<PAGE>

                                                                    Exhibit 10.4


                                                             EXECUTION COPY (V5)
                                                          ELAN LICENSE AGREEMENT


                                            ***TEXT OMITTED AND FILED SEPARATELY
                                                CONFIDENTIAL TREATMENT REQUESTED
                                          UNDER 17 C.F.R. SECTIONS 200.80(B)(4),
                                                            200.83 AND 240.24B-2

                                                                    29 June 2001



                               LICENSE AGREEMENT


                                    BETWEEN


                             ELAN CORPORATION, PLC


                                      AND


                            SAFESCIENCE NEWCO, LTD.

                                       1
<PAGE>

                               TABLE OF CONTENTS

<TABLE>
<S>                                                                 <C>
1     DEFINITIONS

2     ELAN LICENSE TO NEWCO

3     INTELLECTUAL PROPERTY

4     [...***...]

5     FINANCIAL PROVISIONS

6     RIGHT OF INSPECTION AND AUDIT

7     REPRESENTATIONS AND WARRANTIES

8     TERM AND TERMINATION

9     CONFIDENTIAL INFORMATION

10    GOVERNING LAW AND JURISDICTION

11    IMPOSSIBILITY OF PERFORMANCE - FORCE MAJEURE

12    ASSIGNMENT

13    NOTICES

14    MISCELLANEOUS
</TABLE>

                                       2
<PAGE>

THIS AGREEMENT dated 29 June 2001, and effective as of the Effective Date (as
defined below)

between:

(1)  Elan Corporation, plc., a public limited company incorporated under the
     laws of Ireland, and having its registered office at Lincoln House, Lincoln
     Place, Dublin 2, Ireland; and

(2)  SafeScience Newco, Ltd., an exempted limited liability company incorporated
     under the laws of Bermuda and having its registered office at Clarendon
     House, 2 Church St., Hamilton, Bermuda ("Newco").


RECITALS:
---------

A.   Simultaneously herewith, SafeScience, Elan, EIS, and Newco are entering
     into the JDOA for the purpose of recording the terms and conditions of the
     joint venture and of regulating their relationship with each other and
     certain aspects of the affairs of, and their dealings with, Newco.

B.   Newco desires to enter into this Agreement with Elan so as to permit Newco
     to utilize the Elan Intellectual Property in making, having made,
     importing, using, offering for sale and selling the Products in the Field
     in the Territory.

C.   Simultaneously herewith Newco and SafeScience are entering into the
     SafeScience License Agreement relating to Newco's use of the SafeScience
     Intellectual Property.


1    DEFINITIONS

1.1  In this Agreement unless the context otherwise requires:

     "Affiliate" shall mean any corporation or entity controlling, controlled by
     or under the common control of Elan or SafeScience or any third party, as
     the case may be, excluding, in the case of Elan, an Elan JV.  For the
     purpose of this definition, (i)"control" shall mean direct or indirect
     ownership of [...***...] or more of the stock or shares entitled to vote
     for the election of directors; and (ii) Newco shall not be an Affiliate of
     Elan, Elan Corp, or EIS nor shall Elan, Elan Corp, or EIS be an Affiliate
     of Newco.

     "After Acquired Technology" shall have the meaning as such term is defined
     in Clause 4.1.

                                       3
<PAGE>

     "Agreement" shall mean this license agreement (which expression shall be
     deemed to include the Recitals and Schedules hereto).

     "Change of Control of SafeScience/Newco" shall mean circumstances where:

          (a)  a Technological Competitor of Elan shall, directly or indirectly,
               (i) acquire [...***...] or more of the voting stock of
               SafeScience or Newco, or otherwise control or influence in any
               material respect their management or business; or (ii) otherwise
               have entered into any joint venture, collaborative, license or
               other arrangement with SafeScience or Newco, as the case may be,
               to such an extent that such a Technological Competitor of Elan
               controls or influences in any material respect the business or
               management of SafeScience or Newco, as the case may be; or

          (b)  any person or entity shall, directly or indirectly, acquire
               [...***...] or more of the then voting stock of SafeScience or
               Newco, or otherwise merge, consolidate or enter into any similar
               transaction (or binding agreement in respect thereof) with
               SafeScience or Newco.

     "Compounds" shall mean SafeScience's human therapeutic drug GBC-590, the
     structure of which is described in Schedule 1, such derivatives or analogs
     thereof, or other compounds which are approved in writing by the Steering
     Committee, in accordance with Clause 2.4 of the JDOA.

     "Confidential Information" shall have the meaning as such term is defined
     in Clause 9.

     "Definitive Documents" shall mean the definitive agreements relating to the
     transaction including finance, stock purchase, research and license
     agreements.

     "Effective Date" shall mean the Initial Closing Date.

     "EIS" shall mean Elan International Services, Ltd., a Bermudan exempted
     limited liability company having its registered office at Clarendon House,
     2 Church St., Hamilton, Bermuda.

     "Elan" shall mean Affiliates and subsidiaries of Elan Corp within the
     division of Elan Corp carrying on business as Elan Pharmaceutical
     Technologies.  For the avoidance of doubt, "Elan" shall exclude the
     Excluded Entities.

     "Elan Corp" shall mean Elan Corporation, plc., a public limited company
     incorporated under the laws of Ireland.

     "Elan Improvements" shall mean improvements to the Elan Patents and/or the
     Elan Know-How, developed (i) by Elan outside the Project, (ii) by Elan,
     SafeScience or

                                       4
<PAGE>

     Newco or by a third party (under contract with Newco) pursuant to the
     Project, and/or (iii) jointly by any combination of Elan, SafeScience,
     Newco or a third party (under contract with Newco) pursuant to the Project,
     except as limited by agreements with third parties.

