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                                                                    Exhibit 10.1


* CERTAIN CONFIDENTIAL INFORMATION CONTAINED IN THIS DOCUMENT, MARKED BY
BRACKETS, HAS BEEN OMITTED AND FILED WITH THE SECURITIES AND EXCHANGE COMMISSION
PURSUANT TO RULE 406 OF THE SECURITIES ACT OF 1933, AS AMENDED.

              DEVELOPMENT, COMMERCIALIZATION AND LICENSE AGREEMENT

        This DEVELOPMENT, COMMERCIALIZATION AND LICENSE AGREEMENT (the
"Agreement") is entered into on October 26, 2001 (the "Signing Date") and made
effective as of the Effective Date (as defined below) between CORIXA
CORPORATION, a Delaware corporation, with its principal place of business at
1124 Columbia Street, Suite 200, Seattle, WA 98104, U.S.A. ("Corixa
Corporation"), and AMERSHAM PLC, a company incorporated under the laws of
England, with its principal place of business at Amersham Place, Little
Chalfont, Buckinghamshire, England HP7 9NA ("Amersham"). Both Corixa and
Amersham are referred to individually as a "Party" and collectively as the
"Parties."

        WHEREAS, Corixa, as the successor to Coulter Pharmaceutical, Inc.
("Coulter"), has rights to and is developing Bexxar, an antibody product pending
FDA approval; and

        WHEREAS, Amersham possesses development, manufacturing, marketing and
distribution capability for radiolabeled products in Europe; and

        WHEREAS, Amersham desires to obtain rights to develop and commercialize
such product in Europe for the treatment of humans and Corixa is willing to
grant such rights on the terms and conditions hereof; and

        WHEREAS, Amersham desires to obtain bulk or finished antibody for such
product from Corixa and Corixa is willing to provide such antibody on the terms
and conditions as set forth in the supply agreement by and between the Parties
of even date herewith (the "Supply Agreement"); and

        NOW THEREFORE, in consideration of the foregoing premises and the mutual
promises, covenants and conditions contained in this Agreement, the Parties
agree as follows:

1.      DEFINITIONS

        The following terms shall have the following meanings as used in this
Agreement:

        1.1 "AFFILIATE" means, with respect to a particular Party, a person,
corporation, partnership, or other entity that controls, is controlled by or is
under common control with such Party. For the purposes of the definition in this
Section 1.1, the word "control" (including, with correlative meaning, the terms
"controlled by" or "under the common control with") means the actual power,
either directly or indirectly through one or more intermediaries, to direct or
cause the direction of the management and policies of such entity, whether by
the ownership of at least fifty percent (50%) of the voting stock of such
entity, or by contract or otherwise. Anything to the contrary, notwithstanding,
the term "Affiliate" shall not include Nihon Medi-Physics, Inc., a Japanese
company.


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        1.2 "AMERSHAM IODINE I 131 TOSITUMOMAB" shall mean any Iodine I 131
Tositumomab that Amersham or its agent prepares from Tositumomab.

        1.3 "AMERSHAM MATTER" shall mean any issue relating to:

            (a) development (including without limitation clinical development
and Regulatory Filings) of the Product for and in the Territory other than those
issues related to obtaining Initial Approval;

            (b) the European Facility or the manufacture of the Amersham Iodine
I 131 Tositumomab in the Territory; or

            (c) sale and/or marketing of the Product in the Territory.

        1.4 "ANNUAL NET SALES" shall mean, with respect to a particular calendar
year, the total Net Sales for such calendar year.

        1.5 "BLA" shall mean a Biologics License Application, as defined by the
regulations promulgated under the United States FD&C Act and Public Health
Services Act and any supplements thereunder, as amended from time to time.

        1.6 "CLINICAL TRIAL" shall mean a trial, conducted by a Party or a
licensee of a Party, in which a Product is administered to humans with the goal
of generating data (a) to support an application for Regulatory Approval of such
Product or (b) for purposes of marketing the Product. The Clinical Trials
initiated or planned by Corixa prior to the Effective Date are listed in Exhibit
D.

        1.7 "CLINICAL TRIAL COSTS" shall mean the direct and indirect costs
incurred by one or both Parties and any licensees thereof in connection with a
particular Clinical Trial, including, without limitation, fees paid to clinical
sites, fees paid to human subjects participating in such Clinical Trial, and FTE
and other overhead expenses, if any, directly attributable to such Clinical
Trial.

        1.8 "COLLABORATION STEERING COMMITTEE" and "CSC" shall have the meanings
given such terms in Section 3.1(a).

        1.9 "CONTROLLED" means, with respect to any gene, protein, compound,
material, Information or intellectual property right, that the Party owns or has
a license to such gene, protein, compound, material, Information or intellectual
property right and has the ability to grant to the other Party access, a license
or a sublicense (as applicable) to such gene, protein, compound, material,
Information or intellectual property right on the terms and conditions set forth
herein without violating the terms of any agreement or other arrangements with
any Third Party existing at the time such Party would be first required
hereunder to grant the other Party such access, license or sublicense.

        1.10 "CORIXA" shall mean Corixa Corporation and its Affiliates.


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        1.11 "CORIXA INTELLECTUAL PROPERTY RIGHTS" shall mean all Intellectual
Property Rights in existence on the Effective Date that are Controlled by Corixa
during the term of this Agreement, including those Patents set forth in Exhibit
A (which Corixa may update from time to time).

        1.12 "CORIXA IODINE I 131 TOSITUMOMAB" shall mean any Iodine I 131
Tositumomab that Corixa provides to Amersham hereunder.

        1.13 "CORIXA MATTER" shall mean any issue relating to (a) obtaining
Initial Approval (including without limitation clinical development and
Regulatory Filings) or (b) manufacture (except for those issues relating solely
to the European Facility) of the Product for use in the Territory. For clarity,
all issues concerning whether a particular Clinical Trial shall be designated as
an Initial Approval Clinical Trial pursuant to Section 4.5 or 5.4 are Corixa
Matters.

        1.14 "CORIXA TERRITORY" shall mean all countries and territories of the
world except those in the Territory.

        1.15 "CROSS-TERRITORY CLINICAL TRIAL" shall mean a Clinical Trial
conducted in the Territory and the Corixa Territory.

        1.16 "DANA FARBER AGREEMENTS" shall mean:

            (a) the Agreement between Sidney Farber Cancer Institute and Coulter
Electronics, Inc., dated July 23, 1981;

            (b) Modification Agreement between Dana-Farber Cancer Institute and
Coulter Electronics, Inc., dated March 1, 1983;

            (c) License Agreement between Dana-Farber Cancer Institute and
Coulter Immunology, Division of Coulter Corporation, dated April 28, 1983;

            (d) Modification Agreement No. 2 between Dana-Farber Cancer
Institute and Coulter Immunology, Division of Coulter Corporation, dated April
1, 1987;

            (e) Agreement between Coulter Corporation and Dana-Farber Cancer
Institute, Inc., dated April 1, 1994;

            (f) Agreement between Coulter Pharmaceutical and Coulter
Corporation, dated February 24, 1995; and

            (g) Agreement among Dana-Farber Cancer Institute, Coulter
Corporation and Coulter Pharmaceutical, Inc. dated December 2, 1998.

        1.17 "DEVELOPMENT BUDGET" shall mean the detailed budget for the
activities described in the Development Plan (whether the Initial Development
Plan or the Subsequent Development Plan), approved as a part of the Initial
Development Plan or Subsequent Development Plan, as applicable, pursuant to
Section 4.2, 4.3 or 4.4.


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        1.18 "DEVELOPMENT PLAN" shall mean the Initial Development Plan or the
Subsequent Development Plan, as the context indicates.

        1.19 "DILIGENT EFFORTS" means [*].

        1.20 "EFFECTIVE DATE" shall mean the First Closing Date, as such term is
defined in the Stock Purchase Agreement.

        1.21 "EUROPEAN FACILITY" shall have the meaning set forth in the Supply
Agreement.

        1.22 "FD&C ACT" shall mean the United States Federal Food, Drug and
Cosmetic Act, as amended.

        1.23 "FDA" shall mean the United States Food and Drug Administration or
its successor.

        1.24 "FIELD" shall mean [*].

        1.25 "FIRST COMMERCIAL SALE" shall mean the first commercial sale of a
Product in a given regulatory jurisdiction after the Product has been granted
Regulatory Approval by the competent authorities in such jurisdiction.

        1.26 "FTE RATE" shall mean the amount to be paid by Amersham for [*] the
Corixa's employees. The FTE Rate for calendar year 2001 will be [*] per
employee. For each subsequent calendar year, this rate will be [*].

        1.27 "FULLY ALLOCATED COST" shall mean [*].

        1.28 "GOOD MANUFACTURING PRACTICE" or "GMP" shall mean the current
standards for the manufacture of pharmaceuticals, as set forth in the FD&C Act
and applicable regulations and guidances promulgated thereunder, including
without limitation the Code of Federal Regulations, as amended from time to
time, and any other applicable manufacturing requirements under the laws, rules
or regulations of the Territory.

        1.29 "INFORMATION" means [*].

        1.30 "INITIAL APPROVAL" shall mean the first approval of an MAA for the
Product by the EMEA.

        1.31 "INITIAL APPROVAL CLINICAL TRIALS" shall mean the Clinical Trials
that the CSC designates pursuant to Section 4.5 or 5.4 as the Clinical Trials
that the Parties expect to be used to seek Initial Approval.

        1.32 "INITIAL APPROVAL TRIAL COSTS" shall mean [*].



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        1.33 "INITIAL DEVELOPMENT PLAN" shall mean a [*] plan [*] that includes
[*] and (b) which has been approved by the CSC in accordance with Section
4.2 or 4.3.

        1.34 "INITIAL REGULATORY FILINGS" shall have the meaning set forth in
Section 5.6.

        1.35 "INTELLECTUAL PROPERTY RIGHTS" shall mean [*].

        1.36 "INVENTION" means any [*].

        1.37 "IODINE I 131 TOSITUMOMAB" shall mean any [*] product [*] with
131Iodine that was [*] anti CD20 murine monoclonal antibody.

        1.38 "JOINT COMMERCIALIZATION COMMITTEE" and "JCC" shall have the
meanings given such terms in Section 3.3(a).

        1.39 "JOINT DEVELOPMENT COMMITTEE" and "JDC" shall have the meanings
given such terms in Section 3.2(a).

        1.40 "JOINT OTHER INVENTIONS" means [*].

        1.41 "KNOW-HOW" shall mean [*].

        1.42 "MAA" shall mean a Marketing Authorization Application, the
regulatory application in the European Community that is the equivalent of a
BLA, for the Product.

        1.43 "MAJOR MARKET COUNTRIES" means [*].

        1.44 "MARKETING PLAN" shall mean a [*] plan [*] prepared by [*] that
[*].

