Document:

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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 24b-2 of the Securities Exchange Act of 1934, 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 the carrying out of obligations or tasks
in a sustained manner consistent with the efforts a Party devotes to a product
or a development or marketing project of similar market potential, profit
potential or strategic value resulting from its own efforts, based on conditions
then prevailing.

        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 the treatment, prevention or palliation of any
indication in humans. In no event shall "Field" include diagnosis of such
indications.

        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
consulting services rendered by the Corixa's employees. The FTE Rate for
calendar year 2001 will be the lesser of: (a) [*] dollars ($[*]) per hour or (b)
[*] dollars ($[*]) per day per employee. For each subsequent calendar year, this
rate will be adjusted by the percentage change in the monthly Consumer Price
Index for the immediately preceding October as compared to the base month of
October, 2000. The index source will be the Consumer Price Index published by
the Bureau of Labor Statistics of the United States Department of Labor and
covering San Francisco, California, Seattle, Washington and Missoula, Montana.
Should indices covering all of the foregoing areas not be available, then the
national index will be used as the reference.

        1.27 "FULLY ALLOCATED COST" shall mean the direct and indirect costs of
Tositumomab provided by Corixa to Amersham or Corixa Iodine I 131 Tositumomab
and shall be computed in accordance with United States generally accepted
accounting principles, consistently applied. To the extent that any such costs
arise from activities performed for Amersham as well as other Corixa partners
for the Product, the amounts allocated to Amersham shall be a fair, pro rata
allocation based upon the performance for Amersham relative to the performance
for other Corixa partners for the Product. Fully Allocated Cost shall include
without limitation:

               (a) cost and expenses incurred by Corixa, including, but not
limited to, payments owed by Corixa to Third Parties (including Third Party
licensors such as Dana Farber

* Confidential treatment requested.

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and University of Michigan), for the manufacture or supply to Amersham of such
Tositumomab or Corixa Iodine I 131 Tositumomab, including, but not limited to,
the transfer price for such antibody, cancellation payments (limited to Amersham
cancellations), payments related to failed batches (to the extent not otherwise
charged to Amersham pursuant to this Agreement), readiness payments, and
facilities charges owed to such Third Parties, plus

               (b) QA/QC Costs, plus

               (c) If applicable, the cost of forward foreign currency contracts
to protect against risk of changes in foreign exchange rates, provided that such
costs are approved in advance by the Parties, plus

               (d) Corixa's internal and external expenses, including
out-of-pocket expenses and employee expenses, if any, with respect to freight
and tariffs associated with transporting Tositumomab or Corixa Iodine I 131
Tositumomab from the source of manufacture to the end user, inclusive of interim
points of delivery, but excluding any such costs which are separately invoiced
to a customer, plus

               (e) The cost of Corixa employees engaged in Tositumomab or Corixa
Iodine I 131 Tositumomab manufacturing-related activities, including, without
limitation, employees engaged in oversight of manufacture by Third Parties, plus

               (f) A reasonable allocation, with respect to such Tositumomab or
Corixa Iodine I 131 Tositumomab, of Corixa's: (i) indirect labor (to the extent
not previously included in (d) or (e)), (ii) administrative costs, and (iii)
facilities costs including electricity, water, sewer, waste disposal, property
taxes, and depreciation over the expected life of buildings and equipment. Such
allocations shall be in accordance with reasonable cost accounting methods,
consistently applied, of Corixa.

        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 information, results and data of any type
whatsoever, in any tangible or intangible form whatsoever, including without
limitation, databases, inventions, practices, methods, techniques,
specifications, formulations, formulae, knowledge, know-how, skill, experience,
test data including pharmacological, biological, chemical, biochemical,
toxicological and clinical test data, analytical and quality control data,
stability data, studies and procedures, and patent and other legal information
or descriptions.

        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.

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        1.32 "INITIAL APPROVAL TRIAL COSTS" shall mean, with respect to the
Initial Approval Clinical Trials and the Initial Regulatory Filings:

               (a) the direct and indirect costs incurred by Corixa and its
Third Party contractors, including contract research organizations (CRO's), and
consultants in connection with such Clinical Trials and the Initial Regulatory
Filings, including, without limitation, the costs of all Tositumomab and Corixa
Iodine I 131 Tositumomab purchased by Corixa for use in such Clinical Trials,
fees paid to clinical sites for such Clinical Trial, fees paid to human subjects
participating in such Clinical Trials, and FTE and other overhead expenses, if
any, directly attributable to such Clinical Trials or the Initial Regulatory
Filings;

               (b) the direct and indirect external costs agreed to in writing
by Corixa and incurred by Amersham and its Third Party contractors and
consultants in connection with such Clinical Trials (including, without
limitation, fees paid to clinical sites for such Clinical Trials and fees paid
to human subjects participating in such Clinical Trials) and the Initial
Regulatory Filings; and

               (c) the direct FTE costs incurred by Amersham pursuant the
Section 4.1 or otherwise as provided under this Agreement in connection with
such Clinical Trials and the Initial Regulatory Filings, but excluding all of
Amersham's indirect FTE costs and non-FTE internal costs, including without
limitation overhead expenses, if any, attributable to such Clinical Trial or the
Initial Regulatory Filings.

        1.33 "INITIAL DEVELOPMENT PLAN" shall mean a full plan (rather than a
summary thereof) (a) that includes a detailed budget and specifies the means by
which (i) Corixa will seek to obtain Initial Approval for the Product in the
Territory, including a description of and estimated timeline for all regulatory
activities, and (ii) Amersham will establish the European Facility 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 all Patents, copyrights,
regulatory filings, Know-How, or any other intellectual property other than
trademarks, that are Controlled during the term of this Agreement by a Party or
jointly by the Parties and that relate to the development, manufacture,
importing, use, marketing and/or sale of the Product. The term "Intellectual
Property Rights" shall include any rights obtained by either Party from a Third
Party, including those obtained pursuant to Section 2.7, subject to the terms
and conditions of the agreements in which such rights were conferred. The term
"Intellectual Property Rights," however, shall not include Patents, copyrights,
regulatory filings, know-how and/or trade secrets, or any other intellectual
property of either Party for the manufacture or purification of monoclonal
antibodies, whether developed prior to or after the Effective Date.

        1.36 "INVENTION" means any invention, development, result, Know-How or
other Information, and all intellectual property relating thereto, made,
discovered or developed (i) solely by a Party and its employees or agents
pursuant to work performed under the Agreement or (ii) jointly by the Parties
and their employees or agents pursuant to work performed under the Agreement.

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        1.37 "IODINE I 131 TOSITUMOMAB" shall mean any therapeutic, prophylactic
or palliative product containing or comprising the composition of matter
conjugated with 131Iodine that was one of the active agents tested in Corixa's
clinical trial with Protocol No. RIT-II-004 as referred to in that Protocol as
[*] 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 any and all Other Inventions made
jointly by employees or agents of both Parties pursuant to work conducted under
the Agreement.

        1.41 "KNOW-HOW" shall mean any technical information that is secret and
identified.

        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 UK, France, Germany, Spain and
Italy.

        1.44 "MARKETING PLAN" shall mean a full plan (rather than a summary
thereof) prepared by Amersham (as amended from time to time) that specifies the
means by which Amersham intends to commercialize the Product in the Territory,
including a description of and estimated timeline for all marketing and
promotional activities.

        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 gross amounts invoiced for sales of the
Product in the Territory by either Party, its Affiliates or sublicensees, as
appropriate, to Third Parties, less the following items: (i) trade, quantity and
cash discounts or rebates actually allowed and taken and any other adjustments,
including, without limitation, those granted on account of price adjustments,
billing errors, rejected goods, damaged goods and recall returns; (ii) credits,
rebates, charge-back and prime vendor rebates, fees, reimbursements or similar
payments granted or given to wholesalers and other distributors, buying groups,
health care insurance carriers, pharmacy benefit management companies, health
maintenance organizations or other institutions or health care organizations;
(iii) any tax, tariff, customs duties, excise or other duties or other
governmental charge (other than an income tax) levied on the sale,
transportation or delivery of a Product and borne by the seller thereof; (iv)
payments or rebates paid in connection with sales of Products to any
governmental or regulatory authority in respect of any medical insurance funded
by a state or federal government; and (v) any charge for freight, insurance or
other transportation costs charged to the customer. For clarity, Net Sales shall
not include: sales of the Product by and between a Party and its Affiliates
(except where such Affiliates are end users).

* Confidential treatment requested.

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        1.47 "OTHER INVENTION" means any Invention that is not a Product
Invention.

        1.48 "PATENT" means (i) unexpired letters patent (including inventor's
certificates) that have not been held invalid or unenforceable by a court of
competent jurisdiction from which no appeal can be taken or has been taken
within the required time period, including without limitation any substitution,
extension, registration, confirmation, reissue, re-examination, renewal or any
like filing thereof and (ii) pending applications for letters patent, including
without limitation any continuation, division or continuation-in-part thereof
and any provisional applications.

        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 therapeutic, prophylactic or palliative product
containing or comprising Tositumomab as defined in Section 1.65 for use in
connection with a Iodine I 131 Tositumomab, in any formulation or mode of
administration.

        1.51 "PRODUCT IMPROVEMENT" means any Invention that pertains to the
formulation, packaging, storage, administration or dosimetry of the Product but
does not pertain to radiolabeling of Tositumomab. For clarity, a particular
Product Improvement may be a Product Invention or an Other Invention.

        1.52 "PRODUCT INVENTION" means any Invention that pertains solely to, or
the sole use of which is limited to, the Product or its development, manufacture
or use.

        1.53 "QA/QC COSTS" shall mean Corixa's internal and external costs of
quality assurance and quality control work performed by or on behalf of Corixa
related to Product release and Product testing of Tositumomab and Corixa Iodine
I 131 Tositumomab, but only to the extent that such quality assurance and
quality control work is required by the FDA or other relevant regulatory
authorities. QA/QC Costs shall include a reasonable allocation of Corixa's
facility overhead, and shall include any allocation of the costs of establishing
or validating a facility or any costs of excess capacity directly related to
Tositumomab.

        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.

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        1.57 "SOLE OTHER INVENTIONS" means any and all Other Inventions made,
discovered or developed solely by a Party and its employees or agents pursuant
to work performed under the Agreement.

        1.58 "SPECIFICATIONS" shall mean the requirements and standards
pertaining to Tositumomab or Iodine I 131 Tositumomab (depending upon context)
and consistent with filings made for Regulatory Approval and all relevant
written agreements between Corixa and a Third Party with respect to manufacture
or supply of Tositumomab, Iodine I 131 Tositumomab or Product, which
specifications are set forth in the BLA identified by Biologics License
Application Submission Tracking Number 125011, provided that such specifications
may be modified in writing by the Parties from time to time as follows: any
modifications to the Specifications shall be reasonably acceptable to both
Parties or required for approval of the Product in the Territory and shall be
reasonably consistent with respect to products manufactured by or on behalf of
Corixa for use in markets in the Corixa Territory. The Specifications shall be
release or stability specifications, as applicable, and each reference to
Specifications shall mean the type of such Specifications appropriate to the
context.

        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 full plan (rather than a
summary thereof) that includes a detailed budget and specifies the means by
which Amersham will develop the Product other than in connection with the
Initial Approval, including the means by which Amersham will seek to obtain
Regulatory Approvals other than the Initial Approval for the Product in each
country in the Territory and including a description of and estimated timeline
for all regulatory activities, Subsequent Clinical Trials and any further
activities related to establishing the European Facility and which has been
approved by the CSC in accordance with Section 4.2 or 4.3.

        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 the composition of matter that (i) has not
been conjugated with 131Iodine or any other isotope, molecule, compound or
moiety and (ii) was administered to patients in Corixa's clinical trial with
Protocol No. RIT-II-004 as referred to in

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that Protocol as [*] anti CD20 murine monoclonal antibody. Except as otherwise
specified in this Agreement, Tositumomab shall mean both bulk and filled
material.

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) in the Major Market Countries, with
the prior written consent of Corixa and (ii) in all other countries in the
Territory, with prior written notification to Corixa.

               (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, 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) Iodine I 131 Tositumomab from
Tositumomab provided by Corixa, and (ii) Product from Tositumomab provided by
Corixa. 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 co-exclusive among Amersham, Corixa and Corixa's
Third Party supplier(s) of Iodine I 131 Tositumomab. After the end of such
period, such license shall be exclusive to Amersham, subject to conversion of
such license to non-exclusive pursuant to Section 2.1(d). For clarity, the
foregoing license shall not be interpreted to prevent Corixa from making in the
Territory Tositumomab or Iodine I 131 Tositumomab for use outside the Territory.

        (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

* Confidential Treatment Requested

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a written agreement for the limited purpose of carrying out Amersham's
manufacturing obligations under this Agreement.

               (d) CONVERSION TO NON-EXCLUSIVE LICENSES. The licenses set forth
in Sections 2.1(a) and (b) shall automatically convert to non-exclusive licenses
on 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 and (ii) 10 years after the First Commercial
Sale of the Product in the Territory.

        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.

        2.3 LICENSE TO CORIXA. Subject to the terms and conditions of this
Agreement, Amersham hereby grants Corixa a worldwide, non-exclusive,
royalty-free, perpetual license (with the right to sublicense only in
conjunction with a Corixa product or other intellectual property Controlled by
Corixa) to make and use, for any purpose, 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 COVENANT NOT TO SUE. Amersham hereby agrees that it shall not assert
in any way any Patent or Know-How against Corixa or its Affiliates, or any of
their licensees, distributors, manufacturers or customers, direct or indirect,
in connection with the manufacture, use, import, offer for sale or sale of
Products manufactured in accordance the manufacturing procedures in use on the
Effective Date. If Amersham assigns or attempts to assign ownership of any of
its Patents to a Third Party not bound by this covenant not to sue (whether
directly or by operation of law), then effective upon such assignment or
attempted assignment, Corixa and its Affiliates and each of their licensees,
distributors and manufacturers, shall have and Amersham hereby grants Corixa in
the event of such circumstance, a worldwide, nonexclusive, nontransferable,
royalty-free license, without right of sublicense, under such assigned Patents
to make, use, import, offer for sale and sell Products manufactured in
accordance the manufacturing procedures in use on the Effective Date.

        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.

                                       11
<PAGE>

        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 necessary in order to
assure Amersham that its activities under this Agreement involving the Product
as formulated and administered as of the Effective Date do not infringe the
intellectual property rights of such Third Party, then the Parties will discuss
the situation in good faith and Amersham shall make the determination as to
whether or not to license such intellectual property. Any license fees or
royalties payable to Third Parties pursuant to such a license agreement between
Amersham and a Third Party shall be borne by Amersham and deducted from
Amersham's Net Sales.

               (b) In the event Amersham believes that one or more licenses
under intellectual property held by a Third Party are desirable in order to
assure Amersham that its activities under this Agreement do not infringe the
intellectual property rights of such Third Party, then the Parties will discuss
the situation in good faith and Amersham shall make the determination as to
whether or not to license such intellectual property. Any license fees or
royalties payable to Third Parties pursuant to such a license agreement between
Amersham and a Third Party shall be borne by Amersham.

               (c) In the event Corixa believes that one or more licenses under
intellectual property held by a Third Party are necessary in order to assure
Corixa that its manufacture of Tositumomab or Iodine I 131 Tositumomab and other
activities under this Agreement for the Territory do not infringe the
intellectual property rights of such Third Party, then the Parties will discuss
the situation in good faith and Corixa shall make the determination as to
whether or not to license such intellectual property. Any license fees or
royalties payable to Third Parties pursuant to such a license agreement between
Corixa and a Third Party shall be initially borne by Corixa and, to the extent
applicable to the manufacture of Tositumomab or Corixa Iodine I 131 Tositumomab
provided by Corixa hereunder for the sale of Product in the Territory, shall be
passed on to Amersham as part of the Fully Allocated Cost of such Tositumomab or
Corixa Iodine I 131 Tositumomab and such increase in Fully Allocated Cost shall
be deducted from Amersham's Net Sales.