     Subject to third party agreements, Elan Improvements shall constitute part
     of Elan Intellectual Property and be included in the Elan License pursuant
     to Clause 2.1 solely for the purposes set forth therein.  If the inclusion
     of an Elan Improvement in the Elan License is restricted or limited by a
     third party agreement, Elan shall use reasonable commercial efforts to
     minimize any such restriction or limitation.

     "Elan Intellectual Property" shall mean the Elan Know-How, the Elan Patents
     and the Elan Improvements.

     For the avoidance of doubt, Elan Intellectual Property shall exclude
     inventions, patents and know-how owned, licensed or controlled by the
     Excluded Entities.

     "Elan JV" shall mean an entity that Elan and a third party (i) establish or
     have established, (ii) take shareholdings in or have a right to take
     shareholdings in, and (iii) grant certain licenses in and to certain
     intellectual property rights for the purpose of implementing a strategic
     alliance.

     "Elan Know-How" shall mean, subject to Clause 4.1, any and all rights
     owned, licensed or controlled by Elan to any scientific, pharmaceutical or
     technical information, data, discovery, invention (whether patentable or
     not), know-how, substances, techniques, processes, systems, formulations,
     designs and expertise relating to Elan's proprietary [...***...] Drug
     Delivery Technology, which is not generally known to the public

     "Elan License" shall have the meaning set forth in Clause 2.1.

     "Elan Patents" shall mean, subject to Clause 4.1, any and all rights under
     any and all patent applications and/or patents, now existing, currently
     pending or hereafter filed or obtained or licensed by Elan relating to
     Elan's proprietary [...***...] Drug Delivery Technology, as set forth in
     Schedule 2, and any foreign counterparts thereof and all divisionals,
     continuations, continuations-in-part, any foreign counterparts thereof and
     all patents issuing on any of the foregoing, and any foreign counterparts
     thereof, together with all registrations, reissues, re-examinations,
     supplemental protection certificates, or extensions thereof, and any
     foreign counterparts thereof.

     "Elan Trademark(s)" shall mean one or more trademarks, trade names, or
     service marks that are owned or licensed by or on behalf of Elan which Elan
     may nominate and approve in writing from time to time for use in connection
     with the sale or promotion of the Products by Newco.

                                       5
<PAGE>

     "Excluded Entities" shall mean The Liposome Company, Inc. and its
     subsidiaries; Axogen Limited; Neuralab Limited; Dura Pharmaceuticals, Inc.
     and its subsidiaries; and Affiliates (present or future) of Elan Corp
     within the division of Elan Corp carrying on business as Elan
     Pharmaceuticals which incorporates, inter alia, Elan Pharma International,
     Ltd. (only to the extent that it is the owner of patents, know-how or other
     intellectual property or technology invented and/or developed within the
     division of Elan Corp carrying on business as Elan Pharmaceuticals), Athena
     Neurosciences, Inc., Elan Pharmaceuticals, Inc. and  Elan Europe Limited.

     "Field" shall mean the prevention and treatment of oncology indications in
     humans.

     "Financial Year" shall mean each year commencing on 1 January (or in the
     case of the first Financial Year, the Effective Date) and expiring on 31
     December of each year.

     "Initial Formulation" shall have the meaning as such term is defined in
     Clause 2.3 of the JDOA.

     "Initial Mode of Administration" shall have the meaning as such term is
     defined in Clause 2.3 of the JDOA.

     "Initial Closing Date" shall have the meaning as such term is defined in
     Section 1(a) of the SafeScience Securities Purchase Agreement.

     "JDOA" shall mean that certain subscription, joint development and
     operating agreement, of even date herewith, by and between Elan,
     SafeScience, EIS and Newco.

     [...***...]

     "NDA" shall mean New Drug Application.

     "Newco Intellectual Property" shall mean all rights to patents, know-how
     and other intellectual property arising out of the conduct of the Project
     by any person, including any technology acquired by Newco from a third
     party, which does not constitute Elan Intellectual Property or SafeScience
     Intellectual Property.

     For the avoidance of doubt (i) any preclinical and clinical data and/or
     toxicity, stability and pharmacological data generated pursuant to the
     Project shall constitute Newco Intellectual Property; and (ii) any patent
     application filed by Newco, or by Elan or SafeScience on behalf of Newco,
     and any patent issued pursuant thereto, covering a Product shall constitute
     Newco Intellectual Property.

     "Party" shall mean Elan or Newco, as the case may be, and "Parties" shall
     mean both parties together.

     "Product" shall mean the Initial Formulation and Initial Mode of
     Administration of the Compound in the Field, and such other formulations
     and modes of administration of the Compound as may be agreed to by the
     Steering Committee in accordance with Clause 2.4

                                       6
<PAGE>

     of the JDOA.

     "[...***...] Drug Delivery Technology" shall mean Elan's proprietary
     [...***...] [...***...].  For the avoidance of doubt, [...***...] Drug
     Delivery Technology shall not include Elan's [...***...].

     "Project" shall mean all activities as undertaken by Elan, SafeScience and
     Newco in order to develop the Products.

     "SafeScience" shall mean SafeScience, Inc., a Nevada corporation and its
     Affiliates.

     "SafeScience Improvements" shall have the meaning as such term is defined
     in the SafeScience License Agreement.

     "SafeScience Intellectual Property" shall mean the SafeScience Know-How,
     the SafeScience Patents and the SafeScience Improvements.

     "SafeScience Know-How" shall have the meaning as such term is defined in
     the SafeScience License Agreement.

     "SafeScience License Agreement" shall mean that certain license agreement,
     of even date herewith, entered into between SafeScience and Newco.

     "SafeScience Patents" shall have the meaning as such term is defined in the
     SafeScience License Agreement.

     "SafeScience Securities Purchase Agreement" shall mean that certain
     securities purchase agreement, dated June 22, 2001, by and between
     SafeScience and EIS.

