<PAGE>   1

                                                                   EXHIBIT 10.01


                               CORIXA CORPORATION

                                       AND

                          INPHARZAM INTERNATIONAL, S.A.

                             COLLABORATION AGREEMENT

                                    ---------




<PAGE>   2

                                TABLE OF CONTENTS



<TABLE>
<S>   <C>                                                                                   <C>
1.    DEFINITIONS............................................................................1

2.    SCOPE OF RESEARCH PROGRAM AND CLINICAL DEVELOPMENT PROGRAM.............................4

3.    RESEARCH PROGRAM TERM AND TERMINATION..................................................5

4.    RESEARCH AND DEVELOPMENT STEERING COMMITTEE; MARKETING COMMITTEE; [***]*...............5

5.    LICENSE GRANTS; OPTION.................................................................6

6.    PAYMENTS...............................................................................7

7.    SHARING OF PROFITS.....................................................................8

8.    REPORTS, PAYMENTS AND ACCOUNTING FOR ROYALTY AND/OR SUBLICENSE FEESHARE................9

9.    COMMERCIAL DEVELOPMENT................................................................12

10.   MANUFACTURING; SUPPLY.................................................................12

11.   INVENTIONS............................................................................12

12.   PATENTS; PROSECUTION AND LITIGATION...................................................12

13.   CONFIDENTIALITY; PUBLICITY; PUBLICATIONS..............................................15

14.   GOVERNING LAW; ARBITRATION............................................................16

15.   MISCELLANEOUS.........................................................................16

16.   NOTICES...............................................................................17

17.   ASSIGNMENT............................................................................19

18.   WARRANTIES AND REPRESENTATIONS........................................................19

19.   TERM AND TERMINATION..................................................................20

20.   RIGHTS AND DUTIES UPON TERMINATION....................................................20

21.   INDEMNIFICATION.......................................................................21
</TABLE>



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                                    EXHIBITS


      Exhibit A                    Corixa Research and Discovery Methodologies

      Exhibit A-1                  Corixa Patents

      Exhibit A-2                  Corixa Adjuvant Patents

      Exhibit A-3                  Microsphere Patents

      Exhibit B                    Research Program

      Exhibit C                    List of Third Party Agreements

      Exhibit D                    Stock Purchase Agreement

      Exhibit E                    Net Sales Definition

      Exhibit F                    Form of Supply Agreement

      Exhibit G                    Clinical Development Program



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<PAGE>   4

                             COLLABORATION AGREEMENT

        This COLLABORATION AGREEMENT (together with the attachments and exhibits
hereto, the "Agreement") is entered into as of May 21, 1999 (the "Effective
Date") by and between Corixa Corporation, a corporation organized and existing
under the laws of the State of Delaware and having its principal office at 1124
Columbia Street, Suite 200, Seattle, Washington, and Inpharzam International,
S.A., a corporation organized and existing under the laws of Switzerland, and a
wholly-owned subsidiary of Zambon Group spa, a corporation organized and
existing under the laws of Italy.

RECITALS

        WHEREAS, Corixa and Zambon desire to collaborate in the development of
vaccine products for the treatment of lung cancer, which vaccines will contain
certain protein or DNA antigens and may be formulated in microspheres, with
Corixa adjuvant admixed, and may have applications for cancers other than lung
cancer;

        WHEREAS, Corixa has expertise in the field of cancer antigen discovery
and vaccine formulation, including, but not limited to, expertise in the
practice of the research and discovery methodologies set forth on Exhibit A
hereto, and has agreed to apply such expertise to the performance of the
Collaboration;

        WHEREAS, Corixa has agreed to license to Zambon intellectual property
rights related to the Collaboration, including discoveries to be made during the
Collaboration, on the terms and conditions of this Agreement for Zambon's
exploitation to develop and commercialize certain products that are the focus of
the Collaboration;

        WHEREAS, Zambon and Corixa have also entered into a Common Stock
Purchase Agreement [***]* of even date herewith (the "Stock Purchase
Agreement" and the "Standstill Agreement", respectively) with respect to
Zambon's purchase of Common Stock of Corixa and Zambon and Corixa intend to
enter into a Supply Agreement on mutually agreed upon terms and conditions based
on the form attached as Exhibit F (the "Supply Agreement"), in order to develop
and commercialize certain applications of such technology;

        NOW, THEREFORE, for and in consideration of the mutual observance of the
covenants hereinafter set forth and other good and valuable  consideration,  the
receipt of which is hereby acknowledged, the parties hereto agree as follows:

        1.      DEFINITIONS.

        All references to particular Exhibits, Articles and Sections shall mean
the Exhibits to, and Articles and Sections of, this Agreement, unless otherwise
specified. References to this "Agreement" include the Exhibits. For the purposes
of this Agreement, the following words and phrases shall have the following
meanings:



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                1.1     "Affiliate" of an entity means, for so long as one of
the following relationships is maintained, any corporation or other business
entity owned, owning, or under common ownership with a party to this Agreement
to the extent of at least fifty percent (50%) of the equity (or such lesser
percentage which is the maximum allowed to be owned by a foreign corporation in
a particular jurisdiction) having the power to vote on or direct the affairs of
the entity and any person, firm, partnership, corporation, or other entity
actually controlled by, controlling or under common control with a party to this
Agreement. For purposes of clarification and not of limitation, Zambon Group spa
and all Affiliates thereof shall be deemed "Affiliates" of Zambon for purposes
of this Agreement.

                1.2     "Antigen(s)" shall mean any antigen [***]* covered by
one (1) or more claim(s) of any of the Corixa Patents that are identified on
Exhibit A-1.

                1.3     "Collaboration" means the joint collaboration of Corixa
and Zambon pursuant to the terms of this Agreement and the Research Program and
the Clinical Development Program.

                1.4     "Commercialization Period" shall have the meaning set
forth in Section 4.1.

                1.5     "Corixa" shall mean Corixa and its Affiliates.

                1.6     "Corixa Adjuvant" shall mean the protein Leishmania
Elongation Initiation Factor, known as LeIF, [***]* covered by one (1) or more
of claim(s) of any of the Corixa Patents that are identified on Exhibit A-2, as
may be amended from time to time.

                1.7     "Corixa Patents" shall mean [***]*. Corixa Patents shall
specifically not include either Zambon Patents or Joint Research Program
Patents.

                1.8     "Clinical Development Program" shall have the meaning
set forth in Section 2.2.

                1.9     "Development Period" shall have the meaning set forth in
Section 4.1.

                1.10    "GAAP" or "U.S. generally accepted accounting
principles" shall mean the conventions, rules and procedures governing
accounting practices as established, and revised or amended, by the U.S.
Financial Accounting Standards Board or the U.S. Securities and Exchange
Commission.

                1.11    "Interpretive Rules". For purposes of this Agreement,
except as otherwise expressly provided herein or unless the context otherwise
requires: (a) defined terms include the plural as well as the singular and the
use of any gender shall be deemed to include the other gender; (b) references to
"Articles," "Sections" and other subdivisions and to "Schedules" and "Exhibits"
without reference to a document, are to designated Articles, Sections and other
subdivisions of, and to Schedules and Exhibits to, this Agreement; (c) unless
otherwise set forth herein, the use of the term "including" means "including but
not limited to"; and (d) the words



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"herein," "hereof," "hereunder" and other words of similar import refer to this
Agreement as a whole and not to any particular provision.

                1.12    "Joint Research Program Patents" shall mean all [***]*.
In no event shall Joint Research Program Patents be deemed to include Corixa
Patents or Zambon Patents.

                1.13    "Joint Inventions" shall have the meaning set forth in
Section 11.

                1.14    "Know-How" shall mean [***]*.

                1.15    "Licensed Field" shall mean [***]*.

                1.16    "Marketing Committee" shall have the meaning set forth
in Section 4.1.

                1.17    "Microspheres" shall mean the encapsulated antigen
delivery system owned, developed or in-licensed by Corixa and covered by one (1)
or more claim(s) of any of the Corixa Patents that are identified on Exhibit
A-3.

                1.18    "Product" shall mean any and all [***]* Vaccines that
include at least one [***]*.

                1.19    "Research Period" shall have the meaning set forth in
Section 4.1.

                1.20    "Research Program" shall have the meaning set forth in
Section 2.1.

                1.21    "Research Program Term" shall have the meaning set forth
in Section 3.1.

                1.22    "Research and Development Steering Committee" shall have
the meaning set forth in Section 4.1.

                1.23    "SPC" shall mean all Supplementary Protection
Certificates for medicinal products and their equivalents provided under the
Council Regulation (EEC) N# 1768/92 of June 18, 1992.

                1.24    "Territory A" shall mean [***]* European countries,
including the former Soviet Union, Argentina, Brazil and Colombia.

                1.25    "Territory B" shall mean China and its territories,
possessions and protectorates.

                1.26    "Third Party(ies)" shall mean any party other than a
party to this Agreement or an Affiliate.

                1.27    "US Partner" shall have the meaning set forth in Section
9.3.

                1.28    "Vaccine" shall mean the administration of (an)
antigen(s) [***]*.



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                1.29    "Zambon" shall mean Inpharzam International, S.A.,
Zambon Group spa and each of their respective Affiliates.

                1.30    "Zambon Patents" shall mean all [***]*. In no event
shall Zambon Patents be deemed to include either Corixa Patents or Joint
Research Program Patents.

                1.31    "FTE" shall mean a minimum of [***]* for individual
Corixa employees assigned to the Research Program, or its equivalent if a given
employee is assigned on a part-time basis and therefore multiple employees are
added to provide a single FTE.

                1.32    "Research Field" shall mean lung cancer in humans.

                1.33    "Therapeutic Drug Monitoring" shall mean the use of
Antigens solely for the purpose of [***]*.

