretion, to
terminate this Agreement upon thirty (30) days written notice to BUKWANG.

                      ARTICLE 4. CONSIDERATION FOR LICENSE

      4.1 Research Gift. As partial consideration for the license granted to
BUKWANG under this Agreement, BUKWANG shall provide nonrefundable research
funding to UGARF and YALE according to the following schedule:

            ***

      Such payments shall be made on a quarterly basis on each of the first
(1st), ninetieth (90th), one-hundred eightieth (180th), and two-hundred
seventieth (270th) days of the indicated License Agreement Year. In the event
that this Agreement is terminated for any reason during one of the first ***
License

***   Portions of this page have been omitted pursuant to a request for
      Confidential Treatment and filed separately with the Commission. 


                                       9
<PAGE>

Agreement Years, BUKWANG agrees to make all four quarterly payments due under
this paragraph for the License Agreement Year in which this Agreement is
terminated.

      4.2 Milestone Payments. As partial consideration for the license granted
to BUKWANG under this Agreement, BUKWANG shall pay LICENSOR nonrefundable
milestone payments according to the following schedule:

            Milestone:                                Payment:

                                      ***

*** of the milestone payments shall be credited against royalties actually due
and payable under Article 4.3; provided, however, that in any single License
Agreement Year, such credit shall not exceed *** of the royalties otherwise due.

      4.3 Royalties. As partial consideration for the license granted to BUKWANG
under this Agreement, BUKWANG shall pay LICENSOR a royalty equal to *** of the
Net Selling Price of all Licensed Products Sold by BUKWANG or its Affiliates
during the term of this Agreement.

      4.4 Reimbursement for Patent Expenses. BUKWANG shall reimburse LICENSOR
for all external fees, costs and expenses heretofore and hereafter during the
term of this Agreement paid or incurred by LICENSOR in filing, prosecuting, and
maintaining the Licensed Patents in the Licensed Territory.

                         ARTICLE 5. REPORTS AND PAYMENTS

      5.1 Payments. All royalty payments required under this Agreement pursuant
to Article 4. 3 shall be due *** days following the end of a quarter, for Sales
occurring during the immediately preceding

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                                       10
<PAGE>

quarter of each License Agreement Year. Such royalties shall be accompanied by a
royalty report, as detailed in paragraph 5.3. All other payments required under
this Agreement are payable on the due date, or, for payments due under Article
4.4, such reimbursement shall be delivered within thirty (30) days after receipt
by BUKWANG from time to time of an invoice from UGARF, including all supportive
documentation of such fees and costs.

      (a)   Payments due under Articles 4.2 and 4.3 shall be made in person, via
            the United States mail, or by private carrier to the following
            addresses:

            ***, made payable to:

                                 University of Georgia Research Foundation, Inc.
                                 Attention:  Patsy Songer
                                 Boyd Graduate Studies Research Center
                                 Athena, Georgia, U.S.A. 30602-7411
                                 Facsimile: (706) 542-5638

            ***, made payable to:

                                 Yale University
                                 Attention: Office of Cooperative Research
                                 246 Church Street, Suite 401
                                 New Haven, Connecticut, U.S.A. 06510
                                 Facsimile: (203) 432-7245

      (b)   Payments due under Article 4.4 shall be made payable to UGARF and
            sent to the address given in 5.1(a) for UGARF

      5.2 Progress Reports. BUKWANG will provide UGARF with semi-annual reports
detailing the activities of BUKWANG described in BUKWANG's Development Plan.
Such reports shall be due on July 1 and January 1 of each License Agreement
Year, beginning with July 1, 1996, for the immediately preceding half-year.

      5.3 Royalty Reports. Within sixty (60) days of the first (1st), ninetieth
(90th), one-hundred eightieth (180th), and two-hundred seventieth (270th) days
of each License Agreement Year, beginning

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                                       11
<PAGE>

with the License Agreement Year in which the first approval for marketing
Licensed Products in any country of the Licensed Territory is granted, and
ending with the year following the termination of expiration of this Agreement,
BUKWANG shall provide a written report to LICENSOR setting forth for the
preceding calendar quarter, the following as may be applicable:

      (a)   all Sales (including Net Selling Price of each product sold) of
            Licensed Products by BUKWANG and its Affiliates on a
            country-by-country basis throughout the Licensed Territory;

      (b)   the amount of royalties payable pursuant to this Agreement;

      (c)   any other information reasonably necessary to show the basis on
            which such royalties have been computed;

      (d)   the amount of any credits taken pursuant to Article 4.2; 

      (e)   in case no payment is due, BUKWANG shall so report.

      5.4 Currency Conversion. If any Licensed Products are Sold for monies
other than United States dollars, the Net Selling Price of such Licensed
Products shall first be determined in the foreign currency of the country in
which such Licensed Products are Sold and then converted to United States
dollars at the spot rate published by the Wall Street Journal (U.S. edition) for
conversion of that foreign currency into United States dollars on the last day
of the quarter for which such payment is due.

      5.5 Interest. Payments required under this Agreement shall, if overdue,
bear interest until payment at a per annum rate *** above the prime rate in
effect at the *** in ***, on the due date. The payment of such interest shall
not foreclose LICENSOR from exercising any other rights it may have because any
payment is late.

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    Confidential Treatment and filed separately with the Commission.


                                       12
<PAGE>

                               ARTICLE 6. RECORDS

      6.1 Records of Sales. During the term of this Agreement and for a period
of *** thereafter, BUKWANG shall keep at its principal place of business true
and accurate records of all Sales in accordance with generally accepted
accounting principals and in such form and manner so that all royalties owed to
LICENSOR may be readily and accurately determined. BUKWANG shall furnish
LICENSOR copies of such records upon LICENSOR's request, which shall not be made
more often than once per License Agreement Year.

      6.2 Audit of Records. LICENSOR shall have the right, from time to time at
reasonable times during normal business hours through an independent certified
public accountant, to examine the records of BUKWANG maintained in accordance
with the provisions of paragraph 6.1 in order to verify the calculation of any
royalties payable under this Agreement. Such examination and verification shall
not occur more than once each License Agreement Year and the calendar year
immediately following termination of this Agreement. Unless otherwise agreed in
writing by BUKWANG, the fees and expenses of performing such examination and
verification shall be borne by LICENSOR. If such examination reveals an
underpayment by BUKWANG of more than *** for any quarter examined, BUKWANG shall
pay LICENSOR the amount of such underpayment plus interest and shall reimburse
LICENSOR for all expenses of the accountant performing the examination.

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    Confidential Treatment and filed separately with the Commission.


                                       13
<PAGE>

                          ARTICLE 7. PATENT PROSECUTION

      7.1 Prosecution and Maintenance of Licensed Patents. The prosecution and
maintenance of the Licensed Patents shall be the primary responsibility of
LICENSOR. LICENSOR shall keep BUKWANG informed as to all developments with
respect to Licensed Patents. BUKWANG shall be afforded reasonable opportunities
to advise LICENSOR and cooperate with LICENSOR in such prosecution and
maintenance. On or before March 1, 1996, BUKWANG shall notify LICENSOR of the
countries in which BUKWANG wishes the International Patent Cooperation Treaty
Application No. US94/06080, filed May 27, 1994 to be filed. LICENSOR may, at its
own expense, file patent applications in those countries in which BUKWANG elects
not to file national applications. Such non-elected countries in which LICENSOR
has filed a patent application will no longer be included in the Licensed
Territory and BUKWANG shall not have the right to Sell Licensed Products in
non-elected countries. Prior to the execution of any third party licenses in
such non-elected countries, LICENSOR shall offer BUKWANG a right of first
refusal, which, if it is to be exercised, shall be exercised within thirty (30)
days of BUKWANG's receipt in writing from LICENSOR of a written proposal
outlining the terms of a third party license. If BUKWANG elects to exercise its
right of first refusal, then LICENSOR and BUKWANG shall execute a license on the
same terms and conditions as those referred to in the third party license. If
BUKWANG elects not to exercise its right of first refusal or fails to exercise
its right of first refusal before the expiration of the aforesaid thirty (30)
day period, then LICENSOR shall be free to execute the third party license.

      If BUKWANG should fail to timely make reimbursement for patent expenses
incurred in filing, prosecuting or maintaining applications or patents in a
particular country(ies) as required by Article 4.4 of this Agreement, LICENSOR
shall have no further obligation to prosecute or maintain the Licensed Patents
in said country(ies).