     "Steering Committee" shall have the meaning as such term is defined in the
     JDOA.

     "Technological Competitor of Elan" shall mean a person or entity listed in
     Schedule 3, and divisions, subsidiaries and successors thereof, or any
     additional broad-based technological competitor of Elan added to such
     Schedule from time to time upon mutual agreement of SafeScience and Elan.

     "Term" shall have the meaning set forth in Clause 8.

     "Territory" shall mean all the countries of the world.

     "United States Dollar" and "US$" shall mean the lawful currency for the
     time being of the United States of America.

1.2  In this Agreement:

     1.2.1  The singular includes the plural and vice versa, and the masculine
            includes the feminine and vice versa and the neuter includes the
            masculine and the feminine.

                                       7
<PAGE>

     1.2.2  Any reference to a Clause or Schedule shall, unless otherwise
            specifically provided, be to a Clause or Schedule of this Agreement.

     1.2.3  The headings of this Agreement are for ease of reference only and
            shall not affect its construction or interpretation.


2    ELAN LICENSE TO NEWCO

2.1  Elan hereby grants to Newco for the Term [...***...]license to the Elan
     Intellectual Property to make, have made, import, use, offer for sale and
     sell the Product in the Field in the Territory (the "Elan License"),
     subject to [...***...].

2.2  [...***...] shall be responsible for payments related to the financial
     provisions and obligations of any third party agreement with respect to the
     Elan Intellectual Property to which it is a party on the Effective Date
     (including amendments thereto) (the "[...***...] Effective Date
     Agreements"), including without limitation, any royalty or other
     compensation obligations triggered thereunder on the Effective Date, or
     triggered thereunder after the Effective Date.

     For the avoidance of doubt, royalties, milestones or other payments which
     arise from the process of the commercialization or exploitation of products
     under the Elan Effective Date Agreements (for example, a milestone payment
     payable upon successful completion of Phase II clinical trials, the filing
     of an NDA application, obtaining NDA approval, or first commercial sale)
     shall be payments for which [...***...] will be responsible under this
     Clause 2.2.

2.3  SafeScience shall be a third party beneficiary under this Agreement and
     shall have the right to cause Newco to enforce Newco's rights under this
     Agreement against Elan.

2.4  Notwithstanding anything contained in this Agreement to the contrary, Elan
     shall have the right outside the Field, to exploit and grant licenses and
     sublicenses of the Elan Intellectual Property.

     For the avoidance of doubt, Newco shall have no right to use the Elan
     Intellectual Property outside the Field.

2.5  Newco shall not be permitted to assign, or, except as provided in Clause 11
     of the JDOA, license or sublicense any of its rights under the Elan
     Intellectual Property without the prior consent in writing of Elan.

2.6  Any agreement between Newco and any permitted third party for the
     development or exploitation of the Elan Intellectual Property shall require
     such third party to maintain the

                                       8
<PAGE>

     confidentiality of all information concerning the Elan Intellectual
     Property.

     Insofar as the obligations owed by Newco to Elan are concerned, Newco shall
     remain responsible for all acts and omissions of any permitted sub-
     licensee, including SafeScience, as if they were acts and omissions by
     Newco.


3    INTELLECTUAL PROPERTY

3.1  Ownership of Intellectual Property:
     -----------------------------------

     3.1.1  Newco shall own the Newco Intellectual Property.

     3.1.2  Elan shall own the Elan Intellectual Property.

3.2  Trademarks:
     -----------

     3.2.1  Elan hereby grants to Newco for the Term a [...***...] license to
            use the Elan Trademarks solely to make, have made, import, use,
            offer for sale and sell the Products in the Field in the Territory
            and the following provisions shall apply as regards the license of
            the Elan Trademarks by Elan to Newco hereunder:

            3.2.1.1  Newco shall ensure that each reference to and use of an
                     Elan Trademark by Newco is in a manner approved by Elan and
                     accompanied by an acknowledgement, in a form approved by
                     Elan, that the same is a trademark (or registered
                     trademark) of Elan.

                     From time to time, upon the reasonable request of Elan,
                     Newco shall submit samples of the Product to Elan or its
                     duly appointed agent to ensure compliance with quality
                     standards and specifications. Elan, or its duly appointed
                     agent, shall have the right to inspect the premises of
                     Newco where the Product is manufactured, held or stored,
                     and Newco shall permit such inspection, upon advance notice
                     at any reasonable time, of the methods and procedures used
                     in the manufacture, storage and sale of the Product. Newco
                     shall not sell or otherwise dispose of any Product under
                     the Elan Trademarks that fails to comply with the quality
                     standards and specifications referred to in this Clause
                     3.2, as determined by Elan.

            3.2.1.2  Newco shall not use an Elan Trademark in any way which
                     might materially prejudice its distinctiveness or validity
                     or the goodwill of Elan therein.

            3.2.1.3  The Parties recognize that the Elan Trademarks have
                     considerable goodwill associated therewith. Newco shall not
                     use in relation to the

                                       9
<PAGE>

                     Products any trademarks other than the Elan Trademarks,
                     except the SafeScience Trademarks (as such term is defined
                     in the SafeScience License Agreement) licensed to Newco
                     under the SafeScience License Agreement, without obtaining
                     the prior consent in writing of Elan, which consent may not
                     be unreasonably withheld. However, such use shall not
                     conflict with the use and display of the Elan Trademark and
                     such use and display shall require the prior written
                     approval of Elan.

            3.2.1.4  Newco shall not use in the Territory any trademarks or
                     trade names so resembling the Elan Trademark as to be
                     likely to cause confusion or deception.

            3.2.1.5  Newco shall promptly notify Elan in writing of any alleged
                     infringement or unauthorized use of which it becomes aware
                     by a third party of the Elan Trademarks and provide Elan
                     with any applicable evidence of infringement or
                     unauthorized use.