                1.34    "Therapeutic Drug Monitoring Product" shall mean a
diagnostic product formulated solely for use in Therapeutic Drug Monitoring.

                1.35    "Net Sales" shall have the meaning set forth in Exhibit
E.

                1.36    "Valid Claim" shall mean, with respect to each country
in the territory, a claim of [***]*.

                1.37    "Co-Development Committee" shall have the meaning set
forth in Section 9.3.

                1.38    [***]*

                1.39    "Research Program [***]*" shall have the meaning set
forth in Section 4.5.

                1.40    "Third Party Agreements" shall have the meaning set
forth in Section 5.2.

        2.      SCOPE OF RESEARCH PROGRAM AND CLINICAL DEVELOPMENT PROGRAM.

                2.1     During the Research Program Term, Corixa shall undertake
the program of research activities as set forth in Exhibit B (the "Research
Program"), which may be amended annually upon the anniversary of the Effective
Date, upon mutual agreement of the parties. The parties agree that the end goal
of the Research Program shall be [***]*.

                2.2     Subsequent to the completion of the Research Program,
Zambon shall undertake, [***]*.



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        3.      RESEARCH PROGRAM TERM AND TERMINATION.

                3.1     The Research Program shall be effective from the
Effective Date and shall terminate on the [***]* anniversary of the Effective
Date, unless extended or earlier terminated in accordance with Section 19 (the
"Research Program Term").

                3.2     In the event that Corixa achieves [***]* then upon the
mutual agreement of the parties, the Research Program shall be extended for an
additional [***]* beyond the termination date set forth in Section 3.1. In the
event of achievement of [***]* and upon the agreement of both parties, the
parties shall negotiate in good faith and agree upon the terms and conditions
including the financial elements regarding such extension. In the event that
Corixa does not achieve [***]* on or before the [***]* anniversary of the
Effective Date, then Zambon shall have the [***]*.

        4.      RESEARCH AND DEVELOPMENT STEERING COMMITTEE; MARKETING
COMMITTEE; [***]* .

                4.1     A Research and Development Steering Committee (the
"Research and Development Steering Committee") shall be established within
thirty (30) days after the full execution of this Agreement. The Research and
Development Steering Committee shall consist of [***]*. During the period
beginning on the date hereof and ending on the earlier of (i) a date mutually
agreed by the parties and (ii) [***]* or such later time as is mutually agreed
by the parties (the "Research Period"), the Research and Development Steering
Committee shall be responsible for [***]*. During the period following the
Research Period but prior to commercialization (the "Development Period"), the
Research and Development Steering Committee shall be responsible for [***]*.
Following the Development Period, at the time of commercialization of [***]*,
the parties shall establish a Marketing Committee (the "Marketing Committee"),
consisting of [***]*. During the period following the Development Period and
throughout the commercialization of Product(s) and/or Therapeutic Drug
Monitoring Product(s) (the "Commercialization Period"), the Marketing Committee
shall be responsible for [***]*.

                4.2     To facilitate coordination during the Research Period,
the parties shall [***]*. Corixa shall provide Zambon with [***]* on the
progress of the Research Program. The data generated shall be subject to the
confidentiality provisions of Section 13 of this Agreement. The Research and
Development Steering Committee shall review the Research Program [***]*.

                4.3     To facilitate coordination during the Development
Period, the parties shall share [***]*. Zambon shall provide Corixa with [***]*
on the progress of the Clinical Development Program, including [***]* . The
information generated shall be subject to the confidentiality provisions of
Section 13 of this Agreement. The Research and Development Steering Committee
shall review the Clinical Development Program [***]*.

                4.4     To facilitate coordination during the Commercialization
Period, the parties shall [***]*. Zambon shall provide Corixa with [***]* on the
progress of commercialization,



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[***]*, The information generated shall be subject to the confidentiality
provisions of Section 13 of this Agreement. The Marketing Committee shall review
the commercialization plans and progress [***]*

                4.5     During the Research Program Term (as it may be extended
from time to time), Zambon shall have the [***]*.

        5.      LICENSE GRANTS; [***]* .

                5.1     License.

                        5.1.1   Subject to the terms and conditions of this
Agreement, including, without limitation, the payments set forth in Section 6
hereof, Corixa hereby grants to Zambon an exclusive license, [***]* Products and
Therapeutic Drug Monitoring Products in the Licensed Field in Territory A.

                        5.1.2   Subject to the terms and conditions of this
Agreement, including, without limitation, the payments set forth in Section 6
hereof, Corixa hereby grants to Zambon a co-exclusive license [***]* Products
and Therapeutic Drug Monitoring Products in the Licensed Field in Territory B.

                        5.1.3   Subject to the terms and conditions of this
Agreement, including, without limitation, the payments set forth in Section 6
hereof [***]*, Corixa hereby grants to Zambon a non-exclusive license, [***]*
Microspheres [***]* Corixa Adjuvant in the Licensed Field in Territories A and
B, but solely to the extent that same are incorporated in a Product that
includes Antigens.

                        5.1.4   Subject to the terms and conditions of this
Agreement, including, without limitation, the payments set forth in Section 6
hereof, Corixa hereby grants to Zambon a non-exclusive license, [***]*
Therapeutic Drug Monitoring Products solely for Therapeutic Drug Monitoring in
Territory A and Territory B.

                        5.1.5   During the Research Program Term, [***]*

                5.2     Sublicenses of Third Party Rights to Zambon. Zambon
understands and agrees that the licenses granted to it under this Agreement
include, with respect to certain products, sublicenses and licenses by Corixa
under agreements between Corixa and certain Third Parties regarding licenses
and/or assignments. Exhibit C includes a list of agreements (the "Third Party
Agreements") pursuant to which Third Party rights are sublicensed or licensed by
Corixa to Zambon as of the Effective Date. Zambon understands and agrees that
such sublicenses or licenses may in some respects be more restrictive than the
terms and conditions of this Agreement or may require payments in addition to
those set forth herein. [***]* .


                5.3  [***]*.


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                        5.4     [***]*.

                        5.5     Exploitation of [***]*. Corixa and Zambon each
agree that except as provided in the immediately following sentence, neither
party will [***]*. Corixa and Zambon each further agree only to [***]*.

        6.      PAYMENTS.

        Zambon shall make the following payments to Corixa under this Agreement
in U.S. Dollars by wire transfer of immediately available funds:

                6.1     [***]* Fees. A [***]* fee of [***]* upon execution of
this Agreement. The full amount of the technology access fee shall be [***]*
paid directly to Corixa.

                6.2     Equity Purchase. Zambon shall purchase shares of Common
Stock of Corixa, pursuant to the terms and conditions of a Common Stock Purchase
Agreement of even date herewith and attached as Exhibit D (the "Stock Purchase
Agreement"), and all Exhibits thereto, as follows. Zambon shall purchase the
number of shares of Common Stock of Corixa equal to [***]*. The payment amount
for the foregoing Common Stock shall be [***]* paid directly to Corixa.

                6.3     [***]* Funding. [***]* payments in the following amounts
and on the following dates, it being acknowledged and agreed that each such
payment shall be for [***]* conducted during the three month period immediately
preceding such payment date:

<TABLE>
<CAPTION>
             ------------------------- ------------------------
                   PAYMENT DATE        PAYMENT AMOUNT (U.S.$)
             ------------------------- ------------------------
<S>                                    <C>
             [***]*
             ------------------------- ------------------------
</TABLE>

                        The payment amounts set forth in the above table shall
be [***]* paid directly to Corixa. The Research Plan, and corresponding
payments, may be extended as set forth in Section 3.2 above.

                6.4     Milestone Payments. In addition to the amounts payable
pursuant to Sections 6.1, 6.2 and 6.3 above, Zambon also agrees to pay Corixa
the following [***]* milestone payments, to be made via wire transfer of
immediately available funds, within [***]* achievement of each of the following
milestones with respect to [***]*:


<TABLE>
<CAPTION>
------------------------------------- -----------------------------------
             MILESTONE                         PAYMENT (U.S.$)
------------------------------------- -----------------------------------
<S>                                   <C>
[***]*                                      [***]*
------------------------------------- -----------------------------------
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        Notwithstanding the foregoing, in the event the Product developed by
[***]*.

        7.      ROYALTY PAYMENTS; SUBLICENSE PAYMENTS SHARE.

                7.1     Royalties.

                        (A)     [***]*

                        (B)     Royalties shall be earned and paid to Corixa
until [***]*.

                7.2     Sublicense Sales.

                        For any Products or Therapeutic Drug Monitoring Products
[***]* which are the subject of a sublicense granted to a Third Party by Zambon
hereunder, Corixa shall receive the greater of:

                [***]*

                7.3     [***]*.

                7.4     [***]*.

                7.5     Currency. All amounts payable to Corixa under this
Agreement shall be payable in United States Dollars, either by a check payable
to Corixa or by wire transfer of immediately available funds to a bank account
designated by Corixa, at Corixa's option. Monthly sales amounts shall be
translated from Italian Lira to U.S. Dollars by using an average rate of
exchange. This average shall be computed using the rate of exchange quoted under
Foreign Exchange in the Wall Street Journal as of the end of the current month
plus the rate as of the end of the prior month and dividing by 2. With respect
to sales made by sublicensees (either Affiliates or non-Affiliates) of Zambon,
sales amounts will be converted from any foreign currencies to Italian Lira
using average rates of exchange published by the journal Sole 24 One in
accordance with Zambon's standard methodology, consistently applied.

                7.6     Withholding Taxes. If any law or regulation in any
country requires the withholding by Zambon or its Affiliates or sublicensees of
any taxes due on payments to be remitted to Corixa, such taxes shall be deducted
from the amounts paid to Corixa. If the taxes are deducted from the amounts paid
to Corixa, then Zambon or its Affiliates or sublicensees shall furnish Corixa
the originals of all official receipts for such taxes and shall reasonably
cooperate with Corixa in any efforts by Corixa to obtain a credit for such
taxes.