      BUKWANG, upon ninety (90) days advance written notice to LICENSOR, may
advise LICENSOR that it no longer wishes to pay expenses for filing, prosecuting
or maintaining one or more Licensed Patents. LICENSOR may, at its option, elect
to pay such expenses or permit such Licensed Patents to become abandoned or
lapsed. If LICENSOR elects to pay such expenses, such patents shall not be
subject to any license granted to BUKWANG hereunder.


                                       14
<PAGE>

      7.2 Extension of Licensed Patents. In the event that it is possible to
have the normal term of any Licensed Patent extended or restored under a
country's procedure of extending patent terms for time lost in government
regulatory approval processes, BUKWANG agrees to cooperate full with LICENSOR
and provide all necessary documentation and information needed to enable
LICENSOR to timely apply for such extension(s). All out-of-pocket expenses
incurred by LICENSOR in applying for such extension(s) shall be borne in
accordance with the terms of Article 4.4. In the case of such extension(s),
royalties due LICENSOR pursuant to Article 4.3 hereof shall be payable until the
end of the extended term of the Licensed Patent.

                      ARTICLE 8. ABATEMENT OF INFRINGEMENT

      8.1 BUKWANG shall promptly inform LICENSOR of any suspected infringement
of any Licensed Patents. During the term of this Agreement, LICENSOR and BUKWANG
shall have the right to institute an action for infringement of the Licensed
Patents against such third party in accordance with the following:

      (a)   If LICENSOR and BUKWANG agree to institute suit jointly, the suit
            shall be brought in both their names and out-of-pocket costs thereof
            shall be borne equally. Any recovery or settlement received by
            LICENSOR and/or BUKWANG for punitive or exemplary damages shall be
            shared equally, and any other recovery or settlement received,
            including compensatory damages or damages based on a loss of
            revenues, shall be paid to BUKWANG, and BUKWANG shall pay to
            LICENSOR an amount representing the royalty which would have been
            paid by BUKWANG on such amount in accordance with the provisions of
            Article 4 had such amount been accrued by BUKWANG as Sales. BUKWANG
            and LICENSOR shall agree upon the manner in which they shall
            exercise control over such action. LICENSOR may, if it so desires,
            also be represented by


                                       15
<PAGE>

            separate counsel of its own selection, the fees for which counsel
            shall be paid by LICENSOR;

      (b)   In the absence of agreement to institute a suit jointly, LICENSOR
            may institute a suit, and, at its option, name BUKWANG as a
            plaintiff. LICENSOR shall bear the entire cost of such litigation,
            including defending any counterclaims brought against BUKWANG and
            paying any judgments rendered against BUKWANG, and shall be entitled
            to retain the entire amount of any recovery or settlement; and

      (c)   In the absence of agreement to institute a suit jointly and if
            LICENSOR notifies BUKWANG that it has decided not to join in or
            institute a suit as provided in (a) or (b) above, BUKWANG may
            institute suit and, at its option, name LICENSOR as a plaintiff.
            BUKWANG shall bear the entire cost of such litigation, including
            defending any counterclaims brought against LICENSOR and paying any
            judgment rendered against LICENSOR, and shall be entitled to retain
            the entire amount of any recovery or settlement.

      8.2 Should either LICENSOR or BUKWANG commence suit under the provisions
of this Article and thereafter elect to abandon such suit, the abandoning party
shall give timely notice to the other party who may, if it so desires, continue
prosecution of such suit, provided that the sharing of expenses and any recovery
in such suit shall be as agreed upon between LICENSOR and BUKWANG.

            ARTICLE 9. DISCLOSURE OF INFORMATION AND CONFIDENTIALITY

      9.1 It will be necessary for LICENSOR to disclose to BUKWANG and for
BUKWANG to disclose to LICENSOR such information and technology as will assist
the parties to successfully carry out the objectives of this Agreement. BUKWANG
will need to disclose to LICENSOR such information and technology relating to
the filing of any patents related to Licensed Products and such other
information


                                       16
<PAGE>

as may be requested by LICENSOR which is necessary for LICENSOR to ascertain to
BUKWANG is performing its obligations pursuant to this Agreement. All such
information and technology to be exchanged will be in writing and marked
"CONFIDENTIAL". BUKWANG or LICENSOR, as the case may be, shall not, during the
life of this Agreement and for a period of *** after the termination or
expiration of this Agreement, disclose to any third party the other's
technology, except to an Affiliate under appropriate written confidentiality
provisions who requires such information to carry out the objectives of this
Agreement; shall use the same degree of care as is exercised with respect to its
own confidential information to prevent disclose of the same to any third party;
and shall not use the same for any purpose other than exercising any right or
rights granted to it herein; provided, however, that nothing herein contained
shall restrict either party with respect to the disclosure or use of information
which the recipient party can show:

      (a)   was in its possession at the time of its receipt of same from the
            disclosing party; or

      (b)   was part of the public knowledge or literature at the time of its
            receipt from the disclosing party, or thereafter becomes part of the
            public knowledge or literature through no fault of either party,
            their Affiliates, employees representatives or any third party to
            whom such information was disclosed in accordance with the
            provisions of this Agreement; or

      (c) was received form a third party having the right to disclose such
information. Specific technology was disclosed by one party to the other
hereunder shall not be deemed to be within any of the above three (3) exclusions
merely because it is embraced by more general information included within one of
the exclusions.

      9.2 Notwithstanding the provisions of paragraph 9.1 above, and to the
extent necessary; 

      (a)   a party may disclose and use the other party's information for
purposes of securing the registration of, and or governmental approval to
market, pursuant to this Agreement, any Licensed Products;

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    Confidential Treatment and filed separately with the Commission.


                                       17
<PAGE>

      (b)   a party may disclose and use the other party's information where the
            disclosure and use of such will be necessary to the procurement of
            patent protection, pursuant to this Agreement, for a Licensed
            Product;

      (c)   a party may disclose and use the other party's information to the
            extent that it is necessary to aid in the development and
            commercialization, pursuant to this Agreement, of any Licensed
            Product provided that any such disclosure of the disclosing party's
            information shall be in confidence and subject to provisions the
            same, or substantially the same, as those in paragraph 9.1 hereof.

If this Agreement is terminated for any reason whatsoever, LICENSOR shall have
the unrestricted right to use and disclose information generated by LICENSOR or
BUKWANG pertaining to methods of synthesis, pharmacokinetics, toxicology,
efficacy, clinical and other technical data related to Licensed Products. Such
use and disclosure shall not be subject to the confidentiality provisions of
paragraph 9.1 that survive termination of this Agreement.

      9.3 Prior Agreements. The provisions of this Agreement supersede and shall
be substituted for any terms of any prior confidentiality agreements between
BUKWANG and LICENSOR which are not consistent with this Agreement.

                  ARTICLE 10. REPRESENTATIONS, MERCHANTABILITY
                           AND EXCLUSION OF WARRANTIES

      10.1 LICENSOR represents and warrants that it has the right and authority
to enter into this Agreement and that neither the execution of this Agreement
nor the performance of its obligations hereunder will constitute a breach of the
terms and provisions of any other agreement to which UGARF or YALE is a party.
LICENSOR does not warrant the validity of the Licensed Patents licensed
hereunder and makes no representation whatsoever with regard to the scope of the
Licensed


                                       18
<PAGE>

Patents or that such Licensed Patents may be exploited by BUKWANG or its
Affiliates without infringing other patents.

      10.2 BUKWANG has the necessary expertise and skill in the technical areas
in which the Licensed Products and Licensed Technology are involved to make, and
has made, its own evaluation of the capabilities, safety, utility, and
commercial application of the Licensed Patents and Licensed Technology.
ACCORDINGLY, LICENSOR MAKES NO REPRESENTATION OR WARRANTY OF ANY KIND WITH
RESPECT TO THE LICENSED PATENTS OR LICENSED TECHNOLOGY AND EXPRESSLY DISCLAIMS
ANY WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE AND ANY
OTHER IMPLIED WARRANTIES WITH RESPECT TO THE CAPABILITIES, SAFETY, UTILITY, OR
COMMERCIAL APPLICATION OF LICENSED PATENTS OR LICENSED TECHNOLOGY.

