<PAGE>
                                                                   Exhibit 10.64

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


                                 --------------

                               CORIXA CORPORATION

                                       AND

                             ZENYAKU KOGYO CO., LTD.

                                 --------------

                                   DEVELOPMENT
                                       AND
                                LICENSE AGREEMENT

                                 --------------


                                       -i-
<PAGE>

                                    EXHIBITS

        Exhibit A                    Corixa Patents

        Exhibit B                    PVAC Specifications

        Exhibit C                    Development and Commercialization Program

        Exhibit D                    Other Autoimmunue Indications

        Exhibit E                    Form of Supply Agreement

        Exhibit F                    Corixa Third Party Agreements


                                      -ii-
<PAGE>

                        DEVELOPMENT AND LICENSE AGREEMENT

        This DEVELOPMENT AND LICENSE AGREEMENT (together with the attachments
and exhibits hereto, the "Agreement") is entered into as of August 16, 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 98104-2040, and Zenyaku
Kogyo Co., Ltd., a corporation organized and existing under the laws of Japan
and having its principal office at 6-15 Otsuka, 5-Chome, Bunkyo-Ku, Tokyo
112-8650, Japan.

                                    RECITALS

        WHEREAS, Corixa has scientific expertise, proprietary information and
biological materials related to the development of immune system modulating, or
immunomodulatory, materials;

        WHEREAS, ZKC has expertise in developing and commercializing therapeutic
products;

        WHEREAS, Corixa and ZKC desire to collaborate in the development of
immunomodulatory products for the therapy of human psoriasis; and

        WHEREAS, in connection with the collaboration, Corixa has agreed to
license to ZKC in Japan certain intellectual property rights related to the
Licensed Product, subject to the terms and conditions of this Agreement.

        NOW, THEREFORE, for and in consideration of the mutual observance of the
covenants hereinafter set forth and other good and valuable consideration, the
receipt and sufficiency 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:

        1.1 "Additional Technology" shall have the meaning set forth in Section
4.1(c).

        1.2 "Affiliate" of an entity means, for so long as one of the following
relationships is maintained, any corporation or other business entity owned by,
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 that 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.


                                       -1-
<PAGE>

        1.3 "Commercial Launch" shall mean the first revenue generating sale of
the Licensed Product in the Territory by ZKC or an Affiliate of ZKC.

        1.4 "Development and Commercialization Program" shall have the meaning
set forth in Section 2.1.

        1.5 "Collaboration" shall mean the joint collaboration of Corixa and ZKC
pursuant to the terms of this Agreement and the Development and
Commercialization Program.

        1.6 "Corixa" shall mean Corixa Corporation and each of its Affiliates.

        1.7 "Corixa Know-How" shall mean all technical information, materials
and know-how owned and/or controlled by Corixa which directly relates to the
Licensed Product and which Corixa has the ability to license and shall include,
without limitation, all chemical, pharmacological, toxicological, clinical,
assay, control and manufacturing data and any other information, biological
materials or manufacturing or related technology relating to the Licensed
Product and that can reasonably be deemed to be useful for the development and
commercialization of the Licensed Product and strains, samples, analytical
tools, libraries, clones, etc.

        1.8 "Corixa Patents" shall mean (a) all patents and patent applications
that are identified on Exhibit A attached hereto and (b) all patents and patent
applications that cover inventions or discoveries that are made by Corixa solely
or jointly with any Third Party (other than ZKC), provided that any such joint
inventions or discoveries shall only be included in Corixa Patents to the extent
that Corixa has the right to grant licenses thereunder on the terms and
conditions of this Agreement, now or in the future in connection with and as a
result of the performance of the Development and Commercialization Program and
that generically or specifically claim all or any part of the Licensed Product,
a process for manufacturing the Licensed Product, intermediates used in such
process or a use of the Licensed Product. Included within the definition of
Corixa Patents are any continuations, continuations-in-part (solely to the
extent such continuation(s)-in-part contain(s) subject matter on which claims
issuing obtain the benefit of a priority date of any other patent application
included herein), divisions, patents of addition, reissues, renewals, extensions
and/or foreign counter-parts thereof. Also included within the definition of
Corixa Patents are all patents and patent applications which generically or
specifically claim any improvements on Licensed Product or uses of Licensed
Product or intermediates or manufacturing processes required or useful for
production of any Licensed Product which are developed by Corixa solely or
jointly with any Third Party (other than ZKC), provided that any such joint
inventions or discoveries shall only be included in Corixa Patents to the extent
that Corixa has the right to grant licenses thereunder on the terms and
conditions of this Agreement, in connection with and as a result of the
performance of the Development and Commercialization Program. Corixa Patents
shall specifically not include either ZKC Patents or Joint Patents.