                7.7     Currency Transfer Restrictions. If in any country in
Territory A or B payment or transfer of funds out of such country is prohibited
by law or regulation, the parties hereto shall confer regarding the terms and
conditions on which Products or Therapeutic Drug Monitoring Products shall be
sold in such countries, including the possibility of payment of royalties to
Corixa in local currency to a bank account in such country or the renegotiation
of royalties for such sales, and in the absence of any other agreement by the
parties, such funds



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payable to Corixa shall be deposited in whatever currency is allowable by Zambon
or such other Affiliate in an accredited bank in that country that is acceptable
to Corixa.

                7.8     Royalty and/or Sublicense Fee Sharing Upon Termination.
If this Agreement is terminated in accordance with Section 19 with respect to
all or some of the Products or Therapeutic Drug Monitoring Products, Zambon
shall continue to pay Corixa all amounts earned pursuant to this Article 7 with
respect to Products or Therapeutic Drug Monitoring Products prior to the date of
termination and any amounts earned thereafter as a result of sales of residual
inventory of Products or Therapeutic Drug Monitoring Products, as well as its
share of sublicense payment with respect to Products or Therapeutic Drug
Monitoring Products. In addition, Zambon shall continue to pay all amounts
payable hereunder with respect to Products and Therapeutic Drug Monitoring
Products, if any, with respect to which this Agreement is not terminated.

        8.      REPORTS, PAYMENTS AND ACCOUNTING FOR ROYALTY AND/OR SUBLICENSE
FEE SHARE.

                8.1     Payments and Reports.

                        8.1.1   Zambon agrees to make written reports
(consistent with GAAP [***]*) and payments to Corixa within [***]* after the
close of each calendar quarter during the term of this Agreement. These reports
shall show for such calendar quarter sales by Zambon, its Affiliates and
sublicensees of the Products or Therapeutic Drug Monitoring Products [***]*, Net
Sales and the royalties and/or share of sublicense payments due to Corixa
thereon pursuant to Article 7. Concurrently with the making of each such report,
Zambon shall make payment to Corixa of (i) amounts payable for the period
covered by such report and/or (ii) payment of all accrued amounts incurred by
Corixa as costs and expenses for which statements of account have been submitted
by Corixa and which have not been previously reimbursed under this Agreement.

                        8.1.2   Corixa agrees to submit a detailed statement of
account to Zambon within [***]* days after the close of each calendar quarter
(consistent with GAAP [***]*), for any costs or expenses incurred related to
patents in accordance with Section 12.1, and other agreed upon expenses during
such calendar quarter and not previously reimbursed. In addition, upon execution
of this Agreement, Zambon shall reimburse Corixa for costs and expenses incurred
to [***]*.

                8.2     Termination Report. For each Product and Therapeutic
Drug Monitoring Product, Zambon also agrees to make a written report to Corixa
within ninety (90) days after the date on which Zambon, its Affiliates or
sublicensees last sell that Product or Therapeutic Drug Monitoring Product
stating in such report the same information required for quarterly reports of
sales of all such Products or Therapeutic Drug Monitoring Products made, sold or
otherwise disposed of which were not previously reported to Corixa.

                8.3     Accounting.



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                        8.3.1   Zambon agrees to keep clear, accurate and
complete records, all in [***]* accordance with GAAP, for a period of at least
[***]* years (or such longer period as may correspond to Zambon's internal
records retention policy) for each reporting period in which sales occur showing
the manufacturing, sales, use and other disposition of Products and Therapeutic
Drug Monitoring Products in sufficient detail to enable amounts payable pursuant
to Section 7, and the costs and expenses reimbursable hereunder to be
determined, and further agrees to permit its books and records to be examined by
an independent accounting firm selected by Corixa and reasonably satisfactory to
Zambon, and that is bound in confidence to disclose only evidence of
noncompliance, from time-to-time to the extent necessary, but not more than once
a year. Corixa shall have the right, at Corixa's sole expense except as
hereinafter provided, through a certified public accountant reasonably
acceptable to Zambon, and following reasonable notice, to examine such records
during regular business hours during the life of Zambon's payment obligations to
Corixa under this Agreement and for three (3) years thereafter; provided,
however, that such examination shall not (i) be of records for more than the
prior three (3) years, (ii) take place more often than once a year, and (iii)
cover any records which date prior to the date of the last examination, and
provided, further, that such accountants shall report to Corixa only as to the
accuracy of the royalty statements and payments. Copies of such reports shall be
supplied to Zambon. In the event the report demonstrates that Zambon has
underpaid Corixa, Zambon shall pay the amount of such underpayment immediately
upon request of Corixa and to the extent such underpayment is more than [***]*
for the audited period, shall reimburse Corixa for the expense of the audit. If
Zambon has overpaid Corixa, Zambon may deduct such overpayments from future
amounts owed to Corixa.

                        8.3.2   Corixa agrees to [***]*.

                8.4     Confidentiality of Reports. Each party agrees that the
information set forth in (a) the reports required by Sections 8.1 and 8.2, and
(b) the records subject to examination under Section 8.3, shall be subject to
Section 13 hereof and maintained in confidence by the receiving party and any
independent accounting firm selected by such party, shall not be used by such
party or such accounting firm for any purpose other than verification of the
performance by the other party of its obligations hereunder, and shall not be
disclosed by the receiving party or such accounting firm to any other person
except for purposes of enforcing this Agreement.



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        9.      COMMERCIAL DEVELOPMENT.

                9.1     Diligence in Research and Commercial Development.

                        (A)     Corixa will [***]*.

                        (B)     Zambon and its Affiliates will [***]*.

                9.2     Research and Development Steering Committee Reports.
Subject to modification by the Research and Development Steering Committee,
within [***]* after each [***]* during the Research Program Term, and within
[***]* after each [***]* after the Research Program Term, each party shall
provide the other party with [***]* period, respectively, under this Section 9
and the progress and results [***]*.

                9.3     [***]*

        10.     MANUFACTURING; SUPPLY.

                10.1    Materials.

                        (A)     Corixa shall provide reasonable quantities of
[***]* for Zambon as required through the course of the Research Program [***]*
the terms set forth in a Supply Agreement to be mutually agreed by the parties
based on the form attached hereto as Exhibit F.

                        (B)     Materials manufactured [***]* the terms set
forth in a Supply Agreement to be mutually agreed by the parties based on the
form attached hereto as Exhibit F.

                10.2    Delivery. Subject to revision by the Research and
Development Steering Committee, all materials delivered to Zambon pursuant to
Section 10.1(A) above shall [***]*. Corixa shall use [***]*. All customs,
duties, costs, taxes, insurance premiums, and other expenses relating to such
transportation and delivery, shall be at Zambon's expense.

                10.3    [***]*.

        11.     INVENTIONS.

                Patentable inventions or discoveries which arise from the
Research Program or the Clinical Development Program [***]*. Patentable
inventions or discoveries which arise from the Research Program or the Clinical
Development Program [***]*. Patentable inventions or discoveries which arise
from the Research Program or the Clinical Development Program [***]*.

        12.     PATENTS; PROSECUTION AND LITIGATION.

                12.1    Corixa shall have the right [***]* to prosecute and
maintain all Corixa Patents and Joint Research Program Patents [***]*. Corixa
shall disclose to Zambon [***]*.



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                                      -11-
<PAGE>   15

Zambon shall have the right [***]*. Corixa agrees to keep Zambon [***]* informed
of [***]*. Corixa shall provide such patent consultation [***]*. Zambon shall
hold all information disclosed to it under this Section as confidential in
accordance with Section 13. Zambon shall reimburse Corixa [***]*. All expenses
reimbursed by Zambon pursuant to this Section shall be obligations that are
separate and apart from other payment obligations described in this Agreement
and shall be invoiced and paid separately, with no right of offset.

                12.2    [***]*

                12.3    Third Party Infringement Actions.

                        12.3.1  In the event of the initiation of any suit by a
Third Party against Corixa, Zambon or the Affiliates of either for patent
infringement with respect to Corixa Patents and involving the manufacture, use,
sale, distribution or marketing of Product or Therapeutic Drug Monitoring
Product anywhere in Territory A or Territory B, the party sued shall promptly
notify the other party in writing. [***]*.

                        12.3.2  In connection with any action pursuant to this
Section 12.3, [***]*.

                        12.3.3  In connection with any action pursuant to this
Section 12.3, in the event such action [***]*.

                        12.3.4  Following any termination pursuant to subsection
12.3.3, Corixa shall [***]*.

                        12.3.5  In the event Zambon [***]*.

                        12.3.6  In the event any judgment of damages enforceable
against Zambon is awarded to a Third Party in connection with any infringement
action contemplated by this Section 12.3, Zambon shall [***]*.

                12.4    In the event that Corixa or Zambon becomes aware of
actual or threatened infringement of a patent covered by this Agreement with
respect to Products or Therapeutic Drug Monitoring Products anywhere in
Territory A or Territory B, that party shall promptly notify the other party in
writing. In connection with any such actual or threatened infringement in
Territory A, [***]*.

                12.5    Corixa and Zambon shall recover their respective actual
out-of-pocket expenses, or equitable proportions thereof, associated with any
litigation or settlement thereof from any recovery made by any party. [***]*.

                12.6    The parties shall keep one another informed of the
status of their respective activities regarding any litigation or settlement
thereof concerning any Product or Therapeutic Drug Monitoring Product.