               ARTICLE 11. DAMAGES, INDEMNIFICATION AND INSURANCE

      11.1 NO LIABILITY. LICENSOR shall not be liable to BUKWANG or BUKWANG's
customers for special, incidental, indirect or consequential damages resulting
from defects in the testing, labeling, manufacture, or other application of
Licensed Products manufactured, tested or Sold pursuant to this Agreement.

      11.2 Indemnification. BUKWANG shall defend, indemnify, and hold harmless
the Indemnitees from and against any and all claims, demands, loss, liability,
expense, or damage (including investigative costs, court costs and attorneys'
fees) Indemnitees may suffer, pay or incur as a result of claims, demands or
actions against any of the Indemnitees arising or alleged to arise by reason of
or in connection with any and all personal injury and property damage caused or
contributed to in whole or in part by BUKWANG's manufacture, testing, use, sale,
or labeling of any Licensed Products, or the practice by BUKWANG of any Licensed
Patents. BUKWANG's obligations under


                                       19
<PAGE>

this Article shall survive the expiration or termination of this Agreement for
any reason. 

            11.3 Insurance. Without limiting LICENSEE's indemnity obligations
under the preceding paragraph, LICENSEE shall maintain throughout the term of
this Agreement and for *** thereafter a commercial, general liability insurance
policy, written by a reputable insurance company authorized to do business in
the United States of America, which:

            (a)   insures Indemnification for all claims, damages, and actions
                  mentioned in Article 11.1 of this Agreement;

            (b)   includes a contractual endorsement providing coverage for all
                  liability which may be incurred by Indemnitees in connection
                  with this Agreement;

            (c)   Requires the insurance carrier to provide UGARF with no less
                  than thirty (30) days written notice of any change in the
                  terms or coverage of the policy or its cancellation; and

            (d)   Provides Indemnitees product liability coverage in an amount
                  no less than *** per occurrence for bodily injury and *** per
                  occurrence for property damage, subject to a reasonable
                  aggregate amount.

BUKWANG shall provide LICENSOR with Certificates of Insurance evidencing the
above.

      11.4 Notice of Claims. BUKWANG shall promptly notify LICENSOR of all
claims involving the Indemnitees and will advise LICENSOR of the policy amounts
that might be needed to defend and pay any such claims.

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                                       20
<PAGE>

                        ARTICLE 12. TERM AND TERMINATION

      12.1 Term. Unless sooner terminated as otherwise provided in this
Agreement, the term of this Agreement shall commence on the Operative Date and
shall continue until the date of expiration of the last-to-expire of the
Licensed Patents, including any renewals or extensions thereof. In the event
that there are no Valid Claims, this Agreement shall terminate on the tenth
anniversary of the date of this Agreement.

      12.2 Termination by LICENSOR. LICENSOR shall have the right to terminate
this Agreement upon the occurrence of any one or more of the following events:

      (a)   failure to BUKWANG to make any payment required pursuant to this
            Agreement when due; or

      (b)   failure of BUKWANG to render reports to LICENSOR as required by this
            Agreement; or

      (c)   failure of BUKWANG to comply with BUKWANG's Development Plan,
            attached hereto as Exhibit B; or

      (d)   the insolvency of BUKWANG; or

      (e)   the institution of any proceeding by BUKWANG under any bankruptcy,
            insolvency or moratorium law; or

      (f)   any assignment by BUKWANG of substantially all of its assets for the
            benefit of creditors; or

      (g)   placement of BUKWANG's assets in the hands of a trustee or a
            receiver unless the receivership or trust is dissolved within thirty
            (30) days thereafter; or

      (h)   the breach of any other material term of this Agreement by BUKWANG.

      12.3 Notice of Bankruptcy. BUKWANG must inform LICENSOR of its intention
to file a voluntary petition in bankruptcy or of another's intention to file an
involuntary petition in bankruptcy to be received at least thirty (30) days
prior to filing such a petition. A party's filing without conforming to this
requirement shall be deemed a material, pre-petition incurable breach.


                                       21
<PAGE>

      12.4 Exercise. LICENSOR may exercise its right of termination by giving
BUKWANG, its trustees or receivers or assigns, thirty (30) days prior written
notice of the occurrence of an event giving cause for termination hereunder and
of LICENSOR's election to terminate. Upon the expiration of such period, this
Agreement shall automatically terminate unless BUKWANG has cured the breach.
Such notice and termination shall not prejudice LICENSOR's right to receive
royalties or other sums due hereunder and shall not prejudice any cause of
action or claim of LICENSOR accrued or to accrue on account of any breach or
default by BUKWANG.

      12.5 Failure to Enforce. The failure of LICENSOR at any time, or for any
period of time, to enforce any of the provisions of this Agreement shall not be
construed as a waiver of such provisions or as a waiver of the right of LICENSOR
thereafter to enforce each and every such provision.

      12.6 Termination by BUKWANG. LICENSEE may terminate this Agreement at its
sole discretion upon six (6) month's written notice to UGARF.

      12.7 Effect.

      (a)   In the event this Agreement is terminated for any reason whatsoever,
            BUKWANG shall return, or at LICENSOR's directory destroy, all plans,
            notes, writings and other documents, samples, and other materials
            pertaining to the Licensed Patents and Licensed Technology,
            retaining only one copy in its corporate counsel's office for the
            sole purpose of compliance with surviving terms of this Agreement or
            defense against any legal actions related to this Agreement.
            Immediately upon termination of this Agreement, BUKWANG shall cease
            manufacturing, processing, producing, using, Selling or distributing
            Licensed Products; provided, however, that BUKWANG may continue to
            Sell in the ordinary course of business for a period of three (3)
            months reasonable quantities of Licensed Products which are fully
            manufactured and in BUKWANG's normal inventory at the date of
            termination if (a) all monetary


                                       22
<PAGE>

            obligations of BUKWANG to LICENSOR have been satisfied and (b)
            royalties on such sales are paid to LICENSOR in the amounts and in
            the manner provided in this Agreement.

      (b)   Upon termination of the Agreement for any reason whatsoever, BUKWANG
            shall provide LICENSOR with full and complete copies of all
            toxicology, pharmacokinetics, efficacy, clinical and other technical
            data and all correspondence to and from regulatory agencies relating
            to approval of Licensed Products generated by BUKWANG and/or its
            Affiliates, contractors and agents in the course of BUKWANG's
            efforts to develop Licensed Products and/or obtain governmental
            approval for the Sale of Licensed Products.

      12.8 Survival. The provisions of Articles 9 (except as explicitly stated
in paragraph 9.2), 10, and 11 of this Agreement shall remain in full force and
effect notwithstanding the termination of this Agreement.

                             ARTICLE 13. ASSIGNMENT

      This Agreement is dependent upon the special relationship between the
parties and the special knowledge and unique skills of BUKWANG. Therefore,
BUKWANG shall not grant, transfer, convey or otherwise assign any of its rights
or delegate any of its obligations under this Agreement, without the prior
written consent of LICENSOR. This Agreement shall be assignable by UGARF to UGA,
the University of Georgia Foundation, or any other nonprofit corporation which
promotes the research purposes of UGA.


                                       23
<PAGE>

                            ARTICLE 14. MISCELLANEOUS

      14.1 Export Controls. BUKWANG acknowledges that LICENSOR is subject to
United States laws and regulations controlling the export of technical data,
computer software, laboratory prototypes, and other commodities and that
LICENSOR's obligations under this Agreement are contingent upon compliance with
applicable United States export laws and regulations. The transfer of technical
data and commodities may require a license from the cognizant agency of the
United States government or written assurances by BUKWANG that BUKWANG shall not
export data or commodities to certain foreign countries without the prior
approval of certain United States agencies. LICENSOR neither represents that an
export license shall not be required nor that, if required, such export license
shall issue.

      14.2 Legal Compliance. BUKWANG shall comply with all laws and regulations
relating to its manufacture, processing, producing, use, Selling or distributing
of Licensed Products. BUKWANG shall not take any action which would cause
LICENSOR or BUKWANG to violate any laws and regulations.

      14.3 Independent Contractor. BUKWANG's relationship to LICENSOR shall be
that of a licensee only. BUKWANG shall not be the agent of LICENSOR and shall
have no authority to act for or on behalf of LICENSOR in any matter. Persons
retained by BUKWANG as employees or agents shall not by reason thereof be deemed
to be employees or agents of UGARF, UGA or YALE.