               (d) In the event Corixa believes that one or more licenses under
intellectual property held by a Third Party are desirable in order to assure
Corixa that its manufacture of Tositumomab or Iodine I 131 Tositumomab and other
activities under this Agreement for the Territory do not infringe the
intellectual property rights of such Third Party, then the Parties will discuss
the situation in good faith and Corixa shall make the determination as to
whether or not to license such intellectual property. Any license fees or
royalties payable to Third Parties pursuant to such a license agreement between
Corixa and a Third Party shall be borne by Corixa and shall not be passed on to
Amersham as part of the Fully Allocated Cost of such Tositumomab or Corixa
Iodine I 131 Tositumomab.

               (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.

                                       12
<PAGE>

        2.8 EXCLUSIVITY. If Amersham or any Affiliate of Amersham files an MAA
or other application for Regulatory Approval in the Territory, to market an
antibody directed at CD20 (other than a Product and whether unconjugated or
conjugated to any isotope, molecule, compound or moiety) for the same indication
for which Corixa and/or Amersham plans to seek Initial Approval for a Product or
for which Amersham plans to seek, is seeking or has received any other
Regulatory Approval in the Territory for a Product, Amersham shall immediately
notify Corixa. Corixa may at any time thereafter, upon six months prior written
notice to Amersham, terminate the licenses contained in Section 2.1 or convert
such licenses to nonexclusive.

        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 oversee, coordinate and provide strategic
direction to the development, registration and commercialization of the Product
for and in the Territory and to approve the plans, budgets and resource
allocations for such activities (the "Collaboration Steering Committee" or
"CSC").

               (b) MEMBERSHIP. Each Party shall initially appoint two (2)
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. At least one (1) of each Party's representatives on the CSC will have the
title of Vice-President (or a comparable position) or above for such Party. The
CSC may invite nonmembers to participate in the discussions and meetings of the
CSC, provided that such participants shall have no voting authority at the CSC.

               (c) CO-CHAIRPERSONS. Each Party will name, from among its two (2)
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 unanimous vote, with
each Party having one (1) vote. If the CSC becomes deadlocked on an issue that
is not a Corixa Matter or an Amersham Matter, then either Party may refer the
matter for dispute resolution pursuant to Section 14.1 by written notice to the
other Party. If the CSC becomes deadlocked on an issue that is a Corixa Matter,
then Corixa shall decide how such issue shall be handled. Such Corixa decision
shall be final and not subject to the dispute resolution procedures set forth in
Section 14.1. If the CSC becomes deadlocked on an issue that is an Amersham
Matter, then Amersham

                                       13
<PAGE>

shall decide how such issue shall be handled. Such Amersham decision shall be
final and not subject to the dispute resolution procedures set forth in Section
14.1.

               (e) MEETINGS. The CSC shall meet at least once per calendar
quarter after the Effective Date until Initial Approval, and at least two (2)
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 oversee, monitor, review, coordinate and provide
strategic direction to the development, registration and commercialization 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;

                      (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 strategies, plans and
budgets 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 two (2) years following Initial
Approval.

                                       14
<PAGE>

               (b) MEMBERSHIP. Each Party shall initially appoint two (2)
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. At least one (1) of each Party's representatives will have the title of
Vice-President (or a comparable position) or above for such Party. The JDC may
invite nonmembers to participate in the discussions and meetings of the JDC,
provided that such participants shall have no voting authority at the JDC. A
member of the JDC may also be a member of the JCC.

               (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 unanimous vote, with
each Party having one (1) vote. Should the JDC become deadlocked on any issue,
then it shall submit such issue to the CSC for resolution.

               (e) MEETINGS. The JDC shall meet at least once per calendar
quarter after the Effective Date until Initial Approval, and at least two (2)
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 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 manage, monitor, review and coordinate the development
and Regulatory Approval of the Product in the Territory according to the
Development Plans and to ensure a regular flow of development information among
the Parties, the JDC shall in particular:

                      (i) revise each draft Development Plan prepared by the
Parties and present the revised draft Development Plan to the CSC, all in
accordance with Sections 4.2 and 4.3;

                      (ii) review, coordinate and approve all plans for
clinical, manufacturing and radiolabeling activities with respect to the Product
in or for the Territory;

                                       15
<PAGE>

                      (iii) facilitate the flow of information between the
Parties with respect to all development of the Product for and in the Territory;

                      (iv) establish the levels of supply of Product needed for
the Initial Approval Clinical Trials as provided in Section 4.5 and for
Subsequent Clinical Trials; and

                      (v) perform any other responsibilities set forth for the
JDC in this Agreement.

               (g) LIMITED AUTHORITY. The JDC shall have only those powers
expressly assigned it in this Agreement. Without limiting the generality of the
foregoing, the JDC shall have no authority to amend the Development Plan or this
Agreement. The CSC may, at its discretion, review any decision of the JDC. The
JDC shall have no authority to override any decision of the CSC, any decision of
Corixa with respect to any Corixa Matter or any decision of Amersham with
respect to any Amersham Matter.

        3.3 JOINT COMMERCIALIZATION COMMITTEE (JCC).

               (a) PURPOSE; FORMATION. Within ninety (90) days after the
Effective Date the Parties will appoint their respective representatives to a
joint commercialization committee to manage the strategies, plans and budgets
for commercialization of the Product in the Territory (the "Joint
Commercialization Committee" or "JCC").

               (b) MEMBERSHIP. Each Party shall initially appoint two (2)
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. At least one (1) of each Party's representatives will have the title of
Vice-President (or a comparable position) or above for such Party. The JCC may
invite nonmembers to participate in the discussions and meetings of the JCC,
provided that such participants shall have no voting authority at the JCC. A
member of the JCC may also be a member of the JDC.

               (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 unanimous vote, with
each Party having one (1) vote. Should the JCC become deadlocked on any issue,
then it shall submit such issue to the CSC for resolution.

               (e) MEETINGS. The JCC shall meet at least two (2) times per year
after the Effective Date until submission of the MAA, and at least once per
calendar quarter thereafter until one (1) year following the First Commercial
Sale after which the JCC shall again meet at least two (2) times per year
throughout the term of this Agreement, unless the Parties mutually

                                       16
<PAGE>

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 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 manage, monitor, review and coordinate the
commercialization of the Product in the Territory according to the Marketing
Plan and to ensure a regular flow of development information among the Parties,
the JCC shall in particular:

                      (i) Oversee the activities of Amersham in marketing,
selling and distributing Product in the Territory, including pre-launch and
post-launch activities;

                      (ii) Review and comment on the Marketing Plan and all
updates thereto, as provided in Section 7.1;

                      (iii) Monitor Amersham's compliance with the Marketing
Plan; and

                      (iv) Perform any other responsibilities set forth for the
JDC in this Agreement.

               (g) LIMITED AUTHORITY. The JCC shall have only those powers
expressly assigned it in this Agreement. Without limiting the generality of the
foregoing, the JCC shall have no authority to amend the Marketing Plan or this
Agreement. The CSC may, at its discretion, review any decision of the JCC. The
JCC shall have no authority to override any decision of the CSC, any decision of
Corixa with respect to any Corixa Matter or any decision of Amersham with
respect to any Amersham Matter.

4. DEVELOPMENT; GOVERNANCE; DILIGENCE

        4.1 OVERVIEW. Corixa shall be responsible, under the direction of the
JDC and CSC, 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

                                       17
<PAGE>

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
60 days after Amersham's receipt of the data to be provided by Corixa pursuant
to Section 5.1(b), the Parties shall develop their appropriate portions (as
decided by the JDC) of a draft of the Initial Development Plan. When the JDC has
finished its review of, commentary upon and revision of such draft Initial
Development Plan, it shall present the revised draft Initial Development Plan to
the CSC for its approval, provided that such draft shall be presented to the CSC
not later than four (4) months following the Signing Date unless the Parties
agree otherwise. The CSC may approve such revised draft Initial Development
Plan, request that the JDC further revise such draft, or itself revise such
draft. The Initial Development Plan and all updates thereto shall become
contractual obligations of the Parties once such Development Plan is approved by
the CSC.

        4.3 UPDATES TO DEVELOPMENT PLAN.

               (a) INITIAL DEVELOPMENT PLAN. On or before July 1st of each year
commencing in 2002 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 September 1st 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 October 1st of the preceding calendar
year.

               (b) SUBSEQUENT DEVELOPMENT PLAN. On or before July 1st of each
year commencing in the year that the MAA for Initial Approval is filed with the
EMEA or such earlier year as the Parties may agree, 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 September 1st 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 October 1st 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

                                       18
<PAGE>

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)
those Amersham employees performing work related to the Initial Approval
Clinical Trials who shall be considered FTEs for the purposes of calculating
Initial Approval Trial Costs and (ii) the amount to be paid by Corixa (as part
of the Initial Approval Trial Costs) for each such FTE as determined in
accordance with Section 1.32(c).

               (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 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. The JDC
will agree upon the levels of supply of Product required for the Initial
Approval Clinical Trial, which amounts Amersham will include in the Amersham
Forecasts (and separately identify as Products for the Initial Approval Clinical
Trial) pursuant to the Supply Agreement. For the avoidance of doubt, such levels
shall be deemed to be a Corixa Matter, and if the JDC is unable to agree such
levels, Corixa shall make the final decision.

        4.7 DEVELOPMENT DILIGENCE.

               (a) GENERAL REQUIREMENT. Corixa shall use efforts of a sustained
manner consistent with the efforts Corixa devotes to other product development
of similar market potential, profit potential or strategic value resulting from
Corixa's own efforts, based on conditions then prevailing 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.

                                       19
<PAGE>

               (b) DILIGENCE BY CORIXA. Corixa shall initiate, perform and
complete the Initial Approval Clinical Trial in a timely manner and in
accordance with the approved Development Plan and shall file an MAA in a timely
manner after completion of the Initial Approval Clinical Trial and the
availability of an integrated full report (i.e., containing clinical and
statistical descriptions, presentations and analyses) 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 a delay caused by Amersham, Corixa shall be entitled to an extension of
such timeframe equal to the amount of such Amersham delay.

               (c) DILIGENCE BY AMERSHAM. Amersham shall use Diligent Efforts 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 a delay caused by Corixa, Amersham shall be entitled to an
extension of such timeframe equal to the amount of such Corixa delay.

5. CLINICAL TRIALS AND REGULATORY ISSUES

        5.1 TRANSFER OF PRE-EXISTING FILES AND DATA.

               (a) FILES. Within thirty (30) days after the Effective Date,
Corixa shall transfer to Amersham copies of all relevant 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 for any purpose, including, but not limited to,
cross-referencing such files in clinical and regulatory filings in the Corixa
Territory.

               (b) DATA. Within thirty (30) days after the Effective Date,
Corixa shall provide Amersham with copies of all preclinical data relating to
the Product in Corixa's possession on the Effective Date and all 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 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. Corixa shall also 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 the Clinical
Trials that are identified as "Closed" on Exhibit D, as well as from Clinical
Trials CP-98-020 and CP-98-021. 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.

                                       20
<PAGE>

        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
(i.e., enrollment began for the trial as a whole) 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 CP-98-020
and CP-98-021.

                      (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 if Amersham incurs such costs at the express direction of Corixa
in accordance with Section 4.1, Corixa shall reimburse Amersham therefor.
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 own and 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. If Amersham becomes, pursuant to Section 5.7, the owner of any
Regulatory Filing containing data from the Initial Approval Clinical Trials,
Corixa shall continue to own such data and Amersham shall take all appropriate
measures to grant Corixa a right of reference to such Regulatory Filing for such
purpose.

                      (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 [*] percent ([*]%) of Clinical Trial Costs

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<PAGE>

associated with such Clinical Trial and Amersham shall bear the remaining [*]
percent ([*]%) 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 [*] percent
([*]%) of Clinical Trial Costs associated with such Clinical Trial and Amersham
shall bear the remaining [*] percent ([*]%) 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 identified as
"Closed" on Exhibit D or Clinical Trial CP-98-020 and CP-98-021, 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 [*] percent ([*]%) of Clinical Trial Costs associated with such
Clinical Trial and Corixa shall bear the remaining [*] percent ([*]%) 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. If either Party
desires to conduct a new Cross-Territory Clinical Trial (which may be an
expansion of an existing Clinical Trial solely in the Territory or the Corixa
Territory), the JDC shall discuss such proposed Cross-Territory Clinical Trial.
If the JDC agrees upon a proposed protocol, budget and the allocation between
the Parties of the Clinical Trial Costs for such proposed Cross-Territory
Clinical Trial, then the JDC will present a proposal containing such information
to the CSC for approval. The CSC shall be entitled to approve, reject, revise or
request that the JDC revise and resubmit to the CSC such proposal. If the CSC
approves any such proposal, Amersham shall be responsible for the performance of
such Cross-Territory Clinical Trial in the Territory and Corixa (together with
Glaxo SmithKline in the United States) shall be responsible for the performance
of such Cross-Territory Clinical Trial in the Corixa Territory. In the event
that the Parties do not agree, neither Party shall have the right to conduct a
Clinical Trial in the other Party's Territory. In the event of a disagreement
between the Parties regarding the design or conduct of a Cross-Territory
Clinical Trial, either may opt out of the trial. If a Party does so opt out of a
Cross-Territory Clinical Trial, it shall have no further obligation to the other
Party to conduct such Cross-

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<PAGE>

Territory Clinical Trial in its territory (the Corixa Territory or the
Territory, as the case may be). Notwithstanding anything herein to the contrary,
the Initial Approval Clinical Trial shall not be deemed to be a Cross-Territory
Trial even if it is conducted in both the Territory and the Corixa Territory.

               (b) ACCESS TO DATA. The Parties shall have equal access to all
data generated in the course of a Cross-Territory Clinical Trial. Corixa shall
own all such data and such data shall be deemed to be Product Inventions.
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.

        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
thirty (30) 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

                                       23
<PAGE>

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. Subject to Section 5.9, Corixa will bear, as part of
the Initial Approval Trial Costs, all direct external costs and direct FTE costs
incurred by Amersham in the course of Amersham's preparation, filing,
prosecution and maintenance of the Initial Regulatory Filings, provided such
costs are approved in advance as part of a Development Budget, or otherwise
approved in advance in writing by Corixa.

        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;

               (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
thirty (30) days 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.
Amersham shall keep Corixa informed on an ongoing basis of Amersham's strategy
for seeking and results it obtains in seeking Pricing Approval for the Product
in each such country of the Territory, including without limitation the results
of any discussion or other communication with relevant governmental authorities
regarding Pricing Approval, via regular reports to the JDC no less frequently
than such committee is required to meet pursuant to Section 3.2. Amersham shall
also inform Corixa regarding its general pricing plans (that do not require
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,

                                       24
<PAGE>

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 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 reasonable best 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.

                                       25
<PAGE>

        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 a report
of an actual or potential failure of the Product to meet the standards set forth
in regulatory filings or in agreements among the Parties. 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.

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

                                       26
<PAGE>

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 five (5) business days after occurrence of each of
the events specified below:

               (a) $[*] million upon [*].

               (b) $[*] million upon the first time that Annual Net Sales exceed
$[*] million.

               (c) $[*] million upon the first time that Annual Net Sales exceed
$[*] million.

               (d) $[*] million upon the first time that Annual Net Sales exceed
$[*] million.

               (e) $[*] million upon the first time that Annual Net Sales exceed
$[*] million.

               (f) $[*] million upon first [*].