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                                      -12-
<PAGE>   16

                12.7    CORIXA MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS
OR IMPLIED, OTHER THAN THOSE EXPRESSLY SET FORTH IN SECTION 18 BELOW, WITH
RESPECT TO THE ANTIGENS, CORIXA ADJUVANT, MICROSPHERES, CORIXA PATENTS, THE
JOINT RESEARCH PROGRAM PATENTS OR KNOW-HOW AND ANY PRODUCTS OR THERAPEUTIC DRUG
MONITORING PRODUCTS RELATED THERETO, INCLUDING WITHOUT LIMITATION ANY WARRANTY
OF NONINFRINGEMENT, PATENTABILITY, MERCHANTABILITY OR FITNESS FOR A PARTICULAR
PURPOSE.



                                      -13-
<PAGE>   17

        13.     CONFIDENTIALITY; PUBLICITY; PUBLICATIONS.

                13.1    During the term of this Agreement, Corixa shall [***]*.
During the term of this Agreement, Zambon shall [***]*. In addition, each party
shall provide the other party with [***]*.

                13.2    During the term of this Agreement, each party shall
[***]*.

                13.3    During the term of this Agreement and for [***]*
thereafter, irrespective of any termination earlier than the expiration of the
term of this Agreement, Corixa and Zambon shall not use or reveal or disclose to
any Third Party any confidential information received from the other party or
otherwise developed by either party in the performance of activities in
furtherance of this Agreement without first obtaining the written consent of the
disclosing party, except as may be otherwise provided herein, or [***]*. This
confidentiality obligation shall not apply to such information which is or
becomes a matter of public knowledge, or is already in the possession of the
receiving party, or is disclosed to the receiving party by a Third Party having
the right to do so, or is subsequently and independently developed by employees
of the receiving party or Affiliates thereof who had no knowledge of the
confidential information disclosed. The parties shall take reasonable measures
to assure that no unauthorized use or disclosure is made by others to whom
access to such information is granted.

                13.4    Nothing herein shall be construed as [***]*.

                13.5    All confidential information disclosed by one party to
the other shall remain the intellectual property of the disclosing party. In the
event that a court or other legal or administrative tribunal, directly or
through an appointed master, trustee or receiver, assumes partial or complete
control over the assets of a party to this Agreement based on the insolvency or
bankruptcy of such party, the bankrupt or insolvent party shall promptly notify
the court or other tribunal (i) that confidential information received from the
other party under this Agreement remains the property of the other party and
(ii) of the confidentiality obligations under this Agreement. In addition, the
bankrupt or insolvent party shall, to the extent permitted by law, take all
steps necessary or desirable to maintain the confidentiality of the other
party's confidential information and to insure that the court, other tribunal or
appointee maintains such information in confidence in accordance with the terms
of this Agreement.

                13.6    The parties to this Agreement may disclose [***]*.
Notwithstanding the foregoing, each party shall have the right to issue press
releases immediately and without prior consent of the other that disclose any
information required by the rules and regulations of the Securities and Exchange
Commission or similar federal, state or foreign authorities, as determined in
good faith by the disclosing party.

                13.7    Neither party shall publish or provide public disclosure
of information or inventions arising from the Research Program or the Clinical
Development Program (a "Dissemination") without at least [***]* prior written
notice of such planned publication or



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                                      -14-
<PAGE>   18

disclosure sent to the other party. In the event any such Dissemination is
determined by the other party to be [***]*, the disseminating party shall delay
such publication for a period sufficient, but in no event greater than an
additional [***]*, to allow the other party to take the steps necessary to
protect such intellectual property, including the filing of any patent
applications and/or deletion of the other party's confidential information.
Notwithstanding the foregoing, Corixa shall have the right to disclose
information immediately and without prior consent of Zambon if such disclosure
is required by the rules and regulations of the Securities and Exchange
Commission or similar federal or state authority, as determined in good faith by
Corixa.

        14.     GOVERNING LAW; ARBITRATION.

                This Agreement shall be governed by the laws of [***]*. Judgment
upon the award may be entered in any court having jurisdiction, or application
may be made to such court for judicial acceptance of the award and/or an order
of enforcement as the case may be.

        15.     MISCELLANEOUS.

                15.1    Trademarks. [***]*.

                15.2    Force Majeure. If the performance of any part of this
Agreement by either party, or of any obligation under this Agreement, is
prevented, restricted, interfered with or delayed by reason of any cause beyond
the reasonable control of the party liable to perform, unless conclusive
evidence to the contrary is provided, the party so affected shall, upon giving
written notice to the other party, be excused from such performance to the
extent of such prevention, restriction, interference or delay, provided that the
affected party shall use its reasonable best efforts to avoid or remove such
causes of nonperformance and shall continue performance with the utmost dispatch
whenever such causes are removed. When such circumstances arise, the parties
shall discuss what, if any, modification of the terms of this Agreement may be
required in order to arrive at an equitable solution.

                15.3    Severability.

                        15.3.1  In the event any portion of this Agreement shall
be held illegal, void or ineffective, the remaining portions hereof shall remain
in full force and effect.

                        15.3.2  If any of the terms or provisions of this
Agreement are in conflict with any applicable statute or rule of law, then such
terms or provisions shall be deemed inoperative to the extent that they may
conflict therewith and shall be deemed to be modified to conform with such
statute or rule of law.

                15.4    Entire Agreement. This Agreement and all Exhibits
hereto, entered into as of the date first written above, constitutes the entire
agreement between the parties relating to the subject matter hereof and
supersedes all previous writings and understandings except that the Confidential
Information and Non Disclosure Agreement dated [***]*, remains in full force and
effect. No terms or provisions of this Agreement shall be varied or modified by
any prior or subsequent statement, conduct or act of either of the parties,
except that the parties may mutually



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                                      -15-
<PAGE>   19

amend this Agreement by written instruments specifically referring to and
executed in the same manner as this Agreement.

        16.     NOTICES.

                16.1    Any notice required or permitted under this Agreement
shall be deemed given if delivered (i) personally, (ii) by facsimile
transmission (receipt verified), (iii) by registered or certified mail (return
receipt requested), postage prepaid, or (iv) sent by express courier service
(receipt verified), to the following addresses of the parties:


                  If to Corixa:
                         Corixa Corporation
                         1124 Columbia Street, Suite 200
                         Seattle, WA  98104-2040
                         Attention: Chief Operating Officer
                             with a copy to Director of Legal Affairs
                         Telephone: (206) 754-5717
                         Telecopy: (206) 754-5762

                  with a copy to:

                         Venture Law Group
                         4750 Carillon Point
                         Kirkland, Washington 98033
                         Attention: William W. Ericson
                         Telephone: (425) 739-8700
                         Telecopy: (425) 739-8750

                  If to Inpharzam:

                         Inpharzam, S.A.
                         Via Industria 1
                         6814 Cadempino
                         Switzerland
                         Attention:  Managing Director
                         Telecopy:  011-419-196-643-51

                  with a copy to:

                         Zambon Group spa
                         Via Lillo del Duca, 10
                         20091 Bresso
                         Milan, Italy
                         Attention:  Managing Director
                         Telecopy: 011-39-02-66501-492




                                      -16-
<PAGE>   20

                16.2    Any notice required or permitted to be given concerning
this Agreement shall be effective upon receipt by the party to whom it is
addressed. Any notice required or permitted to be given to Corixa concerning
this Agreement shall be effective even if Venture Law Group was not provided a
copy of such notice.



                                      -17-
<PAGE>   21

        17.     ASSIGNMENT.

                Neither this Agreement nor any interest hereunder shall be
assignable by either party without the written consent of the other; provided,
however, [***]*. Transfer in contravention of this Section 17 shall be
considered a material breach of this Agreement pursuant to Section 19.6 below.
Subject to other provisions of this Section 17, this Agreement and the licenses
herein granted shall be binding upon and inure to the benefit of the successors
in interest of the respective parties.

        18.     WARRANTIES AND REPRESENTATIONS.

                18.1    Each party warrants that it has the right to enter into
this Agreement.

                18.2    To the best of Corixa's knowledge as of the date hereof,
[***]*.

                18.3    The parties warrant to one another that neither of them
has any present knowledge of [***]*.

                18.4    Zambon acknowledges that the licenses granted to Zambon
herein include sublicenses under technology that has been licensed by Corixa
from certain Third Parties pursuant to the Third Party Agreements, and Zambon
warrants and represents that it shall comply with all applicable terms and
conditions of the Third Party Agreements, provided that [***]*.

                18.5    Commencing at the time of Zambon's [***]* Product or
Therapeutic Drug Monitoring Product, Zambon shall maintain product liability
insurance with respect to its development, manufacture, if any, and sale of the
Products or Therapeutic Drug Monitoring Products as follows:

                (a)     Workers' Compensation as required by applicable
statutes; (b) Employer's Liability insurance in the amount of $[***]*; (c)
Commercial General Liability (including without limitation, products,
contractual, fire, legal and personal injury) in the amount of $[***]* combined
single limits for bodily injury and property damage; (d) Umbrella liability in
the amount of $[***]*. Zambon shall maintain such insurance for so long as it
continues to develop, manufacture or sell any Product or Therapeutic Drug
Monitoring Product, and thereafter for so long as Zambon maintains insurance for
itself covering such manufacture or sales. Zambon's general liability insurance
shall name Corixa as an additional insured.

                18.6    Zambon agrees it shall [***]*.

                18.7    LIMITED LIABILITY. NOTWITHSTANDING ANYTHING ELSE IN THIS
AGREEMENT OR OTHERWISE, NEITHER CORIXA NOR ZAMBON WILL BE LIABLE WITH RESPECT TO
ANY SUBJECT MATTER OF THIS AGREEMENT UNDER ANY CONTRACT, NEGLIGENCE, STRICT
LIABILITY OR OTHER LEGAL OR EQUITABLE THEORY FOR (i) ANY INCIDENTAL OR
CONSEQUENTIAL DAMAGES OR LOST PROFITS OR (ii) COST OF PROCUREMENT OF SUBSTITUTE
GOODS,



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                                      -18-
<PAGE>   22

TECHNOLOGY OR SERVICES. NEITHER CORIXA NOR ZAMBON SHALL HAVE ANY LIABILITY FOR
ANY FAILURE OR DELAY DUE TO MATTERS BEYOND THEIR RESPECTIVE REASONABLE CONTROL.