        1.45 "MICHIGAN AGREEMENT" shall mean the Commercialization Agreement
between Coulter Corporation and the Regents of the University of Michigan, dated
November 1, 1994, and the Amendment to Commercialization Agreement between
Coulter and the Regents of the University of Michigan, dated June 1, 1997.

        1.46 "NET SALES" shall mean [*].

        1.47 "OTHER INVENTION" means any [*].

        1.48 "PATENT" means (i) [*] and (ii) [*].

        1.49 "PRICING APPROVAL" shall mean any and all Regulatory Approvals with
respect to the price of the Product in a regulatory jurisdiction in the
Territory.

        1.50 "PRODUCT" shall mean (a) Iodine I 131 Tositumomab as defined in
Section 1.37 or (b) any [*] product [*] Tositumomab as defined in Section 1.65
for use in connection with a Iodine I 131 Tositumomab, in any formulation or
mode of administration.



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        1.51 "PRODUCT IMPROVEMENT" means [*].

        1.52 "PRODUCT INVENTION" means [*].

        1.53 "QA/QC COSTS" shall mean [*].

        1.54 "REGULATORY APPROVAL" means any and all approvals (including
supplements, amendments, pre- and post-approvals, pricing and reimbursement
approvals), licenses, registrations or authorizations of any national,
supra-national (e.g., the European Commission or the Council of the European
Union), regional, state or local regulatory agency, department, bureau,
commission, council or other governmental entity, that are necessary for the
manufacture, distribution, use or sale of a product in a regulatory
jurisdiction.

        1.55 "REGULATORY FILING" shall mean a regulatory filing for the Product
in the Territory.

        1.56 "SECOND INDICATION" shall mean label claim(s) that are approved in
a Regulatory Approval received for a Product in the Territory, wherein such
Regulatory Approval is subsequent to the Initial Approval and such label claims
are for a different indication than the indication approved in the Initial
Approval.

        1.57 "SOLE OTHER INVENTIONS" means [*].

        1.58 "SPECIFICATIONS" shall mean [*].

        1.59 "STOCK PURCHASE AGREEMENT" shall mean that certain Stock Purchase
Agreement entered into by Corixa Corporation and Nycomed, Inc. as of the Signing
Date.

        1.60 "SUBSEQUENT CLINICAL TRIAL" shall mean each Clinical Trial
conducted hereunder except for the Initial Approval Clinical Trials.

        1.61 "SUBSEQUENT DEVELOPMENT PLAN" shall mean a [*] plan [*] that
includes [*].

        1.62 "SUBSEQUENT REGULATORY FILINGS" shall have the meaning set forth in
Section 5.8.

        1.63 "TERRITORY" shall mean the countries and territories of Europe set
forth on Exhibit B.

        1.64 "THIRD PARTY" means any entity other than (i) Corixa, (ii) Amersham
or (iii) an Affiliate of either of them.

        1.65 "TOSITUMOMAB" shall mean [*].


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2.      LICENSES AND EXCLUSIVITY

        2.1 LICENSES TO AMERSHAM.

            (a) DEVELOPMENT AND COMMERCIALIZATION. Subject to Sections 5.2 and
5.3 and the other terms and conditions of this Agreement, Corixa hereby grants
Amersham an exclusive, royalty-bearing license under Corixa Intellectual
Property Rights, Product Inventions and Product Improvements Controlled by
Corixa, to develop, use, sell, offer for sale and import Product in the Field
and in the Territory. Notwithstanding the exclusivity of the foregoing license,
Corixa retains the right to continue and complete any and all Clinical Trials in
the Territory for which enrollment commenced prior to the Effective Date and the
right to carry out Initial Approval Clinical Trials and prepare and file Initial
Regulatory Filings as set forth herein. The license granted in this Section
2.1(a) may be sublicensed by Amersham (i) [*] and (ii) [*].

            (b) MANUFACTURING. Subject to the terms and conditions of this
Agreement, Corixa hereby grants Amersham a royalty-bearing license, under Corixa
Intellectual Property Rights, Product Inventions and Product Improvements
Controlled by Corixa, to make and have made, [*] Iodine I 131 Tositumomab [*]
and (ii) Product [*]. The license granted in this Section 2.1(b) may be
sublicensed by Amersham, with the prior written consent of Corixa, to an
Affiliate of Amersham or to a Third Party with whom Amersham has entered into a
written agreement for the limited purpose of carrying out Amersham's
manufacturing obligations under this Agreement. During the period that Corixa is
supplying Corixa Iodine I 131 Tositumomab to Amersham pursuant to the Supply
Agreement, the license granted in this Section 2.1(b) shall be [*]. After the
end of such period, such license shall be [*].

            (c) SECOND SITE SUPPLY. If the events described in Section 3.1(e) of
the Supply Agreement occur, Corixa shall grant Amersham, subject to the terms
and conditions of this Agreement, a non-exclusive, royalty-bearing license under
Corixa Intellectual Property Rights, to make and have made, solely for the
purpose of satisfying Amersham's requirements for Product for use (as permitted
in Section 2.1(a)) in the Field and in the Territory, (i) Tositumomab, (ii)
Iodine I 131 Tositumomab manufactured from such Tositumomab, and (iii) Product
from such Tositumomab. The license granted in this Section 2.1(c) may be
sublicensed by Amersham, with the prior written consent of Corixa, which consent
shall not be unreasonably withheld, to an Affiliate of Amersham or to a Third
Party with whom Amersham has entered into a written agreement for the limited
purpose of carrying out Amersham's manufacturing obligations under this
Agreement.

            (d) [*].

        2.2 NEGATIVE COVENANT. Amersham covenants that it shall not, nor shall
it cause any Affiliate or sublicensee to, knowingly use or practice directly or
indirectly, any Corixa Intellectual Property Rights, Product Inventions or
Product Improvements Controlled by Corixa for any purposes other than those
expressly permitted by this Agreement.



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        2.3 LICENSE TO CORIXA. Subject to the terms and conditions of this
Agreement, Amersham hereby grants Corixa [*] Product Improvements Controlled by
Amersham.

        2.4 NEGATIVE COVENANT. Corixa covenants that it shall not, nor shall it
cause any Affiliate or sublicensee to, knowingly use or practice directly or
indirectly any Product Improvements Controlled by Amersham for any other
purposes other than those expressly permitted by this Agreement.

        2.5 [*].

        2.6 EXISTING THIRD PARTY LICENSES. Amersham acknowledges and agrees to
be bound by all applicable provisions of the Dana Farber Agreements and Michigan
Agreement (including without limitation those provisions regarding royalty
payments, insurance and indemnification) as set forth in the letter between the
Parties of even date herewith, provided that such applicable provisions do not
violate any law or regulations in the Territory. Corixa and Amersham agree that
in the event any of the royalty obligations contained in the Third Party
licenses decrease or cease for whatever reason, Amersham shall also be entitled
to such a decrease or cessation of such royalty obligations.

        2.7 NEW THIRD PARTY LICENSES.

            (a) In the event Amersham believes that one or more licenses under
intellectual property held by a Third Party are [*] activities under this
Agreement involving the Product [*] do not infringe the intellectual property
rights of such Third Party, then the Parties will [*].

            (b) In the event Amersham believes that one or more licenses under
intellectual property held by a Third Party are [*] do not infringe the
intellectual property rights of such Third Party, then the Parties will [*].

            (c) In the event Corixa believes that one or more licenses under
intellectual property held by a Third Party are [*] do not infringe the
intellectual property rights of such Third Party, then the Parties will [*].

            (d) In the event Corixa believes that one or more licenses under
intellectual property held by a Third Party are [*] do not infringe the
intellectual property rights of such Third Party, then the Parties will [*].

            (e) If the Parties disagree whether a particular Third Party
intellectual property is necessary or desirable to avoid infringing activities
by a Party pursuant to this Agreement, such disagreement shall be settled in
accordance with the dispute resolution procedures set forth in Section 14.1.

        2.8 [*].


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        2.9 U.N. CONVENTION NOT APPLICABLE. The Parties agree that the U.N.
Convention on Contracts for International Sales of Goods shall not apply to this
Agreement.

3.      GOVERNANCE STRUCTURES

        3.1 COLLABORATION STEERING COMMITTEE (CSC).

            (a) PURPOSE; FORMATION. Within thirty (30) days after the Effective
Date, the Parties will appoint their respective representatives to a
collaboration steering committee to [*] (the "Collaboration Steering Committee"
or "CSC").

            (b) MEMBERSHIP. Each Party shall initially appoint [*]
representatives to the CSC. The CSC may change its size from time to time by
mutual consent of its members; provided that the CSC shall at all times consist
of an equal number of representatives of each of Corixa and Amersham. Each Party
may replace its CSC representatives at any time upon written notice to the other
Party. [*].

            (c) CO-CHAIRPERSONS. Each Party will name, from among its [*] CSC
representatives, a co-chairperson of the CSC. The co-chairpersons of the CSC
shall be responsible for the administering CSC meetings but shall have no
additional powers or rights beyond those held by the other CSC representatives.
The Parties' co-chairpersons will alternate responsibility for preparing minutes
of CSC meetings, which shall be circulated for review and approval by all
members within thirty (30) days after each meeting.

            (d) DECISION-MAKING. The CSC shall act by [*].

            (e) MEETINGS. The CSC shall meet at least [*] per calendar quarter
after the Effective Date until Initial Approval, and at least [*] times per year
thereafter during the term of this Agreement, unless the Parties mutually agree
in writing to a different frequency. Either co-chairperson may call a special
meeting of the CSC from time to time to address issues in connection with which
a decision or review is reasonably required prior to the next regularly
scheduled CSC meeting. The CSC will meet at locations alternately selected by
Corixa and by Amersham. The CSC may meet by video or audio conference. Meetings
of the CSC will be effective only if a representative of each Party is present
or participating. Each Party shall bear all expenses it incurs in regard to
participating in CSC meetings, including all travel and living expenses.

            (f) SPECIFIC RESPONSIBILITIES OF THE CSC. In addition to its general
responsibility to [*] of the Product for and in the Territory, the CSC shall in
particular:

                (i) Review, revise and approve each Development Plan (including
without limitation the Development Budget contained therein) as provided in
Sections 4.2, 4.3 and 4.4;


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                (ii) Resolve, in accordance with Section 3.1(d), issues
presented to it by, and disputes among the JDC and/or the JCC;

                (iii) Review as it deems appropriate the decisions of each of
the JDC and the JCC;

                (iv) Designate the Initial Approval Clinical Trials pursuant to
Section 4.5 or 5.4; and

                (v) Perform any other functions set forth for the CSC in this
Agreement.

            (g) LIMITED AUTHORITY. The CSC shall have no authority to amend this
Agreement. The CSC shall have no authority to override any decision of Corixa
with respect to a Corixa Matter or any decision of Amersham with respect to an
Amersham Matter.