            3.2.1.6  Newco shall favorably consider promoting and using the Elan
                     Trademarks in each country of the Territory and provide
                     proof of such use upon request by Elan.

            3.2.1.7  Newco shall not be permitted to assign or sublicense any of
                     its rights under the Elan Trademarks without the prior
                     written consent of Elan.

     3.2.2  Elan may, at its sole discretion [...***...] file and prosecute
            applications to register and maintain registrations of the Elan
            Trademarks in the Territory. Newco shall reasonably co-operate with
            Elan in such efforts. Upon the reasonable request of Newco, Elan
            shall provide registration information, including classifications,
            for each country where the Elan Trademark has been registered.

     3.2.3  Elan will be entitled to conduct all enforcement proceedings
            relating to the Elan Trademarks and shall at its sole discretion
            decide what action, if any, to take in respect to any enforcement
            proceedings of the Elan Trademarks or any other claim or counter-
            claim brought in respect to the use or registration of the Elan
            Trademarks. Any such proceedings shall be conducted [...***...] for
            its own benefit. Newco and SafeScience shall reasonably co-operate
            with Elan in such efforts.

     3.2.4  Newco shall promptly notify Elan in writing in the event that any
            Elan Trademark has been challenged, or is threatened to be
            challenged in writing, by a third party in a judicial or
            administrative proceeding in a country in the Territory as
            infringing on the rights of a third party and Elan shall have the
            first right to decide whether or not to defend such allegations, or
            to adopt an alternative mark. If Elan

                                       10
<PAGE>

            decides not defend the Elan Trademark, then Newco may request Elan
            to defend the Elan Trademark, [...***...] unless such requested
            defense is believed by Elan to be unsubstantiated and without merit.
            In such a case, Elan may elect not to initiate defense proceedings.

     3.2.5  Newco will have no ownership rights in respect of the Elan
            Trademarks or of the goodwill associated therewith, and Newco hereby
            acknowledges that, except as expressly provided in this Agreement,
            it shall not acquire any rights in respect thereof and that all such
            rights and goodwill are, and will remain, vested in Elan.

     3.2.6  Nothing in this Agreement shall be construed as a warranty on the
     -----
            part of Elan regarding the Elan Trademarks, including without
            limitation, that use of the Elan Trademarks in the Territory will
            not infringe the rights of any third parties. Accordingly, Newco
            acknowledges and agrees that Elan makes no such warranty.

     3.2.7  Neither Elan nor Elan Corp assume liability to Newco, SafeScience,
            or to any third parties with respect to the quality, performance or
            characteristics of any of the goods manufactured or sold by Newco
            under the Elan Trademarks pursuant to this Agreement.


4  [...***...]

[...***...]

5    FINANCIAL PROVISIONS

5.1  License Fee: In consideration of the license to Newco of the Elan Patents
     -----------
     under Clause 2.1, Newco shall pay to Elan Corp a non-refundable license fee
     of $15 million in cash (the "License Fee"), the receipt of which is hereby
     acknowledged by Elan Corp.

     The License Fee shall not be subject to future performance obligations of
     Elan to Newco or SafeScience and shall not be applicable against future
     services provided by Elan to Newco or SafeScience.

     The terms of this Clause 5.1 relating to the License Fee are independent
     and distinct from the other terms of this Agreement.

5.2  Royalties: Prior to the commercialization of the Product, the Steering
     ---------
     Committee shall consider and if appropriate, determine reasonable royalties
     with respect to the commercialization of the Product by Newco that shall be
     payable by Newco to Elan Corp and SafeScience, [...***...].

     At such time, the Steering Committee will agree on an appropriate
     definition of "Net

                                       11
<PAGE>

     Sales" as such term is used in this Agreement.

     The provisions set forth in Clauses 5.2 to 5.8 and Clause 6 relate to the
     payment of any royalties which the Steering Committee may determine to be
     payable by Newco to Elan under this Agreement.

5.3  Payment of royalties pursuant to Clause 5.2 shall be made quarterly in
     arrears during each Financial Year within 30 days after the expiry of the
     calendar quarter. The method of payment shall be by wire transfer to an
     account specified by Elan Corp. Each payment made to Elan Corp shall be
     accompanied by a true accounting of all Products sold by Newco or Newco's
     permitted sublicensees, if any, during such quarter.

     Such accounting shall show, on a country-by-country and Product-by-Product
     basis, Net Sales (and the calculation thereof) and each calculation of
     royalties with respect thereto, including the calculation of all
     adjustments and currency conversions.

5.4  During the Term and for a period of five (5) years thereafter, Newco shall
     maintain and keep clear, detailed, complete, accurate and separate records.
     All costs and expenses incurred with respect to maintenance of such records
     shall be borne by Newco for up to a period of three (3) years, from the
     date such records are created, and thereafter, such costs and expenses
     shall be borne solely by SafeScience:

     5.4.1  to enable any royalties on Net Sales that shall have accrued
            hereunder to be determined; and

     5.4.2  to enable any deductions made in the Net Sales calculation to be
            determined.

5.5  All payments due hereunder shall be made in United States Dollars. Payments
     due on Net Sales of any Product for each calendar quarter made in a
     currency other than United States Dollars shall first be calculated in the
     foreign currency and then converted to United States Dollars on the basis
     of the exchange rate in effect on the last working day for such quarter for
     the purchase of United States Dollars with such foreign currency quoted in
     the Wall Street Journal (or comparable publication if not quoted in the
     Wall Street Journal).