      14.4 Patent Marking. BUKWANG shall mark Licensed Products Sold in the
United States with United States patent numbers. Licensed Products manufactured
or Sold in other countries shall be marked in compliance with the intellectual
property laws in force in such foreign countries.

      14.5 Use of Names. BUKWANG shall obtain the prior written approval of
YALE, UGARF, UGA or the Inventors prior to making use of their names for any
commercial purpose, except as required by law. As an exception to the foregoing,
both BUKWANG and LICENSOR shall have the right to publicize the existence of
this Agreement; however, neither BUKWANG nor LICENSOR shall disclose the terms
and conditions of this Agreement without the other party's consent, except as
may be required by law.


                                       24
<PAGE>

      14.6 Place of Execution. This Agreement and any subsequent modifications
or amendments hereto shall be deemed to have been executed in the State of
Georgia, U.S.A.

      14.7 Governing Law. This Agreement and all amendments, modifications,
alternations or supplements hereto, and the rights of the parties hereunder,
shall be construed under and governed by the laws of the *** and the United
States of America.

      14.8 Entire Agreement. This Agreement constitutes the entire agreement
between LICENSOR and BUKWANG with respect to the subject matter hereof and shall
not be modified, amended or terminated except as herein provided or except by
another agreement in writing executed by the parties hereto.

      14.9 Severability. All rights and restrictions contained herein may be
exercised and shall be applicable and binding only to the extent that they do
not violate any applicable laws and are intended to be limited to the extent
necessary so that they will not render this Agreement illegal, invalid or
unenforceable. If any provision or portion of any provision of this Agreement
not essential to the commercial purpose of this Agreement shall be held to be
illegal, invalid or unenforceable by a court of competent jurisdiction, it is
the intention of the parties that the remaining provisions or portions thereof
shall constitute their agreement with respect to the subject matter hereof, and
all such remaining provisions or portions thereof shall remain in full force and
effect. To the extent legally permissible, any illegal, invalid or unenforceable
provision of this Agreement shall be replaced by a valid provision which will
implement the commercial purpose of the illegal invalid or unenforceable
provision. In the event that any provision essential to the commercial purpose
of this Agreement is held to be illegal, invalid or unenforceable and cannot be
replaced by a valid provision which will implement the commercial purpose of
this Agreement, this Agreement and the rights granted herein shall terminate.

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       25
<PAGE>

      14.10 Force Majeure. Any delays in, or failure of, performance of any part
to this Agreement shall not constitute default hereunder, or give rise to any
claim for damages, if and to the extent cause by occurrences beyond the control
of the party affected, including, but not limited to, acts of God, strikes or
other work stoppages; civil disturbances, fires, floods, explosions, riots, war,
rebellion, sabotage, acts of governmental authority or failure of governmental
authority to issue licenses or approvals which may be required.

                               ARTICLE 16. NOTICES

      All notices and other communications shall be hand delivered, sent by
private mail service, or sent by registered or certified U.S. mail, postage
prepaid, return receipt requested, and addressed to the party to receive such
notice or other communication at the address given below, or such other address
as may hereafter be designated by notice in writing:

If to LICENSOR:               Executive Vice President
                              University of Georgia Research Foundation, Inc.
                              Boyd Graduate Studies Research Center, 6th Floor
                              Athena, Georgia 30602 Facsimile: (404) 542-5638

If to BUKWANG:                Attn:  Dr. C.H. Koo
                              Bukwang Pharm.Ind.Co.Ltd.
                              398-1 Daebang-Dong
                              Dongjak-ku
                              Seoul 156-020
                              Republic of Korea       Facsimile 82-2-816-2792

Such notices or other communications shall be effective upon receipt by an
employee, agent or representative of the receiving party authorized to receive
notices or other communications sent or delivered in the manner set forth above.


                                       26
<PAGE>

      IN WITNESS WHEREOF, LICENSOR and BUKWANG have caused this Agreement to be
signed by their duly authorized representatives, under seal, as of the day and
year indicated above.

LICENSOR:                                BUKWANG:

UNIVERSITY OF GEORGIA
RESEARCH FOUNDATION                      BUKWANG PHARM. IND. CO., LTD.


By: /s/ Joe L. Key                       By: /s/ C.H. Koo
    -----------------------                  ---------------------
    Name:  Joe L. Key                        Name:  C.H. Koo
    Title: Executive Vice President          Title: Managing Director

(corporate seal)                         (corporate seal)

YALE UNIVERSITY:


By: /s/ Janet H. Ackerman
    ------------------------
Name:  Janet Ackerman
       ---------------------
Title: Associate V.P. for Finance
       --------------------------


                                       27
<PAGE>

                                   EXHIBIT A
                                Licensed Patents

U.S.S.N. 08/189,070 filed January 28, 1994, entitled "L-Nucleosides for the
Treatment of Hepatitis B Virus and Epstein-Barr Virus"

U.S.S.N. 08/466,274 filed June 6, 1995 as a continuation application of USSN
08/189,070, entitled "L-Nucleosides for the Treatment of Hepatitis B Virus and
Epstein-Barr Virus"

U.S.S.N. 08/467,010 filed June 6, 1995 as a divisional application of USSN
08/189,070, entitled "L- Nucleosides for the Treatment of Hepatitis B Virus and
Epstein-Barr Virus"

International Patent Cooperation Treaty Application No. US94/06080, Filed May
27, 1994


                                       28
<PAGE>

                                    EXHIBIT B

                      <The Development Schedule for L-FMAU>

                                       ***

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       29
<PAGE>

                                    AMENDMENT

                                       to

                                LICENSE AGREEMENT

                                     between

                 UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC.

                              YALE UNIVERSITY, and

                          BUKWANG PHARM. IND. CO., LTD.

      This AMENDMENT to LICENSE AGREEMENT (AMENDMENT) is effective on September
1, 1997, by and among the UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC., a
nonprofit Georgia corporation with offices located in Boyd Graduate Studies
Research Center, The University of Georgia, Athens, Georgia 30602-7411 (UGARF),
YALE UNIVERSITY, located in New Haven, Connecticut (YALE), and BUKWANG PHARM.
IND. CO., LTD., a Korean corporation with headquarters located at 398-1 
Daebong-dong, Dongjak-ku, Seoul 156-020, Republic of Korea (BUKWANG).

                                   WITNESSETH

      WHEREAS, UGARF, YALE and BUKWANG entered into a License Agreement
(LICENSE) as of December 28, 1995; and

      WHEREAS, UGARF, YALE and BUKWANG desire to amend the LICENSE to provide
sublicensing rights to BUKWANG;

      NOW, THEREFORE, UGARF, YALE and BUKWANG agree as follows:

1.    The partial consideration of the grant by UGARF and YALE of sublicensing
      rights to BUKWANG, BUKWANG agrees to pay a one-time, nonrefundable,
      nonceditable fee of *** to be split equally between UGARF and YALE.

2.    The following new paragraphs are added to the LICENSE.

      2.5   BUKWANG shall have the right to enter into sublicensing agreements
            for the rights, privileges and licenses granted hereunder. Upon any
            termination of this Agreement, sublicensees' rights shall also
            terminate.

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                  Page 1 of 3
<PAGE>

      2.6   BUKWANG agrees that any sublicenses granted by it shall provide that
            the obligations to UGARE and YALE of Articles 2, 3.3, 5, 6, 8, 9,
            10, 11, 12 and 14 of this Agreement shall be binding upon the
            sublicensee as if it were a party to this Agreement. BUKWANG further
            agrees to attach copies of these Articles to sublicense agreements.

      2.7   BUKWANG shall not receive from sublicenses anything of value in lieu
            of cash payments in consideration for any sublicense under this
            Agreement without the prior written permission of UGARF and YALE.

      2.8   BUKWANG shall obtain in advance the written approval of UGARF and
            YALE before it enters into any sublicense agreements. However, in
            the event that the sublicense from BUKWANG is with a company ***,
            then such written approval is not needed in advance.

      2.9   BUKWANG agrees to forward to UGARF and YALE a copy of any and all
            sublicense agreements promptly upon execution by the parties.