        3.2 JOINT DEVELOPMENT COMMITTEE (JDC).

            (a) PURPOSE; FORMATION. Within thirty (30) days after the Effective
Date the Parties will appoint their respective representatives to a joint
development committee to manage the development [*] for Regulatory Approval of
the Product in the Territory (the "Joint Development Committee" or "JDC"). The
JDC shall dissolve upon mutual agreement of the Parties, but in no event prior
to [*].

            (b) MEMBERSHIP. Each Party shall initially appoint [*]
representatives to the JDC. The JDC may change its size from time to time by
mutual consent of its members; provided that the JDC shall consist at all times
of an equal number of representatives of each Corixa and Amersham. Each Party
may replace its JDC representatives at any time upon written notice to the other
Party. [*].

            (c) CHAIRPERSON. Corixa shall name, from among its JDC
representatives, a chairperson of the JDC who shall act as chairperson until
Initial Approval. Following Initial Approval, Amersham shall name, from among
its JDC representatives, a chairperson of the JDC who shall act as chairperson
thereafter. The chairperson shall be responsible for administering JDC meetings
but shall have no additional powers or rights beyond those held by the other
representatives on the JDC. The chairperson will be responsible for preparing
minutes of JDC meetings, which shall be circulated for review and approval by
all members within thirty (30) days after each meeting.

            (d) DECISION-MAKING. The JDC shall act by [*].

            (e) MEETINGS. The JDC shall meet at least [*] per calendar quarter
after the Effective Date until Initial Approval, and at least [*] times per year
thereafter until completion of all activities to be performed pursuant to the
Subsequent Development Plan, unless the Parties mutually agree in writing to a
different frequency or to earlier disband the JDC. The chairperson

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may call a special meeting of the JDC from time to time to address issues in
connection with which a decision or review is reasonably required prior to the
next regularly scheduled JDC meeting. The JDC will meet at locations alternately
selected by Corixa and by Amersham. The JDC may meet by video or audio
conference. Meetings of the JDC shall be effective only if a representative of
each Party is present or participating. Each Party shall report to the JDC on
all material issues relating to the development of Product for and in the
Territory promptly after such issues arise. Each Party shall bear all expenses
it incurs in regard to participating in meetings of the JDC.

            (f) SPECIFIC RESPONSIBILITIES OF THE JDC. In addition to its general
responsibility to [*] Regulatory Approval of the Product in the Territory
according to the Development Plans and to [*] the JDC shall in particular:

        [*]

            (g) LIMITED AUTHORITY. The JDC shall have only those powers
expressly assigned it in this Agreement. [*].

        3.3 JOINT COMMERCIALIZATION COMMITTEE (JCC).

            (a) PURPOSE; FORMATION. Within [*] after the Effective Date the
Parties will appoint their respective representatives to a joint
commercialization committee to manage the [*] commercialization of the Product
in the Territory (the "Joint Commercialization Committee" or "JCC").

            (b) MEMBERSHIP. Each Party shall initially appoint [*]
representatives to the JCC. The JCC may change its size from time to time by
mutual consent of its members; provided that the JCC shall consist at all times
of an equal number of representatives of each Corixa and Amersham. Each Party
may replace its JCC representatives at any time upon written notice to the other
Party. [*].

            (c) CHAIRPERSON. Amersham shall name, from among its JCC
representatives, a chairperson of the JCC. The chairperson shall be responsible
for administering JCC meetings but shall have no additional powers or rights
beyond those held by the other representatives on the JCC. The chairperson will
be responsible for preparing minutes of JCC meetings, which shall be circulated
for review and approval by all members within thirty (30) days after each
meeting.

            (d) DECISION-MAKING. The JCC shall act by [*].

            (e) MEETINGS. The JCC shall meet at least [*] times per year after
the Effective Date until submission of the MAA, and at least [*] thereafter
until [*] after which the JCC shall again meet at [*] throughout the term of
this Agreement, unless the Parties mutually agree in writing to a different
frequency or to disband the JCC. The chairperson may call a special meeting of
the JCC from time to time to address issues in connection with which a

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decision or review is reasonably required prior to the next regularly scheduled
JCC meeting. The JCC will meet at locations alternately selected by Corixa and
by Amersham. The JCC may meet by video or audio conference. Meetings of the JCC
shall be effective only if a representative of each Party is present or
participating. Each Party shall report to the JCC on all material issues
relating to the commercialization of Product for and in the Territory promptly
after such issues arise. Each Party shall bear all expenses it incurs in regard
to participating in meetings of the JCC.

            (f) SPECIFIC RESPONSIBILITIES OF THE JCC. In addition to its general
responsibility to [*] the commercialization of the Product in the Territory
according to the Marketing Plan and to [*], the JCC shall in particular:

        [*]

            (g) LIMITED AUTHORITY. The JCC shall have only those powers
expressly assigned it in this Agreement. [*].

4.      DEVELOPMENT; GOVERNANCE; DILIGENCE

        4.1 OVERVIEW. Corixa shall be responsible, [*], for carrying out all
development activities for the Product in the Territory in accordance with the
Initial Development Plan, including without limitation clinical development and
regulatory filing for the Initial Approval of the Product. Amersham shall, upon
Corixa's request, mutual agreement of the Parties and under Corixa's management,
perform any of the foregoing development activities. Corixa will be responsible
for and bear all costs included in the Development Budget to achieve Initial
Approval of the Product throughout the Territory as further specified in this
Agreement, with the exception that Amersham shall be responsible for and bear
all costs of establishing a radiolabeling facility in the Territory as further
specified in this Agreement and the Supply Agreement. The initial focus of the
development efforts for the Product in the Territory will be for the treatment
of relapsed and/or refractory low grade non-Hodgkin's lymphoma. Corixa shall be
responsible for such development as specified in Section 5.2(a)(iv). The
development shall be performed in accordance with the Development Plan and
within the Development Budget contained therein as amended from time to time.
Corixa and Amersham shall provide the JDC with regular reports detailing their
respective development activities and the results thereof, so that the JDC can
monitor the Product's development progress in the Territory.

        4.2 INITIAL DEVELOPMENT PLAN. An outline of the general areas to be
covered by the Initial Development Plan is attached hereto as Exhibit C. Within
[*] after [*], the Parties shall develop their appropriate portions [*] of a
draft of the Initial Development Plan. [*] The CSC may approve such revised
draft Initial Development Plan, request that the JDC further revise such draft,
or itself revise such draft. [*].


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        4.3 UPDATES TO DEVELOPMENT PLAN.

            (a) INITIAL DEVELOPMENT PLAN. On or before [*] until Initial
Approval, Corixa and Amersham shall develop their appropriate portions and
present to the JDC a draft updated Initial Development Plan that reflects the
goals and Development Budget for the Initial Approval activities for the
upcoming calendar year. The JDC shall review and, if necessary, revise such
draft updated Initial Development Plan. The JDC shall present the resulting
draft updated Initial Development Plan to the CSC for the upcoming calendar year
on or before [*] of each year. The CSC may approve, revise or request that the
JDC revise the draft updated Initial Development Plan. The CSC shall approve an
updated Initial Development Plan for the upcoming calendar year on or before [*]
of the preceding calendar year.

            (b) SUBSEQUENT DEVELOPMENT PLAN. On or before [*], Amersham shall
develop and present to the JDC a draft Subsequent Development Plan that reflects
the goals and Development Budget for any activities proposed by Amersham to be
carried out to develop the Product in the Territory other than in connection
with the Initial Approval. The JDC shall review and, if necessary, revise such
draft updated Subsequent Development Plan. The JDC shall present the resulting
draft updated Subsequent Development Plan to the CSC for the upcoming calendar
year on or before [*] of each year. The CSC may approve, revise or
request that the JDC revise the draft updated Subsequent Development Plan. The
CSC shall approve an updated Subsequent Development Plan for the upcoming
calendar year on or before [*] of the preceding calendar year.

            (c) INTERMITTENT. Either Party may at any time propose updates and
changes to the then-current Development Plan to the JDC for its consideration.
If the JDC considers that such update of change is desirable, then it may revise
the Development Plan accordingly and submit such revised draft to the CSC for
its approval. Until and unless the CSC approves any proposed update or change to
the Development Plan, the Development Plan last approved by the CSC, and not the
draft revised Development Plan shall be effective.

        4.4 DEVELOPMENT BUDGET.

            (a) The Development Plan shall contain a separate Development Budget
for each Clinical Trial. The Development Plan shall also specify (i) [*] and
(ii) [*].

            (b) Corixa shall pay, in accordance with the mechanism set forth in
Section 8.7, all Initial Approval Trial Costs solely to the extent that such
Initial Approval Trial Costs are within the Development Budget for the Initial
Approval Clinical Trials. All costs within the Development Budget that are not
Initial Approval Trial Costs for the Initial Approval Clinical Trials shall be
the responsibility of Amersham.

        4.5 RESPONSIBILITY, APPROVAL AND DESIGNATION OF CLINICAL TRIALS.

            (a) INITIAL CLINICAL TRIAL. Corixa shall have the responsibility to
conduct all Clinical Trials required for Initial Approval in the Territory. If a
particular Clinical Trial

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<PAGE>

included in the Development Plan is an Initial Approval Clinical Trial, the JDC
shall designate it as such.

            (b) SUBSEQUENT CLINICAL TRIALS. All Clinical Trials not needed for
Initial Approval shall be automatically designated as Subsequent Clinical Trials
and shall be the responsibility of Amersham. Corixa shall have the right to
reject any Subsequent Clinical Trial proposed by Amersham if Corixa reasonably
believes would negatively affect Regulatory Approval in the US of an expanded
label for the Product. Amersham shall have the right to have any such rejection
by Corixa discussed at the next-scheduled CSC meeting.

        4.6 FORECASTS OF SUPPLY FOR INITIAL APPROVAL CLINICAL TRIAL. [*].

        4.7 DEVELOPMENT DILIGENCE.

            (a) GENERAL REQUIREMENT. Corixa shall use efforts [*] to obtain
Initial Approval of the Product and to carry out the tasks set forth in the
Initial Development Plan then in effect, as specified therein.

            (b) DILIGENCE BY CORIXA. Corixa shall [*] the Initial Approval
Clinical Trial [*] the approved Development Plan and shall [*] for the Initial
Approval Clinical Trial. Notwithstanding the foregoing, if Corixa's failure to
perform an action specified in this Section 4.7(b) within the timeframe
specified in the Initial Development Plan, or otherwise in a timely manner, is
due, at least in part, to [*], Corixa shall be entitled to [*].

            (c) DILIGENCE BY AMERSHAM. Amersham shall [*] to carry out the tasks
set forth in the (i) Initial Development Plan then in effect, as specified
therein as responsibilities of Amersham or as requested by Corixa in accordance
with Section 4.1; and (ii) Subsequent Development Plan then in effect, as
specified therein. Notwithstanding the foregoing, if Amersham's failure to
perform an action specified in this Section 4.7(c) within the timeframe
specified in the Initial Development Plan or the Subsequent Development Plan, as
applicable, or otherwise in a timely manner, is due, at least in part, to [*],
Amersham shall be entitled to [*].