        19.     TERM AND TERMINATION.

                19.1    This Agreement may not be terminated by either party
except in accordance with this Section 19.

                19.2    Unless otherwise terminated, this Agreement shall expire
upon [***]*.

                19.3    If [***]*.

                19.4    In the event [***]*.

                19.5    If [***]*.

                19.6    If either party materially breaches the material
provisions of this Agreement and if such breach is not cured within [***]* (or
in the case of non-payment pursuant to Section 6 or 7, [***]*) after receiving
written notice from the other party with respect to such breach, the
non-breaching party shall have the right to terminate this Agreement by giving
written notice to the party in breach provided the notice of termination is
given within [***]*. The parties acknowledge that any termination of this
Agreement pursuant to this Section 19.6 will include the termination of all
licenses granted by either party to the other hereunder.

                19.7    Either party may terminate this Agreement if, at any
time, the other party shall file in any court or agency pursuant to any statute
or regulation of the United States or of any individual state or foreign
country, a petition in bankruptcy or insolvency or for reorganization or for an
arrangement or for the appointment of a receiver of trustee of the party or of
its assets, or if the other party proposes a written agreement of composition or
extension of its debts, or if the other party shall be served with an
involuntary petition against it, filed in any insolvency proceeding, and such
petition shall not be dismissed with sixty (60) days after the filing thereof,
or if the other party shall propose or be a party to any dissolution or
liquidation, or if the other party shall make an assignment for the benefit of
creditors.

                19.8    Notwithstanding the bankruptcy of Corixa, or the
impairment of performance by Corixa of its obligations under this Agreement as a
result of bankruptcy or insolvency of Corixa, Zambon shall [***]*.

        20.     RIGHTS AND DUTIES UPON TERMINATION.

                20.1    Upon termination of this Agreement, Corixa shall have
the right to retain any sums already paid by Zambon hereunder, and Zambon shall
pay all sums accrued hereunder which are then due, which, in each case, shall
include all payments under Sections 6 and 7 except



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                                      -19-
<PAGE>   23

to the extent such payments may be considered and reviewed by the arbitrator(s)
pursuant to Section 14 hereof.

                20.2    Upon termination of this Agreement, Zambon shall notify
Corixa of the amount of Product(s) and Therapeutic Drug Monitoring Product(s)
Zambon and its Affiliates, sublicensees and distributors then have on hand, the
sale of which would, but for the termination, be subject to royalty, and Zambon
and its Affiliates, sublicensees and distributors shall thereupon be permitted
to sell that amount of Product(s) and Therapeutic Drug Monitoring Product(s),
provided that Zambon shall pay to Corixa the amounts payable thereon at the time
herein provided for.

                20.3.   Expiration or early termination of this Agreement shall
not relieve either party of its obligations incurred prior to such expiration or
early termination. In addition, Sections 8.2, 8.3, 8.4, 11, 12.3, 12.5 through
12.7, 13 through 15, 18, 20 and 21 shall survive any expiration or early
termination of this Agreement.

        21.     INDEMNIFICATION.

                21.1    Subject to Section 21.2 hereof, from and after the
Effective Date, except as otherwise herein specifically provided, each of the
parties hereto shall defend, indemnify and hold harmless the other party and its
Affiliates, successors and assigns, and their respective officers, directors,
shareholders, partners and employees from and against [***]*.

                21.2    If either Zambon or Corixa, or any Affiliate of Zambon
or Corixa (in each case an "Indemnified Party"), receives any written claim
which it believes is the subject of indemnity hereunder by either Corixa or
Zambon, as the case may be (in each case an "Indemnifying Party"), the
Indemnified Party shall, as soon as reasonably practicable after forming such
belief, give notice thereof to the Indemnifying Party, including full
particulars of such claim to the extent known to the Indemnified Party;
provided, however, that the failure to give timely notice to the Indemnifying
Party as contemplated hereby shall not release the Indemnifying Party from any
liability to the Indemnified Party. The Indemnifying Party shall have the right,
by prompt notice to the Indemnified Party, to assume the defense of such claim
with counsel reasonably satisfactory to the Indemnified Party, and at the cost
of the Indemnifying Party. If the Indemnifying Party does not so assume the
defense of such claim, the Indemnified Party may assume such defense with
counsel of its choice at the sole expense of the Indemnifying Party. If the
Indemnifying Party so assumes such defense, the Indemnified Party may
participate therein through counsel of its choice, but the cost of such counsel
shall be borne solely by the Indemnified Party.

                21.3    The party not assuming the defense of any such claim
shall render all reasonable assistance to the party assuming such defense, and
all out-of-pocket costs of such assistance shall be borne solely by the
Indemnifying Party.



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                                      -20-
<PAGE>   24

                21.4    No such claim shall be settled other than by the party
defending the same, and then only with the consent of the other party, which
shall not be unreasonably withheld; provided, however, that the Indemnified
Party shall have no obligation to consent to any settlement of any such claim
which imposes on the Indemnified Party any liability or obligation which cannot
be assumed and performed in full by the Indemnifying Party.



                            [Signature page follows]



                                      -21-
<PAGE>   25

        IN WITNESS WHEREOF, each of the parties hereto has caused this Agreement
to be executed by its duly authorized officer as of the date first written
above.


Agreed to and accepted by:              Agreed to and accepted by:



CORIXA CORPORATION                      INPHARZAM INTERNATIONAL, S.A.



--------------------------------        ----------------------------------------
Mark McDade                             Andrea Zambon, M.D.
President and COO                       Title:



<PAGE>   26

                      EXHIBIT A TO COLLABORATION AGREEMENT


                   Corixa Research and Discovery Methodologies





[***]*




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<PAGE>   27

                     EXHIBIT A-1 TO COLLABORATION AGREEMENT


                                 Corixa Patents


<TABLE>
<CAPTION>
------------------------------- ----------------------------- ----------------------------
                                                              Filing Date
Patent App. No.                 Country                       (Month/Day/Year)
------------------------------- ----------------------------- ----------------------------
<S>                        <C>                      <C>
[***]*                     [***]*                   [***]*
------------------------------- ----------------------------- ----------------------------
</TABLE>



                                     [***]*



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<PAGE>   28

                     EXHIBIT A-2 TO COLLABORATION AGREEMENT


                             Corixa Adjuvant Patents


<TABLE>
<CAPTION>
------------------------------- ----------------------------- ----------------------------
Patent App. No./Patent No.      Country                       Filing Date/Issue Date
------------------------------- ----------------------------- ----------------------------
<S>                        <C>                      <C>
[***]*                     [***]*                   [***]*
------------------------------- ----------------------------- ----------------------------
</TABLE>



[***]*



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<PAGE>   29


                     EXHIBIT A-3 TO COLLABORATION AGREEMENT

                               Microsphere Patents


<TABLE>
<CAPTION>
------------------------------- ----------------------------- ----------------------------
Patent App. No.                 Country                       Filing Date
------------------------------- ----------------------------- ----------------------------
<S>                             <C>                      <C>
[***]*                          [***]*                   [***]*
------------------------------- ----------------------------- ----------------------------
</TABLE>


[***]*


<TABLE>
<CAPTION>
--------------------- ------------------ -------------------- ------------- --------------
Patent App. No.       Patent No.         Country              Filing Date   Issue Date
--------------------- ------------------ -------------------- ------------- --------------
<S>                   <C>                <C>                  <C>           <C>
[***]*                [***]*             [***]*               [***]*        [***]*
--------------------- ------------------ -------------------- ------------- --------------
</TABLE>


[***]*


<TABLE>
<CAPTION>
--------------------- ------------------ -------------------- ------------- --------------
Patent App. No.       Patent No.         Country              Filing Date   Issue Date
--------------------- ------------------ -------------------- ------------- --------------
<S>                   <C>                <C>                  <C>           <C>
[***]*                [***]*             [***]*               [***]*        [***]*
--------------------- ------------------ -------------------- ------------- --------------
</TABLE>


[***]*


<TABLE>
<CAPTION>
--------------------- ------------------ -------------------- ------------- --------------
Patent App. No.       Patent No.         Country              Filing Date   Issue Date
--------------------- ------------------ -------------------- ------------- --------------
<S>                   <C>                <C>                  <C>           <C>
[***]*                [***]*             [***]*               [***]*        [***]*
--------------------- ------------------ -------------------- ------------- --------------
</TABLE>


[***]*


<TABLE>
<CAPTION>
------------------------------- ----------------------------- ----------------------------
Patent App. No.                 Country                       Filing Date
------------------------------- ----------------------------- ----------------------------
<S>                             <C>                           <C>
[***]*                          [***]*                        [***]*
------------------------------- ----------------------------- ----------------------------
</TABLE>


[***]*



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<PAGE>   30

                      EXHIBIT B TO COLLABORATION AGREEMENT


                                Research Program



[***]*



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<PAGE>   31

                      EXHIBIT C TO COLLABORATION AGREEMENT


                         List of Third Party Agreements

1.      Licensing Agreement, effective as of [***]* between Corixa and [***]*,
a copy of which is attached to this Exhibit C and incorporated herein by
reference. Pursuant to the terms of the foregoing, the parties hereto
acknowledge that Corixa's license thereunder shall remain exclusive for the life
of the last to expire issued patent licensed to Corixa thereunder.