        For the avoidance of doubt, in the event that Annual Net Sales in a
particular year exceed more than one amount that gives rise to a milestone
payment under this Section 8.2, then Amersham shall make all applicable
milestone payments. For example, if Annual Net Sales in a particular year are
$83 million and previous Annual Net Sales were less than $25 million, Amersham
shall make the milestone payments set forth in Sections 8.2(b), (c) and (d) (for
a total of $[*] million) with respect to such year.

        The events described in subsections (b) through (e) above shall be
deemed to have occurred on the earlier of (i) the date upon which Amersham's
accounting system determines that such Annual Net Sales have been achieved and
(ii) the end of the calendar quarter in which the final sale that causes such
achievement is made.

        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 [*]
percent ([*]%) 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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                                       27
<PAGE>

<TABLE>
<CAPTION>
CIRCUMSTANCE                                      RUNNING ROYALTY
------------                                      ---------------
<S>                                               <C>
(i)     there is on sale in such country an [*]   [*]% of Net Sales
that is marketed by [*] or a distributor or
licensee of [*] (other than [*])

(ii)    there is on sale in such country a [*]    [*]% of Net Sales
of [*] that is marketed by [*] which does not
[*] in such country [*]

(iii)   there is on sale in such country a [*]    [*]% of Net Sales
of [*] that is marketed by [*] which [*] in
such country [*]

(iv)    there is on sale in such country an [*]   [*]% of Net Sales
that is marketed by [*] which [*] in such
country from [*] was required to [*] by law,
regulation or governmental agency
</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)
such time as all Know-How in the Corixa Intellectual Property Rights, Product
Inventions or Product Improvements Controlled by Corixa ceases to be secret on
account of Corixa's actions.

               (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 [*] percent ([*]%) 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 30
days following the end of each calendar quarter for which payments are due. Each
such payment shall be

* Confidential Treatment Requested

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<PAGE>

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 5.6. Corixa shall pay the undisputed amount of each
such invoice within thirty (30) days 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 (i) deduct those taxes from the remittable
payment, (ii) pay the taxes to the proper taxing authority, and (iii) send
evidence of the obligation together with proof of tax payment to Corixa within
60 days following that tax payment.

        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 thirty (30) days 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

                                       29
<PAGE>

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 fourteen (14) days after the payment's due date shall accrue
interest, which must be paid by the Party with the payment obligation to the
recipient Party, on a daily basis at a rate equal to two (2) percent above the
then-applicable reference rate of CitiBank, N.A. San Francisco, California (or
the maximum amount permitted by law, if less), 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 Product Inventions, and Patents covering such Product
Inventions. Each Party shall own the entire right, title and interest in and to
any and all of its Sole Other Inventions, and Patents covering such Sole Other
Inventions. Amersham and Corixa shall each own an undivided one-half interest in
and to any and all Joint Other Inventions and Patents and other intellectual
property rights claiming or covering or arising from such Joint Other Inventions
(the "Joint Other Patents"), with inventorship to be determined under the patent
laws of the United States. Amersham and Corixa, as joint owners, shall each have
the right to practice and to grant licenses under such Joint Other Patents
without a duty of accounting, except as otherwise provided in this Agreement.
Amersham hereby covenants that it will not license any Joint Other Patents it
Controls for use in conjunction with an anti-CD20 antibody product.

        9.2 DISCLOSURE. Amersham shall submit a written report to Corixa within
60 days 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 Sole Other Inventions.

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

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

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<PAGE>

        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 thirty (30)
days 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 within a period of sixty (60) days 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 control and bear the expense of its own
defense and, except as set forth in Section 9.5(b), Corixa shall defend,
indemnify and hold harmless Amersham, which shall include costs or judgments
whether for money or equitable relief, and reasonable legal expenses and
reasonable attorney's fees. Corixa shall not enter into a settlement agreement
with such Third Party without the written consent of Amersham, which shall not
be unreasonably withheld. If the Third Party claim arises from Amersham's
activities under the Agreement or from a Product, Amersham shall control and
bear the expense of its own defense and Amersham shall defend, indemnify and
hold harmless Corixa, which shall include costs or judgments whether for money
or equitable relief, and reasonable legal expenses and reasonable attorney's
fees. Amersham shall not enter into a settlement agreement with such Third Party
without the written consent of Corixa, which shall not be unreasonably withheld.

               (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

                                       31
<PAGE>

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 five 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:

               (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;

                                       32
<PAGE>

               (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.

        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

                                       33
<PAGE>

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. At any time during the term of this
Agreement that is after the third (3rd) anniversary of the Effective Date,
Amersham may provide written notice identifying one or more countries in the
Territory (but not all countries in the Territory) for which it no longer wishes
to have rights and obligations under this Agreement. The Parties will
subsequently amend the Territory definition to delete such countries. The
effective date for such amendment will be six months after the date of such
notice and this Agreement shall terminate solely with respect to such
country(ies) upon such effective date.

        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 such Party would
consider to be an acceptable cure of such breach. The allegedly breaching Party
shall have sixty (60) days to either cure such breach or, if cure cannot be
reasonably effected within such sixty (60) 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 fifteen (15) 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 60-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 thirty (30) 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

                                       34
<PAGE>

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 thirty (30) 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 thirty (30) 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.

               (b) Amersham shall have the right to terminate this Agreement
with respect to all countries of the Territory upon six (6) months written
notice to Corixa at any time after the third (3rd) anniversary of the Effective
Date.

               (c) Amersham shall have the right to terminate this Agreement
upon thirty (30) 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
thirty (30) 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
thirty (30) 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.

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<PAGE>

        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 60 days of such termination,
transfer all clinical data, manufacturing data, regulatory filings, 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

                             (1) Amersham shall also supply, for thirty-six (36)
months after such termination, Amersham Iodine I 131 Tositumomab to Corixa at
Amersham's fully burdened manufacturing cost determined in accordance with the
terms of the Supply Agreement;

                             (2) At its sole discretion, Corixa may extend, by
eighteen (18) months, the period in which Amersham is obligated to supply
Amersham Iodine I 131 Tositumomab to Corixa. For all Amersham Iodine I 131
Tositumomab delivered to Corixa during such 18-month extension (if any), Corixa
shall pay Amersham a supply price not to exceed Amersham's fully burdened
manufacturing cost(1) that are directly attributable to the conversion of
Tositumomab to Amersham Iodine I 131 Tositumomab plus [*]% of such costs; and

                             (3) At the request of Corixa, the Parties shall
negotiate in good faith towards an agreement whereby Amersham will supply
Amersham Iodine I 131 Tositumomab to Corixa for a period of time to be
negotiated on commercially reasonable terms, and shall include a supply price
that will not exceed Amersham's fully burdened manufacturing cost that are
directly attributable to the conversion of Tositumomab to Amersham Iodine I 131
Tositumomab plus [*]% of such costs.

In the event of termination with respect to a particular country or particular
countries pursuant to Section 11.2, Amersham shall only be obligated to supply
to Corixa pursuant to this Section 11.7(b)(ii) in the country or countries for
which Amersham has terminated its rights and obligations hereunder.

               (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.

(1) Such cost shall be determined in accordance with the terms of the Supply
Agreement.

* Confidential Treatment Requested

                                       36
<PAGE>

               (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

                      (i) Amersham does not commence manufacture of Amersham
Iodine I 131 Tositumomab by December 31, 2003 or the date (if any) agreed in
writing pursuant to Section 3.3(a) of the Supply Agreement, or

                      (ii) Amersham fails for a period of more than ninety (90)
days, for reasons other than force majeure, routine equipment maintenance,
ordinary course batch failures or other causes occurring in the normal course of
manufacturing to supply Amersham Iodine I 131 Tositumomab to Corixa during the
36-month period set forth in Section 11.7(b)(ii)(1), then Corixa shall have the
right solely during the four (4) months commencing (i) in the case of subsection
11.7(b)(i), on December 31, 2003 or the date (if any) agreed in writing pursuant
to Section 3.3(a) of the Supply Agreement or (ii) in the case of subsection
11.7(b)(ii), at the end of the ninety (90) day period described in subsection
11.7(b)(ii), as applicable, to require Amersham to pay Corixa a termination fee
of [*] million dollars ($[*] million), which fee shall be payable by Amersham
within thirty (30) days of Amersham's receipt of a letter from Corixa stating
with supporting documentation that the conditions set forth in this Section
11.7(d) have occurred and requesting payment of such fee. In the event Corixa
elects payment of such termination fee, then such fee shall be Corixa's sole
remedy at law or in equity for Amersham's failure to commence manufacture as set
forth in subsection 11.7(d)(i) or failure to supply as set forth in subsection
11.7(d)(ii), as applicable. In addition, in the event during the four (4) month
period described above Corixa sues Amersham for material breach based on
Amersham's failure to commence manufacture as set forth in subsection 11.7(d)(i)
or failure to supply as set forth in subsection 11.7(d)(ii), Corixa's right to
require Amersham to pay such termination fee shall immediately terminate with no
further action required by either Party.

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. The
aforesaid liquidated damages of $[*] million shall be Corixa's sole remedy at
law or equity for Amersham's failure to supply as set forth in 11.7(d)ii above.

* Confidential Treatment Requested

                                       37
<PAGE>

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 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 Two U.S.
Million Dollars (U.S. $2,000,000) per occurrence (or claim) and Six U.S.

                                       38
<PAGE>

Million Dollars (U.S. $6,000,000) annual aggregate limit of liability, and after
the First Commercial Sale in the Territory shall always maintain product
liability insurance with a minimum of Ten Million U.S Dollars (U.S. $10,000,000)
per occurrence (or claim) and Twenty U.S. Million Dollars (U.S. $20,000,000)
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 Two
U.S. Million Dollars (U.S. $2,000,000) per occurrence (or claim) and Six U.S.
Million Dollars (U.S. $6,000,000) 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 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

                                       39
<PAGE>

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 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

                                       40
<PAGE>

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.

        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.

                                       41
<PAGE>

               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

        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.

                                       42
<PAGE>

        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.

        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.

                                       43
<PAGE>

        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.

<TABLE>
<S>                                                <C>
AMERSHAM PLC                                       CORIXA CORPORATION

By:                                                By:
   -----------------------------------------          ----------------------------------------

Name:                                              Name:  Steven Gillis
     ---------------------------------------
Title:                                             Title: Chairman and Chief Executive Officer
      --------------------------------------
Date:                                              Date:
     ---------------------------------------            --------------------------------------
</TABLE>

                                       44
<PAGE>

                                    EXHIBIT A

                                 CORIXA PATENTS

<TABLE>
<CAPTION>
 ATTORNEY                SERIAL NO. /   FILED/
DOCKET NO.                PATENT NO.    ISSUED         COUNTRIES DESIGNATED               TITLE
----------               ------------   ------         --------------------               -----
<S>                   <C>              <C>       <C>                             <C>
COUL-003/01EP         98928875.8       6/3/98    Austria, Belgium, Cyprus,       Radioprotectant for
(Corixa owns)         Publication      Pub.      Switzerland & Liechtenstein,    Peptides Labeled
                      No: EP 1 003     Date      Germany, Denmark, Spain,        with Radioisotope
                      560              5/31/00   Finland, France, United
                                                 Kingdom, Greece, Ireland,
                                                 Italy, Luxembourg, Monaco,
                                                 Netherlands, Portugal, Sweden

COUL-003/01NO         1999 5906        6/3/98    Norway                          Radioprotectant for
(Corixa owns)                                                                    Peptides Labeled
                                                                                 with Radioisotope

COUL-005/02EP (UM     96916440.9       5/3/96    Austria, Belgium, Switzerland   Method of
owns--Corixa is       WO 96/34632      Pub.      & Liechtenstein, Germany,       Establishing the
exclusive licensee)                    date      Denmark, Spain, Finland,        Optimal Radiation
                                       11/7/96   France, United Kingdom,         Dose for
                                                 Greece, Ireland, Italy,         Radiopharmaceutical
                                                 Luxembourg, Monaco,             Treatment of Disease
                                                 Netherlands, Portugal, Sweden

COUL-005/04EP         99955224.3 WO    6/4/99    Austria, Belgium, Cyprus,       Patient-Specific
(Corixa/UM            99/62565         Pub.      Switzerland & Liechtenstein,    Dosimetry
co-owners--license                     Date      Germany, Denmark, Spain,
to Corixa)                             12/9/99   Finland, France, United
                                                 Kingdom, Greece, Ireland,
                                                 Italy, Luxembourg, Monaco,
                                                 Netherlands, Portugal,
                                                 Sweden, Albania, Lithuania,
                                                 Latvia, Macedonia, Romania
                                                 and Slovenia
</TABLE>

                                       A-1
<PAGE>

                                    EXHIBIT B

                               COUNTRIES OF EUROPE

<TABLE>
<S>                       <C>                     <C>                     <C>
ANDORRA                   AUSTRIA                 BELGIUM                 BOSNIA
BULGARIA                  CROATIA                 CYPRUS                  CZECH REPUBLIC
DENMARK                   ESTONIA                 FINLAND                 FRANCE
GERMANY                   GREECE                  HUNGARY                 ICELAND
IRELAND                   ITALY                   LATVIA                  LIECHTENSTEIN
LITHUANIA                 LUXEMBOURG              MONACO                  NETHERLANDS
NORWAY                    POLAND                  PORTUGAL                ROMANIA
RUSSIAN REPUBLIC          SAN MARINO              SERBIA                  SLOVAKIA
SLOVENIA                  SPAIN                   SWEDEN                  SWITZERLAND
TURKEY                    UNITED KINGDOM          VATICAN CITY            YUGOSLAVIA
</TABLE>

                                       B-1
<PAGE>

                                    EXHIBIT C

                                DEVELOPMENT PLAN

A. OUTLINE

REGULATORY

        Under [*], several meetings have been held with various national Health
Authorities in Europe and with the EMEA. It was generally felt that the database
was [*]. It was also believed that a [*] with [*] was not necessary, but all of
the Health Authorities who were visited deferred to [*] to make the final call.
The outcome of these meetings identified that an [*] was targeted for late [*].
Subsequently, Amersham, in consultation with Corixa, believes that it is highly
likely that the European regulatory authorities for initial product approval
will [*]. Corixa has agreed to take full responsibility for conducting clinical
trials that will be required to gain initial regulatory approval in Europe.

        Upon execution of this Agreement, Corixa will need to notify EMEA that
Corixa or its designee will be the [*] instead of [*]. Corixa will then notify
the EMEA that it intends to [*] for [*].

        In parallel with this effort, Corixa will begin to prepare for
submission of an [*]. This application will rely on the documentation contained
in the [*] submitted to the [*]. This [*] is currently under review by the [*].

        In addition to this, other activities will be taking place in parallel
with the above activities. Amersham will designate members to serve on the
Collaboration Steering Committee, the Joint Commercialization Committee and the
Joint Development Committee. The representatives on these committees will
include but not be limited to regulatory, manufacturing, commercial marketing,
and business development. Further activities by the appropriate parties will
include:

-     Determination of a decision to submit an [*] to EMEA,

-     Update the [*], and any other documents that should include [*],

-     A [*] will be developed,

-     Determination and, if necessary, conduct of [*],

-     An [*] on a [*] will be made,

-     A Qualified Person to perform [*] using the [*] supplied from [*] will be
      made, and

* Confidential Treatment Requested

                                       C-1
<PAGE>

-     Drafting of final labeling and packaging.

In addition Amersham will begin to draft a mechanism for reporting adverse
events and product complaints in cooperation with Corixa. A full Development
Plan will be drafted by the Parties for review by the Joint Development
Committee within 60 days after the receipt of the data from Corixa.