        1.9 "Development Steering Committee" shall have the meaning set forth in
Section 3.1(a).

        1.10 "IND" shall mean an Investigational New Drug application with an
appropriate regulatory authority.



                                       -2-
<PAGE>

        1.11 "Joint Patents" shall mean all patents and patent applications that
cover Joint Inventions and that generically or specifically claim all or any
part of the Licensed Product, a process for manufacturing the Licensed Product,
intermediates used in such process or a use of the Licensed Product. Included
within the definition of Joint Patents are any continuations,
continuations-in-part (solely to the extent such continuation(s)-in-part
contains subject matter on which claims issuing obtain the benefit of a priority
date of any other patent application included herein), divisions, patents of
addition, reissues, renewals or extensions and/or foreign counterparts thereof.
Also included within the definition of Joint Patents are all patent and patent
applications which cover Joint Inventions and which generically or specifically
claim any inventions, including any improvements on Licensed Product or uses of
Licensed Product or intermediates or manufacturing processes required or useful
for production of any Licensed Product. In no event shall Joint Patents be
deemed to include Corixa Patents or ZKC Patents.

        1.12 "Joint Inventions" shall have the meaning set forth in Section 10.

        1.13 "Licensed Field" shall mean therapy of psoriasis in humans.

        1.14 "Licensed Product" shall mean Corixa's proprietary formulation of
delipidated and deglycolipidated Mycobacterium vaccae, known as PVAC, as further
specified in Exhibit B, and any derivatives thereof.

        1.15 "Net Sales" shall mean the amount invoiced by ZKC, or its Third
Party sublicensee(s), as applicable, for the sale or other disposition to a
Third Party of the Licensed Product, less the following deductions for amounts
actually incurred related to such sale or other disposition: (a) normal,
customary trade discounts (including volume discounts), credits and rebates and
allowances and adjustments for rejections, recalls or returns; and (b) freight,
insurance, sales, use, excise, value-added, consumption and similar taxes or
duties imposed on the sale and included in the gross amount charged.
Additionally, "Net Sales" shall not include sales of Licensed Product between
either ZKC and its Affiliates or between ZKC and its sublicensee(s), unless such
Affiliate(s) or sublicensee(s), as the case may be, are an end-user of the
Licensed Product, nor shall "Net Sales" include the distribution of a reasonable
amount of Licensed Product solely for use in clinical trials or research
performed directly in connection with the Development and Commercialization
Program, provided that ZKC does not receive any compensation in any form for
such use. Any commercial transfer of the Licensed Product by ZKC or its Third
Party sublicensee(s) shall be considered a sale hereunder for accounting and
royalty purposes. For purposes of this Section 1.15, "commercial transfer" shall
mean a sale or other transfer of the Licensed Product for which ZKC receives
consideration. For the avoidance of doubt, "commercial transfer" shall not
include the distribution of samples without charge by ZKC, regardless of the
purpose, in accordance with Section 9 hereof.

        1.16 "Other Autoimmune Indications" shall have the meaning set forth in
Section 4.2.

        1.17 "Territory" shall mean Japan.



                                       -3-
<PAGE>

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

        1.19 "Valid Claim" shall mean a claim of an issued, unexpired patent or
a claim of a patent application, in either case included in the Corixa Patents
or the Joint Patents, that has not been (a) held invalid or unenforceable by a
final decision of a court or governmental agency of competent jurisdiction,
which decision is unappealable or was not appealed within the time allowed
therefor or (b) admitted in writing to be invalid or unenforceable by the
holder(s) by reissue, disclaimer or otherwise.

        1.20 "ZKC" shall mean Zenyaku Kogyo Co., Ltd. and each of its
Affiliates.

        1.21 "ZKC Know-How" shall mean all technical information, materials and
know-how owned and/or controlled by ZKC which directly relates to the Licensed
Product and which ZKC has the ability to license and shall include, without
limitation, all chemical, pharmacological, toxicological, clinical, assay,
control and manufacturing data and any other information, biological materials
or manufacturing or related technology relating to the Licensed Product and that
can reasonably be deemed to be useful for the development and commercialization
of the Licensed Product and strains, samples, analytical tools, libraries,
clones, etc.