      2.10  BUKWANG agrees that any sublicense agreement shall contain a
            provision for the payment of a royalty of no less than *** of the
            Net Selling Price of all Licensed Products by the sublicensee.

      2.11  BUKWANG, UGARF and YALE agree to share income from sublicensing in
            the following manner:

                                                        UGARF/YALE      BUKWANG

            Income from royalties from sublicensee(s)       ***            ***

            Income from sublicense issue fees,              ***            ***
            milestone payments, or fees other than
            royalties

Except as otherwise modified herein, the LICENSE remains in full force and
effect.

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                  Page 2 of 3
<PAGE>

      IN WITNESS WHEREOF, the parties have caused this AMENDMENT to be executed
by their duly authorized representatives, under seal, as of the effective date.

UNIVERSITY OF GEORGIA
RESEARCH FOUNDATION, INC.                BUKWANG PHARM. IND. CO., LTD.


By: /s/ Joe L. Key                       By: /s/ C. H. Koo
    ---------------------------              ----------------------------
Name:  Joe L. Key                        Name: C. H. Koo
Title: Executive Vice President                Managing Director

(corporate seal)                         (corporate seal)

                                         BUKWANG PHARM. IND. CO., LTD.
                                         398-1 Daebang-Dong, Dongjak-ku
YALE UNIVERSITY                          Seoul, 156-020, KOREA


By: /s/ Gregory E. Gardiner
    ---------------------------
Name:  Gregory E. Gardiner, Ph.D.
Title: Director, Cooperative Research

(corporate seal)

                                  Page 3 of 3
<PAGE>

                               AMENDMENT NUMBER 2

                                       to

                         LICENSE AGREEMENT and AMENDMENT

                                     between

                 UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC.

                              YALE UNIVERSITY, and

                          BUKWANG PHARM. IND. CO., LTD.

      This AMENDMENT NUMBER 2 to LICENSE AGREEMENT and AMENDMENT (dated
September 1, 1997) is effective on December 1, 1997, by and among the UNIVERSITY
OF GEORGIA RESEARCH FOUNDATION, INC., a nonprofit Georgia corporation with
offices located in Boyd Graduate Studies Research Center, The University of
Georgia, Athens, Georgia 30602-7411 (UGARF), YALE UNIVERSITY, located in New
Haven, Connecticut (YALE), and BUKWANG PHARM. IND. CO., LTD., a Korean
corporation with headquarters located at 398-1 Daebong-dong, Dongjak-ku, Seoul
156-020, Republic of Korea (BUKWANG).

                                   WITNESSETH

      WHEREAS, UGARF, YALE and BUKWANG entered into a License Agreement
(LICENSE) as of December 28, 1995, and an AMENDMENT dated September 1, 1997; and

      WHEREAS, UGARF, YALE and BUKWANG desire to amend the LICENSE and AMENDMENT
as follows:

      NOW, THEREFORE, UGARF, YALE and BUKWANG agree as follows:

1.    Article 1 of the AMENDMENT dated September 1, 1997, is replaced with the
      following:

      In partial consideration of the grant by UGARF and YALE of sublicensing
      rights to BUKWANG, BUKWANG agrees to pay on completion of a sublicense
      agreement with a third party, a one-time, nonrefundable, noncreditable fee
      of *** to be split equally between UGARF and YALE. This fee is in
      addition to the *** sharing of sublicense fees, milestone payments or fees
      other than royalties received by BUKWANG from a sublicensee, as provided
      in Article 2.11 of this AMENDMENT.

2.    Paragraph 2.6 of the LICENSE is replaced by the following:

      2.6   BUKWANG agrees that any sublicenses granted by it shall provide that
            the obligations to UGARF and YALE of Articles 2, 3.3, 5, 6, 8, 9,
            10, 11, 12 and 14 

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                  Page 1 of 2
<PAGE>

            of this Agreement shall be binding upon the sublicensee as if it
            were a party to this Agreement. BUKWANG further agrees to attach
            copies of these Articles to sublicense agreements. ***

      3.    Exhibit A of the LICENSE is amended to include ***

Except as otherwise modified herein, the LICENSE remains in full force and
effect.

      IN WITNESS WHEREOF, the parties have caused this AMENDMENT to be executed
by their duly authorized representatives, under seal, as of the effective date.

UNIVERSITY OF GEORGIA
RESEARCH FOUNDATION, INC.                BUKWANG PHARM. IND. CO., LTD.


By: /s/ Joe L. Key                       By: /s/ S. K. Lee
    ---------------------------              -------------------------
Name:  Joe L. Key                            Name: S. K. Lee
Title: Executive Vice President              Managing Director

(corporate seal)                         (corporate seal)

YALE UNIVERSITY


By: /s/ Gregory E. Gardiner
    ---------------------------
Name:  Gregory E. Gardiner
Title: Director, Office of Cooperative Research

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                  Page 2 of 2
<PAGE>

                                    Exhibit B

   L-Nucleosides for the Treatment of Hepatitis B-Virus and Epstain Bar Virus

Inventors: Chung K. Chu, Yung-Chi Cheng, Balakrishna S. Pai and Gang-Qing Yao

================================================================================
   Docket   Country     Serial No.   Filing Date Patent No.   Grant Date
    Name
================================================================================
UGA 500     USA         08/189.070   1-28-94     5,587,362    12-24-96
--------------------------------------------------------------------------------
Div (1)     USA         08/467.010   6-6-95      5,567,688    10-22-96
--------------------------------------------------------------------------------
Div (2)     USA         08/466.274   6-9-95      5,565,438    10-15-96
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
PCT                     US95/01253   1-30-95
--------------------------------------------------------------------------------
            Australia   17376/95     1-30-95
--------------------------------------------------------------------------------
            Brazil      PI9506       1-30-95
--------------------------------------------------------------------------------
            Bulgaria    100792       1-30-95
--------------------------------------------------------------------------------
            Canada      2.182.273    1-30-95
--------------------------------------------------------------------------------
            Chile       1353-95      1-30-95
--------------------------------------------------------------------------------
            China       95/191415.4  1-30-95
--------------------------------------------------------------------------------
            Czech       PV2114-96    1-30-95
            Republic
--------------------------------------------------------------------------------
            Europe      95/909404.6  1-30-95
--------------------------------------------------------------------------------
            Finland     962986       1-30-95
--------------------------------------------------------------------------------
            Hungary     P9601774     1-30-95
--------------------------------------------------------------------------------
            Japan       520247/1995  6-30-95
--------------------------------------------------------------------------------
            Mexico      96/3029      1-30-95
--------------------------------------------------------------------------------
            New         281058       1-30-95
            Zealand
--------------------------------------------------------------------------------
            N. Korea    96-0582      1-30-95
--------------------------------------------------------------------------------
            Norway      96-3138      1-30-95
--------------------------------------------------------------------------------


                                                                     Page 1 of 3
<PAGE>

================================================================================
   Docket   Country     Serial No.   Filing Date Patent No.   Grant Date
    Name
================================================================================
            Romania     96-01548     1-30-95
--------------------------------------------------------------------------------
            Russia      96-117323    1-30-95
--------------------------------------------------------------------------------
            Sri Lanka   11021        1-30-95     11021        11/15/95
--------------------------------------------------------------------------------
            S. Korea    96-704125    1-30-95
--------------------------------------------------------------------------------
            Slovak      PV-926-96    1-30-95
            Republic
--------------------------------------------------------------------------------
            Viet Nam    SCO147/96    1-30-95
--------------------------------------------------------------------------------

================================================================================


                                                                     Page 2 of 3
<PAGE>

                         PROCESS FOR THE PREPARATION OF
                 2'-FLUORO-5-METHYL-B-L-ARABINOFURANOSYLURIDINE

Inventors: Chung Kewan Chu, Jinfa Du, Yong Seok Choi

================================================================================
   Docket   Country     Serial No.   Filing Date Patent No.   Grant Date
    Name
================================================================================
     ***        ***         ***          ***
--------------------------------------------------------------------------------
            PCT         IB97/01254   8-29-97
--------------------------------------------------------------------------------
            Argentina   P9701 04409  9-25-97
--------------------------------------------------------------------------------
            China       97116278.6   9-8-97
--------------------------------------------------------------------------------
            India       unknown      9-15-97
--------------------------------------------------------------------------------
            Indonesia   P-973026     9-16-97
--------------------------------------------------------------------------------
            Israel      121.730      9-10-97
--------------------------------------------------------------------------------
            Korea       98-1421      1-19-97
--------------------------------------------------------------------------------
            Malaysia    unknown      9-13-97
--------------------------------------------------------------------------------
            Pakistan    706/97       9-13-97
--------------------------------------------------------------------------------
            Philippines I-57996      9-24-97
--------------------------------------------------------------------------------
            Saudi       98180771     1-4-98
            Arabia
--------------------------------------------------------------------------------
            Taiwan      86111816     8-16-97
--------------------------------------------------------------------------------
            Thailand    039630       9-15-97
--------------------------------------------------------------------------------
            Turkey      97/0151      9-26-97
================================================================================

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                                                     Page 3 of 3
<PAGE>

                                    Exhibit C
                               AMENDMENT NUMBER 3

                                       to

                                LICENSE AGREEMENT

                                      among

                UNIVERSITY OF GEORGIA RESEARCH FOUNDATION, INC.,

                               YALE UNIVERSITY and

                          BUKWANG PHARM. IND. CO., LTD.