CLINICAL

        As a first priority and in parallel with regulatory activities, Corixa
will begin to draft a study design for the conduct of [*] for the indication of
[*]. The end point for this trial will be [*]. The final development plan will
be approved by the JDC. The specific aims and endpoints of this trial will be
worked out by Corixa; this input may be done in consultation with the CPMP/EMEA.

        In addition to the initial [*], Amersham, in consultation with the Joint
Development Committee will plan a [*]. This trial will have the objective of
establishing [*]. Within this plan, consideration will be given to establishment
of a [*]. The endpoints of these trials will be worked out in consultation with
Corixa.

        In addition a prioritized list of clinical development needed to expand
approved labeling will be constructed. This list will direct the next phases of
clinical development. This effort will be directed by Amersham's commercial
marketing.

        If feedback from the EMEA review indicates the necessity to conduct
other clinical programs besides [*], these will be given priority. The endpoints
of these trials will be worked out by Clinical Research, Regulatory Affairs, and
Commercial Marketing.

MANUFACTURING

        Amersham will be responsible for all activities associated with the
development, validation and process for radiolabeling tositumomab with I131 for
human use, as well as to provide Quality Assurance, Quality Control and
regulatory support services in order to commercialize tositumomab and
radiolabeled tositumomab with the shortest possible critical path.

        As a first priority Amersham will identify which of its [*] will be used
to establish [*] capability.

        As a part of the effort to establish radiolabeling process Amersham will
develop:

-     Technology transfer of the radiolabeling process to the selected [*]
      facility

-     QC methods and technology transfer

-     Validate these methods

* Confidential Treatment Requested

                                       C-2
<PAGE>

-     [*] of [*] with that of the [*] (as approved by the FDA)

-     If necessary Amersham will make applications with all relevant regulatory
      authorities for [*]

-     Establish, if necessary, a distribution method for the distribution of
      [*] product

-     Establish a system for [*] of [*]

-     Establish a mechanism for the [*] through Corixa.

        Commercial production for radiolabelled product is expected to begin in
the [*] or a date to be determined by the Parties.

B. INITIAL DEVELOPMENT PLAN [TO BE DEVELOPED FOLLOWING EXECUTION OF THIS
AGREEMENT.]

* Confidential Treatment Requested

                                       C-3

<PAGE>

                                    EXHIBIT D

                             CORIXA CLINICAL TRIALS

<TABLE>
<CAPTION>
  CPI                                                                           ENROLLED
PROTOCOL       SITE                                                            (4/30/01)/               START            END
 NUMBER       (US, EU)             TITLE                   OBJECTIVE             TARGET    STATUS      ACCRUAL         ACCRUAL
--------      --------             -----                   ---------           ----------  ------      -------         --------
                                           [*]
<S>           <C>          <C>                             <C>                 <C>         <C>         <C>             <C>
[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]
</TABLE>
------------
* Confidential Treatment Requested

                                       D-1

<PAGE>

<TABLE>
<CAPTION>
  CPI                                                                           ENROLLED
PROTOCOL       SITE                                                            (4/30/01)/               START            END
 NUMBER       (US, EU)             TITLE                   OBJECTIVE             TARGET    STATUS      ACCRUAL         ACCRUAL
--------      --------             -----                   ---------           ----------  ------      -------         --------
<S>           <C>          <C>                             <C>                 <C>         <C>         <C>             <C>
                           [*]                             [*]

                                      [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                      [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

</TABLE>

------------
* Confidential Treatment Requested

                                       D-2
<PAGE>

<TABLE>
<CAPTION>
  CPI                                                                           ENROLLED
PROTOCOL       SITE                                                            (4/30/01)/               START            END
 NUMBER       (US, EU)             TITLE                   OBJECTIVE             TARGET    STATUS      ACCRUAL         ACCRUAL
--------      --------             -----                   ---------           ----------  ------      -------         --------
<S>           <C>          <C>                             <C>                 <C>         <C>         <C>             <C>
[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]
</TABLE>

------------
* Confidential Treatment Requested

                                       D-3
<PAGE>

<TABLE>
<CAPTION>
  CPI                                                                           ENROLLED
PROTOCOL       SITE                                                            (4/30/01)/               START            END
 NUMBER       (US, EU)             TITLE                   OBJECTIVE             TARGET    STATUS      ACCRUAL         ACCRUAL
--------      --------             -----                   ---------           ----------  ------      -------         --------
<S>           <C>          <C>                             <C>                 <C>         <C>         <C>             <C>
[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

                                         [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]

[*]           [*]          [*]                             [*]                 [*]         [*]         [*]             [*]
</TABLE>

------------------
* Confidential Treatment Requested

                                       D-4
<PAGE>

<TABLE>
<CAPTION>
  CPI                                                                           ENROLLED
PROTOCOL       SITE                                                            (4/30/01)/               START            END
 NUMBER       (US, EU)             TITLE                   OBJECTIVE             TARGET    STATUS      ACCRUAL         ACCRUAL
--------      --------             -----                   ---------           ----------  ------      -------         --------
<S>           <C>          <C>                             <C>                 <C>         <C>         <C>             <C>
                           [*]                             [*]

                                         [*]

[*]            [*]         [*]                             [*]                  [*]        [*]          [*]            [*]
</TABLE>

-----------------
* Confidential Treatment Requested

                                       D-5
<PAGE>

                                TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
1.      DEFINITIONS.........................................................................1

        1.1    "Affiliate"..................................................................1

        1.2    "Amersham Iodine I 131 Tositumomab"..........................................1

        1.3    "Amersham Matter"............................................................2

        1.4    "Annual Net Sales"...........................................................2

        1.5    "BLA"........................................................................2

        1.6    "Clinical Trial".............................................................2

        1.7    "Clinical Trial Costs".......................................................2

        1.8    "Collaboration Steering Committee"...........................................2

        1.9    "Controlled".................................................................2

        1.10   "Corixa".....................................................................3

        1.11   "Corixa Intellectual Property Rights"........................................3

        1.12   "Corixa Iodine I 131 Tositumomab"............................................3

        1.13   "Corixa Matter"..............................................................3

        1.14   "Corixa Territory"...........................................................3

        1.15   "Cross-Territory Clinical Trial".............................................3

        1.16   "Dana Farber Agreements".....................................................3

        1.17   "Development Budget".........................................................4

        1.18   "Development Plan"...........................................................4

        1.19   "Diligent Efforts"...........................................................4

        1.20   "Effective Date".............................................................4

        1.21   "European Facility"..........................................................4

        1.22   "FD&C Act"...................................................................4

        1.23   "FDA"........................................................................4

        1.24   "Field"......................................................................4

        1.25   "First Commercial Sale"......................................................4

        1.26   "FTE Rate"...................................................................4

        1.27   "Fully Allocated Cost".......................................................5

        1.28   "Good Manufacturing Practice"................................................5

        1.29   "Information"................................................................6
</TABLE>

                                       -i-
<PAGE>

                                TABLE OF CONTENTS
                                   (continued)

<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
        1.30   "Initial Approval"...........................................................6

        1.31   "Initial Approval Clinical Trials"...........................................6

        1.32   "Initial Approval Trial Costs"...............................................6

        1.33   "Initial Development Plan"...................................................6

        1.34   "Initial Regulatory Filings".................................................7

        1.35   "Intellectual Property Rights"...............................................7

        1.36   "Invention"..................................................................7

        1.37   "Iodine I 131 Tositumomab"...................................................7

        1.38   "Joint Commercialization Committee"..........................................7

        1.39   "Joint Development Committee.................................................7

        1.40   "Joint Other Inventions".....................................................7

        1.41   "Know-How"...................................................................7

        1.42   "MAA"........................................................................8

        1.43   "Major Market Countries".....................................................8

        1.44   "Marketing Plan".............................................................8

        1.45   "Michigan Agreement".........................................................8

        1.46   "Net Sales"..................................................................8

        1.47   "Other Invention"............................................................8

        1.48   "Patent".....................................................................8

        1.49   "Pricing Approval"...........................................................9

        1.50   "Product"....................................................................9

        1.51   "Product Improvement"........................................................9

        1.52   "Product Invention"..........................................................9

        1.53   "QA/QC Costs"................................................................9

        1.54   "Regulatory Approval"........................................................9

        1.55   "Regulatory Filing"..........................................................9

        1.56   "Second Indication"..........................................................9

        1.57   "Sole Other Inventions"......................................................9

        1.58   "Specifications"............................................................10

        1.59   "Stock Purchase Agreement"..................................................10
</TABLE>

                                      -ii-
<PAGE>

                                TABLE OF CONTENTS
                                   (continued)

<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
        1.60   "Subsequent Clinical Trial".................................................10

        1.61   "Subsequent Development Plan"...............................................10

        1.62   "Subsequent Regulatory Filings".............................................10

        1.63   "Territory".................................................................10

        1.64   "Third Party"...............................................................10

        1.65   "Tositumomab"...............................................................10

2.      LICENSES AND EXCLUSIVITY...........................................................11

        2.1    Licenses to Amersham........................................................11

        2.2    Negative Covenant...........................................................12

        2.3    License to Corixa...........................................................12

        2.4    Negative Covenant...........................................................12

        2.5    Covenant Not to Sue.........................................................12

        2.6    Existing Third Party Licenses...............................................12

        2.7    New Third Party Licenses....................................................13

        2.8    Exclusivity.................................................................14

        2.9    U.N. Convention Not Applicable..............................................14

3.      GOVERNANCE STRUCTURES..............................................................14

        3.1    Collaboration Steering Committee (CSC)......................................14

        3.2    Joint Development Committee (JDC)...........................................16

        3.3    Joint Commercialization Committee (JCC).....................................17

4.      DEVELOPMENT; GOVERNANCE; DILIGENCE.................................................19

        4.1    Overview....................................................................19

        4.2    Initial Development Plan....................................................19

        4.3    Updates to Development Plan.................................................20

        4.4    Development Budget..........................................................20

        4.5    Responsibility, Approval and Designation of Clinical Trials.................21

        4.6    Forecasts of Supply for Initial Approval Clinical Trial.....................21

        4.7    Development Diligence.......................................................21

5.      CLINICAL TRIALS AND REGULATORY ISSUES..............................................22

        5.1    Transfer of Pre-existing Files and Data.....................................22
</TABLE>

                                      -iii-
<PAGE>

                                TABLE OF CONTENTS
                                   (continued)

<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
        5.2    Clinical Trials Solely in the Territory.....................................22

        5.3    Clinical Trials Solely in the Corixa Territory..............................24

        5.4    Cross-Territory Clinical Trials.............................................24

        5.5    Clinical Trial Costs Audit..................................................25

        5.6    Initial Regulatory Filings..................................................25

        5.7    Transfer of Initial Regulatory Filings......................................26

        5.8    Subsequent Regulatory Filings...............................................26

        5.9    Pricing Approvals and Pricing...............................................26

        5.10   Updates.....................................................................27

        5.11   Records.....................................................................27

6.      REGULATORY COMPLIANCE..............................................................27

        6.1    Adverse Event Reporting.....................................................27

        6.2    Compliance..................................................................28

        6.3    Product Complaints..........................................................28

        6.4    Product Recall..............................................................28

7.      MARKETING..........................................................................28

        7.1    Marketing Plan..............................................................28

        7.2    Diligence...................................................................29

        7.3    Reporting...................................................................29

8.      ECONOMICS..........................................................................29

        8.1    Equity Investment...........................................................29

        8.2    Milestones..................................................................29

        8.3    Royalties...................................................................30

        8.4    Independent Manufacture Royalties...........................................31

        8.5    Quarterly Payments and Payment Reports......................................31

        8.6    Payment Method..............................................................31

        8.7    Invoicing of Initial Approval Trial Costs...................................32

        8.8    Taxes.......................................................................32

        8.9    Currency of Payment.........................................................32

        8.10   Blocked Currency............................................................32
</TABLE>

                                      -iv-
<PAGE>

                                TABLE OF CONTENTS
                                   (continued)

<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
        8.11   Sublicenses.................................................................32

        8.12   Foreign Exchange............................................................32

        8.13   Records; Inspection.........................................................32

        8.14   Late Payment Penalty........................................................33

9.      INTELLECTUAL PROPERTY..............................................................33

        9.1    Ownership...................................................................33

        9.2    Disclosure..................................................................33

        9.3    Patent Prosecution and Maintenance; Abandonment.............................33

        9.4    Enforcement of Patent Rights................................................34

        9.5    Defense of Third Party Claims...............................................34

        9.6    Trademarks..................................................................35

10.     CONFIDENTIALITY....................................................................35

        10.1   Nondisclosure of Confidential Information...................................35

        10.2   Exceptions..................................................................35

        10.3   Authorized Disclosure.......................................................36

        10.4   Termination of Prior Agreements.............................................37

        10.5   Publicity...................................................................37

        10.6   Publications................................................................37

11.     TERM AND TERMINATION...............................................................37

        11.1   Term........................................................................37

        11.2   Amendment of Territory......................................................37

        11.3   Termination for Material Breach.............................................38

        11.4   Termination By Amersham.....................................................39

        11.5   Termination by Corixa.......................................................39

        11.6   Termination by Mutual Agreement.............................................39

        11.7   Effect of Termination; Survival.............................................39

12.     REPRESENTATIONS AND COVENANTS......................................................41

        12.1   Mutual Authority............................................................41

        12.2   Performance by Affiliates...................................................41

13.     INDEMNIFICATION AND LIMITATION OF LIABILITY........................................41
</TABLE>

                                       -v-
<PAGE>

                                TABLE OF CONTENTS
                                   (continued)

<TABLE>
<CAPTION>
                                                                                          PAGE
<S>                                                                                       <C>
        13.1   Indemnification.............................................................41

        13.2   Limitation of Liability.....................................................42

        13.3   Insurance...................................................................42

14.     MISCELLANEOUS......................................................................43

        14.1   Dispute Resolution..........................................................43

        14.2   Governing Law...............................................................43

        14.3   Patents and Trademarks......................................................43

        14.4   Entire Agreement; Amendment.................................................44

        14.5   Export Control..............................................................44

        14.6   Bankruptcy..................................................................44

        14.7   Force Majeure...............................................................45

        14.8   Notices.....................................................................45

        14.9   Consents Not Unreasonably Withheld or Delayed...............................46

        14.10  Maintenance of Records......................................................46

        14.11  United States Dollars.......................................................47

        14.12  No Strict Construction......................................................47

        14.13  English.....................................................................47

        14.14  Assignment..................................................................47

        14.15  Hardship....................................................................47

        14.16  Electronic Data Interchange.................................................47

        14.17  Counterparts................................................................47

        14.18  Further Actions.............................................................47

        14.19  Severability................................................................47

        14.20  Ambiguities.................................................................48

        14.21  Headings....................................................................48

        14.22  No Waiver...................................................................48
</TABLE>

                                      -vi-<PAGE>
                                                                   EXHIBIT 10.2

*Certain confidential information contained in this document, marked by
brackets, has been omitted and filed with the Securities and Exchange Commission
pursuant to Rule 24b-2 of the Securities Exchange Act of 1934, as amended.

                       MANUFACTURING AND SUPPLY AGREEMENT

        This MANUFACTURING AND SUPPLY AGREEMENT (the "Agreement") is entered
into as of 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 and Amersham are parties to a development,
commercialization and license agreement of even date herewith wherein Corixa and
Amersham shall develop, and Corixa grants Amersham rights to commercialize,
Bexxar, Corixa's proprietary antibody product, in Europe for the treatment of
humans (the "License Agreement"); and

        WHEREAS, in order to carry out the development and commercialization
goals expressed by the Parties in the License Agreement, Amersham desires to
obtain bulk and finished antibody for products from Corixa and Corixa is willing
to provide such antibody on the terms and conditions hereof; 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 capitalized terms in this Agreement that are not defined below shall
have the meanings set forth in the License Agreement. The following terms shall
have the following meanings as used in this Agreement:

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

                1.2     "BI PHARMA AGREEMENTS" shall mean the Supply Agreement
between Coulter and Boehringer Ingelheim Pharma KG dated November 3, 1998 and
the Contract Research and Development Agreement between Coulter and Dr. Karl
Thomae GmbH dated October 22, 1997.