2.      License Agreement, made and entered into as of [***]*, by and among
[***]* and Corixa, as amended [***]*.




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<PAGE>   32

                      EXHIBIT D TO COLLABORATION AGREEMENT


                            Stock Purchase Agreement





                               CORIXA CORPORATION

                         COMMON STOCK PURCHASE AGREEMENT

                                 EFFECTIVE AS OF

                                  MAY 21, 1999




<PAGE>   33

                      EXHIBIT E TO COLLABORATION AGREEMENT


                              Net Sales Definition

"Net Sales" shall mean [***]* to a Third Party of a product, less the following
deductions for amounts actually incurred related to the sale or other
disposition:


[***]*



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<PAGE>   34
                      EXHIBIT F TO COLLABORATION AGREEMENT


                            Form of Supply Agreement

                                SUPPLY AGREEMENT


        This Supply Agreement (this "Agreement") is made as of _______ (the
"Effective Date") by and between Inpharzam International, S.A., a corporation
organized and existing under the laws of Switzerland and a wholly-owned
subsidiary of Zambon Group spa ("Zambon") and Corixa Corporation, a Delaware
corporation ("Corixa").

                                    RECITALS

        A. Zambon and Corixa have entered into a Collaboration Agreement dated
as of May 21, 1999 (the "Collaboration Agreement"), pursuant to which Corixa
licensed to Zambon certain of its intellectual property rights related to the
development of vaccine products for the treatment of lung cancer.

        B. In connection with, and in accordance with the terms and conditions
of Section 10.1 of, the Collaboration Agreement, Corixa is willing to supply to
Zambon, and Zambon agrees to purchase from Corixa upon the terms and subject to
the conditions set forth in this Agreement, certain [***]*.

        NOW THEREFORE, in consideration of the premises and the mutual covenants
herein set forth, the receipt and sufficiency of which are hereby acknowledged,
the parties hereto agree as follows:

        1. DEFINITIONS.

        Capitalized terms used herein shall have the respective meanings set
forth in the Collaboration Agreement unless otherwise defined herein.

               1.1 "Commercialization Materials" shall mean those Materials that
are required by governmental law or regulation to be manufactured in accordance
with Good Manufacturing Practices.

               1.2 "FDA" shall mean the U.S. Food and Drug Administration or any
successor agency thereof.

               1.3 "Fully Burdened Manufacturing Cost" shall mean [***]*.

               1.4 "Materials" shall mean [***]*, set forth on Exhibit A
attached hereto, as amended from time to time upon mutual agreement of the
parties.

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<PAGE>   35
               1.5 "Specifications" means written specifications related to the
manufacture of the Materials that will be developed pursuant to Section 3.1 and
shall be attached hereto and made a part hereof as Exhibit B.

               1.6 Singular and Plural. Where the context hereto requires, the
singular number shall be deemed to include the plural and vice versa.

        2. PRODUCT SUPPLY.

               2.1 Purchase and Sale. Upon the terms and subject to the
conditions of this Agreement, Corixa shall sell and supply to Zambon all of its
reasonable requirements of the Materials, in accordance with Section 2.2. Zambon
agrees, for itself, its Affiliates and sublicensees, to satisfy solely through
Zambon's purchase of the Materials under this Agreement one hundred percent
(100%) of Zambon's, its Affiliates' and sublicensees' reasonable requirements of
the Materials ("Requirements"). The parties agree that Corixa shall have the
right in connection with the supply of Materials hereunder to contract with
respect to manufacture of the Materials with such third parties as Corixa deems
advisable; provided, however, that Corixa shall remain fully responsible for all
of its obligations hereunder.

               2.2 Purchase Price, Price Adjustments and Payment.

                      (a) For Materials supplied by Corixa to Zambon pursuant to
this Agreement, Zambon shall pay a purchase price equal to [***]* (the "Purchase
Price"). Corixa agrees to [***]* allow representatives of Zambon to audit
Corixa's accounting records pertaining to the manufacture of the Materials once
per year. Zambon agrees that all information relating to accounting records
pertaining to the manufacture of Materials shall be treated as confidential
information under Section 13 of the Collaboration Agreement and for purposes of
Section 10 hereof. [***]*.

                      (b) Corixa shall invoice Zambon [***]*. Zambon shall pay
such invoice [***]* receipt of the invoice.

               2.3 Forecast and Orders.

                      (a) Within [***]* of the Effective Date (or such other
date as may be agreed upon by the parties), and at least every [***]*
thereafter, Zambon shall furnish to Corixa a rolling [***]* forecast for the
quantities of Materials that Zambon intends to order during the [***]* period
commencing [***]* from the date of such forecast. Prior to the Commercialization
Period, such forecast shall be [***]*. Following the Commercialization Period,
the first [***]* of such forecast shall constitute a binding commitment upon
Zambon to purchase such quantities as evidenced by purchase orders received from
Zambon in accordance with Section 2.3(b). The balance of such forecast shall
merely represent [***]*.

                      (b) Zambon shall place each purchase order with Corixa for
Materials to be delivered hereunder at least [***]* prior to the delivery date
specified in each respective

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<PAGE>   36
order. Corixa hereby [***]* delivery from the receipt of each firm purchase
order and shall accept such firm purchase orders placed by Zambon within [***]*
of receipt for that amount of Materials which is within [***]* of the then
current forecast for the applicable period. For orders of Materials that exceed
[***]* of the then current forecast for the applicable period, Corixa shall
[***]* delivery date. If Corixa is unable to deliver on the specified date,
Corixa may decline to provide that amount of Materials which [***]* of the most
current forecast underlying such order, provided that such purchase order is
declined in writing and is delivered to Zambon within [***]* of Corixa's receipt
of the order. Corixa shall deliver against each firm purchase order accepted by
Corixa in accordance with Section 2.4. Zambon shall be obligated to purchase all
Materials ordered and delivered by the delivery date, unless such Materials are
rejected pursuant to Section 4.1. The terms and conditions of this Agreement
shall control as to a particular purchase order unless otherwise agreed to in
writing by the parties.

               2.4 Delivery. Delivery terms shall be F.O.B. Corixa's
manufacturing facility in Seattle, Washington, or such other facility as may be
designated by Corixa. Corixa shall [***]* to assist Zambon in arranging any
desired insurance (in amounts that Zambon shall determine) and transportation,
via air freight unless otherwise specified in writing, to any destinations
specified in writing from time to time by Zambon. All customs, duties, costs,
taxes, insurance premiums, and other expenses relating to such transportation
and delivery, shall be at Zambon's sole expense. Corixa shall ship Materials
under appropriate storage conditions and in reasonable accordance with Zambon's
purchase order form and pursuant to Corixa's purchase terms and conditions then
in effect. Any cost of compliance with such storage conditions shall be added to
the calculation of Fully Burdened Manufacturing Cost.

               2.5 Safety Stock. After the Commercialization Period, Corixa
shall maintain a fresh safety stock of Materials, equivalent to the forecasted
purchases for the most recent [***]* period, [***]*. Deliveries by Corixa to
Zambon may be taken from Corixa's inventory identified as safety stock. Corixa's
safety stock shall be rotated with its regular inventory of Materials to
maintain a reasonable shelf-life. Corixa shall keep Zambon reasonably informed
of the level of inventory identified as the safety stock. In the event of any
termination of this Agreement, Zambon will be obligated to purchase the unsold
portion of such safety stock from Corixa, to the extent the quantity on
termination is equal to or less than the most recent [***]* forecast provided by
Zambon.

               2.6 Payment Instructions.

               All payments due hereunder shall be made in U.S. dollars by (a)
check payable to Corixa Corporation or (b) wire transfer of immediately
available funds to the following account:


<TABLE>
<S>                                 <C>
                      Account No.   1131907
                      Bank:         Commerce Bank of Washington
                      ABA Code:     125008013
</TABLE>


or to such other account as Corixa may designate from time to time.


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<PAGE>   37
               2.7 Past Due Amounts. Any past due payments under this Agreement
shall accrue interest until paid at [***]* per annum, or the maximum rate
permitted by law, whichever is less.

               2.8 Foreign Currency. Currency conversions to U.S. Dollars, if
any, shall be calculated using an average rate of exchange, which rate of
exchange shall be computed by adding the rate of exchange quoted under Foreign
Exchange in The Wall Street Journal as of the end of the current month to the
rate as of the end of the prior month and dividing by two (2).

        3. PRODUCT MANUFACTURE.

               3.1 Incoming Specifications. The parties will in good faith
cooperate with one another to develop the Specifications, which shall be
acceptable to both parties. The Specifications shall be agreed upon in writing
and shall be attached hereto and incorporated into this Agreement as Exhibit B,
and may be amended from time to time by mutual written agreement of the parties.
The Specifications shall be considered confidential information pursuant to
Section 13 of the Collaboration Agreement and for the purposes of Section 10
hereof.

               3.2 Manufacturing Process.

                      (a) During the Commercialization Period, Corixa shall
manufacture the Commercialization Materials in accordance in all material
respects with "Good Manufacturing Practices" and the Specifications.

                      (b) Corixa shall not [***]* modify the processes or
materials used in the manufacturing process without the prior approval of
Zambon.

               3.3 Testing of Materials. Corixa shall test or cause to be tested
each batch of Materials manufactured pursuant to this Agreement before delivery
to Zambon. Each test shall set forth the Specifications, the items tested and
test results in a certificate of analysis for each batch delivered. Corixa shall
send or cause to be sent such certificates to Zambon along with delivery of
Materials.

        4. QUALITY ASSURANCE AND INSPECTION.

               4.1 Rejected Goods/Shortages.

                      (a) Zambon shall notify Corixa in writing of any claim
that any Materials do not conform to the Specifications or any shortage in
quantity of any shipment of Materials within [***]* of receipt of such shipment.
Upon confirming any such nonconformance or shortage, Corixa shall replace the
Materials or make up the shortage within [***]* of receiving such notice,
[***]*, and shall make arrangements with Zambon for the return or destruction of
any rejected Materials, with any reasonable return shipping charges or costs of
destruction to be paid by Corixa.