5.      CLINICAL TRIALS AND REGULATORY ISSUES

        5.1 TRANSFER OF PRE-EXISTING FILES AND DATA.

            (a) FILES. Within [*] after the Effective Date, Corixa shall
transfer to Amersham [*] clinical files and regulatory files for the Product in
the Territory in Corixa's possession on the Effective Date. Corixa shall retain
ownership of such clinical and regulatory files and may use such files [*].

            (b) DATA. Within [*] after the Effective Date, Corixa shall provide
Amersham with copies of [*] data relating to the Product in Corixa's possession
on the Effective Date and [*] data in Corixa's possession at such time from
Clinical Trials initiated prior to the Effective Date. Corixa will provide
Amersham all pertinent information that is owned by Corixa and that




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is necessary to establish a radiolabeling facility and/or that is related to the
manufacture of Corixa Iodine I 131 Tositumomab or Amersham Iodine 131
Tositumomab and is required to file for approval of the Product by Regulatory
Authorities in the Territory. The data described in this Section 5.1(b) above is
the Confidential Information of Corixa, and Amersham may use such data solely
for the purpose of obtaining Regulatory Approval of or marketing the Product in
the Territory. [*] Amersham shall have the right to use, solely for the purpose
of obtaining Regulatory Approval of or marketing the Product in the Territory,
any data generated or created in relation to or as a result of such regulatory
filings.

        5.2 CLINICAL TRIALS SOLELY IN THE TERRITORY.

            (a) RESPONSIBILITIES.

                (i) EXISTING. Corixa shall retain responsibility for and shall
solely bear the costs of all Clinical Trials in the Territory initiated [*]
prior to the Effective Date, which Clinical Trials are identified on Exhibit D
hereto. Corixa shall promptly provide Amersham with copies of, the data from
such Clinical Trials that are identified as "Closed" on Exhibit D, as well as
from Clinical Trials [*].

                (ii) ADDITIONAL. Responsibility for carrying out all Clinical
Trials that the Development Plan specifies shall be initiated after the
Effective Date and conducted solely in the Territory shall be in accordance with
Section 4.5.

                (iii) COSTS OF TRIALS. Corixa will bear the Initial Approval
Trial Costs for the Initial Approval Clinical Trials, provided the Initial
Approval Clinical Trials are within the Development Budget for the Initial
Approval Clinical Trials. In the event a Party incurs costs (including its own
internal costs) associated with the Initial Approval Clinical Trials that are
not within the Development Budget for the Initial Approval Clinical Trials, the
Party incurring such costs shall be solely responsible therefore, provided that
[*]. Amersham will bear the Clinical Trial Costs of all Subsequent Clinical
Trials conducted solely in the Territory.

                (iv) CORIXA ASSISTANCE. Amersham may seek Corixa's advice and
assistance regarding the conduct of Subsequent Clinical Trials solely in the
Territory. Corixa shall provide all such advice and assistance that is
reasonably requested by Amersham. Amersham shall reimburse Corixa for all
out-of-pocket and personnel expenses (at the FTE Rate) incurred in connection
with providing such advice and assistance with respect to any Subsequent
Clinical Trial.

            (b) ACCESS TO DATA.

                (i) Corixa shall [*] have the right to use (and sublicense
others to use) all data from the Initial Approval Clinical Trials for the
purpose of obtaining Regulatory Approval of or marketing the Product outside the
Territory. [*].



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                (ii) If Corixa desires to use the data from any Subsequent
Clinical Trial conducted by Amersham solely in the Territory during the term of
the Agreement, for the purpose of Corixa or its corporate partner, Affiliate or
sublicensee obtaining Regulatory Approval of or marketing the Product in the
United States, Corixa shall provide written notice of such desire to Amersham
and Corixa shall bear [*] of Clinical Trial Costs associated with such Clinical
Trial and Amersham shall bear the remaining [*] of such Clinical Trial Costs. If
Corixa desires to use the data from any Subsequent Clinical Trial conducted by
Amersham solely in the Territory during the term of the Agreement, for the
purpose of Corixa or its corporate partner, Affiliate or sublicensee obtaining
Regulatory Approval of or marketing the Product in all other countries of the
Corixa Territory, Corixa shall provide written notice of such desire to Amersham
and Corixa shall bear [*] of Clinical Trial Costs associated with such Clinical
Trial and Amersham shall bear the remaining [*] of such Clinical Trial Costs.
Amersham shall arrange for Corixa to have a right of cross reference to all
Regulatory Filings made by or on behalf of Amersham that include data from a
Subsequent Clinical Trial for which Corixa paid a percentage of the costs in
accordance with this Section 5.2(b)(ii). Corixa shall have the right to use,
solely for the purpose of obtaining Regulatory Approval of or marketing the
Product in the Corixa Territory, any data generated or created in relation to or
as a result of any such Regulatory Filing.

        5.3 CLINICAL TRIALS SOLELY IN THE CORIXA TERRITORY. In the event that
Amersham desires to use the data from any Clinical Trial conducted in the Corixa
Territory during the term of the Agreement, including any data from any of the
Clinical Trials identified on Exhibit D other than those that are [*], for the
purpose of obtaining Regulatory Approval of or marketing the Product in the
Territory, Amersham shall provide written notice of such desire to Corixa and,
Amersham shall bear [*] of Clinical Trial Costs associated with such Clinical
Trial and Corixa shall bear the remaining [*] of such Clinical Trial Costs.
Corixa shall arrange for Amersham to have a right of cross reference to all
regulatory filings in the Corixa Territory made by or on behalf of Corixa that
include data from a Clinical Trial for which Amersham paid a percentage of the
costs in accordance with this Section 5.3. Amersham shall have the right to use,
solely for the purpose of obtaining Regulatory Approval of or marketing the
Product in the Territory, any data generated or created in relation to or as a
result of such regulatory filing.

        5.4 CROSS-TERRITORY CLINICAL TRIALS.

            (a) INITIATION OF CROSS-TERRITORY CLINICAL TRIAL. [*].

            (b) ACCESS TO DATA. The Parties shall have [*] data generated in the
course of a Cross-Territory Clinical Trial. [*] Amersham shall be entitled to
use such data in the Territory and Corixa shall be entitled to use such data in
the Corixa Territory. Each Party (the "Filing Party") shall arrange for the
other Party (the "Non-filing Party") to have a right of cross reference to all
regulatory filings in the Filing Party's territory made by or on behalf of the
Filing Party that include data from a Cross-Territory Clinical Trial. The
Non-filing Party shall have the right to use, solely for the purpose of
obtaining Regulatory Approval of or marketing the Product in the Non-filing
Party's territory, any data generated or created in relation to or as a result
of such regulatory filing.


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        5.5 CLINICAL TRIAL COSTS AUDIT. Each Party (the "Auditing Party") shall
have the right, upon prior written notice to the other Party (the "Audited
Party") and at the Auditing Party's cost, to have the certified public
accountants of the Auditing Party's choice, bound by confidentiality and
reasonably acceptable to the Audited Party, audit the Audited Party's books and
records to verify the Audited Party's calculations of any Clinical Trial Costs
of which the Auditing Party is obligated to pay a percentage. Each Party may
exercise this right no more than once per contract year.

        5.6 INITIAL REGULATORY FILINGS.

            (a) ACTIONS. Subject to Section 5.7, Corixa or its designee shall be
the owner of any and all MAAs for Initial Approval and all other applicable
Regulatory Filings for Initial Approval (collectively, "Initial Regulatory
Filings"). Corixa shall, in accordance with the then-current Development Plan
and the guidance of the JDC and CSC:

                (i) prepare, file and prosecute in Corixa's name all Initial
Regulatory Filings;

                (ii) be responsible for attending to all administrative matters
necessary to compile and submit the Initial Regulatory Filings; and

Amersham shall be responsible for maintaining the Initial Regulatory Filings
after the MAA has been transferred to Amersham pursuant to Section 5.7. The JDC
shall determine which Party shall be responsible for preparing the various
sections of the Initial Regulatory Filings and such responsibilities shall be
set forth in the Initial Development Plan. Corixa will keep Amersham informed of
its regulatory activities on an ongoing and timely basis at least as frequently
as the JDC is required to meet pursuant to Section 3.2. In addition, Corixa
shall provide Amersham with drafts of all Initial Regulatory Filings at least
[*] days before they are filed and Amersham shall have the right to comment
thereon; provided that Corixa shall not be obligated to provide such drafts nor
shall Amersham have the right to comment thereon if the Parties have agreed that
Amersham shall not participate in the Initial Regulatory Filings. Without
limiting the foregoing, the responsible party, as determined by the JDC, shall
provide the other with each section of any draft MAA filing as it is completed
in order that the other may review and comment thereon.

            (b) COSTS. [*].

        5.7 TRANSFER OF INITIAL REGULATORY FILINGS. Unless the Parties agree
otherwise, reasonably promptly after Amersham makes the milestone payment set
forth in Section 8.2(a), Corixa shall transfer and assign to Amersham all
Initial Regulatory Filings.

        5.8 SUBSEQUENT REGULATORY FILINGS. Amersham shall at its own expense:

            (a) prepare, file and prosecute in its name all Regulatory Filings
for purposes other than Initial Approval ("Subsequent Regulatory Filings"),
including without limitation all Regulatory Filings to enable the lawful sale of
the Product to treat any Second Indication;


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            (b) be responsible for all administrative matters necessary to
compile and submit Subsequent Regulatory Filings;

            (c) be responsible for maintaining the Subsequent Regulatory
Filings; and

            (d) bear the registration renewal fees for the Subsequent Regulatory
Filings.

Amersham will keep Corixa informed of its regulatory activities pursuant to this
Section 5.8 on an ongoing and timely basis at least as frequently as the JDC is
required to meet at such time pursuant to Section 3.2. In addition, Amersham
shall provide Corixa with drafts of all Subsequent Regulatory Filings at least
[*] before they are filed and the JDC shall have the right to comment
thereon. Without limiting the foregoing, Amersham shall provide Corixa with each
section of any draft "subsequent" MAA filing as it is completed in order that
Corixa may review and comment thereon.

        5.9 PRICING APPROVALS AND PRICING. Amersham shall be responsible, at its
own expense, for seeking Pricing Approval for the Product in the Territory. [*].

        5.10 UPDATES. Amersham shall prepare and provide to the JDC in advance
of each JDC meeting a written report summarizing the work done by Amersham
pursuant to this Agreement, including without limitation under the Development
Plan. Between such reports, Amersham shall keep Corixa via its JDC members
reasonably informed of material developments relating to the activities
performed by Amersham hereunder, especially as to the manufacture of Amersham
Iodine I 131 Tositumomab and Initial Approval of the Product in the Territory.

        5.11 RECORDS. Amersham shall maintain complete and accurate records of
all work conducted under this Agreement and all results, data and developments
made pursuant to its efforts under this Agreement. Such records shall fully and
properly reflect all work done and results achieved in the performance of this
Agreement in sufficient detail and in good scientific manner appropriate for
patent and regulatory purposes. Corixa shall have the right to review such
records at reasonable times to the extent necessary for Corixa to monitor
Amersham's performance of its obligations under this Agreement.