                1.3     "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.

                                       1
<PAGE>

                1.4     "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.

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

                1.6     "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).

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

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

                1.9     "DILIGENT EFFORTS" means the carrying out of obligations
or tasks in a sustained manner consistent with the efforts a Party devotes to a
product or a development or marketing project of similar market potential,
profit potential or strategic value resulting from its own efforts, based on
conditions then prevailing.

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

                1.11    "EUROPEAN FACILITY" shall have the meaning set forth in
Section 3.3(a).

                1.12    "FULLY ALLOCATED COST" shall mean the direct and
indirect costs of Tositumomab provided by Corixa to Amersham or Corixa Iodine I
131 Tositumomab and shall be computed in accordance with United States generally
accepted accounting principles, consistently applied. To the extent that any
such costs arise from activities performed for Amersham as well as other Corixa
partners for the Product, the amounts allocated to Amersham shall be a fair, pro
rata allocation based upon the performance for Amersham relative to the
performance for other Corixa partners for the Product. Fully Allocated Cost
shall include without limitation:

                        (a)     cost and expenses incurred by Corixa, including,
but not limited to, payments owed by Corixa to Third Parties (including Third
Party licensors such as Dana Farber and University of Michigan), for the
manufacture or supply to Amersham of such Tositumomab or Corixa Iodine I 131
Tositumomab, including, but not limited to, the transfer price for such
antibody, cancellation payments (limited to Amersham cancellations), payments
related to failed

                                       2
<PAGE>

batches (to the extent not otherwise charged to Amersham pursuant to this
Agreement), readiness payments, and facilities charges owed to such Third
Parties, plus

                        (b)     QA/QC Costs, plus

                        (c)     If applicable, the cost of forward foreign
currency contracts to protect against risk of changes in foreign exchange rates,
provided that such costs are approved in advance by the Parties, plus

                        (d)     Corixa's internal and external expenses,
including out-of-pocket expenses and employee expenses, if any, with respect to
freight and tariffs associated with transporting Tositumomab or Corixa Iodine I
131 Tositumomab from the source of manufacture to the end user, inclusive of
interim points of delivery, but excluding any such costs which are separately
invoiced to a customer, plus

                        (e)     The cost of Corixa employees engaged in
Tositumomab or Corixa Iodine I 131 Tositumomab manufacturing-related activities,
including, without limitation, employees engaged in oversight of manufacture by
Third Parties, plus

                        (f)     A reasonable allocation, with respect to such
Tositumomab or Corixa Iodine I 131 Tositumomab, of Corixa's: (i) indirect labor
(to the extent not previously included in (d) or (e)), (ii) administrative
costs, and (iii) facilities costs including electricity, water, sewer, waste
disposal, property taxes, and depreciation over the expected life of buildings
and equipment. Such allocations shall be in accordance with reasonable cost
accounting methods, consistently applied, of Corixa.

                1.13    "GOOD CLINICAL PRACTICE" or "GCP" shall mean the then
current standards for clinical trials for pharmaceuticals, as set forth in (i)
the rules and regulations of the International Conference on Harmonization, and
(ii) any other applicable requirements for clinical trial activities under the
laws, rules or regulations of the Territory.

                1.14    "GOOD LABORATORY PRACTICE" or "GLP" shall mean the then
current standards for laboratory activities for 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 requirements for laboratory activities
under the laws, rules or regulations of the Territory.

                1.15    "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.

                1.16    "INFORMATION" means information, results and data of any
type whatsoever, in any tangible or intangible form whatsoever, including
without limitation, databases, inventions, practices, methods, techniques,
specifications, formulations, formulae, knowledge, know-how, skill, experience,
test data including pharmacological, biological,

                                       3
<PAGE>

chemical, biochemical, toxicological and clinical test data, analytical and
quality control data, stability data, studies and procedures, and patent and
other legal information or descriptions.

                1.17    "INITIAL APPROVAL CLINICAL TRIALS" shall have the
meaning set forth in the License Agreement.

                1.18    "INITIAL DEVELOPMENT PLAN" shall have the meaning set
forth in the License Agreement.

                1.19    "INTELLECTUAL PROPERTY RIGHTS" shall mean all Patents,
copyrights, regulatory filings, Know-How, or any other intellectual property
other than trademarks, that are Controlled during the term of this Agreement by
a Party or jointly by the Parties and that relate to the development,
manufacture, importing, use, marketing and/or sale of the Product. The term
"Intellectual Property Rights" shall include any rights obtained by either Party
from a Third Party, subject to the terms and conditions of the agreements in
which such rights were conferred. The term "Intellectual Property Rights,"
however, shall not include Patents, copyrights, regulatory filings, know-how
and/or trade secrets, or any other intellectual property of either Party for the
manufacture or purification of monoclonal antibodies, whether developed prior to
or after the Effective Date.

                1.20    "INVENTION" means any invention, development, result,
Know-How or other Information, and all intellectual property relating thereto,
made, discovered or developed (i) solely by a Party and its employees or agents
pursuant to work performed under the Agreement or (ii) jointly by the Parties
and their employees or agents pursuant to work performed under the Agreement.

                1.21    "IODINE I 131 TOSITUMOMAB" shall mean any therapeutic,
prophylactic or palliative product containing or comprising the composition of
matter conjugated with 131Iodine that was one of the active agents tested in
Corixa's clinical trial with Protocol No. RIT-II-004 as referred to in that
Protocol as [*] anti CD20 murine monoclonal antibody.

                1.22    "JOINT OTHER INVENTIONS" means any and all Other
Inventions made jointly by employees or agents of both Parties pursuant to work
conducted under the Agreement.

                1.23    "KNOW-HOW" shall mean any technical information that is
secret and identified.

                1.24    "NET SALES" shall mean gross amounts invoiced for sales
of the Product in the Territory by either Party, its Affiliates or sublicensees,
as appropriate, to Third Parties, less the following items: (i) trade, quantity
and cash discounts or rebates actually allowed and taken and any other
adjustments, including, without limitation, those granted on account of price
adjustments, billing errors, rejected goods, damaged goods and recall returns;
(ii) credits, rebates, charge-back and prime vendor rebates, fees,
reimbursements or similar payments granted or given to wholesalers and other
distributors, buying groups, health care insurance carriers, pharmacy benefit
management companies, health maintenance organizations or other institutions

* Confidential Treatment Requested

                                       4
<PAGE>

or health care organizations; (iii) any tax, tariff, customs duties, excise or
other duties or other governmental charge (other than an income tax) levied on
the sale, transportation or delivery of a Product and borne by the seller
thereof; (iv) payments or rebates paid in connection with sales of Products to
any governmental or regulatory authority in respect of any medical insurance
funded by a state or federal government; and (v) any charge for freight,
insurance or other transportation costs charged to the customer. For clarity,
Net Sales shall not include: sales of the Product by and between a Party and its
Affiliates (except where such Affiliates are end users).

                1.25    "NORDION AGREEMENTS" shall mean (a) the Supply Agreement
between Coulter Pharmaceutical, Inc. and MDS Nordion Inc. dated August 31, 1998;
(b) the Supply Agreement for I-131 between Coulter Pharmaceutical, Inc. and MDS
Nordion, Inc. dated September 13, 2000; (c) the Development Agreement between
Coulter Pharmaceutical, Inc. and MDS Nordion, Inc. dated November 13, 1995; and
(d) the Facilities Agreement between Coulter Pharmaceutical, Inc. and MDS
Nordion, Inc. dated August 31, 1998.

                1.26    "OTHER INVENTION" means any Invention that is not a
Product Invention.

                1.27    "PATENT" means (i) unexpired letters patent (including
inventor's certificates) that have not been held invalid or unenforceable by a
court of competent jurisdiction from which no appeal can be taken or has been
taken within the required time period, including without limitation any
substitution, extension, registration, confirmation, reissue, re-examination,
renewal or any like filing thereof and (ii) pending applications for letters
patent, including without limitation any continuation, division or
continuation-in-part thereof and any provisional applications.

                1.28    "PRODUCT" shall mean (a) Iodine I 131 Tositumomab as
defined in Section 1.21 or (b) any therapeutic, prophylactic or palliative
product containing or comprising Tositumomab as defined in Section 1.37 for use
in connection with a Iodine I 131 Tositumomab, in any formulation or mode of
administration.

                1.29    "PRODUCT INVENTION" means any Invention that pertains
solely to or the sole use of which is limited to, the Product or its
development, manufacture or use.

                1.30    "QA/QC COSTS" shall mean Corixa's internal and external
costs of quality assurance and quality control work performed by or on behalf of
Corixa related to Product release and Product testing of Tositumomab and Corixa
Iodine I 131 Tositumomab, but only to the extent that such quality assurance and
quality control work is required by the FDA or other relevant regulatory
authorities. QA/QC Costs shall include a reasonable allocation of Corixa's
facility overhead, and shall include any allocation of the costs of establishing
or validating a facility or any costs of excess capacity directly related to
Tositumomab.

                1.31    "SOLE OTHER INVENTIONS" means any and all Other
Inventions made, discovered or developed solely by a Party and its employees or
agents pursuant to work performed under the Agreement.

                                       5
<PAGE>

                1.32    "SPECIFICATIONS" shall mean the requirements and
standards pertaining to Tositumomab or Iodine I 131 Tositumomab (depending upon
context) and consistent with filings made for Regulatory Approval and all
relevant written agreements between Corixa and a Third Party with respect to
manufacture or supply of Tositumomab, Iodine I 131 Tositumomab or Product, which
specifications are set forth in the BLA identified by Biologics License
Application Submission Tracking Number 125011, provided that such specifications
may be modified in writing by the Parties from time to time as follows: any
modifications to the Specifications shall be reasonably acceptable to both
Parties or required for approval of the Product in the Territory and shall be
reasonably consistent with respect to products manufactured by or on behalf of
Corixa for use in markets in the Corixa Territory. The Specifications shall be
release or stability specifications, as applicable, and each reference to
Specifications shall mean the type of such Specifications appropriate to the
context.

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

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

                1.35    "THERAPY" shall mean two doses of Tositumomab and two
doses of Corixa Iodine I 131 Tositumomab (one for dosimetric purposes and one
for therapeutic purposes, including "top-off" vials) for administration to a
single patient, unless otherwise adjusted by mutual agreement of the Parties.

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

                1.37    "TOSITUMOMAB" shall mean the composition of matter that
(i) has not been conjugated with 131Iodine or any other isotope, molecule,
compound or moiety and (ii) was administered to patients in Corixa's clinical
trial with Protocol No. RIT-II-004 as referred to in that Protocol as [*] anti
CD20 murine monoclonal antibody. Except as otherwise specified in this
Agreement, Tositumomab shall mean both bulk and filled material.

                1.38    "TRANSFER PRICE" shall have the meaning set forth in
Section 4.1(a).

        2.      GENERAL UNDERSTANDING. Pursuant to the BI Pharma Agreements and
the Nordion Agreements, Corixa has the ability to have Tositumomab and Corixa
Iodine I 131 Tositumomab manufactured and supplied to it and its licensees.
Under this Agreement, Corixa will provide certain amounts of Tositumomab and
Corixa Iodine I 131 Tositumomab for use in the Initial Approval Clinical Trials
and to Amersham for Amersham's use in the Territory in accordance with the
License Agreement. Amersham acknowledges and understands that Corixa's ability
to supply Tositumomab and Corixa Iodine I 131 Tositumomab to Amersham under this
Agreement is limited by the BI Pharma Agreements, the Nordion Agreements and
Corixa's agreements with other suppliers and other licensees, including Glaxo
SmithKline.

* Confidential Treatment Requested

                                       6
<PAGE>

Amersham hereby agrees to be legally bound by and to comply with all applicable
(as a result of this Agreement) provisions of the BI Pharma Agreements and the
Nordion Agreements. Corixa shall consult with Amersham before entering into a
new supply agreement during the term of this Agreement to replace or supplement
the BI Pharma Agreements.

        3.      MANUFACTURING AND SUPPLY OF ANTIBODY.

                3.1     TOSITUMOMAB.

                        (a)     OVERVIEW. Except as set forth in Sections 3.1(e)
and 3.11, and subject to availability of Tositumomab and Amersham's compliance
with the terms and conditions of this Agreement and the License Agreement,
Corixa shall use commercially reasonable efforts to have manufactured and supply
to Amersham all of its requirements in the Territory for Tositumomab in
accordance with the BI Pharma Agreements and the volume allocation methodology
set forth in Section 3.11. Amersham shall pay for such Tositumomab as set forth
in Article 4. Except as set forth in Section 3.1(e), Amersham shall obtain from
Corixa all of Amersham's requirements for Tositumomab in the Territory, whether
for development or commercial sale.

                        (b)     FORECASTS AND ORDERING.

                                (i)     Corixa has already submitted to BI
Pharma the forecast shown in Exhibit A for the supply of Tositumomab to
Amersham, including the supply of Tositumomab designated for use in an Initial
Approval Clinical Trial, for the period from the Effective Date until December
31, 2003 (the "Corixa Forecast"). Within thirty (30) days after the approval by
the JDC of the Initial Development Plan, and no later than the tenth (10th) day
of the second month of each calendar quarter thereafter, Amersham shall furnish
to Corixa a written rolling three (3) year forecast of its anticipated purchase
of bulk Product (including Tositumomab to be used in the manufacture of Corixa
Iodine I 131 Tositumomab or Amersham Iodine I 131 Tositumomab) or filled and
finished Product for the Territory which shall be consistent with the terms and
conditions of the BI Pharma Agreements (the "Amersham Forecast"). Each Amersham
Forecast shall cover a three (3) year forecast period starting the first (1st)
day of the second calendar quarter after the quarter in which Amersham provided
such Amersham Forecast to Corixa. The Amersham Forecast shall be submitted to
Corixa in the format specified in writing by Corixa. Unless the JDC agrees
otherwise, Amersham shall include in the Amersham Forecasts and shall
specifically identify within the Amersham Forecasts, those quantities of
Tositumomab intended for use in an Initial Approval Clinical Trial in the
Territory, as decided by the JDC or Corixa pursuant to Section 4.6 of the
License Agreement.

                                (ii)    Subject to subsection (iii) below,
Amersham shall be obligated to purchase from Corixa those portions of the
Amersham Forecasts that are binding in accordance with the criteria set forth in
Appendix 2B of the BI Pharma Agreement. Amersham shall pay Corixa, in accordance
with the terms of Article 4 of this Agreement, for all such quantities of
Tositumomab.

                                       7
<PAGE>

                                (iii)   Corixa shall be obligated, for the
period from the Effective Date until the end of an Initial Approval Clinical
Trial, to pay for all Tositumomab designated for use in an Initial Approval
Clinical Trial in the Territory, to the extent that such Tositumomab is
manufactured pursuant to a binding portion of the Corixa Forecast or an Amersham
Forecast. All amounts paid by Corixa pursuant to this subsection 3.1(b)(iii)
shall be included in the Development Budget for the Initial Approval Clinical
Trials and shall be Initial Approval Trials Costs for the Initial Approval
Clinical Trials and subject to the terms and conditions of the License
Agreement, including but not limited to Section 5.2(a)(iii) thereof.

                                (iv)    In the event that Corixa is informed by
BI Pharma that BI Pharma, pursuant to Section 3.1.2 of the BI Pharma supply
agreement, will not be able to supply enough Tositumomab to satisfy Amersham's
projected requirements for Tositumomab during a particular period, Corixa shall
inform Amersham of such projected shortfall and Section 3.1(e) shall apply.