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<PAGE>   38
                      (b) In the event of a conflict regarding any nonconforming
Materials which Corixa and Zambon are unable to resolve, a sample of such
Materials, together with mutually agreed upon questions, shall be submitted by
Zambon to an independent laboratory reasonably acceptable to both parties for
testing against the Specifications, and the test results obtained by such
laboratory shall be final and binding upon the parties. The test results shall
be considered confidential information pursuant to Section 13 of the
Collaboration Agreement and for purposes of Section 10 hereof. The fees and
expenses of such laboratory testing shall be borne entirely by the party against
whom such laboratory's findings are made. In the event the test results indicate
that the Materials in question do not conform to the Specifications, Corixa
shall replace such Materials with conforming [***]*.

               4.2 Regulatory.

                      (a) In the event that regulatory certification is required
by the applicable regulatory authority in Territory A or Territory B for
Materials, Corixa will ensure that such certification is met, [***]* .

                      (b) Each party shall keep the other informed of any formal
or informal inquiry by any regulatory agency of any state or national government
or supranational authority relating to either Materials used or sold hereunder.

                      (c) Upon reasonable prior notice at least [***]* days,
Corixa shall permit representatives of any regulatory agency having jurisdiction
over the manufacture and/or marketing of the Materials or of any diagnostic
assay or other product in which the Materials are incorporated, to inspect its
facilities in conjunction with the manufacture, testing, packaging, storage,
handling and shipping of the Materials. Further, Corixa shall advise Zambon
immediately if Corixa receives notice of an impending inspection or if an
authorized agent of the FDA or other governmental agency visits any of Corixa's
manufacturing facilities concerning the Materials. [***]*.

               4.3 Inspection by Zambon. Notwithstanding Corixa's obligation to
provide the certificate set forth in Section 3.3, Corixa shall permit Zambon
upon reasonable prior notice, but not less than [***]* days, and during regular
business hours, but no more often than [***]* or as otherwise mutually agreed by
the parties, access to (a) those areas of Corixa's manufacturing facilities
where the Materials are manufactured, tested, packaged, stored, handled and
shipped, and (b) the manufacturing records for the Materials manufactured for
Zambon.

        5. FAILURE TO SUPPLY.

               5.1 Failure. In the event that Corixa notifies Zambon that it is
unable, for any reason beyond Corixa's control (including an event of force
majeure) to supply quantities of Materials in accordance with Section 2.3 for a
period of [***]* beyond the delivery date for such Materials, Zambon may at its
discretion (a) require Corixa to supply the undelivered Materials at a future
date agreed upon by the parties; or (b) manufacture or have manufactured by a
Third Party designated by Zambon that quantity of the Materials required by
Zambon which Corixa is unable


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<PAGE>   39
to supply. If Zambon determines to manufacture or have manufactured by a Third
Party such Materials, Corixa will give Zambon and/or any such Third Party all
reasonably necessary information and cooperation to enable Zambon or such Third
Party to manufacture the Materials in accordance with the Specifications.

               5.2 Supply Resumption. Corixa will have [***]* from the original
delivery date of any Materials in which Corixa fails to supply to Zambon, as set
forth in Section 5.1, in which to resume supply of the Materials to Zambon;
provided, however, such [***]* limitation shall not apply to a failure by Corixa
to supply that results from a force majeure event as set forth in Section 12.7.
At the time that Corixa resumes supply of the Materials, Zambon will cease
manufacture of the Materials or have the Third Party cease such manufacture in a
reasonable time and manner, and shall purchase Materials exclusively from Corixa
upon the terms and subject to the conditions of this Agreement.

        6. TERM/TERMINATION.

               6.1 Term and Expiration.

                      (a) The initial term of this Agreement shall expire upon
the expiration or termination of the Collaboration Agreement, unless earlier
termination by mutual agreement of the parties.

                      (b) [***]*.

               6.2 Termination With Cause. Upon any material breach of this
Agreement by either party, the non-breaching party may terminate this Agreement
upon [***]* written notice to the breaching party. The notice shall become
effective at the end of such [***]*period unless the breaching party shall have
cured such breach within such period.

               6.3 Termination for Insolvency. Either party may terminate this
Agreement upon written notice to the other in the event of (a) insolvency of the
other party, or the appointment of a receiver by the other party for all or any
substantial part of its properties, provided that such receiver is not
discharged within sixty (60) days of its appointment, (b) the adjudication of
the other party as a bankrupt, (c) the admission by the other party in writing
of its inability to pay its debts as they become due, (d) the execution by the
other party of an assignment for the benefit of its creditors or (e) the filing
by the other party of a petition to be adjudged as a bankrupt, or a petition or
answer admitting the material allegations of a petition filed against the other
party in any bankruptcy proceeding, or the acts of the other party to any other
judicial proceeding intended to effect a discharge of the debts of the other
party, in whole or in part.

               6.4 Consequences of Expiration or Early Termination. Upon the
expiration or termination of this Agreement:

                      (a) Each party shall return or destroy, and certify to
such destruction of, all confidential information of the other party provided or
obtained pursuant to this


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<PAGE>   40
Agreement, except that each party may maintain one (1) copy for archival
purposes solely to confirm compliance with the provisions of Section 10 hereof;

                      (b) Zambon shall purchase the safety stock inventory held
by Corixa in accordance with Section 2.5; and

                      (c) [***]*.

               6.5 Inclusive Remedy. Except as otherwise provided in this
Agreement, each party shall have the rights and remedies set forth herein in
addition to any other remedies which it may have under applicable statutory or
common law. Each party shall have the sole discretion to determine which of its
rights and remedies, if any, it shall pursue and such party shall not be
required to exhaust any of its other rights or remedies before pursuing any one
of the rights and remedies set forth in this Agreement.

               6.6 Survival. Expiration or early termination of this Agreement
shall not relieve either party of its obligations incurred prior to expiration
or early termination. The obligations under Sections 4, 6.4, 6.5, 6.6 and 7-12
shall survive any expiration or termination of this Agreement. Further, Zambon
shall make all payments as are required for the final quarter of the
effectiveness of this Agreement.

        7. REPRESENTATIONS AND WARRANTIES.

               7.1 By Corixa. Corixa represents and warrants to Zambon that:

                      (a) it has full right to enter into and perform Corixa's
obligations under this Agreement and to supply the Materials; and

                      (b) the execution, delivery, and performance of this
Agreement does not conflict with, violate or breach any agreement to which
Corixa is a party.

               7.2 By Zambon. Zambon represents and warrants to Corixa that:

                      (a) it has the full right to enter into and perform
Zambon's obligations under this Agreement; and

                      (b) the execution, delivery and performance of this
Agreement does not conflict with, violate or breach any agreement to which
Zambon is a party.

               7.3 Extent of Warranties. EXCEPT AS SPECIFICALLY PROVIDED IN THIS
AGREEMENT, THE MATERIALS ARE SUPPLIED "AS IS" AND CORIXA HEREBY DISCLAIMS ANY
AND ALL REPRESENTATIONS AND WARRANTIES OF ANY KIND WITH REGARD TO THE MATERIALS,
WHETHER EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR


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<PAGE>   41
FITNESS FOR A PARTICULAR PURPOSE OR USE, AND ANY OTHER STATUTORY WARRANTIES OR
ANY WARRANTY OF PATENTABILITY OR NONINFRINGEMENT.

        8. INDEMNIFICATION.

               8.1 Damages. Subject to Section 8.2 hereof, from and after the
Effective Date, except as otherwise herein specifically provided, each of the
parties hereto shall defend, indemnify and hold harmless the other party and its
Affiliates, successors and assigns, and their respective officers, directors,
shareholders, partners and employees from and against all losses, damage,
liability and expense including legal fees but excluding punitive or
consequential damages (including lost profits) ("Damages") incurred thereby or
caused thereto arising out of or relating to (a) [***]*.

               8.2 Notice of Claim. If either Zambon or Corixa, or any Affiliate
of Zambon or Corixa (in each case an "Indemnified Party"), receives any written
claim which it believes is the subject of indemnity hereunder by either Corixa
or Zambon, as the case may be (in each case an "Indemnifying Party"), the
Indemnified Party shall, as soon as reasonably practicable after forming such
belief, give notice thereof to the Indemnifying Party, including full
particulars of such claim to the extent known to the Indemnified Party;
provided, however, that the failure to give timely notice to the Indemnifying
Party as contemplated hereby shall not release the Indemnifying Party from any
liability to the Indemnified Party. The Indemnifying Party shall have the right,
by prompt notice to the Indemnified Party, to assume the defense of such claim
with counsel reasonably satisfactory to the Indemnified Party, and at the cost
of the Indemnifying Party. If the Indemnifying Party does not so assume the
defense of such claim, the Indemnified Party may assume such defense with
counsel of its choice at the sole expense of the Indemnifying Party. If the
Indemnifying Party so assumes such defense, the Indemnified Party may
participate therein through counsel of its choice, but the cost of such counsel
shall be borne solely by the Indemnified Party.

               8.3 Assistance; Costs. The party not assuming the defense of any
such claim shall render any reasonable assistance that may be requested by the
party assuming such defense, and all out-of-pocket costs of such assistance
shall be borne solely by the Indemnifying Party.

               8.4 Settlement. No such claim shall be settled other than by the
party defending the same, and then only with the consent of the other party,
which shall not be unreasonably withheld; provided, however, that the
Indemnified Party shall have no obligation to consent to any settlement of any
such claim which imposes on the Indemnified Party any liability or obligation
which cannot be assumed and performed in full by the Indemnifying Party.