5.6  If, at any time, legal restrictions in the Territory prevent the prompt
     payment when due of royalties or any portion thereof, the Parties shall
     meet to discuss suitable and reasonable alternative methods of paying Elan
     Corp the amount of such royalties. In the event that Newco is prevented
     from making any payment under this Agreement by virtue of the statutes,
     laws, codes or government regulations of the country from which the payment
     is to be made, then such payments may be paid by depositing them in the
     currency in which they accrue to Elan Corp's account in a bank acceptable
     to Elan Corp in the country the currency of which is involved, or as
     otherwise agreed by the Parties.

                                       12
<PAGE>

5.7  Elan, SafeScience and Newco agree to co-operate in all respects necessary
     to take advantage of any double taxation agreements or similar agreements
     as may, from time to time, be available.

5.8  Any taxes payable by Elan Corp on any payment made to Elan Corp pursuant to
     this Agreement shall be for the account of Elan Corp. If so required by
     applicable law, any payment made pursuant to this Agreement shall be made
     by Newco after deduction of the appropriate withholding tax, in which event
     the Parties shall co-operate to obtain the appropriate tax clearance as
     soon as is practicable. On receipt of such clearance, Newco shall forthwith
     arrange payment to Elan Corp of the amount so withheld.

6    RIGHT OF INSPECTION AND AUDIT

6.1  Once during each Financial Year, or more often not to exceed quarterly as
     reasonably requested by Elan, Newco shall permit Elan or its duly
     authorized representatives, upon reasonable notice and at any reasonable
     time during normal business hours, to have access to inspect and audit the
     accounts and records of Newco and any other book, record, voucher, receipt
     or invoice relating to the calculation of the royalty payments on Net
     Sales.

     Any such inspection of Newco's records shall be at the expense of Elan,
     except that if any such inspection reveals a deficiency in the amount of
     the royalty actually paid to Elan Corp hereunder in any Financial Year
     quarter of [...***...] or more of the amount of any royalty actually due to
     Elan Corp hereunder, then the expense of such inspection shall be borne
     solely by Newco.  Newco shall promptly pay to Elan Corp any amount of
     deficiency.

     If such inspection reveals a surplus in the amount of royalties actually
     paid to Elan Corp by Newco, Elan Corp shall reimburse Newco the surplus
     within 15 days after determination.

6.2  In the event of any unresolved dispute regarding any alleged deficiency or
     overpayment of royalty payments hereunder, the matter will be referred to
     an independent firm of chartered accountants chosen by agreement of
     SafeScience and EIS for a resolution of such dispute. Any decision by the
     said firm of chartered accountants shall be binding on the Parties.

7    REPRESENTATIONS AND WARRANTIES

7.1  Elan represents and warrants to Newco and SafeScience, as of the Effective
     Date, with respect to the Compound as it relates to the Elan Intellectual
     Property, as follows:

     7.1.1  Elan has the right to grant the Elan License;

                                       13
<PAGE>

     7.1.2  there are no agreements between Elan and any third party that
            conflict with the Elan License;

     7.1.3  [...***...]; and

     7.1.4  [...***...].

7.2  Except to the extent Newco shall have the obligation to indemnify Elan
     pursuant to Clause 7.3 hereof and SafeScience and Elan pursuant to Clause
     10 of the JDOA, in addition to any other indemnities provided for herein,
     Elan shall indemnify and hold harmless Newco and its Affiliates and their
     respective employees, agents, officers and directors from and against any
     claims, losses, liabilities or damages (including reasonable attorney's
     fees and expenses) incurred or sustained by Newco arising out of or in
     connection with any:

     7.2.1  breach of any representation, covenant, warranty or obligation by
            Elan hereunder; or

     7.2.2  negligent act or omission on the part of Elan or any of its
            employees, agents, officers or directors in the performance of this
            Agreement.

7.3  In addition to any other indemnities provided for herein, Newco shall
     indemnify and hold harmless Elan and its Affiliates and their respective
     employees, agents, officers and directors from and against any claims,
     losses, liabilities or damages (including reasonable attorney's fees and
     expenses) incurred or sustained by Elan arising out of or in connection
     with any:

     7.3.1  breach of any representation, covenant, warranty or obligation by
            Newco hereunder; or

     7.3.2  negligent act or omission on the part of Newco or any of its
            employees, agents, officers or directors in the performance of this
            Agreement.

7.4  A party to this Agreement seeking an indemnity (the "Indemnified Party"),
     pursuant to this Clause 7, shall:

     7.4.1  fully and promptly notify the Party responsible for indemnifying
            such Indemnified Party (the "Indemnifying Party") of any claim or
            proceeding, or threatened claim or proceeding;

     7.4.2  permit the Indemnifying Party to take full care and control of such
            claim or proceeding;

     7.4.3  co-operate in the investigation and defense of such claim or
            proceeding;

                                       14
<PAGE>

     7.4.4  not compromise or otherwise settle any such claim or proceeding
            without the prior written consent of the Indemnifying Party, which
            consent shall not be unreasonably withheld or delayed; and

     7.4.5  take all reasonable steps to mitigate any loss or liability in
            respect of any such claim or proceeding.

7.5  EXCEPT AS SET FORTH IN THIS CLAUSE 7, ELAN IS GRANTING THE ELAN LICENSE
     HEREUNDER ON AN "AS IS" BASIS WITHOUT REPRESENTATION OR WARRANTY WHETHER
     EXPRESS OR IMPLIED INCLUDING WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
     PARTICULAR PURPOSE, OR INFRINGEMENT OF THIRD PARTY RIGHTS, AND ALL SUCH
     WARRANTIES ARE EXPRESSLY DISCLAIMED.