6.      REGULATORY COMPLIANCE

        6.1 ADVERSE EVENT REPORTING. Each Party shall advise the other Party of
any adverse reaction to the use of the Product or any increase in the severity
or frequency of such an adverse reaction, by telephone or facsimile as soon as
possible and within such time as is required by the FDA or the equivalent
agencies in the Territory after the Party becomes aware of such adverse
reaction. Such advising Party shall provide the other Party with a written
report delivered by confirmed facsimile of any reported adverse reaction,
stating the full facts known to it, including but not limited to an identifiable
patient (identified by a unique identifier that does not reveal the identity of
the patient, whenever possible); a suspect medicinal product (including batch,
lot, or serial number, as appropriate); an identifiable reporting source
(including name, address, and telephone numbers); and an identifiable outcome or
event. Amersham shall report all adverse reactions occurring in the Territory to
the relevant authorities in accordance with applicable law. Promptly after the
Effective Date, the JDC shall begin to develop written

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adverse event reporting procedures including but not limited to provision of
Periodic Safety Update Reports and other safety reports required by regulatory
authorities, and shall submit a set of such procedures to the CSC for approval
as promptly as is reasonably practicable. Within six (6) months after the
Effective Date, the Parties shall agree in writing, upon adverse event reporting
procedures that are consistent with and effectuate the goals of this Section
6.1.

        6.2 COMPLIANCE.

            (a) Amersham shall comply with all applicable laws, statutes,
regulations, orders and health registration laws of any government entity in the
Territory and with all other governmental requirements relating to the
development, regulatory registration, manufacturing and supply, and marketing of
the Product in the Territory.

            (b) Corixa shall use its [*] efforts to cause its Third Party
suppliers engaged in the manufacture of the Product to comply with all of such
Third Party's obligations to Corixa related to compliance with applicable laws,
statutes, regulations, orders and health registration laws of any government
entity in the Territory and with all other governmental requirements relating to
the development, regulatory registration, manufacturing and supply, and
marketing of the Product in the Territory.

        6.3 PRODUCT COMPLAINTS. Each Party shall maintain a record of all
complaints it receives with respect to the Product (each, a "Product
Complaint"). For purposes of this Section 6.3, a "Product Complaint" is [*].
The responsibilities of the Parties with respect to (a) notification of the
Product Complaint from the receiving Party to the other Party and (b) the
handling of Product Complaints shall all be performed in accordance with a
procedure to be mutually agreed by the Parties after the Effective Date.

        6.4 PRODUCT RECALL. The Parties shall immediately inform each other in
writing of all information related to (a) any incident relating to a Product
and/or any lot of a Product that is the subject of recall, market withdrawal or
correction, or (b) any Product that may require, whether based on manufacturing
defect, tampering, or otherwise, a recall, field alert, product withdrawal or
field correction arising from any defect in any such Product. If either Party
believes that a recall of Tositumomab and/or Iodine I 131 Tositumomab is
desirable or required by law, it will promptly notify the other Party. The
Parties will then discuss reasonably and in good faith whether such recall is
appropriate or required and the manner in which any recall shall be handled;
provided, however, in the event either Party determines that a recall is
necessary, such recall shall be implemented. Amersham shall be solely
responsible for the handling and disposition of such recalls of Product in the
Territory, and Amersham shall be responsible for all costs related to any such
recall. Corixa shall cooperate with Amersham in allowing such recall in the
Territory to occur. Within six (6) months after the Effective Date, the Parties
shall agree in writing, upon product recall procedures that are consistent with
and effectuate the goals of this Section 6.4.



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7.      MARKETING

        7.1 MARKETING PLAN. Amersham shall submit a proposed initial Marketing
Plan to the JCC within thirty (30) days after filing the MAA in the Territory.
The JCC may suggest revisions to the Marketing Plan or any updated Marketing
Plan and Amersham shall consider in good faith the JCC's proposed revisions to
such Marketing Plan and incorporate those that are commercially reasonable.
Amersham shall update the Marketing Plan each time a new Regulatory Approval is
obtained for the Product in the Territory and no less often than once a year.

        7.2 DILIGENCE.

            (a) Amersham shall use its best efforts to promote, market and sell
the Product in each country and territory in the Territory in which Regulatory
Approval has been received and to carry out the tasks set forth in the Marketing
Plan at the times specified therein.

            (b) In addition to the obligations set forth in Section 7.2(a),
Amersham shall make the First Commercial Sale of each Product in each country
within three (3) months after receiving Regulatory Approval of the Product in
such country.

        7.3 REPORTING. Amersham will keep the JDC informed of its marketing
activities on an ongoing and timely basis. In addition, upon request by Corixa,
Amersham shall inform Corixa in writing and in advance of implementation, of any
decisions that may significantly impact any part of the Corixa Territory for
Product.

8.      ECONOMICS

        8.1 EQUITY INVESTMENT. Amersham shall make an equity investment in
Corixa equal to a total of fifteen million dollars ($15,000,000) in accordance
with the terms set forth in the Stock Purchase Agreement.

        8.2 MILESTONES. Amersham shall pay Corixa the following non-refundable,
non-creditable amounts within [*] days after occurrence of each of the events
specified below:

        [*]

        8.3 ROYALTIES.

            (a) Subject to Section 8.3(b), in respect of the licenses granted in
Sections 2.1(a) and (b), Amersham shall pay Corixa a running royalty of [*] of
Net Sales.

            (b) The running royalty owed by Amersham pursuant to Section 8.3(a)
shall be reduced to the applicable percentage of Net Sales shown below in a
particular country of the Territory during such time as one of the following
circumstances is then in effect in such country:



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<TABLE>
<CAPTION>
--------------------------------------- ----------------------------------------
CIRCUMSTANCE                            RUNNING ROYALTY
<S>                                     <C>
--------------------------------------- ----------------------------------------
[*]                                     [*]
--------------------------------------- ----------------------------------------
[*]                                     [*]
--------------------------------------- ----------------------------------------
[*]                                     [*]
--------------------------------------- ----------------------------------------
[*]                                     [*]
--------------------------------------- ----------------------------------------
</TABLE>


            (c) In the event that more than one circumstance set forth in
Section 8.3(b) occurs simultaneously in a particular country, Amersham's running
royalty rate shall be the lowest running royalty applicable to any of the
circumstances. Multiple such simultaneous circumstances shall not have an
additive effect on running royalty rates.

            (d) On a country-by-country basis, Amersham shall pay the royalties
set forth in this Section 8.3 until the later of: (i) the expiration,
cancellation or abandonment of the last surviving issued patent or pending
patent application in the Territory that claims any Corixa Intellectual Property
Right, Product Invention or Product Improvement Controlled by Corixa, or (ii)
[*].

            (e) The royalties set forth in this Section 8.3 do not include
royalties that Amersham is obligated to pay to Third Parties, including Dana
Farber and the University of Michigan.

        8.4 INDEPENDENT MANUFACTURE ROYALTIES. In the event that the license set
forth in Section 2.1(c) is granted, Amersham shall pay Corixa a running royalty
of [*] of Net Sales (excluding Net Sales of Product supplied by Corixa under the
Supply Agreement). The percentage rate of such running royalty shall be subject
to reduction, if applicable, in accordance with the rates and conditions set
forth in Section 4.1(b) of the Supply Agreement.

        8.5 QUARTERLY PAYMENTS AND PAYMENT REPORTS. All payments due under
Sections 8.3 and 8.4 shall be made to Corixa or its designee quarterly within
[*] following the end of each calendar quarter for which payments are due. Each
such payment shall be accompanied by a statement stating the number,
description, and aggregate Net Sales, by country, of each Product sold during
the relevant calendar quarter.

        8.6 PAYMENT METHOD. All payments due under this Agreement to Corixa
shall be made by bank wire transfer in immediately available funds to an account
designated by Corixa. All payments hereunder shall be made in U.S. dollars and
shall be noncreditable and nonrefundable.

        8.7 INVOICING OF INITIAL APPROVAL TRIAL COSTS. Amersham shall invoice
Corixa quarterly for Initial Approval Trial Costs that Amersham bears pursuant
to Sections 4.4, 5.2 and


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5.6. Corixa shall pay the undisputed amount of each such invoice within [*]
after its receipt of such invoice. Corixa shall be entitled to require Amersham
to substantiate each invoice, and to audit Amersham's records relating to the
costs invoiced on the same basis as provided for in Section 8.13, and late
payments (on undisputed amounts) shall bear interest, pursuant to Section 8.14.

        8.8 TAXES. Corixa shall pay any and all taxes levied on account of all
payments it receives under this Agreement. If laws or regulations require that
taxes be withheld, Amersham will [*].

        8.9 CURRENCY OF PAYMENT. All dollar amounts contained in this Agreement
are in United States Dollars (US$).

        8.10 BLOCKED CURRENCY. In each country in the Territory where the local
currency is blocked and cannot be removed from the country, royalties accrued in
that country shall be paid to Corixa in the country in local currency by deposit
in a local bank designated by Corixa, unless the Parties otherwise agree.

        8.11 SUBLICENSES. In the event Amersham grants licenses or sublicenses
to others to sell Products which are subject to payments under Sections
8.2(b)-(e), 8.3 or 8.4, such licenses or sublicenses shall include an obligation
for the licensee or sublicensee to account for and report its sales of Products
on the same basis as if such sales were Net Sales by Amersham, and Amersham
shall pay to Corixa, with respect to such sales, royalties as if such sales of
the licensee or sublicensee were Net Sales of Amersham.

        8.12 FOREIGN EXCHANGE. Payments due on sales of the Product shall be
calculated and paid by Amersham in United States Dollars. Sales will be
converted into U.S. Dollars from locally billed currency on a monthly basis
using the exchange rates for the last trading day of the month as published by
Reuters. Royalties will be calculated on a quarterly calendar basis and payments
shall be due [*] after the completion of the quarter.

        8.13 RECORDS; INSPECTION. Amersham shall keep complete, true and
accurate books of account and records for the purpose of determining the
payments to be made under this Agreement. Such books and records shall be kept
for at least three years following the end of the calendar quarter to which they
pertain. Such records will open for inspection during such three year period by
independent accountants, solely for the purpose of verifying payment statements
hereunder. Such inspections shall be made no more than once each calendar year,
at reasonable time and on reasonable notice. Inspections conducted under this
Section 8.13 shall be at the expense of Corixa, unless a variation or error
producing an increase exceeding [*] of the royalty amount stated for any period
covered by the inspection is established in the course of such inspection,
whereupon all costs relating to the inspection for such period and any unpaid
amounts (plus interest) that are discovered will be paid promptly by Amersham

        8.14 LATE PAYMENT PENALTY. Any payment due under this Article 5 that is
not paid by [*] after the payment's due date shall accrue interest, which must
be paid by the Party with the


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payment obligation to the recipient Party, on a daily basis at a rate equal to
[*], from the date first owed until paid.