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<PAGE>   42
        9. LIMITATION OF LIABILITY.

               IN NO EVENT WILL EITHER PARTY HERETO BE LIABLE FOR ANY SPECIAL,
INCIDENTAL, CONSEQUENTIAL OR INDIRECT DAMAGES SUFFERED BY THE OTHER PARTY
ARISING IN ANY WAY OUT OF THIS AGREEMENT, HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY. THIS LIMITATION WILL APPLY EVEN IF THE PARTY HAS BEEN ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE. IN NO EVENT SHALL THE LIABILITY OF CORIXA TO ZAMBON
UNDER ANY PROVISION OF THIS AGREEMENT EXCEED THE AMOUNTS ACTUALLY RECEIVED BY
CORIXA FROM ZAMBON HEREUNDER.

        10. CONFIDENTIALITY; PUBLICITY; PUBLICATIONS.

               10.1 Confidential Information. During the term of this Agreement
and for [***]* thereafter, irrespective of any termination earlier than the
expiration of the term of this Agreement, Corixa and Zambon shall not use or
reveal or disclose to any Third Party any confidential information received from
the other party or otherwise developed by either party in the performance of
activities in furtherance of this Agreement without first obtaining the written
consent of the disclosing party, except as may be otherwise provided herein, or
as may be required for purposes of [***]*. This confidentiality obligation shall
not apply to such information which is or becomes a matter of public knowledge,
or is already in the possession of the receiving party, or is disclosed to the
receiving party by a Third Party having the right to do so, or is subsequently
and independently developed by employees of the receiving party or Affiliates
thereof who had no knowledge of the confidential information disclosed. The
parties shall take reasonable measures to assure that no unauthorized use or
disclosure is made by others to whom access to such information is granted.

               10.2 Permitted Disclosure. Nothing herein shall be construed as
preventing Zambon from disclosing any information received from Corixa to
[***]*.

               10.3 Intellectual Property; Bankruptcy. All confidential
information disclosed by one party to the other shall remain the intellectual
property of the disclosing party. In the event that a court or other legal or
administrative tribunal, directly or through an appointed master, trustee or
receiver, assumes partial or complete control over the assets of a party to this
Agreement based on the insolvency or bankruptcy of such party, the bankrupt or
insolvent party shall promptly notify the court or other tribunal (a) that
confidential information received from the other party under this Agreement
remains the property of the other party and (b) of the confidentiality
obligations under this Agreement. In addition, the bankrupt or insolvent party
shall, to the extent permitted by law, take all steps necessary or desirable to
maintain the confidentiality of the other party's confidential information and
to ensure that the court, other tribunal or appointee maintains such information
in confidence in accordance with the terms of this Agreement.


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<PAGE>   43
               10.4 Press Release. The parties to this Agreement may disclose
the nature and general terms of the Agreement in a press release following the
Effective Date with the prior approval of such release by the other party, which
approval shall not be unreasonably withheld. Notwithstanding the foregoing,
Corixa shall have the right to issue press releases or other announcements
immediately and without prior consent of Zambon that disclose any information
required by the rules and regulations of the Securities and Exchange Commission
or similar federal or state authority, as determined in good faith by Corixa.

               10.5 Publicity. Neither party shall publish or provide public
disclosure of information or inventions arising from the Research Program or the
Clinical Development Program or the manufacture of Materials pursuant to this
Agreement (a "Dissemination") without at least [***]* days prior written notice
of such planned publication or disclosure sent to the other party. In the event
any such Dissemination is determined by the other party to be [***]*, the
disseminating party shall delay such publication for a period sufficient to
allow the other party to take the steps necessary to protect such intellectual
property, including the filing of any patent applications and/or deletion of the
other party's confidential information. Notwithstanding the foregoing, Corixa
shall have the right to issue disclose information immediately and without prior
consent of Zambon to the extent that such disclosure is required by the rules
and regulations of the Securities and Exchange Commission or similar federal or
state authority, as determined in good faith by Corixa.

        11. GOVERNING LAW; ARBITRATION.

               This Agreement shall be governed by the laws of [***]*. Prior to
engaging in any formal dispute resolution with respect to any dispute,
controversy or claim arising out of or in relation to this Agreement or the
breach, termination or invalidity thereof (each, a "Dispute"), the Chief
Executive Officers of the respective parties shall attempt for a period not less
than sixty (60) days to resolve such Dispute. Any dispute, controversy or claim
arising out of or in relation to this Agreement or the breach, termination or
invalidity thereof, that cannot be settled amicably by agreement of the parties
pursuant to the preceding sentence, shall be finally settled by arbitration in
[***]*, in accordance with the international arbitration rules of the [***]*,
then in force, by one or more arbitrators appointed in accordance with said
rules, provided that the appointed arbitrators shall have appropriate experience
in the biopharmaceutical industry; provided, however, that arbitration
proceedings may not be instituted until the party alleging breach of this
Agreement by the other party has given the other party not less than sixty (60)
days notice (or, in the event of any alleged failure to make payments due
hereunder, not less than fourteen (14) days notice) to remedy any alleged breach
and the other party has failed to do so. The award rendered shall be final and
binding upon both parties. The judgment rendered by the arbitrator(s) shall
include costs of arbitration, reasonable attorneys' fees and reasonable costs
for any expert and other witnesses. Nothing in this Agreement shall be deemed as
preventing either party from seeking injunctive relief (or any other provisional
remedy) from any court having jurisdiction over the parties and the subject
matter of the dispute as necessary to protect either party's name, proprietary
information, trade secrets, know-how or any other proprietary rights. Judgment
upon


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<PAGE>   44
the award may be entered in any court having jurisdiction, or application may be
made to such court for judicial acceptance of the award and/or an order of
enforcement as the case may be.

        12. GENERAL PROVISIONS.

               12.1 Independent Contractors. Corixa and Zambon shall be
independent contractors and shall not be deemed to be partners, joint venturers
or each other's agents, and neither party shall have the right to act on behalf
of the other except as is expressly set forth in this Agreement.

               12.2 Entire Agreement. This Agreement, including all appendices
hereto, together with the Collaboration Agreement, including all appendices
thereto, sets forth the entire agreement and understanding between the parties
and supersedes all previous agreements, promises, representations,
understandings, and negotiations, whether written or oral between the parties
with respect to the subject matter hereof. There shall be no amendments or
modifications to this Agreement, except by a written document signed by both
parties.

               12.3 Assignment. Neither this Agreement nor any interest
hereunder shall be assignable by either party without the written consent of the
other; [***]*. Transfer in contravention of this Section 12.3 shall be
considered a material breach of this Agreement. This Agreement shall be binding
upon and inure to the benefit of the successors in interest of the respective
parties.

               12.4 Unenforceable Provisions. If any provision of this Agreement
is finally held to be invalid, illegal or unenforceable by a court of competent
jurisdiction, the validity, legality and enforceability of the remaining
provisions shall not be affected or impaired in any way.

               12.5 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 a party's right to the future enforcement of its rights
under this Agreement.

               12.6 Notices. Any notice required or permitted by this Agreement
to be given to either party shall be in writing and shall be deemed given when
delivered personally, by confirmed telecopy to a fax number designated in
writing by the party to whom notice is given, or by registered, recorded or
certified mail, return receipt requested, and addressed to the party to whom
such notice is directed, at:

                      If to Corixa:

                      Corixa Corporation
                      1124 Columbia Street, Suite 200
                      Seattle, Washington  USA 98104-2040
                      Attention:  Chief Operating Officer
                            With a copy to Director of Legal Affairs
                      Facsimile: (206) 754-5762

                      with a copy to:


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<PAGE>   45
                      Venture Law Group
                      4750 Carillon Point
                      Kirkland, Washington  USA 98033
                      Attention:  William W. Ericson
                      Facsimile:  (425) 739-8750

                      If to Zambon/Inpharzam:

                      Inpharzam International, S.A.
                      Via Industria 1
                      6814 Cadempino
                      Switzerland
                      Facsimile: 011-419-196-643-51


<PAGE>   46
                      with a copy to:

                      Zambon Group spa
                      Via Lillo del Duca, 10
                      20091 Bresso
                      Milan, Italy
                      Attention:  Managing Director
                      Facsimile: 011-39-02-66501-492

or at such other address or telecopy number as such party to whom notice is
directed may designate to the other party in writing.

               12.7 Force Majeure. If the performance of this Agreement or any
obligations hereunder is prevented, restricted or interfered with by reason of
fire or other casualty or accident, strikes or labor disputes, war or other
violence, any law, order, proclamation, ordinance, demand or requirement of any
government agency, or any other act or condition beyond the control of the
parties hereto, the party so affected, upon giving prompt notice to the other
party shall be excused from such performance (other than the obligation to pay
money) during such prevention, restriction or interference.

               12.8 Counterparts. This Agreement may be signed in counterparts,
each of which shall be deemed an original and all of which together shall
constitute one instrument.


                            [Signature page follows.]


<PAGE>   47
        IN WITNESS WHEREOF, the parties hereto have executed this Agreement as
of the date first above written.

                                CORIXA CORPORATION


                                By:________________________________________

                                Name:______________________________________

                                Title:_____________________________________



                                INPHARZAM INTERNATIONAL, S.A.


                                By:________________________________________

                                Name:______________________________________

                                Title:_____________________________________


<PAGE>   48
                                    EXHIBIT A

                                    MATERIALS
<PAGE>   49
                                    EXHIBIT B

                                 SPECIFICATIONS
<PAGE>   50
                    EXHIBIT G TO THE COLLABORATION AGREEMENT


                          Clinical Development Program


   To be added in accordance with Section 2.2 of the Collaboration Agreement.





<PAGE>   51

                    EXHIBIT G TO THE COLLABORATION AGREEMENT


                          Clinical Development Program


                                     [***]*


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