                        (c)     DELIVERY; SHIPMENT; TITLE. It is anticipated
that BI Pharma will manufacture Tositumomab twice a year. Tositumomab will be
delivered to Amersham FOB at the manufacturing facility of BI Pharma or an
alternate Corixa supplier. "FOB" shall be construed in accordance with INCOTERMS
2000 of the International Chamber of Commerce. Amersham shall be the importer of
record for all Tositumomab delivered hereunder. Title to individual shipments of
Tositumomab that are not designated for use in an Initial Approval Clinical
Trial shall pass to Amersham upon Amersham's payment of that portion of the
Transfer Price set forth in Section 4.1(a)(i). Amersham shall bear the
responsibility for all expenses related to the delivery of Tositumomab from BI
Pharma to Amersham's storage facility.

                        (d)     VIAL LABELING; STORAGE. Amersham shall vial
label, store and distribute Tositumomab in accordance with (i) Corixa's and BI
Pharma's Specifications for vial labeling and storage and (ii) all applicable
laws, rules and regulations. It shall be Amersham's sole responsibility to
establish and maintain a site for such activities. Distribution of Tositumomab
hereunder shall be in accordance with Section 3.4.

                        (e)     CORIXA INABILITY TO SUPPLY. If Corixa is unable
to supply any Tositumomab to Amersham due to BI Pharma's inability to supply as
set forth in Section 3.1.2 of the BI Pharma Agreement, Corixa shall have the
right to establish a second source of Tositumomab and Amersham shall remain
obligated to obtain all Tositumomab from Corixa. If by ninety (90) days after
the date of the most recent delivery of Tositumomab to Amersham, Corixa has not
established a second source, then Corixa shall provide Amersham with a written
description of its plan to establish such a second source within the next ninety
(90) days. If Corixa does not successfully establish a second source of
Tositumomab within one hundred eighty (180) days following the date of the most
recent delivery of Tositumomab to Amersham, then Corixa shall grant to Amersham
the license set forth in Section 2.1(c) of the License Agreement and Amersham
will thereafter have the right to supply such antibody itself at its expense.

                                       8
<PAGE>

                3.2     CORIXA IODINE I 131 TOSITUMOMAB.

                        (a)     OVERVIEW. Except as set forth in Section 3.11
and subject to Amersham's compliance with the terms and conditions of this
Agreement, Corixa shall use commercially reasonable efforts to provide Corixa
Iodine I 131 Tositumomab to Amersham until the earlier of: (i) the first date
that Amersham is able to manufacture Amersham Iodine I 131 Tositumomab in
sufficient quantities to fulfill its requirements for Iodine I 131 Tositumomab,
(ii) December 31, 2003, or (iii) Nordion's last date of production in 2003 for
Corixa Iodine I 131 Tositumomab. In no event will Corixa be obligated to supply
Corixa Iodine I 131 Tositumomab to Amersham after December 31, 2003. Corixa will
supply Corixa Iodine I 131 Tositumomab to Amersham in accordance with the
Nordion Agreements and the volume allocation methodology set forth in Section
3.11. Amersham acknowledges that such supply may be subject to delays or
interruptions due to suspended production during periods of Nordion's scheduled
maintenance of its facilities in accordance with Section 5.3 of the Nordion
Supply Agreement dated August 31, 1998. Amersham shall pay for Corixa Iodine I
131 Tositumomab as set forth in Article 4.

                        (b)     ANTICIPATED NUMBER OF THERAPIES. Corixa
anticipates being able to provide the number of Therapies set forth below in the
Territory in the specified calendar years:

<TABLE>
<CAPTION>
                            Calendar Year            Maximum Number of Therapies
                            -------------            ---------------------------
                            <S>                      <C>
                                2001                              [*]
                                2002                              [*]
                                2003                              [*]
</TABLE>

        The foregoing estimates are based on assumptions that: (i) the demand
for Corixa Iodine I 131 Tositumomab in the Territory will be spread evenly
throughout each calendar year and (ii) the percentage of patients requiring a
second vial of Corixa Iodine I 131 Tositumomab will not exceed [*]%. Amersham
acknowledges that if one or both of these assumptions is not correct, then
Corixa's ability to provide the anticipated number of Therapies will be
adversely affected and the number of available Therapies will be adjusted
accordingly.

        If Corixa becomes able to supply more than the specified number of
Therapies in calendar year 2001, 2002 or 2003, then the Parties will mutually
agree whether Corixa will provide additional Therapies in the Territory.
Notwithstanding the foregoing, Amersham acknowledges and agrees that Corixa may
be unable to meet the anticipated Therapy requirement for the Territory for a
specified week or a specified year even if the amounts of Corixa I 131
Tositumomab ordered by Amersham are in weekly amounts balanced over the
applicable calendar year.

                        (c)     FORECASTS AND ORDERING.

                                (i)     Within thirty (30) days after the
approval of the Initial Development Plan, Amersham shall provide Corixa with its
projected requirements for Corixa

* Confidential Treatment Requested

                                       9
<PAGE>

Iodine I 131 Tositumomab through December 31, 2003 in accordance with the
Amersham Forecast mechanism set forth in Section 3.1(b). Unless the JDC agrees
otherwise, Amersham shall include in all of its forecasts and firm orders and
specifically identify within such forecasts and firm orders, those quantities of
Corixa Iodine I 131 Tositumomab intended for use in an Initial Approval Clinical
Trial in the Territory, as decided by the JDC or Corixa pursuant to Section 4.6
of the License Agreement. Amersham shall update such forecast for its entire
projected requirements of Corixa Iodine I 131 Tositumomab quarterly. Such
forecasts shall be consistent with the quantities of Corixa I 131 Tositumomab
set forth in Section 3.2(b).

                                (ii)    On the Effective Date and on the first
day of each month thereafter, Amersham will submit a rolling two (2) month
forecast to Corixa for Corixa I 131 Tositumomab in the Territory (the "Corixa I
131 Tositumomab Forecast"). The Corixa I 131 Tositumomab Forecast shall be
consistent with (A) the forecasting and ordering mechanisms required under the
Nordion Agreements and (B) the quantities of Corixa I 131 Tositumomab set forth
in Section 3.2(b). Each Corixa I 131 Tositumomab Forecast shall cover, in weekly
amounts, the two (2) months that follow the month in which such forecast was
submitted to Corixa.

                                (iii)   Every Monday during the period that
Corixa is supplying Corixa Iodine I 131 Tositumomab to Amersham, Amersham shall
place a firm order for all Corixa Iodine I 131 Tositumomab that it wishes to
receive, including for so long as applicable the Corixa Iodine I 131 Tositumomab
designated for use in an Initial Approval Clinical Trial, during the week that
is two weeks after the week of such firm order. Such firm order shall be
consistent with the quantities of Corixa I 131 Tositumomab set forth in Section
3.2(b) and shall be considered binding on Amersham. Subject to the next
sentence, Amersham shall pay for all Corixa Iodine I 131 Tositumomab delivered
pursuant to such a firm order in accordance with Article 4. Corixa shall pay for
all Corixa Iodine I 131 Tositumomab delivered pursuant to such a firm order that
is designated in such firm order for use in an Initial Approval Clinical Trial
in the Territory. Any shortfalls of Corixa I 131 Tositumomab shall be handled as
set forth in Section 3.11.

                        (d)     DELIVERY; SHIPMENT. The Corixa Iodine I 131
Tositumomab will be delivered to Amersham FOB Nordion's facility. "FOB" shall be
construed in accordance with INCOTERMS 2000 of the International Chamber of
Commerce. Amersham shall be the importer of record for all Corixa Iodine I 131
Tositumomab delivered hereunder. Title to individual shipments of Corixa Iodine
I 131 Tositumomab that are not designated for use in an Initial Approval
Clinical Trial shall pass to Amersham upon Amersham's payment of that portion of
the Transfer Price set forth in Section 4.1(a)(i). Subject to the next sentence,
Amersham shall also bear the responsibility for all expenses related to the
delivery of Amersham's portion of Tositumomab to Nordion's facility (which will
be coordinated by Corixa) and the subsequent delivery of Corixa Iodine I 131
Tositumomab from Nordion's facility to Initial Approval Clinical Trial sites,
Subsequent Clinical Trial sites and Amersham's customers in the Territory.
Corixa shall bear the foregoing costs for all Corixa Iodine I 131 Tositumomab
that is designated for use in an Initial Approval Clinical Trial. Distribution
of Corixa Iodine I 131 Tositumomab for use in an Initial Approval Clinical Trial
shall be in accordance with Section 3.4.

                                       10
<PAGE>

                        (e)     INITIAL APPROVAL TRIAL COSTS. All amounts paid
by Corixa pursuant to subsection 3.1(c) and 3.2(d) shall be included in the
Development Budget for the Initial Approval Clinical Trials and shall be Initial
Approval Trials Costs for the Initial Approval Clinical Trials and subject to
the terms and conditions of the License Agreement, including but not limited to
Section 5.2(a)(iii) thereof.

                3.3     AMERSHAM IODINE I 131 TOSITUMOMAB.

                        (a)     No later than December 31, 2003 or the later
date agreed in writing by the Parties (such date shall take into account the
date upon which the Parties expect Initial Approval for the Product in the
Territory and any delays in establishing the radiolabeling facility that are
attributable to regulatory agencies and are beyond Amersham's control), Amersham
shall establish a radiolabeling facility that, in accordance with all applicable
laws and regulations, converts Tositumomab to Amersham Iodine I 131 Tositumomab
and supplies all of Amersham's requirements for Iodine I 131 Tositumomab for
development and commercial sale in the Territory (the "European Facility").
Amersham may begin supplying Amersham Iodine I 131 Tositumomab at any time prior
to December 31, [*] or such agreed date.

                        (b)     Within sixty (60) days after the Effective Date,
Amersham shall provide Corixa with a timetable for the establishment of the
European Facility and a copy of Amersham's full plan (rather than a summary
thereof) for the manufacture of Amersham Iodine I 131 Tositumomab, which plan
shall include the milestones and timelines set forth on Exhibit B hereto.
Amersham shall update such timetable and plan semi-annually, provided that any
updates or modifications to the milestones and timelines set forth on Exhibit B
shall require Corixa's prior written consent. Corixa may comment on the initial
and updated timetables and plans. Amersham's failure to provide the first
timetable and the first plan within ninety (90) days after the Effective Date
shall constitute a material breach of this Agreement. Amersham shall be
responsible for all capital and other expenses related to the establishment of
the European Facility and its operation.

                        (c)     At the request of Amersham, during the period
commencing on the Effective Date and ending three (3) years after the date
determined in accordance with Section 3.3(a), Corixa shall provide reasonable
assistance, within Corixa's area of expertise, to help Amersham establish and
operate the European Facility. Provision of such assistance shall include, but
not be limited to, supply of any Corixa know-how which Amersham may require to
the extent such Corixa know-how can be provided to Amersham under applicable
agreements with Third Parties. In the event that Amersham requests that Corixa
perform work, including providing consultation services, under this Section
3.3(c), Amersham shall reimburse Corixa for all out-of-pocket expenses and
personnel expenses (at the applicable FTE Rate) incurred by Corixa with respect
to such performance within thirty (30) days of receipt of an invoice from
Corixa.

                        (d)     In the event that based on Amersham's progress
against the milestones and timelines set forth on Exhibit B (as may be amended
in accordance with

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<PAGE>

Section 3.3(b)), Corixa makes a good faith determination that the European
Facility is not reasonably likely to be completed and available to manufacture
and supply Amersham's requirements of Iodine I 131 Tositumomab for development
and commercial sale in the Territory by the later of December 31, [*] or the
date agreed in writing pursuant to Section 3.3(a), Corixa may give notice to
Amersham that Corixa intends to (i) terminate this Agreement and the License
Agreement or (ii) adjust the licenses granted by Corixa under the License
Agreement to become non-exclusive. Amersham hereby acknowledges that if Corixa
proceeds under subsection (ii), (1) the License Agreement shall otherwise remain
in full force and effect in accordance with its terms, including, but not
limited to, all payment terms, and (2) Corixa shall retain the right to
terminate this Agreement pursuant to Section 7.2 on account of Amersham's
material breach of this Agreement, including (without limitation) the
obligations set forth in Sections 3.3(a) and 3.3(b).

                        (e)     Delivery of Tositumomab to the European Facility
for radiolabeling will be the responsibility of Amersham. Amersham shall be
responsible for all shipping, manufacturing and supply expenses associated with
the conversion of Tositumomab to Amersham Iodine I 131 Tositumomab.

                        (f)     Amersham shall establish and maintain a site for
the vial labeling, storage, allocating and distribution of Amersham Iodine I 131
Tositumomab in accordance with Corixa's and BI Pharma's Specifications and
applicable legal and regulatory requirements in the Territory for vial labeling
and storage.

                        (g)     At the request of Corixa, Amersham shall
negotiate in good faith a supply agreement with Corixa pursuant to which
Amersham would supply Amersham Iodine I 131 Tositumomab to Corixa for
development or commercialization in the Corixa Territory.

                3.4     DISTRIBUTION. Distribution of Tositumomab, Iodine I 131
Tositumomab and Product in the Territory shall be handled exclusively by
Amersham and shall be in accordance with applicable law and regulations,
including regulations promulgated by nuclear regulatory agencies. Except as set
forth below, the expenses related to such distribution shall be solely the
responsibility of Amersham. Notwithstanding the foregoing, Corixa may elect to
itself or through a Third Party designee distribute some or all of the
Tositumomab, Iodine I 131 Tositumomab and Product in the Territory in connection
with an Initial Approval Clinical Trial. Corixa, or Amersham at Corixa's
request, shall coordinate product release, customs clearance and delivery of
Tositumomab, Iodine I 131 Tositumomab and Product to Initial Approval Clinical
Trial sites in the Territory. Amersham shall coordinate product release, customs
clearance and delivery of Tositumomab, Iodine I 131 Tositumomab and Product to
all Subsequent Clinical Trial sites and customer sites in the Territory. All
expenses related to the distribution of the Tositumomab, Iodine I 131
Tositumomab and Product designated for use in the Initial Approval Clinical
Trials shall be solely the responsibility of Corixa. All amounts paid by Corixa
pursuant to this Section 3.4 shall be included in the Development Budget for the
Initial Approval Clinical Trials and shall be Initial Approval Trials Costs for
the Initial Approval Clinical Trials and subject to the terms and conditions of
the License Agreement, including but not limited to Section 5.2(a)(iii) thereof.

* Confidential Treatment Requested

                                       12
<PAGE>

                3.5     CUSTOMER ORDERS. Amersham shall establish and maintain
infrastructure to collect and collate customer orders for Tositumomab or Iodine
I 131 Tositumomab and Product and to transfer information regarding such
customer orders to Corixa's order fulfillment system.

                3.6     ENHANCEMENTS. Upon mutual agreement of the Parties to
effect one or more Product enhancements in the manufacturing process (including
without limitation the [*] at BI Pharma and [*] Iodine-131), the Parties shall
cooperate to effect such enhancements. Amersham shall bear all expenses
(including, without limitation, the cost of any studies, Clinical Trials and
changes in Product manufacturing) for enhancements that are only applicable to
the Territory. Amersham shall bear [*] percent ([*]%) of all world-wide expenses
(including, without limitation, the cost of any studies, Clinical Trials and
changes in Product manufacturing) for enhancements that are applicable
throughout the world, provided Amersham has access to such enhancements and has
agreed to participate in such enhancement process. 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 Audited Party's books and
records to verify the Audited Party's calculations of expenses for enhancements
for which the Auditing Party is obligated to pay a percentage of the world-wide
expenses therefor. Each Party may exercise this right no more than once per
contract year. If Amersham elects not to participate in the development of a
particular Product enhancement, then in the event that such Product enhancement
would otherwise reduce the Fully Allocated Cost, Amersham nonetheless shall pay
a Fully Allocated Cost that does not include such a reduction.