7.6  NOTWITHSTANDING ANYTHING TO THE CONTRARY IN THIS AGREEMENT, ELAN AND NEWCO
     SHALL NOT BE LIABLE TO THE OTHER BY REASON OF ANY REPRESENTATION OR
     WARRANTY, CONDITION OR OTHER TERM OR ANY DUTY OF COMMON LAW, OR UNDER THE
     EXPRESS TERMS OF THIS AGREEMENT, FOR ANY CONSEQUENTIAL, SPECIAL OR
     INCIDENTAL OR PUNITIVE LOSS OR DAMAGE (WHETHER FOR LOSS OF CURRENT OR
     FUTURE PROFITS, LOSS OF ENTERPRISE VALUE OR OTHERWISE) AND WHETHER
     OCCASIONED BY THE NEGLIGENCE OF THE RESPECTIVE PARTIES, THEIR EMPLOYEES OR
     AGENTS OR OTHERWISE.

8    TERM AND TERMINATION

8.1  The term of this Agreement shall commence as of the Effective Date and
     shall, subject to the rights of termination outlined in this Clause 8 and
     to the provisions of applicable laws, expire on the last to occur of:

     8.1.1  the date of expiration or lapse of the last to expire or lapse of
            patent rights within the Elan Intellectual Property and the
            SafeScience Intellectual Property in the Territory; or

     8.1.2  the date which is [...***...] years following the date of the first
            commercial sale of a Product in the Territory provided, however,
            that neither Elan nor SafeScience shall be obligated to license the
            Elan Intellectual Property or the SafeScience Intellectual Property,
            respectively, beyond any period in which Elan or SafeScience has
            rights to such intellectual property pursuant to any agreement
            between Elan or SafeScience and their respective licensors as such
            agreements are in effect as of the Effective Date.

                                       15
<PAGE>

     (the "Term").

8.2  If either Party commits a Relevant Event, the other Party shall have, in
     addition to all other legal and equitable rights and remedies hereunder,
     the right to terminate this Agreement upon 30 days' prior written notice to
     the defaulting Party.

8.3  For the purpose of this Clause 8, a "Relevant Event" is committed by a
     Party if:

     8.3.1  such Party commits a material breach of its representations,
            warranties or obligations under this Agreement or the JDOA and fails
            to cure it within 60 days of being specifically required in writing
            to do so by the other Party; provided, that if the breaching Party
            has proposed a course of action to cure the breach and is acting in
            good faith to cure same but has not cured the breach by the 60th
            day, such period shall be extended by such period as is reasonably
            necessary to permit the breach to be cured, provided that such
            period shall not be extended by more than 90 days, unless otherwise
            agreed in writing by the Parties;

     8.3.2  a distress, execution, sequestration or other process is levied or
            enforced upon or sued out against a material part of its property
            which is not discharged within 30 days;

     8.3.3  it is unable to pay its debts in the normal course of business;

     8.3.4  it ceases wholly or substantially to carry on its business,
            otherwise than for the purpose of a reconstruction or amalgamation,
            without the prior written consent of the other Party (such consent
            not to be unreasonably withheld);

     8.3.5  the appointment of a liquidator, receiver, administrator, examiner,
            trustee or similar officer of such Party or over all or
            substantially all of its assets under the law of any applicable
            jurisdiction, including without limitation, the United States of
            America, Bermuda or Ireland; or

     8.3.6  an application or petition for bankruptcy, corporate re-
            organization, composition, administration, examination, arrangement
            or any other procedure similar to any of the foregoing under the law
            of any applicable jurisdiction, including without limitation, the
            United States of America, Bermuda or Ireland, is filed, and is not
            discharged within 60 days, or a Party applies for or consents to the
            appointment of a receiver, administrator, examiner or similar
            officer of it or of all or a material part of its assets, rights or
            revenues.

8.4  Elan shall be entitled to forthwith terminate this Agreement by notice in
     writing to SafeScience in the event of a Change of Control of
     SafeScience/Newco, provided that the foregoing right shall not be triggered
     by the exercise by Elan of any options granted by the Definitive Documents.

                                      16
<PAGE>

     SafeScience and Newco shall promptly notify Elan in writing of the
     occurrence of a Change of Control of SafeScience/Newco.

8.5  Upon expiration or termination of the Agreement:

     8.5.1  any sums that were due from Newco to Elan on Net Sales in any part
            of the Territory shall be paid in full within 60 days;

     8.5.2  any provisions that expressly survive termination or expiration of
            this Agreement, including without limitation this Clause 8, shall
            remain in full force and effect;

     8.5.3  all representations, warranties and indemnities shall insofar as are
            appropriate remain in full force and effect;

     8.5.4  the rights of inspection and audit set out in Clause 6 shall
            continue in force for a period of one year;

     8.5.5  subject to Clause 8.5.7, all rights and licenses granted to Newco
            pursuant to this Agreement and to the Elan Intellectual Property
            pursuant to the JDOA (including the rights of Newco pursuant to
            Clause 11 of the JDOA) shall cease for the Territory and shall
            revert to or be transferred to Elan, and Newco shall not thereafter
            use in the Territory any rights covered by this Agreement;

     8.5.6  subject to any license granted by Newco to Elan, if any, or granted
            by Newco to SafeScience, if any, pursuant to the provisions of
            Clause 11.3 of the JDOA, all rights to Newco Intellectual Property
            shall be assigned to and jointly owned by SafeScience and Elan and
            may be exploited by both Elan and SafeScience separately provided
            that Elan and SafeScience shall co-operate reasonably in the
            prosecution and maintenance of patents within the Newco Intellectual
            Property and provided further that nothing hereunder shall grant, or
            be construed to grant, a license to Elan under the SafeScience
            Intellectual Property; and

     8.5.7  the rights of permitted third party sub-licensees in and to the Elan
            Intellectual Property shall survive the termination of this
            Agreement; and Newco, Elan and SafeScience shall in good faith agree
            upon the form most advantageous to Elan and SafeScience in which the
            rights of Newco under any such licenses and sublicenses are to be
            held (which form may include continuation of Newco solely as the
            holder of such licenses or assignment of such rights to a third
            party or parties, including an assignment to both Elan and
            SafeScience).