9.      INTELLECTUAL PROPERTY

        9.1 OWNERSHIP. Corixa shall own the entire right, title and interest in
and to any and all [*]. Each Party shall own the entire right, title and
interest in and to any and all [*]. Amersham and Corixa shall each own [*].
Amersham hereby covenants that it will not [*].

        9.2 DISCLOSURE. Amersham shall submit a written report to Corixa within
[*] of the end of each June and December during the term of this Agreement
describing any Product Invention arising during the prior half-year. The Parties
shall mutually decide whether to file a patent application for a Joint Other
Invention, as discussed in Section 9.3.

        9.3 PATENT PROSECUTION AND MAINTENANCE; ABANDONMENT.

            (a) Each Party shall retain control over and bear all expenses
associated with the filing, prosecution and maintenance of all Patents claiming
its [*].

            (b) Corixa shall retain control over and bear all expenses
associated with the filing, prosecution and maintenance of all Patents claiming
[*].

            (c) The Parties' rights and obligations with respect to the filing,
prosecution and maintenance of [*] shall be decided on a case-by-case basis.

        9.4 ENFORCEMENT OF PATENT RIGHTS.

            (a) If either Party becomes aware of any Third Party activity in the
Territory that infringes an issued Patent in the Corixa Intellectual Property
Rights or an issued Patent claiming a Product Invention, then that Party shall
give prompt written notice to the other Party within [*] after having knowledge
of such infringement. Corixa shall have the primary right, but not the
obligation, to institute, prosecute or control any action or proceeding with
respect to such infringement by counsel of its own choice.

            (b) If Corixa enforces a Patent that is part of the Corixa
Intellectual Property Rights or covers a Product Invention made by Amersham,
then (i) Amersham shall have the right (at its own expense) to participate in
such action and to be represented by counsel of its own choice, and (ii)
Amersham shall, at the request and expense of Corixa, be joined as a party to
the suit. Any damages or monetary award recovered shall be applied to reimburse
the reasonable costs and expenses of the Parties in connection with such
litigation and the balance shall be divided between Corixa and Amersham in
accordance with the percentage to which each such entity funded the suit.

            (c) If Corixa fails to bring an action or proceeding to enforce a
Patent that is part of the Corixa Intellectual Property Rights or covers a
Product Invention made by Amersham




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<PAGE>


within a period of [*] after such notice, then Amersham shall have the right,
but not the obligation, to bring and control any such action by counsel of its
own choice, and Corixa shall have the right to participate in such action and to
be represented, at its own expense, by counsel of its own choice. Any damages or
monetary award recovered shall be applied to reimburse the reasonable costs and
expenses of the Parties in connection with such litigation and the balance shall
be divided between Corixa and Amersham in accordance with the percentage to
which each such entity funded the suit.

        9.5 DEFENSE OF THIRD PARTY CLAIMS.

            (a) If a claim is brought by a Third Party that any activity related
to the Agreement or a Product infringes the intellectual property rights of such
Third Party, each Party will give prompt written notice to the other Party of
such claim. If the Third Party claim arises from Corixa's activities under the
Agreement, Corixa shall [*].

            (b) Except as set forth in Section 9.5(a), each Party shall be
responsible for its own defense of such Third Party claims, at its own expense
and without indemnification by the other Party. In any event, neither Party
shall be required to conduct any work under this Agreement which it believes may
infringe Third Party rights. In the event the Third Party claim arises from the
manufacture, sale or use of a Product by Amersham or its licensee, the indemnity
obligations of Amersham under Section 9.5(a) shall apply, and Corixa shall not
have any indemnity obligation to Amersham in respect of such claims.

        9.6 TRADEMARKS. Amersham shall be responsible for the acquisition and
maintenance of trademarks for the Product in the Territory. Amersham is not
licensed to use any trademark Controlled by Corixa.

10.     CONFIDENTIALITY

        10.1 NONDISCLOSURE OF CONFIDENTIAL INFORMATION. All Information
disclosed by one Party to the other Party pursuant to this Agreement shall be
"Confidential Information." The Parties agree that during the term of this
Agreement, and for a period of [*] years after this Agreement expires or
terminates, a Party receiving Confidential Information of the other Party will
(i) maintain in confidence such Confidential Information to the same extent such
Party maintains its own proprietary industrial information of similar kind and
value (but at a minimum each Party shall use commercially reasonable efforts),
(ii) not disclose such Confidential Information to any Third Party without prior
written consent of the other Party, except for disclosures made in confidence to
any Third Party manufacturer of Tositumomab or Iodine I 131 Tositumomab, and
(iii) not use such Confidential Information for any purpose except those
permitted by this Agreement.

        10.2 EXCEPTIONS. The obligations in Section 10.1 shall not apply with
respect to any portion of the Confidential Information that the receiving Party
can show by competent written proof:



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            (a) Is publicly disclosed by the disclosing Party, either before or
after it is disclosed to the receiving Party hereunder; or

            (b) Was known to the receiving Party, without obligation to keep it
confidential, prior to disclosure by the disclosing Party; or

            (c) Is subsequently disclosed to the receiving Party by a Third
Party lawfully in possession thereof and without obligation to keep it
confidential; or

            (d) Has been published by a Third Party; or

            (e) Has been independently developed by the receiving Party without
the aid, application or use of Confidential Information.

        10.3 AUTHORIZED DISCLOSURE. A Party may disclose the Confidential
Information belonging to the other Party to the extent such disclosure is
reasonably necessary in the following instances:

            (a) Filing or prosecuting Patents relating to Sole Inventions, Joint
Inventions or Products;

            (b) Regulatory filings;

            (c) Prosecuting or defending litigation;

            (d) Complying with applicable governmental regulations; and

            (e) Disclosure, in connection with the performance of this
Agreement, to Affiliates, sublicensees, research collaborators, employees,
consultants, or agents, each of whom prior to disclosure must be bound by
similar obligations of confidentiality and non-use at least equivalent in scope
to those set forth in this Article 10.

        In addition, Corixa shall have the right to disclose Confidential
Information under in connection with discussing potential business transactions
involving the Product outside of the Territory provided that Corixa and the
party to which Corixa is disclosing the Confidential Information are parties to
a written confidentiality agreement.

        The Parties acknowledge that the terms of this Agreement shall be
treated as Confidential Information of both Parties. Such terms may be disclosed
by a Party to investment bankers, investors, and potential investors, each of
whom prior to disclosure must be bound by similar obligations of confidentiality
and non-use at least equivalent in scope to those set forth in this Article 10.
In addition, a copy of this Agreement may be filed by Corixa with the Securities
and Exchange Commission. In connection with any such filing, Corixa shall
endeavor to obtain confidential treatment of economic and trade secret
information.

        In any event, the Parties agree to take all reasonable action to avoid
disclosure of Confidential Information except as permitted hereunder.


                                       25
<PAGE>

        10.4 TERMINATION OF PRIOR AGREEMENTS. This Agreement supersedes all
mutual non-disclosure agreements entered into by the Parties prior to the
Effective Date. All Information exchanged between the Parties under those
earlier agreements shall be deemed Confidential Information and shall be subject
to the terms of this Article 10.

        10.5 PUBLICITY. The Parties shall agree on the language of the public
announcement of the execution of this Agreement prior to the release thereof.
Any other publication, news release or other public announcement relating to
this Agreement or to the performance hereunder, shall first be reviewed and
approved by both Parties; provided, however, that any disclosure which is
required by law as advised by the disclosing Party's counsel may be made without
the prior consent of the other Party, although the other Party shall be given
prompt notice of any such legally required disclosure and to the extent
practicable shall provide the other Party an opportunity to comment on the
proposed disclosure. The Parties shall agree on language relating to this
Agreement which either Party may use without the repeated approval of the other
Party.

        10.6 PUBLICATIONS. Amersham shall not publish or present the results of
Clinical Trials carried out in the Territory under this Agreement without the
opportunity for prior review by Corixa. Subject to Section 10.3, Amersham agrees
to provide Corixa the opportunity to review any proposed abstracts, manuscripts
or presentations (including verbal presentations) which relate to any Product at
least 30 days prior to its intended submission for publication and agrees, upon
request, not to submit any such abstract or manuscript for publication until
Corixa is given a reasonable period of time to secure patent protection for any
material in such publication which it believes to be patentable. Both Parties
understand that a reasonable commercial strategy may require delay of
publication of information or filing of patent applications. The Parties agree
to review and consider delay of publication and filing of patent applications
under certain circumstances. Neither Party shall have the right to publish or
present Confidential Information of the other Party which is subject to Section
10.1. Nothing contained in this Section 10.6 shall prohibit the inclusion of
information necessary for a patent application, except for Confidential
Information of the nonfiling Party, provided the nonfiling Party is given a
reasonable opportunity to review the information to be included prior to
submission of such patent application.

11.     TERM AND TERMINATION

        11.1 TERM. This Agreement shall become effective on the Effective Date
and shall remain in effect until the expiration of the last payment obligation
pursuant to Article 8 with respect to any Product.

        11.2 AMENDMENT OF TERRITORY. [*].

        11.3 TERMINATION FOR MATERIAL BREACH.

            (a) If either Party believes that the other is in material breach of
this Agreement (including without limitation any material breach of a
representation or warranty made in this Agreement), then the non-breaching Party
may deliver notice of such breach to the other Party. In such notice the
non-breaching Party shall identify the actions or conduct that



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<PAGE>


such Party would consider to be an acceptable cure of such breach. The allegedly
breaching Party shall have [*] days to either cure such breach or, if cure
cannot be reasonably effected within such [*] day period, to deliver to the
other Party a plan for curing such breach which is reasonably sufficient to
effect a cure. Such a plan shall set forth a program for achieving cure as
rapidly as practicable. Following delivery of such plan, the breaching Party
shall use Diligent Efforts to carry out the plan and cure the breach. In the
event of breach for failure to meet any payment obligations under this
Agreement, the breaching Party shall have [*] days to cure such breach for
nonpayment. For the avoidance of any doubt, any failure on the part of Nycomed,
Inc. to fulfill its obligations set forth in the Stock Purchase Agreement shall
be a material breach of this Agreement.

            (b) If the Party receiving notice of breach fails to cure such
breach within the [*]-day period, or the Party providing the notice reasonably
determines that the proposed corrective plan or the actions being taken to carry
it out is not commercially practicable, the Party originally delivering the
notice may terminate this Agreement upon [*] days advance written notice. If
Corixa is the breaching Party, Amersham may elect to not terminate this
Agreement as provided herein but instead retain its licenses granted under
Section 2.1 subject to payment of fees and milestones under Article 8 and other
obligations under this Agreement. If the non-breaching Party elects not to
terminate this Agreement under circumstances in which such non-breaching Party
believes it is entitled to a temporary restraining order against the breaching
Party, it may seek such a temporary restraining order. After the issuance of any
temporary restraining order granted hereunder, any disputes concerning the
appropriateness of such temporary restraining order shall be resolved in
accordance with Section 14.1 and, if arbitration results, the arbitrator shall
have the right to grant the Party subject to such temporary restraining order
any redress that might have been available to such Party if the matter had
remained under the jurisdiction of the courts.