                3.7     MANUFACTURING REGULATORY COMPLIANCE. Any manufacture of
Tositumomab and Iodine I 131 Tositumomab for development purposes or commercial
sale in the Territory shall be performed in full compliance with GCP, GLP and
GMP and all applicable United States laws and regulations (including regulations
promulgated by the Nuclear Regulatory Commission or any successor thereto).
Amersham will notify Corixa of any regulatory requirements for manufacture of
Tositumomab and/or Iodine I 131 Tositumomab for sale in the Territory with which
it wishes Third Party manufacturers of Tositumomab and/or Corixa Iodine I 131
Tositumomab to comply. To the extent Corixa can cause such manufacturers to
comply with such regulatory requirements, Corixa will do so. To the extent
permitted by applicable laws, Amersham or its designee shall serve as the point
of contact with the foreign equivalents of the FDA in the Territory and any
other applicable governmental entity in the Territory concerning the manufacture
and supply of Tositumomab and Iodine I 131 Tositumomab, but may, as appropriate,
request the assistance of Corixa with respect to communications with such
governmental entities. Amersham shall reimburse Corixa for all out-of-pocket and
FTE expenses incurred in connection with providing such assistance.

                3.8     REGULATORY COMPLIANCE. Amersham shall be responsible for
establishing and maintaining infrastructure to ensure that Tositumomab or Iodine
I 131 Tositumomab and Product comply with applicable drug regulations in the
Territory.

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                                       13
<PAGE>

                3.9     QUALITY CONTROL; TESTING. Any Party responsible for the
manufacture of Tositumomab or Iodine I 131 Tositumomab shall maintain a quality
control and testing program consistent with GMP, as required by the FDA and/or
any other governmental entity whether in the United States or part of another
applicable foreign jurisdiction, with respect to the manufacture by or on behalf
of either Party hereunder; provided that regarding such requirements in the
Territory, Corixa shall be obligated to comply only with requirements of the EU
itself and not of individual countries or territories within the Territory to
the extent such requirements may differ from those of the EU. Corixa shall be
entitled to audit the quality control program for the manufacture of Tositumomab
and Iodine I 131 Tositumomab that is manufactured by Amersham. Each Party shall
bear its own expenses for such audits.

                3.10    NON-COMPLIANCE WITH SPECIFICATIONS. Corixa shall provide
to Amersham copies of all analysis certificates and data that Corixa receives
from the Third Party manufacturer with respect to Tositumomab or Corixa Iodine I
131 Tositumomab ordered by Amersham hereunder. In the event that Amersham wishes
to avail itself of the defective product procedures set forth in Section 5.9 of
the BI Pharma Agreement or Section 6.4 of the Nordion Supply Agreement dated
August 31, 1998, it shall provide all relevant information to Corixa, in the
case of Tositumomab, not more than 15 days after receipt of shipment by
Amersham, and, in the case of Corixa I 131 Tositumomab, not more than 5 days
after receipt of shipment of Amersham. Corixa shall use commercially reasonable
efforts to perform the relevant activity in accordance with Section 5.9 of the
BI Pharma Agreement or Section 6.4 of the Nordion Supply Agreement dated August
31, 1998, as applicable. The Parties shall work together, at the [*] expense of
[*], to use commercially reasonable efforts to enable Amersham to avail itself
of such procedures.

                3.11    ALLOCATION IN THE EVENT OF PRODUCT SHORTAGES.

                        (a)     ALLOCATION OF IODINE I 131 TOSITUMOMAB. In the
event of shortages in a batch of Iodine I 131 Tositumomab such that either (i)
Corixa is unable to supply to Amersham from such batch the amount of Corixa
Iodine I 131 Tositumomab estimated to be supplied by Corixa to Amersham per
batch in accordance with Section 3.2(b), or (ii) there is insufficient material
to supply to Corixa from such batch Corixa's pending order for Iodine I 131
Tositumomab for use in the Corixa Territory, then any Iodine I 131 Tositumomab
material produced by Nordion, Kanata, from the facility in existence as of the
Effective Date, shall be allocated as follows: [*] percent ([*]%) of the
manufactured vials in each batch shall be allocated to the Territory and [*]
percent ([*]%) of the manufactured vials in each batch shall be allocated for
use by Corixa in the Corixa Territory (rounded to the nearest whole vial on
weekly basis). If after the Effective Date, Corixa, alone or together with one
or more of Corixa's partners in the Corixa Territory, funds further expansion
[*] for production of Iodine I 131 Tositumomab, this expanded capacity shall not
be available to Amersham unless Amersham funds an appropriate part of the costs
of the additional capacity. If such funding is provided by Amersham,
apportionment of available Iodine I 131 Tositumomab for use in the Territory
shall be limited to the equivalent percentage of the funding contribution made
by Amersham. Shortages of Iodine I 131 Tositumomab which arise from shortages of
Tositumomab rather than a capacity constraint

* Confidential Treatment Requested

                                       14
<PAGE>

in connection with radiolabeling shall not be allocated in accordance with this
Section 3.11(a), but rather the available Tositumomab shall be radiolabeled for
use in the Territory or Corixa Territory in accordance with the allocation by
territory set forth in Section 3.11(b), unless the Parties then agree
differently.

                        (b)     ALLOCATION OF TOSITUMOMAB. Corixa shall place
orders for Tositumomab for use in the Territory following consultation with
Amersham and in accordance with the Forecast for the Territory and as agreed
upon by the Parties. Corixa shall place orders for use in the Corixa Territory
in its own discretion. Any orders placed with BI Pharma or any other vendor of
Tositumomab which is a supplier for use both inside and outside of Territory (a
"Vendor") shall be a "Vested Order" for purposes of this Section 3.11(b), if it
is a firm order which has been accepted by the Vendor and is scheduled for
delivery within twenty-four (24) months after the date of such order.

                                (i)     VESTED ORDERS. To the extent that a
Vendor is able to deliver Tositumomab material in accordance with Vested Orders,
such material shall be purchased by, and the benefits and risks of ownership
shall belong to, the party which was responsible for such portion of the Vested
Order. For clarity, Amersham shall purchase that portion of the Vested Order
that corresponds to Amersham's estimation of its total requirements of Product
contained in Amersham's Forecast corresponding to the same twenty four (24)
month period as the Vested Order. Thus, Vested Orders which had been placed for
the purpose of supply in the Territory shall be allocated solely to the
Territory for use by Amersham and Vested Orders which had been placed for the
purposes of supply outside of the Territory shall be allocated solely to Corixa
for use outside of the Territory, in each case except by the mutual written
agreement of the parties.

                                (ii)    SHORTAGE OF TOSITUMOMAB. Subject to the
terms and conditions of Section 3.1(e), in the event of shortages of
Tositumomab, the following rules shall apply:

                                        (1)     If Corixa seeks to place a
Vested Order for Tositumomab and is advised by a Vendor that such Vendor will
not accept the full amount of such order, whether such order is for purposes of
supply in the Territory or elsewhere in the world, then Corixa shall consult
with Amersham regarding the allocation of available supply. Unless the Parties
otherwise agree, all future Vested Orders shall be allocated [*]% to the
Territory and [*]% for use outside of the Territory so long as such conditions
of supply shortage prevail, with each lot being allocated in such pro rata
manner. In the event that, over the course of the 12 month period following such
Vendor's refusal to accept the full amount of such order, such Vendor also
refuses to accept the full amount of each and every subsequent order which
Corixa attempts to place as a Vested Order, the Parties shall meet to discuss a
plan for remedying such shortage of Tositumomab.

                                        (2)     If a Vendor is unable to deliver
the full amount of a Vested Order, either because the amount delivered is less
than the amount ordered or because

* Confidential Treatment Requested

                                       15
<PAGE>

some or all of the delivery is not accepted for any reason, including, without
limitation, non-compliance with Specifications, then the available Tositumomab
in each calendar year in which a shortage of supply prevails shall be allocated
as between the Territory and the rest of the world pro rata on the basis of the
aggregate Vested Orders for delivery in that calendar year that had been placed
for use in the Territory and in the rest of the world. If the shortfall or
failure occurs in a batch which is part of a manufacturing campaign, then the
acceptable material manufactured as part of that campaign, and all future
deliveries in that calendar year, shall be allocated between the Territory and
the rest of the world so as to make the aggregate allocation of material on a
year-to-date basis equal, as nearly as practicable, to such pro rata allocation.
(Such allocation on a campaign basis could require that material already
received as part of the same campaign for use in one territory be redesignated
for use in a different territory, if such redesignation is necessary in order to
achieve the specified pro rata allocation. However, material received as part of
previous campaigns shall not be redesignated except by mutual consent.) As used
herein, a "manufacturing campaign" shall refer to two or more batches
manufactured in the same manufacturing plant in temporal proximity to each
other. The allocation rule set forth in this Section 3.11(b)(ii)(2) shall
restart for each calendar year, without any carryover of shortfalls realized for
a particular territory in the prior calendar year.

                                (iii)   In the event either Party desires to
reduce the size of a Vested Order previously placed, the percentage by which
such Vested Order may be reduced under the contract with the Vendor shall be
applied equally to the Territory and to the rest of the world unless the Parties
otherwise agree. By way of example, if the supply agreement permits a reduction
in Vested Orders of up to 25% for orders with delivery dates at a specified time
period in the future, and the Parties desire to reduce the Vested Order for that
time period in the Territory by 35% and the rest of the world by 10%, then the
reduction for the Territory shall be limited to 25% while the order for the rest
of the world is reduced by the full 10%. In that case, by mutual agreement, any
further reduction which would have been available for the order for the rest of
the world may be reallocated to permit a further reduction in the Vested Order
for the Territory.

                                (iv)    If under the contract with the Vendor,
Corixa is obligated to take quantities of Tositumomab produced in excess of the
amount specified in the original Vested Order (e.g., as a result of the inherent
uncertainty of the quantity of material produced in each batch or due to minimum
batch sizes), then at Corixa's option any excess quantities which Corixa is
obligated to purchase shall be allocated as between the Territory and the rest
of the world pro rata on the basis of the aggregate Vested Orders for delivery
to each territory in that calendar year.

                                (v)     The purpose of the foregoing allocation
rules is to permit the Parties jointly (with respect to the Territory) and
Corixa independently (with respect to the rest of the world) to make their
respective long-term purchase decisions for Tositumomab, with the benefits and
risks of such purchase decisions to be allocated to the Parties jointly, or
Corixa independently, as the case may be.

                        (c)     ALLOCATION OF TERRITORY SUPPLIES IN FAVOR OF
INITIAL APPROVAL CLINICAL TRIAL. In the event of Product Shortages giving rise
to allocation under this Section

                                       16
<PAGE>

3.11, all quantities of Tositumomab and Iodine I 131 Tositumomab allocated to
the Territory in accordance with this Section 3.11 shall be first allocated to
supply the requirements of an Initial Approval Clinical Trial in the Territory.
After such requirements have been met, Amersham shall decide, in its sole
discretion, how the remainder of the Tositumomab and Iodine I 131 Tositumomab
allocated to the Territory is used.

        4.      ECONOMICS.

                4.1     TRANSFER PRICE.

                        (a)     Subject to the next sentence and Section 4.1(b),
Amersham shall pay Corixa for the Tositumomab Corixa provides to Amersham and
the Corixa Iodine I 131 Tositumomab, a transfer price equal to the sum of (i)
Fully Allocated Costs for such Tositumomab or Corixa Iodine I 131 Tositumomab,
as applicable, and (ii) [*] percent ([*]%) of Net Sales for any Product
containing or comprising such Tositumomab (even if such Tositumomab is
radiolabeled by or on behalf of Amersham) or such Corixa Iodine I 131
Tositumomab (the "Transfer Price"). For clinical trial supplies of Tositumomab
and Corixa Iodine I 131 Tositumomab, the Transfer Price paid by Amersham shall
exclude that part of the Transfer Price described in (ii) above. Corixa shall
pay for all such clinical supplies that are designated for use in an Initial
Approval Clinical Trial. Amersham acknowledges that the Fully Allocated Costs
for Tositumomab and Corixa Iodine I 131 Tositumomab may vary depending on, among
other factors, the then current price paid to BI Pharma by Corixa for
Tositumomab and the then current price paid to Nordion by Corixa for Corixa
Iodine I 131 Tositumomab. Amersham shall pay the amount set forth in (i) within
30 days after the date of Corixa's invoice therefor. It is anticipated that
Corixa will send Amersham semi-annual invoices for Tositumomab (except for
Tositumomab designated for use in an Initial Approval Clinical Trial) and
monthly invoices for Corixa Iodine I 131 Tositumomab (except for Corixa Iodine I
131 Tositumomab designated for use in an Initial Approval Clinical Trial). The
amount set forth in (ii) shall be paid in accordance with Section 4.4.

                        (b)     The percentage of Net Sales owed by Amersham
pursuant to Section 4.1(a)(ii) shall be reduced to the applicable percentage
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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<PAGE>

<TABLE>
<CAPTION>
                                                                                   PERCENTAGE
          CIRCUMSTANCE                                                            OF NET SALES
          ------------                                                            ------------
          <S>                                                                     <C>
          (i)     there is on sale in such country an [*] that is marketed by          [*]%
          [*] or a distributor or licensee of Corixa (other than [*])

          (ii)    there is on sale in such country a [*] of [*] that is marketed       [*]%
          by [*] which does not [*] in such country [*]

          (iii)   there is on sale in such country a [*] of [*] that is marketed       [*]%
          by [*] which [*] in such country [*]

          (iv)    there is on sale in such country an [*] that is marketed by          [*]%
          [*] which [*] in such country from [*] was required to [*] by law,
          regulation or governmental agency

</TABLE>

                        (c)     In the event that more than one circumstance set
forth in Section 4.1(b) occurs simultaneously in a particular country,
Amersham's percentage of Net Sales shall be the [*] percentage applicable to any
of the circumstances. Multiple such simultaneous circumstances shall [*] on the
percentage of Net Sales paid by Amersham.

                4.2     FULLY ALLOCATED COST AUDIT. Amersham shall have the
right, upon prior written notice to Corixa and at Amersham's cost, to have the
certified public accountants of Amersham's choice, bound by confidentiality and
reasonably acceptable to Corixa, audit Corixa's books and records to verify
Corixa's calculations of Fully Allocated Cost. Amersham may exercise this right
no more than once per contract year.

                4.3     QUARTERLY ACCOUNTING FOR TOSITUMOMAB STORED BY NORDION.
Some of the Tositumomab manufactured hereunder may be shipped to Nordion so that
Nordion can use such Tositumomab for the manufacture of Corixa Iodine I 131
Tositumomab. Under normal circumstances, Amersham shall ordinarily pay the
Transfer Price for such Tositumomab after it is made into Corixa Iodine I 131
Tositumomab. Thus, the Transfer Price will include both the Fully Allocated
Costs of manufacturing the Tositumomab and the Fully Allocated Cost of making
Corixa Iodine I 131 Tositumomab from such Tositumomab. Corixa reserves the right
to perform a quarterly assessment of the amount of Amersham-earmarked
Tositumomab being stored by Nordion and the length of time that such Tositumomab
has been stored by Nordion. For all such Tositumomab that Nordion has stored for
more than 6 months, Corixa reserves the right to invoice Amersham for the Fully
Allocated Cost of such Tositumomab. Amersham shall pay such invoice within 30
days. If any such Tositumomab is subsequently converted into Corixa Iodine I 131
Tositumomab, Corixa's invoice for the Fully Allocated Cost of such Corixa Iodine
I 131 Tositumomab shall include a credit for the amount already paid by
Amersham.