      This AMENDMENT NUMBER 3, dated as of this February 27, 1998, and effective
in accordance with paragraph 15 hereof, by and among the UNIVERSITY OF GEORGIA
RESEARCH FOUNDATION, INC., a nonprofit Georgia corporation with offices located
in Boyd Graduate Studies Research Center, The University of Georgia, Athens,
Georgia 30602-7411 ("UGARF"), YALE UNIVERSITY, located in New Haven, Connecticut
("YALE"), and BUKWANG PHARM. IND. CO., LTD., a Korean corporation with
headquarters located at 398-1 Daebong-dong, Dongjak-ku, Seoul 156-020, Republic
of Korea ("BUKWANG").

                                   WITNESSETH:

      WHEREAS, UGARF, YALE, and BUKWANG entered into a License Agreement as of
December 28, 1995, and Amendment Number 1 thereto, dated September 1, 1997 and
Amendment Number 2 thereto dated December 1, 1997 (collectively, the "License
Agreement"); and

      WHEREAS, BUKWANG and TRIANGLE PHARMACEUTICALS, INC., a Delaware
corporation with offices located at 4 University Place, 4611 University Drive,
Durham, North Carolina 27707 ("TRIANGLE") have entered into a license agreement,


                                       1
<PAGE>

dated as of even date herewith (the "Triangle Sublicense Agreement"), pursuant
to which BUKWANG has granted TRIANGLE an exclusive sublicense to the Bukwang
Patents and Bukwang Know-How (each as defined in the Triangle Sublicense
Agreement), in the entire world, except Korea; and

      WHEREAS, TRIANGLE has requested that BUKWANG, UGARF and YALE execute this
Amendment Number 3 in order, inter alia, to reconcile certain inconsistencies
between this License Agreement and the Triangle Sublicense Agreement and
BUKWANG, UGARF and YALE are willing to do so;

      NOW, THEREFORE, UGARF, YALE and BUKWANG agree as follows:

1.    All capitalized terms used in this Amendment Number 3 and not defined in
      this Amendment Number 3 shall have the meanings given them in the License
      Agreement, except as otherwise explicitly set forth herein.

2.    UGARF and YALE hereby expressly consent to BUKWANG's entering into the
      Triangle Sublicense Agreement.

3.    UGARF and YALE confirm that the License Agreement is in full force and
      effect and UGARF and YALE are not aware of any breach thereof by any party
      thereto.

4.    The following amendments are made to Article 2 of the License Agreement:

      (a) Delete the last two sentences of paragraph 2.4 of the License
      Agreement and replace them with the following:

            If at any time during the term of this License Agreement, the United
            States government should take action which terminates this License
            Agreement or requires that this License Agreement be terminated,
            BUKWANG acknowledges this License Agreement will automatically
            terminate. In 


                                       2
<PAGE>

            such event, BUKWANG shall not have any right to the return of any
            payments of any kind made by it to LICENSOR prior to the date of
            termination, other than any overpayment of earned royalties as
            determined by any audit conducted pursuant to paragraph 6.2 of this
            License Agreement.

      (b)   Delete paragraph 2.5 of the License Agreement entitled "Republic of
            Korea Government Approval" and add the following sentences to
            paragraph 2.5 of Amendment Number 1 to the License Agreement:

            Notwithstanding the foregoing, UGARF and YALE agree that, if this
            License Agreement terminates pursuant to paragraph 12.4 or 12.6, the
            Triangle Sublicense Agreement shall, with respect to the Licensed
            Patents and Licensed Technology, automatically become a direct
            license with UGARF and YALE on the terms stated therein; provided,
            however that UGARF and YALE shall be entitled to receive only those
            percentages of milestone payments, royalties and other fees payable
            to UGARF and YALE under the Triangle Sublicense Agreement as are
            specified in paragraph 2.11 hereof on the date of such termination.
            In such event, UGARF and YALE agree promptly to provide Triangle
            with written confirmation of such a direct license.

      (c)   Delete the paragraph 2.6 of Amendment Number 2 and replace it with
            the following:

            UGARF and YALE agree that:

            (i) TRIANGLE's performance of its obligations set forth in the
            Triangle Sublicense Agreement shall be deemed to be complete
            performance of any 


                                       3
<PAGE>

            obligations which Triangle, as BUKWANG's sublicensee, and Bukwang
            have pursuant to the provisions of this License Agreement including,
            but not limited to, any and all obligations set forth herein
            relating to diligence, progress reports, royalties (and the
            calculation thereof), milestone payments and any other amounts
            payable to UGARF and YALE pursuant to the terms of the License
            Agreement and the due dates in respect of any of the foregoing and
            including the provisions of Articles 2, 5, 6, 8, 10, 11, 12 and 14
            of the License Agreement; provided however, BUKWANG agrees that the
            Triangle Sublicense Agreement shall contain a provision for the
            payment of a royalty of no less than *** of the Net Sales of all
            Licensed Products by TRIANGLE (as defined therein);

            (ii) Triangle's sole financial obligations as BUKWANG's sublicensee
            shall be those which are set forth in the Triangle Sublicense
            Agreement and shall be deemed to be performance by BUKWANG of its
            financial obligations hereunder; and

            (iii) Triangle's performance of its diligence obligations as set
            forth in Article 6 of the Triangle Sublicense Agreement shall be
            deemed to be performance by BUKWANG of its diligence obligations
            under the License Agreement including, but not limited to, those set
            forth in Article 3 hereof.

      (d)   Delete paragraph 2.10 of Amendment Number 1 and replace it as
            follows:

            BUKWANG agrees that payments to LICENSOR in respect of royalties
            received by BUKWANG under the Triangle Sublicense Agreement shall
            not be less than *** of Net Sales of Licensed Products (as defined
            in the Triangle Sublicense Agreement) for any royalty period during
            the term 

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       4
<PAGE>

            thereof.

      (e)   Add the following paragraph 2.12 to Article 2 of the License
            Agreement:

            To the extent that the rights have not already been licensed
            exclusively to another party, UGARF and YALE agree not to sue
            BUKWANG or its Affiliates or sublicensees for patent infringement
            for practicing a claim of a patent assigned to UGARF and YALE if
            practicing said claim is required to make, have made, use, import,
            offer for sale, sell or have sold Licensed Products.

5.    Delete paragraph 3.3 of the License Agreement and replace it with the
      following paragraph:

            3.3 Chemical Utility Diligence Obligation. As used herein, the term
            "Compounds" shall mean the compound known as L-FMAU, with the
            chemical name, 2'-fluoro-5-methyl-(beta)-L-arabinofuranosyluracil,
            including any salts and esters thereof. BUKWANG acknowledges that
            viral resistance may limit the clinical utility and commercial
            potential of the Compounds. In the conduct of the BUKWANG
            Development Program, BUKWANG shall use its *** to conduct, or shall
            cause its sublicensee to use its *** to conduct, preclinical and
            clinical studies of the Compounds in combination with other anti-HBV
            drugs or drug candidates in order to determine ***. BUKWANG shall
            conduct, or shall cause its sublicensee to conduct, preclinical
            combination studies with at least *** and shall use, or shall cause
            its sublicensee to use, its *** to conduct clinical combination
            studies with as many other drugs or drug candidates as it deems
            appropriate to determine the optimal combinations or sequence of

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       5
<PAGE>

            combinations necessary to provide maximum efficacy against HBV and
            enhance the clinical utility and commercial potential of the
            Compounds. Such combination studies may include *** and, because the
            outcome of such combination studies cannot be predicted with
            certainty, these studies may include other drugs or drug candidates
            being developed by BUKWANG, its sublicensee or third parties which
            because of various factors are ultimately determined not to be
            additive to, or synergistic with, the Compounds.