            (c) If a Party gives notice of termination under this Section 11.3
and the other Party disputes whether such notice was proper, then the issue of
whether this Agreement has been terminated shall be resolved in accordance with
Section 14.1. If as a result of such dispute resolution process it is determined
that the notice of termination was proper, then such termination shall be deemed
to have been effective [*] days following the date of the notice of termination.
If as a result of such dispute resolution process it is determined that the
notice of termination was improper, then no termination shall have occurred and
this Agreement shall have remained in effect.

        11.4 TERMINATION BY AMERSHAM.

            (a) Amersham shall have the right to terminate this Agreement upon
[*] days written notice to Corixa if the Product is legally blocked from being
marketed in the European Union for the indication for which the Parties were
attempting to obtain Initial Approval, as a result of the designation of a
competing product for such indication as an "orphan medicinal product" pursuant
to the applicable European Commission regulations.



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            (b) Amersham shall have the right to terminate this Agreement with
respect to all countries of the Territory upon [*] written notice to Corixa at
any time after the [*] anniversary of the Effective Date.

            (c) Amersham shall have the right to terminate this Agreement upon
[*] days' written notice in the event that the EMEA fails to validate the MAA
filing because the MAA was deemed by the EMEA to be insufficient.

        11.5 TERMINATION BY CORIXA.

            (a) Corixa shall have the right to terminate this Agreement upon [*]
days written notice to Amersham in the event that Corixa terminates the Supply
Agreement pursuant to (i) Section 7.2 of the Supply Agreement on account of
Amersham's material breach of the Supply Agreement or (ii) Section 3.3(d) of the
Supply Agreement.

            (b) Corixa shall have the right to terminate this Agreement upon [*]
days written notice to Amersham in the event that an MAA containing data from
the first initiated Initial Approval Clinical Trial is not approved.

        11.6 TERMINATION BY MUTUAL AGREEMENT. The Parties may terminate this
Agreement at any time by mutual written agreement.

        11.7 EFFECT OF TERMINATION; SURVIVAL.

            (a) In the event of termination of this Agreement for any reason,
the following provisions of this Agreement shall survive: Sections 2.3, 2.5,
5.5, 8.13, 8.14, 9.1, 9.2, 9.3 and 11.7, and Articles 1, 10, 13 and 14.

            (b) If termination of this Agreement was not due to Corixa's
material breach pursuant to Section 11.3, then

                (i) Amersham shall, within [*] days of such termination,
transfer all [*] data, [*] and other documents owned by Amersham to Corixa at no
cost to Corixa; and

                (ii) if Amersham commenced manufacture of Amersham Iodine I 131
Tositumomab prior to such termination, then

        [*]

            (c) In any event, termination of this Agreement shall not relieve
the Parties of any liability which accrued hereunder prior to the effective date
of such termination nor preclude either Party from pursuing all rights and
remedies it may have hereunder or at law or in equity with respect to any breach
of this Agreement nor prejudice either Party's right to obtain performance of
any obligation.




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            (d) In the event that this Agreement is terminated (except for
termination pursuant to Section 11.3 (due solely to Corixa's material breach),
11.4(a), 11.5(b) or 11.6) and either

        [*]

12.     REPRESENTATIONS AND COVENANTS

        12.1 MUTUAL AUTHORITY. Corixa and Amersham each represents and warrants
to the other that (i) it has the authority and right to enter into and perform
this Agreement and (ii) its execution, delivery and performance of this
Agreement will not conflict in any material fashion with the terms of any other
agreement to which it is or becomes a party or by which it is or becomes bound.

        12.2 PERFORMANCE BY AFFILIATES. The Parties recognize that each may
perform some or all of its obligations under this Agreement through Affiliates,
provided, however, that each Party shall remain responsible and be guarantor of
the performance by its Affiliates and shall cause its Affiliates to comply with
the provisions of this Agreement in connection with such performance. [*].

13.     INDEMNIFICATION AND LIMITATION OF LIABILITY

        13.1 INDEMNIFICATION.

            (a) Amersham hereby agrees to defend and hold harmless Corixa and
its agents and employees from and against any and all suits, claims, actions,
demands, liabilities, expenses and/or loss, including reasonable legal expenses
and reasonable attorneys' fees ("Losses") resulting directly or indirectly from
(i) manufacture, use or storage by Amersham or its sublicensee or agent of
Tositumomab, Iodine I 131 Tositumomab or Product, (ii) sale of Product in the
Territory, or (iii) Amersham's breach of a material obligation under this
Agreement, except to the extent such Losses result from an activity as to which
Corixa is obliged to indemnify Amersham pursuant to Section 13.1(b).

            (b) Corixa hereby agrees to defend and hold harmless Amersham and
its agents and employees from and against any and all suits, claims, actions,
demands, liabilities, expenses and/or loss, including reasonable legal expenses
and reasonable attorneys' fees ("Losses") resulting directly or indirectly from
(i) the failure of Tositumomab provided to Amersham by Corixa or Corixa Iodine I
131 Tositumomab to comply with the relevant Specifications, (ii) the failure of
Corixa to comply with GMP during its manufacture of Tositumomab or Corixa Iodine
I 131 Tositumomab, or (iii) Corixa's breach of a material obligation under this
Agreement, except to the extent such Losses result from an activity as to which
Amersham is obliged to indemnify Corixa pursuant to Section 13.1(a).

            (c) In the event that a Party (the "Indemnified Party") is seeking
indemnification under Section 13.1(a) or (b), the Indemnified Party shall inform
the other Party (the "Indemnifying Party") of a claim as soon as reasonably
practicable after the Indemnified Party receives notice of the claim, shall
permit the Indemnifying Party to assume direction and control of the defense of
the claim (including the right to settle the claim solely for monetary

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<PAGE>

consideration), and shall cooperate as requested by the Indemnifying Party (at
the expense of the Indemnifying Party) in the defense of the claim.

        13.2 LIMITATION OF LIABILITY. EXCEPT AS SPECIFICALLY PROVIDED IN
SECTIONS 11.7(d) AND 13.1, IN NO EVENT SHALL EITHER PARTY, ITS DIRECTORS,
OFFICERS, EMPLOYEES, AGENTS OR AFFILIATES BE LIABLE TO THE OTHER PARTY FOR ANY
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES, WHETHER BASED
UPON A CLAIM OR ACTION OF CONTRACT, WARRANTY, NEGLIGENCE, STRICT LIABILITY OR
OTHER TORT, OR OTHERWISE, ARISING OUT OF THIS AGREEMENT. For clarification, the
foregoing sentence shall not be interpreted to limit or to expand the express
rights specifically granted in the sections of this Agreement.

        13.3 INSURANCE.

            (a) During the term of this Agreement and for a period of five years
after the expiration or termination of this Agreement, Amersham shall maintain
product liability insurance or indemnity policies with an insurer reasonably
satisfactory to Corixa, with a minimum amount not less than [*] per occurrence
(or claim) and [*] annual aggregate limit of liability, and after the First
Commercial Sale in the Territory shall always maintain product liability
insurance with a minimum of [*] per occurrence (or claim) and [*] annual
aggregate limit of liability. Such policies shall insure against liability on
the part of Corixa and any of its Affiliates, as their interests may appear, due
to injury, disability or death of any person or persons, or injury to property
arising from any action or omission for which Amersham has an indemnification
obligation pursuant to Section 13.1(a).

            (b) During the term of this Agreement and for a period of five years
after the expiration or termination of this Agreement, Corixa shall maintain
product liability insurance or indemnity policies with an insurer reasonably
satisfactory to Amersham, with a minimum amount not less than [*] per occurrence
(or claim) and [*] annual aggregate limit of liability. Such policies shall
insure against liability on the part of Amersham and any of its Affiliates, as
their interests may appear, due to injury, disability or death of any person or
persons, or injury to property arising from any action or omission for which
Corixa has an indemnification obligation pursuant to Section 13.1(b).

            (c) Each Party shall promptly notify the other Party of any material
alterations to the terms of such policies or in the amounts for which insurance
is provided.

14.     MISCELLANEOUS

        14.1 DISPUTE RESOLUTION. In the event of any controversy or claim
arising out of, relating to or in connection with any provision of this
Agreement other than a Corixa Matter or a Amersham Matter, the Parties shall try
to settle their differences amicably between themselves first, by referring the
disputed matter to the respective heads of Research and Development of each
Party and, if not resolved by the Research and Development heads, by referring
the


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disputed matter to the respective Chief Executive Officers of each Party. Either
Party may initiate such informal dispute resolution by sending written notice of
the dispute to the other Party, and, within 20 days after such notice, such
representatives of the Parties shall meet for attempted resolution by good faith
negotiations. If such personnel are unable to resolve a dispute within 30 days
of their first meeting of such negotiations, except as provided in Section 14.3,
either Party may seek to have such dispute resolved by binding arbitration with
a single arbitrator under the commercial rules of the American Arbitration
Association. The Parties hereby consent to conduct such binding arbitration
procedures in English in the city of New York, New York.

        14.2 GOVERNING LAW. Resolution of all disputes arising out of or related
to this Agreement or the performance, enforcement, breach or termination of this
Agreement and any remedies relating thereto, shall be governed by and construed
under the substantive laws of the State of Delaware, as applied to agreements
executed and performed entirely in the State of Delaware by residents of the
State of Delaware, without regard to conflicts of law rules.

        14.3 PATENTS AND TRADEMARKS. Any dispute, controversy or claim relating
to the scope, validity, enforceability or infringement of any Patent rights
covering the manufacture, use or sale of any Product or of any trademark rights
related to any Product shall be submitted to a court of competent jurisdiction
in the territory in which such Patent or trademark rights were granted or arose.

        14.4 ENTIRE AGREEMENT; AMENDMENT. This Agreement sets forth the
complete, final and exclusive agreement and all the covenants, promises,
agreements, warranties, representations, conditions and understandings between
the Parties hereto and supersedes and terminates all prior agreements and
understandings between the Parties. There are no covenants, promises,
agreements, warranties, representations, conditions or understandings, either
oral or written, between the Parties other than as are set forth herein and
therein. No subsequent alteration, amendment, change or addition to this
Agreement shall be binding upon the Parties unless reduced to writing and signed
by an authorized officer of each Party.

        14.5 EXPORT CONTROL. This Agreement is made subject to any restrictions
concerning the export of products or technical information from the United
States of America or other countries which may be imposed upon or related to
Corixa or Amersham from time to time. Each Party agrees that it will not export,
directly or indirectly, any technical information acquired from the other Party
under this Agreement or any products using such technical information to a
location or in a manner that at the time of export requires an export license or
other governmental approval, without first obtaining the written consent to do
so from the appropriate agency or other governmental entity.