            Any sublicense agreement between Newco and such permitted
            sublicensee shall, inter alia, permit such an assignment of rights
            by Newco to Elan and shall contain appropriate confidentiality
            provisions.

                                       17
<PAGE>

9    CONFIDENTIAL INFORMATION

9.1  The Parties agree that it will be necessary, from time to time, to disclose
     to each other confidential and proprietary information, including without
     limitation, inventions, works of authorship, trade secrets, specifications,
     designs, data, know-how and other proprietary information relating to the
     Field, the Products, processes, services and business of the disclosing
     Party.

     The foregoing shall be referred to collectively as "Confidential
     Information".

9.2  Any Confidential Information disclosed by the disclosing Party shall be
     used by the receiving Party exclusively for the purposes of fulfilling the
     receiving Party's obligations under this Agreement and for no other
     purpose.

9.3  Save as otherwise specifically provided herein, each Party shall disclose
     Confidential Information of the other Party only to those employees,
     representatives and agents requiring knowledge thereof in connection with
     fulfilling the Party's obligations under this Agreement. Each Party further
     agrees to inform all such employees, representatives and agents of the
     terms and provisions of this Agreement relating to Confidential Information
     and their duties hereunder and to obtain their agreement hereto as a
     condition of receiving Confidential Information. Each Party shall exercise
     the same standard of care as it would itself exercise in relation to its
     own confidential information (but in no event less than a reasonable
     standard of care) to protect and preserve the proprietary and confidential
     nature of the Confidential Information disclosed to it by the other Party.
     Each Party shall promptly, upon request of the other Party, return all
     documents and any copies thereof containing Confidential Information
     belonging to, or disclosed by, such other Party.

9.4  Any breach of this Clause 9 by any person informed by one of the Parties is
     considered a breach by the Party itself.

9.5  Confidential Information shall be deemed not to include:

     9.5.1  information which is in the public domain;

     9.5.2  information which is made public through no breach of this
            Agreement;

     9.5.3  information which is independently developed by a Party, as
            evidenced by such Party's records;

     9.5.4  information that becomes available to a receiving Party on a non-
            confidential basis, whether directly or indirectly, from a source
            other than another Party

                                       18
<PAGE>

            hereto, which source did not acquire this information on a
            confidential basis.

9.6  The receiving Party will be entitled to disclose Confidential Information
     which the receiving Party is required to disclose pursuant to:

     9.6.1  a valid order of a court or other governmental body; or

     9.6.2  any other requirement of law;

     provided that if the receiving Party becomes legally required to disclose
     any Confidential Information hereunder, the receiving Party shall give the
     disclosing Party prompt notice of such fact to enable the disclosing Party
     to seek a protective order or other appropriate remedy concerning any such
     disclosure.  The receiving Party shall fully co-operate with the disclosing
     Party in connection with the disclosing Party's efforts to obtain any such
     order or other remedy.  If any such order or other remedy does not fully
     preclude disclosure, the receiving Party shall make such disclosure only to
     the extent that such disclosure is legally required.

9.7  The provisions relating to confidentiality in this Clause 9 shall remain in
     effect during the term of this Agreement, and for a period of 7 years
     following the expiration or earlier termination of this Agreement.

9.8  The Parties agree that the obligations of this Clause 9 are necessary and
     reasonable in order to protect the Parties' respective businesses, and each
     Party agrees that monetary damages would be inadequate to compensate a
     Party for any breach by the other Party of its covenants and agreements set
     forth herein.

     The Parties agree that any such violation or threatened violation shall
     cause irreparable injury to a Party and that, in addition to any other
     remedies that may be available, in law and equity or otherwise, each Party
     shall be entitled to seek injunctive relief against the threatened breach
     of the provisions of this Clause 9, or a continuation of any such breach by
     the other Party, specific performance and other equitable relief to redress
     such breach together with damages and reasonable counsel fees and expenses
     to enforce its rights hereunder.

10   GOVERNING LAW AND JURISDICTION

10.1 This Agreement shall be governed by and construed in accordance with the
     laws of the State of New York.

10.2 The Parties will attempt in good faith to resolve any dispute arising out
     of or relating to this Agreement promptly by negotiation between executives
     of the Parties.

     In the event that such negotiations do not result in a mutually acceptable
     resolution

                                       19
<PAGE>

     within 60 days of the commencement of such negotiations, the Parties agree
     to consider other dispute resolution mechanisms including mediation.

     In the event that the Parties fail to agree on a mutually acceptable
     dispute resolution mechanism within 10 days of either Party's demand for
     such alternative dispute resolution hereunder, or in the event that the
     dispute is not resolved pursuant to any dispute resolution mechanism agreed
     by the Parties within 6 months, save as otherwise agreed by the Parties,
     any such dispute shall be finally settled by the courts of competent
     jurisdiction.  For the purposes of this Agreement the parties submit to the
     exclusive jurisdiction of the courts of the State and Federal Courts
     located in the State, City and County of New York.


11   IMPOSSIBILITY OF PERFORMANCE - FORCE MAJEURE

     Neither Elan nor Newco shall be liable for delay in the performance of any
     of its obligations hereunder if such delay results from causes beyond its
     reasonable control, including, without limitation, acts of God, strikes,
     acts of war, intervention of a government authority, but any such delay or
     failure shall be remedied by such Party as soon as practicable.


12   ASSIGNMENT

     This Agreement may not be assigned by either Party without the prior
     written consent of the other, save that either Party may assign this
     Agreement to its Affiliates or subsidiaries without such prior written
     consent; provided that such assignment does not have any adverse tax
     consequences on the other Party.