* Confidential Treatment Requested

                                       18
<PAGE>

                4.4     QUARTERLY PAYMENTS AND PAYMENT REPORTS. All payments due
under Section 4.1(a)(ii) shall be made to Corixa or its designee quarterly
within 30 days 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.

                4.5     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.

                4.6     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 (i) deduct those taxes from the
remittable payment, (ii) pay the taxes to the proper taxing authority, and (iii)
send evidence of the obligation together with proof of tax payment to Corixa
within 60 days following that tax payment.

                4.7     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.

                4.8     SUBLICENSES. In the event Amersham grants licenses or
sublicenses to others to sell Products which are subject to payments under
Section 4.1, 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, payments as if such sales of the licensee
or sublicensee were Net Sales of Amersham.

                4.9     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 thirty (30) days after the completion of the quarter.

                4.10    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 4.10 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

* Confidential treatment requested.

                                       19
<PAGE>

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.

                4.11    LATE PAYMENT PENALTY. Any payment due under this Article
4 that is not paid by fourteen (14) days after the payment's due date shall
accrue interest, which must be paid by the Party with the payment obligation to
the recipient Party, on a daily basis at a rate equal to two (2) percent above
the then-applicable reference rate of CitiBank, N.A. San Francisco, California
(or the maximum amount permitted by law, if less), from the date first owed
until paid.

        5.      INTELLECTUAL PROPERTY.

                5.1     OWNERSHIP. Corixa shall own the entire right, title and
interest in and to any and all Product Inventions, and Patents covering such
Product Inventions. Each Party shall own the entire right, title and interest in
and to any and all of its Sole Other Inventions, and Patents covering such Sole
Other Inventions. Amersham and Corixa shall each own an undivided one-half
interest in and to any and all Joint Other Inventions and Patents and other
intellectual property rights claiming or covering or arising from such Joint
Other Inventions (the "Joint Other Patents"), with inventorship to be determined
under the patent laws of the United States. Amersham and Corixa, as joint
owners, shall each have the right to practice and to grant licenses under such
Joint Other Patents without a duty of accounting, except as otherwise provided
in this Agreement. Amersham hereby covenants that it will not license any Joint
Other Patents it Controls for use in conjunction with an anti-CD20 antibody
product.

                5.2     DISCLOSURE. Amersham shall submit a written report to
Corixa within 60 days of the end of each quarter describing any Product
Invention arising during the prior quarter. The Parties shall mutually decide
whether to file a patent application for a Joint Other Invention, as discussed
in Section 5.3.

                5.3     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 Sole Other Inventions.

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

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

                5.4     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
thirty (30) days after having knowledge of such infringement. Corixa shall have
the

                                       20
<PAGE>

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 within a period of sixty (60) days
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.

                5.5     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 control and bear the expense of its
own defense and, except as set forth in Section 5.5(b), Corixa shall defend,
indemnify and hold harmless Amersham, which shall include costs or judgments
whether for money or equitable relief, and reasonable legal expenses and
reasonable attorney's fees. Corixa shall not enter into a settlement agreement
with such Third Party without the written consent of Amersham, which shall not
be unreasonably withheld. If the Third Party claim arises from Amersham's
activities under the Agreement or from a Product, Amersham shall control and
bear the expense of its own defense and Amersham shall defend, indemnify and
hold harmless Corixa, which shall include costs or judgments whether for money
or equitable relief, and reasonable legal expenses and reasonable attorney's
fees. Amersham shall not enter into a settlement agreement with such Third Party
without the written consent of Corixa, which shall not be unreasonably withheld.

                        (b)     Except as set forth in Section 5.5(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

                                       21
<PAGE>

licensee, the indemnity obligations of Amersham under Section 5.5(a) shall
apply, and Corixa shall not have any indemnity obligation to Amersham in respect
of such claims.

                5.6     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.

        6.      CONFIDENTIALITY.

                6.1     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 five 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.

                6.2     EXCEPTIONS. The obligations in Section 6.1 shall not
apply with respect to any portion of the Confidential Information that the
receiving Party can show by competent written proof:

                        (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

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

                6.3     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;

                                       22
<PAGE>

                        (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 6.

        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 6.
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.

                6.4     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 6.

                6.5     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.

                6.6     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 6.3,
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

                                       23
<PAGE>

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 6.1. Nothing contained in this Section 6.6 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.

        7.      TERM AND TERMINATION.

                7.1     TERM. This Agreement shall become effective on the
Effective Date and shall remain in effect until the sooner to occur of (a) the
expiration or termination for any reason by the Parties of the License
Agreement, (b) Corixa's inability to supply Amersham's Product needs in the
Territory pursuant to terms and conditions hereunder, (c) termination by Corixa
due to Amersham's failure to establish a European Facility in accordance with
Section 3.3(d) herein, or (d) termination of this Agreement by a Party for
material breach pursuant to Section 7.2 below, including, without limitation,
Amersham's failure to comply with the terms and conditions of the BI Pharma
Agreements and Nordion Agreements applicable to Amersham.

                7.2     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
such Party would consider to be an acceptable cure of such breach. The allegedly
breaching Party shall have sixty (60) days to either cure such breach or, if
cure cannot be reasonably effected within such sixty (60) 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 fifteen (15) 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 60-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 thirty (30) days advance
written notice. If Corixa is the breaching Party, Amersham may elect to not
terminate this Agreement as provided herein. If the non-breaching Party elects
not to terminate

                                       24
<PAGE>

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
10.1 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 7.2 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 10.1. 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 30 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.

                7.3     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 4.10, 4.11, 5.1, 5.3, 6.1, 6.2, 6.3 and 7.3, and Articles 1, 9 and 10.

                        (b)     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.

                        (c)     In the event of termination of this Agreement as
a result of Amersham's termination of the License Agreement pursuant to Section
11.4(a) of the License Agreement, Corixa may, at its sole discretion, purchase
from Amersham some or all of the Tositumomab and Corixa Iodine I 131 Tositumomab
that Amersham purchased for commercial use and for which Amersham paid Corixa in
full prior to the effective date of such termination. Corixa shall pay Amersham
any mutually agreed purchase price for such Tositumomab and Corixa Iodine I 131
Tositumomab, provided such price does not exceed the price originally paid by
Amersham to Corixa. Amersham shall destroy all Tositumomab and Corixa Iodine I
131 Tositumomab not purchased by Corixa within sixty (60) days of such
termination.

        8.      REPRESENTATIONS AND COVENANTS.

                8.1     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.

                                       25
<PAGE>

                8.2     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.

        9.      INDEMNIFICATION AND LIMITATION OF LIABILITY.

                9.1     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 or (ii)
sale of Product in the Territory, except to the extent such Losses result from
an activity as to which Corixa is obliged to indemnify Amersham pursuant to
Section 9.1(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 or (ii) the failure of Corixa to comply with GMP during its
manufacture of Tositumomab or Corixa Iodine I 131 Tositumomab, except to the
extent such Losses result from an activity as to which Amersham is obliged to
indemnify Corixa pursuant to Section 9.1(a).

                        (c)     In the event that a Party (the "Indemnified
Party") is seeking indemnification under Section 9.1(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 consideration), and shall cooperate as requested by the Indemnifying
Party (at the expense of the Indemnifying Party) in the defense of the claim.

                9.2     LIMITATION OF LIABILITY. EXCEPT AS SPECIFICALLY PROVIDED
IN SECTION 9.1, 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.

                                       26
<PAGE>

        10.     MISCELLANEOUS.

                10.1    DISPUTE RESOLUTION. In the event of any controversy or
claim arising out of, relating to or in connection with any provision of this
Agreement, 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 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 10.3, 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.

                10.2    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.

                10.3    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.

                10.4    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.

                10.5    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.

                                       27
<PAGE>

                10.6    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.

                10.7    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, and 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
                               Amersham Health, Inc.
                               101 Carnegie Center
                               Princeton, NJ 08540

                                       28
<PAGE>

                10.8    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.

                10.9    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.

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

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

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

                10.13   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 10.13 shall
be null and void and of no legal effect.

                10.14   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.

                10.15   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.

                10.16   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.

                10.17   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.

                                       29
<PAGE>

                10.18   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 10.18, 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 months prior written notice to the other
Party. Such termination shall be in accordance with the provisions of Section
7.3 of this Agreement.

                10.19   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.

                10.20   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.

                10.21   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.

<TABLE>
AMERSHAM PLC                                       CORIXA CORPORATION

<S>                                               <C>
By:                                                By:
   -----------------------------------------          -------------------------------------------

Name:                                              Name:  Steven Gillis
     ---------------------------------------            -----------------------------------------
Title:                                             Title: Chairman and Chief Executive Officer
      --------------------------------------             ----------------------------------------
Date:                                              Date:
     ---------------------------------------            -----------------------------------------
</TABLE>

                                       30
<PAGE>

                                    EXHIBIT A

                                 CORIXA FORECAST

<TABLE>
<CAPTION>
              CALENDAR YEAR                        AMOUNT
              -------------                      ---------
              <S>                                <C>
              2001                               [*] grams
              2002                               [*] grams
              2003                               [*] grams
</TABLE>

* Confidential Treatment Requested

                                      A-1

<PAGE>
                                    EXHIBIT B

                                EUROPEAN FACILITY

                            MILESTONES AND TIMELINES

<TABLE>
<CAPTION>
MILESTONE                                             TIMELINE
----------                                            ---------
<S>                                                     <C>
Development of [*] for [*].                             Within [*] days following the Effective Date
Completion of [*], ready for submission for [*].        June 30, [*]
Commencement of [*].                                    Beginning June 30, [*]
Purchase of all [*] required for [*] of Product.        December 30, [*]
Validation of [*] and submission of validation          Completed by September 30, [*]
documents to regulatory agencies as required.
</TABLE>

* Confidential Treatment Requested

                                      B-1
<PAGE>

<TABLE>
<S>     <C>                                                                                  <C>
1.      Definitions..........................................................................1

        1.1    "Amersham Iodine I 131 Tositumomab"...........................................1

        1.2    "BI Pharma Agreements"........................................................1

        1.3    "Clinical Trial"..............................................................1

        1.4    "Controlled"..................................................................1

        1.5    "Corixa"......................................................................2

        1.6    "Corixa Intellectual Property Rights".........................................2

        1.7    "Corixa Iodine I 131 Tositumomab".............................................2

        1.8    "Corixa Territory"............................................................2

        1.9    "Diligent Efforts"............................................................2

        1.10   "Effective Date"..............................................................2

        1.11   "European Facility"...........................................................2

        1.12   "Fully Allocated Cost"........................................................2

        1.13   "Good Clinical Practice"......................................................3

        1.14   "Good Laboratory Practice"....................................................3

        1.15   "Good Manufacturing Practice".................................................3

        1.16   "Information".................................................................3

        1.17   "Initial Approval Clinical Trials"............................................3

        1.18   "Initial Development Plan"....................................................4

        1.19   "Intellectual Property Rights"................................................4

        1.20   "Invention"...................................................................4

        1.21   "Iodine I 131 Tositumomab"....................................................4

        1.22   "Joint Other Inventions"......................................................4

        1.23   "Know-How"....................................................................4

        1.24   "Net Sales"...................................................................4

        1.25   "Nordion Agreements"..........................................................5

        1.26   "Other Invention".............................................................5

        1.27   "Patent"......................................................................5

        1.28   "Product".....................................................................5

        1.29   "Product Invention"...........................................................5

        1.30   "QA/QC Costs".................................................................5

        1.31   "Sole Other Inventions".......................................................5
</TABLE>

<PAGE>
<TABLE>

        <S>    <C>                                                                          <C>
        1.32   "Specifications"..............................................................5

        1.33   "Stock Purchase Agreement"....................................................6

        1.34   "Territory"...................................................................6

        1.35   "Therapy".....................................................................6

        1.36   "Third Party".................................................................6

        1.37   "Tositumomab".................................................................6

        1.38   "Transfer Price"..............................................................6

2.      General Understanding................................................................6

3.      Manufacturing And Supply Of Antibody.................................................6

        3.1    Tositumomab...................................................................6

        3.2    Corixa Iodine I 131 Tositumomab...............................................8

        3.3    Amersham Iodine I 131 Tositumomab............................................10

        3.4    Distribution.................................................................12

        3.5    Customer Orders..............................................................12

        3.6    Enhancements.................................................................12

        3.7    Manufacturing Regulatory Compliance..........................................13

        3.8    Regulatory Compliance........................................................13

        3.9    Quality Control; Testing.....................................................13

        3.10   Non-Compliance with Specifications...........................................13

        3.11   Allocation in the Event of Product Shortages.................................13

4.      Economics...........................................................................16

        4.1    Transfer Price...............................................................16

        4.2    Fully Allocated Cost Audit...................................................17

        4.3    Quarterly Accounting for Tositumomab Stored by Nordion.......................17

        4.4    Quarterly Payments and Payment Reports.......................................18

        4.5    Payment Method...............................................................18

        4.6    Taxes........................................................................18

        4.7    Blocked Currency.............................................................18

        4.8    Sublicenses..................................................................18

        4.9    Foreign Exchange.............................................................18

        4.10   Records; Inspection..........................................................18

        4.11   Late Payment Penalty.........................................................19
</TABLE>

<PAGE>
<TABLE>

<S>     <C>                                                                                <C>
5.      Intellectual Property...............................................................19

        5.1    Ownership....................................................................19

        5.2    Disclosure...................................................................19

        5.3    Patent Prosecution and Maintenance; Abandonment..............................19

        5.4    Enforcement of Patent Rights.................................................19

        5.5    Defense of Third Party Claims................................................20

        5.6    Trademarks...................................................................21

6.      Confidentiality.....................................................................21

        6.1    Nondisclosure of Confidential Information....................................21

        6.2    Exceptions...................................................................21

        6.3    Authorized Disclosure........................................................21

        6.4    Termination of Prior Agreements..............................................22

        6.5    Publicity....................................................................22

        6.6    Publications.................................................................22

7.      Term And Termination................................................................23

        7.1    Term.........................................................................23

        7.2    Termination for Material Breach..............................................23

        7.3    Effect of Termination; Survival..............................................24

8.      Representations And Covenants.......................................................24

        8.1    Mutual Authority.............................................................24

        8.2    Performance by Affiliates....................................................24

9.      Indemnification And Limitation Of Liability.........................................25

        9.1    Indemnification..............................................................25

        9.2    Limitation of Liability......................................................25

10.     Miscellaneous.......................................................................25

        10.1   Dispute Resolution...........................................................25

        10.2   Governing Law................................................................26

        10.3   Patents and Trademarks.......................................................26

        10.4   Entire Agreement; Amendment..................................................26

        10.5   Export Control...............................................................26

        10.6   Force Majeure................................................................26

        10.7   Notices......................................................................27
</TABLE>

<PAGE>
<TABLE>
<S>     <C>                                                                                 <C>
        10.8   Consents Not Unreasonably Withheld or Delayed................................27

        10.9   Maintenance of Records.......................................................27

        10.10  United States Dollars........................................................28

        10.11  No Strict Construction.......................................................28

        10.12  English......................................................................28

        10.13  Assignment...................................................................28

        10.14  Hardship.....................................................................28

        10.15  Electronic Data Interchange..................................................28

        10.16  Counterparts.................................................................28

        10.17  Further Actions..............................................................28

        10.18  Severability.................................................................28

        10.19  Ambiguities..................................................................29

        10.20  Headings.....................................................................29

        10.21  No Waiver....................................................................29
</TABLE>

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00039-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00039-of-00352.parquet"}]]