        14.6 BANKRUPTCY.

            (a) All rights and licenses granted under or pursuant to this
Agreement, including amendments hereto, by each Party to the other Party are,
for all purposes of Section 365(n) of Title 11 of the U.S. Code ("Title 11"),
licenses of rights to intellectual property as defined in Title 11. Each Party
agrees during the term of this Agreement to create and maintain current copies
or, if not amenable to copying, detailed descriptions or other appropriate
embodiments, to the extent feasible, of all such intellectual property. If a
case is commenced by


                                       31
<PAGE>

or against either Party (the "Bankrupt Party") under Title 11, then, unless and
until this Agreement is rejected as provided in Title 11, the Bankrupt Party (in
any capacity, including debtor-in-possession) and its successors and assigns
(including, without limitation, a Title 11 Trustee) shall, at the election of
the Bankrupt Party made within 60 days after the commencement of the case (or,
if no such election is made, immediately upon the request of the non-Bankrupt
Party) either (i) perform all of the obligations provided in this Agreement to
be performed by the Bankrupt Party including, where applicable and without
limitation, providing to the non-Bankrupt Party portions of such intellectual
property (including embodiments thereof) held by the Bankrupt Party and such
successors and assigns or otherwise available to them or (ii) provide to the
non-Bankrupt Party all such intellectual property (including all embodiments
thereof) held by the Bankrupt Party and such successors and assigns or otherwise
available to them.

            (b) If a Title 11 case is commenced by or against the Bankrupt Party
and this Agreement is rejected as provided in Title 11 and the non-Bankrupt
Party elects to retain its rights hereunder as provided in Title 11, then the
Bankrupt Party (in any capacity, including debtor-in-possession) and its
successors and assigns (including, without limitations, a Title 11 Trustee)
shall provide to the non-Bankrupt Party all such intellectual property
(including all embodiments thereof) held by the Bankrupt Party and such
successors and assigns or otherwise available to them immediately upon the
non-Bankrupt Party's written request therefor. Whenever the Bankrupt Party or
any of its successors or assigns provides to the non-Bankrupt Party any of the
intellectual property licensed hereunder (or any embodiment thereof) pursuant to
this Section 14.6, the non-Bankrupt Party shall have the right to perform the
obligations of the Bankrupt Party hereunder with respect to such intellectual
property, but neither such provision nor such performance by the non-Bankrupt
Party shall release the Bankrupt Party from any such obligation or liability for
failing to perform it.

            (c) All rights, powers and remedies of the non-Bankrupt Party
provided herein are in addition to and not in substitution for any and all other
rights, powers and remedies now or hereafter existing at law or in equity
(including, without limitation, Title 11) in the event of the commencement of a
Title 11 case by or against the Bankrupt Party. The non-Bankrupt Party, in
addition to the rights, power and remedies expressly provided herein, shall be
entitled to exercise all other such rights and powers and resort to all other
such remedies as may now or hereafter exist at law or in equity (including,
without limitation, under Title 11) in such event. The Parties agree that they
intend the foregoing non-Bankrupt Party rights to extend to the maximum extent
permitted by law and any provisions of applicable contracts with Third Parties,
including without limitation for purposes of Title 11, (i) the right of access
to any intellectual property (including all embodiments thereof) of the Bankrupt
Party or any Third Party with whom the Bankrupt Party contracts to perform an
obligation of the Bankrupt Party under this Agreement, and, in the case of the
Third Party, which is necessary for the development, registration and
manufacture of licensed products and (ii) the right to contract directly with
any Third Party described in (i) in this sentence to complete the contracted
work. Any intellectual property provided pursuant to the provisions of this
Section 14.6 shall be subject to the licenses set forth elsewhere in this
Agreement and the payment obligations of this Agreement, which shall be deemed
to be royalties for purposes of Title 11.


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<PAGE>

        14.7 FORCE MAJEURE. Both Parties shall be excused from the performance
of their obligations under this Agreement to the extent that such performance is
prevented by force majeure and the nonperforming Party promptly provides notice
of the prevention to the other Party. Such excuse shall be continued so long as
the condition constituting force majeure continues and the nonperforming Party
takes reasonable efforts to remove the condition. For purposes of this
Agreement, force majeure shall include conditions beyond the control of the
Parties, including without limitation, an act of God, voluntary or involuntary
compliance with any regulation, law or order of any government, war, civil
commotion, labor strike or lock-out, epidemic, failure or default of public
utilities or common carriers, destruction of production facilities or materials
by fire, earthquake, storm or like catastrophe; provided, however, the payment
of invoices due and owing hereunder shall not be delayed by the payer because of
a force majeure affecting the payer.

        14.8 NOTICES. Any notice required or permitted to be given under this
Agreement shall be in writing, shall specifically refer to this Agreement and
shall be deemed to have been sufficiently given for all purposes if mailed by
first class certified or registered mail, postage prepaid, express delivery
service or personally delivered. Unless otherwise specified in writing, the
mailing addresses of the Parties shall be as described below.


                  For Corixa:               Senior VP, Chief Operating Officer
                                            Corixa Corporation
                                            1124 Columbia Street, Suite 200
                                            Seattle, WA 98104

                  With a copy to:           General Counsel
                                            Corixa Corporation
                                            1124 Columbia Street, Suite 200
                                            Seattle, WA 98104

                  With a copy to:           Cooley Godward LLP
                                            Five Palo Alto Square
                                            3000 El Camino Real
                                            Palo Alto, CA  94306
                                            Attention:  Robert L. Jones, Esq.

                  For Amersham:             Group Secretary
                                            Amersham PLC
                                            Amersham Place
                                            Little Chalfont
                                            Buckinghamshire
                                            ENGLAND HP7 9NA

                  With a copy to:           General Counsel
                                            Nycomed Amersham
                                            101 Carnegie Center
                                            Princeton, NJ 08540


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<PAGE>

        14.9 CONSENTS NOT UNREASONABLY WITHHELD OR DELAYED. Whenever provision
is made in this Agreement for either Party to secure the consent or approval of
the other, that consent or approval shall not unreasonably be withheld or
delayed, and whenever in this Agreement provisions are made for one Party to
object to or disapprove a matter, such objection or disapproval shall not
unreasonably be exercised.

        14.10 MAINTENANCE OF RECORDS. Each Party shall keep and maintain all
records required by law or regulation with respect to Products and shall make
copies of such records available to the other Party upon request.

        14.11 UNITED STATES DOLLARS. References in this Agreement to "Dollars"
or "$" shall mean the legal tender of the United States of America.

        14.12 NO STRICT CONSTRUCTION. This Agreement has been prepared jointly
and shall not be strictly construed against either Party.

        14.13 ENGLISH. This Agreement has been prepared in English and shall be
interpreted solely in English.

        14.14 ASSIGNMENT. Neither Party may assign or transfer this Agreement or
any rights or obligations hereunder without the prior written consent of the
other, except a Party may make such an assignment without the other Party's
consent to an Affiliate or to a successor to substantially all of the business
of such Party, whether in a merger, sale of stock, sale of assets or other
transaction. Any permitted successor or assignee of rights and/or obligations
hereunder shall, in writing to the other Party, expressly assume performance of
such rights and/or obligations. Any permitted assignment shall be binding on the
successors of the assigning Party. Any assignment or attempted assignment by
either Party in violation of the terms of this Section 14.14 shall be null and
void and of no legal effect.

        14.15 HARDSHIP. If, during the term of the Agreement, performance of the
Agreement should lead to unreasonable hardship for one or other Party taking the
interests of both Parties into account both Parties shall endeavor to agree in
good faith to amend the Agreement in the light of the change in circumstances.

        14.16 ELECTRONIC DATA INTERCHANGE. If both Parties elect to facilitate
business activities hereunder by electronically sending and receiving data in
agreed formats (also referred to as Electronic Data Interchange or "EDI") in
substitution for conventional paper-based documents, the terms and conditions of
this Agreement shall apply to such EDI activities.

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

        14.18 FURTHER ACTIONS. Each Party agrees to execute, acknowledge and
deliver such further instruments, and to do all such other acts, as may be
necessary or appropriate in order to carry out the purposes and intent of this
Agreement.


                                       34
<PAGE>

        14.19 SEVERABILITY. If any one or more of the provisions of this
Agreement is held to be invalid or unenforceable by any court of competent
jurisdiction from which no appeal can be or is taken, the provision shall be
considered severed from this Agreement and shall not serve to invalidate any
remaining provisions hereof. The Parties shall make a good faith effort to
replace any invalid or unenforceable provision with a valid and enforceable one
such that the objectives contemplated by the Parties when entering this
Agreement may be realized. If the Parties, after making good faith effort, are
unable to effectively replace an invalid or unenforceable provision pursuant to
this Section 14.19, and a Party is suffering or reasonably expects to suffer
significant economic harm as a result of the invalidity or unenforceability of
an original provision of this Agreement, such Party shall have the right to
terminate this Agreement upon six (6) months prior written notice to the other
Party. Such termination shall be in accordance with the provisions of Section
11.3(b) of this Agreement.

        14.20 AMBIGUITIES. Ambiguities, if any, in this Agreement shall not be
construed against any Party, irrespective of which Party may be deemed to have
authored the ambiguous provision.

        14.21 HEADINGS. The headings for each article and section in this
Agreement have been inserted for convenience of reference only and are not
intended to limit or expand on the meaning of the language contained in the
particular article or section.

        14.22 NO WAIVER. Any delay in enforcing a Party's rights under this
Agreement or any waiver as to a particular default or other matter shall not
constitute a waiver of such Party's rights to the future enforcement of its
rights under this Agreement, excepting only as to an express written and signed
waiver as to a particular matter for a particular period of time.

        IN WITNESS WHEREOF, the Parties have executed this Agreement in
duplicate originals by their proper officers as of the date and year first above
written.

AMERSHAM PLC                         CORIXA CORPORATION

By: /s/ R.E.B Allnutt                By:/s/ Steven Gillis
    ------------------------------       ---------------------------------------
Name:   R.E.B Allnutt                Name:  Steven Gillis
      ----------------------------         -------------------------------------
Title: Company Secretary             Title: Chairman and Chief Executive Officer
       ---------------------------          ------------------------------------
Date: 11/05/01                       Date:  10/31/01
      ----------------------------         -------------------------------------


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                                   EXHIBIT A
                                 CORIXA PATENTS
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* Confidential Treatment Requested.

                                      A-1.
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                                   EXHIBIT B
                              COUNTRIES OF EUROPE
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* Confidential Treatment Requested.

                                      B-1.
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                                   EXHIBIT C
                                DEVELOPMENT PLAN
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* Confidential Treatment Requested.

                                      C-1.
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                                   EXHIBIT D
                             CORIXA CLINICAL TRIALS
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* Confidential Treatment Requested.

                                      D-1.