13   NOTICES

13.1 Any notice to be given under this Agreement shall be sent in writing in
     English by registered or recorded delivery post or reputable overnight
     courier or telefaxed to the following addresses:

     If to Newco at:

     Clarendon House,
     2 Church St,
     Hamilton,
     Bermuda.
     Attention: Secretary
     Telephone: 441 292 9169

                                       20
<PAGE>

     Fax:  441 292 2224

     with a copy to SafeScience at:

     Park Square Building
     31 St. James Avenue, 8th Floor
     Boston, MA 02116
     USA

     Attention: President
     Telephone  (617) 422-0674
     Fax:       (617) 422-0675

     with a copy to:

     McDermott, Will & Emery
     50 Rockefeller Plaza
     New York, New York 10020-1605

     Attention: Cheryl V. Reicin
     Telephone  (212) 547-5400
     Fax:       (212) 547-5444

     If to Elan at:

     c/o Elan International Services, Ltd.,
     102 St. James Court,
     Flatts, Smiths FL04,
     Bermuda.

     Attention: President
     Telephone: 441-292-9169
     Fax:       441-292-2224

     or to such other address(es) and telefax numbers as may from time to time
     be notified by either Party to the other hereunder in the manner set forth
     in Clause 13.2.

13.2 Any notice sent by mail shall be deemed to have been delivered within 7
     working days after dispatch or delivery to the relevant courier and any
     notice sent by telefax shall be deemed to have been delivered upon
     confirmation of receipt.  Notice of change of address shall be effective
     upon receipt.  Notices by telefax shall also be sent by another method
     permitted hereunder.

                                       21
<PAGE>

14   MISCELLANEOUS

14.1 Waiver:
     -------

     No waiver of any right under this Agreement shall be deemed effective
     unless contained in a written document signed by the Party charged with
     such waiver, and no waiver of any breach or failure to perform shall be
     deemed to be a waiver of any other breach or failure to perform or of any
     other right arising under this Agreement.

14.2 Severability:
     -------------

     If any provision in this Agreement is deemed to be invalid, illegal, void
     or unenforceable under any law that is applicable hereto:

     14.2.1  such provision will be deemed amended to conform to applicable laws
             so as to be valid and enforceable; or

     14.2.2  if it cannot be so amended without materially altering the
             intention of the Parties, it will be deleted and the validity,
             legality and enforceability of the remaining provisions of this
             Agreement shall not be impaired or affected in any way.

14.3 Further Assurances:
     -------------------

     At the request of any Party to this Agreement, the other Party shall (and
     shall use reasonable efforts to procure that any other necessary parties
     shall) execute and perform all such documents, acts and things as may
     reasonably be required subsequent to the signing of this Agreement for
     assuring to or vesting in the requesting Party the full benefit of the
     terms hereof.

14.4 Successors:
     -----------

     This Agreement shall be binding upon and enure to the benefit of the
     Parties hereto, their successors and permitted assigns.

14.5 No Effect on Other Agreements/Conflict:
     ---------------------------------------

     No provision of this Agreement shall be construed so as to negate, modify
     or affect in any way the provisions of any other agreement between the
     Parties unless specifically referred to, and solely to the extent provided
     herein.

     In the event of a conflict between the provisions of this Agreement and the
     provisions of the JDOA, the terms of the JDOA shall prevail unless this
     Agreement specifically provides otherwise.

                                       22
<PAGE>

14.6  Amendments:
      -----------

      No amendment, modification or addition hereto shall be effective or
      binding on any Party unless set forth in writing and executed by a duly
      authorized representative of each Party.

14.7  Counterparts:
      -------------

      This Agreement may be executed in any number of counterparts, each of
      which when so executed shall be deemed to be an original and all of which
      when taken together shall constitute this Agreement.

14.8  Good Faith:
      -----------

      Each Party undertakes to act reasonably in giving effect to the provisions
      of this Agreement.

14.9  No Reliance:
      ------------

      Each Party hereby acknowledges that in entering into this Agreement it has
      not relied on any representation or warranty save as expressly set out
      herein or in any document referred to herein.

14.10 Relationship of the Parties:
      ----------------------------

      Nothing contained in this Agreement is intended or is to be construed to
      constitute Elan and Newco as partners, or Elan as an employee of Newco, or
      Newco as an employee of Elan.

      Neither Party hereto shall have any express or implied right or authority
      to assume or create any obligations on behalf of or in the name of the
      other Party or to bind the other Party to any contract, agreement or
      undertaking with any third party.


14.11 Whole Agreement:
      ----------------

      This Agreement (including the Schedules attached hereto) and the
      Definitive Documents set forth all of the agreements and understandings
      between the Parties with respect to the subject matter hereof, and
      supersede and terminate all prior agreements and understandings between
      the Parties with respect to the subject matter hereof. There are no
      agreements or understandings with respect to the subject matter hereof,
      either oral or written, between the Parties other than as set forth in
      this Agreement and the Definitive Documents.

                                       23
<PAGE>

                                  Schedule 1
                                  ----------

                             Structure of Compound
                             ---------------------



                                  [...***...]

                                       24
<PAGE>

                                  Schedule 2
                                  ----------

                                 Elan Patents
                                 ------------

                                  [...***...]

                                       25
<PAGE>

                                  Schedule 3
                                  ----------

                       Technological Competitors of Elan
                       ---------------------------------


                                  [...***...]

                                       26
<PAGE>

IN WITNESS WHEREOF the Parties hereto have executed this Agreement.



    SIGNED


BY   /s/ Colin Sainsbury
    --------------------------
    For and on behalf of
    Elan Corporation, plc



    SIGNED

BY   /s/ Kevin Insley
    --------------------------
    For and on behalf of
    SafeScience Newco, Ltd.



    AGREED TO AND ACCEPTED



BY   /s/ Bradley J. Carver
    --------------------------
    SafeScience, Inc.

                                       27