6.    Add the following paragraph to paragraph 4.4 of the License Agreement:

      Invoices, including reasonable substantiation thereof, shall be submitted
      once in respect of each fiscal quarter as promptly as practicable after
      the end of such quarter. Payments shall be due net thirty (30) days from
      the date of invoice. BUKWANG hereby authorizes UGARF and YALE to submit,
      and UGARF and YALE hereby agree to submit, all such invoices in respect of
      the Licensed Territory (other than Korea) directly to TRIANGLE for
      reimbursement.

7.    Make the following amendments to Article 5 of the License Agreement:

      (a) Add the following sentence to paragraph 5.1 of the License Agreement:

            Any provision of this License Agreement to the contrary
            notwithstanding, payments and reports due hereunder in respect of
            payments and reports received by BUKWANG from TRIANGLE pursuant to
            the Triangle Sublicense Agreement will not be due to be submitted to
            LICENSOR until ten (10) days after the date of receipt by BUKWANG
            from TRIANGLE.

      (b) Delete the first sentence of paragraph 5.5 and replace it with the
          following:

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       6
<PAGE>

            Payments required under the License Agreement shall, if overdue,
            bear interest at the rate of *** until paid.


      (c) Add the following paragraph 5.6 to Article 5 of the License
          Agreement:

            5.6 Performance of BUKWANG's Sublicensee. UGARF and YALE agree that
            any and all reports required to be submitted by BUKWANG pursuant to
            this Article 5 may instead be submitted by TRIANGLE in respect of
            that portion of the Licensed Territory in which the Triangle
            Sublicense Agreement is in effect and that submission of a report by
            TRIANGLE to UGARF and YALE in accordance with this Article 5 shall
            be deemed to satisfy BUKWANG's obligation to do so under this
            Article 5.

8.    Make the following amendments to Article 7 of the License Agreement:

      (a) Delete the second paragraph of paragraph 7.1 and replace it as
          follows:

            If BUKWANG or its sublicensee, as applicable, fail to reimburse
            LICENSOR for any undisputed patent prosecution expenses respecting
            any patent application or issued patent included in the Licensed
            Patents within the time allowed therefor, upon at least thirty (30)
            days' prior notice to BUKWANG or its sublicensee, as applicable,
            LICENSOR may remove such patent application or issued patent from
            the Licensed Patents and LICENSOR shall be free, at its election, to
            abandon or maintain the prosecution of such patent application or
            issued patent or grant rights to such patent application or issued
            patent to third parties.

      (b)   Add the following paragraph 7.3 to Article 7:

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       7
<PAGE>

      7.3   Further Obligations.

      (a) Except as otherwise provided in Article 8, each party's
      responsibilities for patent prosecution activities pursuant to this
      Article 7 shall also include all ex parte and inter partes activities
      relating to the relevant patent applications and patents, including all
      interference, opposition and observation proceedings before any patent
      offices and litigation to determine the validity, enforceability,
      allowability or subsistence of such patent applications and patents. Each
      party agrees to give due consideration to the other party's or its
      sublicensee's position with respect to any such patent prosecution
      activities (which term, as used herein, shall include without limitation,
      any inter partes activities of the type described in the first sentence of
      this subparagraph (a)). In the event a party fails to initiate or pursue
      any patent prosecution activities for which it is responsible, or having
      commenced such patent prosecution activities, declines to pursue such
      patent prosecution activities, it shall give notice to the other party
      pursuant to the applicable provisions of subparagraph (b) below and the
      other party or its sublicensee, as applicable, may initiate, pursue or
      assume such patent prosecution activities, at its sole expense.

      (b) In conducting its patent prosecution activities under this License
      Agreement, each party may use patent attorneys selected by it in its own
      discretion. In addition to the other obligations set forth in this Article
      7, each party undertakes to keep the other party and, if applicable, such
      other party's sublicensee throughout the term of this License Agreement
      regularly informed of the status and progress of the patent prosecution


                                       8
<PAGE>

      activities it undertakes under this License Agreement including, but not
      limited to, supplying the other party or its sublicensee, as applicable,
      upon reasonable request and at reasonable intervals, with all
      correspondence with the United States, Japan and European patent office
      counterparts with respect to the United States, Japan and European patents
      and patent applications. To the extent that a party has not previously
      done so, or promptly upon request by the other party or its sublicensee,
      in order to assist such other party or its sublicensee in connection with
      any of its activities or the exercise of any of its rights pursuant to
      Articles 7, such party shall provide the other party or its sublicensee
      with such additional relevant documentation which such other party or its
      sublicensee may reasonably request relating to such patent applications
      and patents in the Licensed Patents, including but not limited to, copies
      thereof and access to laboratory notebooks, other supporting data and
      relevant employees. If a party decides to abandon or allow to lapse any
      patent application or patent or not to initiate or any other patent
      prosecution activity for which it has patent prosecution responsibility
      pursuant to this Article 7, it shall give the other party or its
      sublicensee notice thereof in a sufficiently timely manner so as to enable
      such other party or its sublicensee to determine whether to assume patent
      prosecution activity in connection therewith. Each party shall use its ***
      to give such notice at least sixty (60) days before any abandonment, lapse
      or any other relevant deadline.

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       9
<PAGE>

      (c) BUKWANG and LICENSOR agree that, during the term of the Triangle
      Sublicense Agreement, the rights of BUKWANG under this Article 7 shall be
      exercised, if at all, by TRIANGLE with respect to all patent prosecution
      activities in any portion of the Licensed Territory in which the Triangle
      Sublicense Agreement is then in effect. With respect to such patent
      prosecution activities, LICENSOR shall communicate with TRIANGLE directly.

10.   Make the following amendments to Article 8 of the License Agreement:

      (a) Delete subparagraph (c) to paragraph 8.1 and replace it as follows:

            (c) If LICENSOR shall fail with ninety (90) days after receiving
            notice from BUKWANG of a potential infringement, to either (i)
            terminate such infringement or (ii) to institute, either jointly as
            provided in subparagraph (a) above or solely as provided in
            subparagraph (b) above and, thereafter, to prosecute such suit
            diligently, or (iii) if LICENSOR notifies BUKWANG that it does not
            plan to institute or join in such suit, BUKWANG may institute suit
            and, at its option, name LICENSOR as a plaintiff. BUKWANG shall bear
            the entire cost of such litigation, including defending any
            counterclaims brought against LICENSOR and paying any judgments
            rendered against LICENSOR, and shall be entitled to retain the
            entire amount of any recovery or settlement.

      (b) Add the following subparagraph (d) to paragraph 8.1:

            (d) In the event BUKWANG commences a suit pursuant to subparagraph
            (c), BUKWANG may deposit up to *** of any royalties and milestone
            payments which are otherwise payable to LICENSOR during

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       10
<PAGE>

            the pendency of such suit in an interest-bearing escrow account.
            Upon final resolution of such suit, BUKWANG shall provide LICENSOR
            with an accounting of the amounts escrowed and BUKWANG's expenses
            incurred in such infringement suit. BUKWANG shall be entitled to
            offset any expenses which BUKWANG fails to recoup in such suit
            against the escrowed amounts. Any escrowed amounts (and interest
            thereon) in excess of BUKWANG's unrecouped expenses shall be
            promptly paid to LICENSOR.

      (c) Add the following paragraph 8.3 to Article 8:

            8.3 Sublicensee Rights. BUKWANG and LICENSOR agree that, during the
            term of the Triangle Sublicense Agreement, the rights of BUKWANG
            under this Article 8 shall be exercised, if at all, by TRIANGLE with
            respect to any infringements in any portion of the Licensed
            Territory in which the Triangle Sublicense Agreement is then in
            effect. With respect to such infringements, LICENSOR shall contact
            Triangle regarding decisions relating to whether it desires to
            commence any infringement suit and, if so, whether such suit should
            be commenced jointly.

11.   Add the following paragraph 9.4 to Article 9 of the License Agreement:

            9.4 Rights to Disclose. Notwithstanding any provision of this
            Article 9 to the contrary, BUKWANG shall have the right to disclose
            any and all information and technology disclosed to it by LICENSOR
            to TRIANGLE. LICENSOR agrees that TRIANGLE shall have the right to
            disclose such information and technology as provided in Article 13
            of the Triangle Sublicense Agreement.


                                       11
<PAGE>

12.   Exhibit A of the License Agreement is deleted and replaced with Exhibit A
      attached hereto. LICENSOR warrants and represents that, with the exception
      of the two patent cases identified by serial numbers ***, (a) Exhibit A is
      a complete list of all patents and patent applications which it owns as of
      the date hereof which relate to the Compounds per se, the use of the
      Compounds in the Field of Use or the manufacture of the Compounds; and (b)
      no patents or patent applications which relate to the Compounds per se,
      .the use of the Compounds in the Field of Use or the manufacture of the
      Compounds have been filed by LICENSOR in any non-elected countries (as
      defined in paragraph 7.1 hereof).

13.   Attached hereto as Exhibit B is a true and correct copy of the ***.

14.   BUKWANG, UGARF and YALE agree not to amend this Amendment Number 3 in any
      manner which would adversely affect TRIANGLE's rights and obligations
      under the Triangle Sublicense Agreement. Any such purported amendment,
      without TRIANGLE's prior written consent (which Triangle may withhold at
      its sole discretion), shall be void. BUKWANG, UGARF and YALE agree to give
      TRIANGLE at least thirty (30) days' notice of any other proposed amendment
      to the License Agreement (including a true and correct copy thereof) and
      will not enter into such an amendment if prior to such thirty (30) days'
      TRIANGLE identifies any provisions contained in such proposed amendment
      which would adversely affect the rights and obligations of TRIANGLE under
      the Triangle Sublicense Agreement. If TRIANGLE gives such notice in a
      timely fashion, the parties will meet in an attempt to mutually agree on
      acceptable terms of such amendment or, in lieu thereof, BUKWANG, UGARF,
      and YALE may enter into such amendment deleting the adverse provisions
      identified in TRIANGLE's

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.


                                       12
<PAGE>

      notice.

15.   This Amendment Number 3 shall become effective upon the Effective Date of
      the Triangle Sublicense Agreement (as defined therein) provided, however,
      that in the event the Triangle Sublicense Agreement terminates in one or
      more countries, this Amendment Number 3 shall terminate automatically in
      respect of such countries.

16.   Except as otherwise expressly amended hereby, the License Agreement
      remains in full force and effect.

17.   This Amendment Number 3 may be executed in one or more counterparts, each
      of which shall be deemed an original, but all of which together shall
      constitute one and the same instrument.

[REMAINDER OF THIS PAGE HAS BEEN LEFT INTENTIONALLY BLANK]


                                       13
<PAGE>

      IN WITNESS WHEREOF, the parties have caused this Amendment to be executed
by their duly authorized representatives, under seal, as of the date set forth
above.

LICENSOR:                                BUKWANG:

UNIVERSITY OF GEORGIA                    BUKWANG PHARM. IND. CO., LTD.
RESEARCH FOUNDATION, INC.


By: /s/ Joe L. Key                       By: /s/ Sung Koo Lee
    -----------------------------            -----------------------------
Name: Joe L. Key                         Name: Sung Koo Lee
Title: Executive Vice President          Title: Managing Director

[Corporate Seal]                         [Corporate Seal]

YALE UNIVERSITY


By: /s/ Gregory E. Gardiner
    -----------------------------
Name: Gregory E. Gardiner
Title: Director, OCR

[Corporate Seal]


                                       14
<PAGE>

                                    Exhibit A

   L-Nucleosides for the Treatment of Hepatitis B-Virus and Epstein Bar Virus

Inventors: Chung K. Chu, Yung-Chi Cheng, Balakrishna S. Pai and Gang-Qing Yao

================================================================================
   Docket     Country    Serial No.   Filing Date   Patent No.   Grant Date
    Name
================================================================================
UGA 500       USA        08/189.070   1-28-94       5,587,362    12-24-96
--------------------------------------------------------------------------------
Div (1)       USA        08/467.010   6-6-95        5,567,688    10-22-96
--------------------------------------------------------------------------------
Div (2)       USA        08/466.274   6-9-95        5,565,438    10-15-96
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
PCT                      US95/01253   1-30-95
--------------------------------------------------------------------------------
              Australia  17376/95     1-30-95
--------------------------------------------------------------------------------
              Brazil     PI9506       1-30-95
--------------------------------------------------------------------------------
              Bulgaria   100792       1-30-95
--------------------------------------------------------------------------------
              Canada     2.182.273    1-30-95
--------------------------------------------------------------------------------
              Chile      1353-95      1-30-95
--------------------------------------------------------------------------------
              China      95/191415.4  1-30-95
--------------------------------------------------------------------------------
              Czech      PV2114-96    1-30-95
              Republic
--------------------------------------------------------------------------------
              Europe     95/909404.6  1-30-95
--------------------------------------------------------------------------------
              Finland    962986       1-30-95
--------------------------------------------------------------------------------
              Hungary    P9601774     1-30-95
--------------------------------------------------------------------------------
              Japan      520247/1995  6-30-95
--------------------------------------------------------------------------------
              Mexico     96/3029      1-30-95
--------------------------------------------------------------------------------
              New        281058       1-30-95
              Zealand
--------------------------------------------------------------------------------
              N. Korea   96-0582      1-30-95
--------------------------------------------------------------------------------
              Norway     96-3138      1-30-95
================================================================================


                                                                     Page 1 of 3
<PAGE>

================================================================================
   Docket     Country    Serial No.   Filing Date   Patent No.   Grant Date
    Name
================================================================================
              Romania    96-01548     1-30-95
--------------------------------------------------------------------------------
              Russia     96-117323    1-30-95
--------------------------------------------------------------------------------
              Sri Lanka  11021        1-30-95       11021        11/15/95
--------------------------------------------------------------------------------
              S. Korea   96-704125    1-30-95
--------------------------------------------------------------------------------
              Slovak     PV-926-96    1-30-95
              Republic
--------------------------------------------------------------------------------
              Viet Nam   SCO147/96    1-30-95
--------------------------------------------------------------------------------

================================================================================


                                                                     Page 2 of 3
<PAGE>

                         PROCESS FOR THE PREPARATION OF
                 2'-FLUORO-5-METHYL-B-L-ARABINOFURANOSYLURIDINE

Inventors: Chung Kewan Chu, Jinfa Du, Yong Seok Choi

================================================================================
   Docket     Country    Serial No.   Filing Date   Patent No.   Grant Date
    Name
================================================================================
     ***          ***          ***          ***
--------------------------------------------------------------------------------
              PCT        IB97/01254   8-29-97
--------------------------------------------------------------------------------
              Argentina  P9701 04409  9-25-97
--------------------------------------------------------------------------------
              China      97116278.6   9-8-97
--------------------------------------------------------------------------------
              India      unknown      9-15-97
--------------------------------------------------------------------------------
              Indonesia  P-973026     9-16-97
--------------------------------------------------------------------------------
              Israel     121.730      9-10-97
--------------------------------------------------------------------------------
              Korea      98-1421      1-19-97
--------------------------------------------------------------------------------
              Malaysia   unknown      9-13-97
--------------------------------------------------------------------------------
              Pakistan   706/97       9-13-97
--------------------------------------------------------------------------------
              PhilippinesI-57996      9-24-97
--------------------------------------------------------------------------------
              Saudi      98180771     1-4-98
              Arabia
--------------------------------------------------------------------------------
              Taiwan     86111816     8-16-97
--------------------------------------------------------------------------------
              Thailand   039630       9-15-97
--------------------------------------------------------------------------------
              Turkey     97/0151      9-26-97
================================================================================

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    Confidential Treatment and filed separately with the Commission.


                                                                     Page 3 of 3
<PAGE>

                                   Exhibit B

                                      ***

                                      ***

*** Portions of this page have been omitted pursuant to a request for
    Confidential Treatment and filed separately with the Commission.