        1.22 "ZKC Patents" shall mean all patents and patent applications that
(a) cover patentable inventions or discoveries that are made solely by ZKC in
connection with and as a result of the performance of the Development and
Commercialization Program and that generically or specifically claim all or any
part of the Licensed Product, a process for manufacturing the Licensed Product,
intermediates used in such process or a use of the Licensed Product and (b) are
now or become owned and/or controlled by ZKC (other than jointly with Corixa)
and under which ZKC has, now or in the future, the right to grant licenses in
connection with the use of the Licensed Products in the Licensed Field. Included
with the definition of ZKC Patents are any continuations, continuations-in-part
(solely to the extent such continuation(s)-in-part contain subject matter on
which claims issuing obtain the benefit of a priority date of any other patent
application included herein), divisions, patents of addition, reissues,
renewals, extensions and/or foreign counterparts thereof. Also included within
the definition of ZKC Patents are all patents and patent applications which
generically or specifically claim any improvements on Licensed Product or uses
of Licensed Product or intermediates or manufacturing processes required or
useful for production of any Licensed Product which are developed solely by ZKC
in connection with and as a result of the performance of the Development and
Commercialization Program. In no event shall ZKC Patents be deemed to include
either Corixa Patents or Joint Patents.

        1.23 "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 vice versa)
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



                                       -4-
<PAGE>

"including but not limited to"; and (d) the words "herein," "hereof,"
"hereunder" and other words of similar import refer to this Agreement as a whole
and not to any particular provision.

2. DEVELOPMENT AND COMMERCIALIZATION PROGRAM.

        2.1 Commencing on the Effective Date, the parties shall collaborate in
the development and commercialization of the Licensed Product in the Licensed
Field. The program of activities to be conducted by each of Corixa and ZKC
during the term of the Agreement is set forth on Exhibit C (the "Development and
Commercialization Program"), which shall be amended on an annual basis by mutual
agreement of the parties, effective upon each anniversary of the Effective Date.
The Development and Commercialization Program shall include a development plan
setting forth the activities currently contemplated by the parties to be
performed in developing the Licensed Product, as well as a description of each
party's responsibilities in connection with the development and
commercialization of the Licensed Product. Anything herein to the contrary
notwithstanding, the timelines included in the development plan are non-binding
and shall function as guidelines only for the development of Licensed Product
and may be modified from time to time by the Development Steering Committee. The
parties agree that the end goal of the Development and Commercialization Program
shall be the expeditious clinical development and regulatory approval of the
Licensed Product as necessary for the import, manufacture, marketing and/or sale
thereof in the Territory in the Licensed Field. No material deviation in the
subject matter and scope of such Development and Commercialization Program shall
be made without the mutual written agreement of both parties.

        2.2 On the Effective Date, ZKC agrees to diligently undertake, [*],
pre-clinical and clinical development and commercialization of the Licensed
Product within the Territory as determined by the Development Steering Committee
or Commercialization Steering Committee, as applicable. ZKC shall have the
right, subject to the terms and conditions of this Agreement, including, without
limitation, Section 3 hereof, to determine the clinical development and
commercialization plan for the Licensed Product in the Territory.

        2.3 The parties acknowledge and agree that nothing in this Agreement
shall restrict in any manner Corixa's ability to conduct clinical trials of any
nature either inside or outside of the Licensed Field [*] or any of its Third
Party [*], provided, however, Corixa shall not during the term of this Agreement
conduct any clinical trial in the Territory in respect of the Licensed Product
or sell, market or distribute the Licensed Product in the Licensed Field in the
Territory. Notwithstanding the foregoing, Corixa shall provide ZKC access to
clinical data and regulatory filings controlled by Corixa related to the
Licensed Product in the Licensed Field, and shall also use good faith efforts to
cause any Third Party(ies) controlling any such clinical data and regulatory
filings to make such access available to ZKC.

        2.4 The parties acknowledge and agree that nothing in this Agreement
shall restrict in any manner ZKC's ability to conduct clinical trials of any
nature either inside or outside of the Licensed Field at its or any of its Third
Party partner(s)' own cost and expense, provided, however, ZKC shall not during
the term of this Agreement conduct any clinical trial in respect of

--------
* Confidential treatment requested.


                                       -5-
<PAGE>

the Licensed Product other than in the Territory in the Licensed Field.
Notwithstanding the foregoing, ZKC shall provide Corixa access to clinical data
and regulatory filings controlled by ZKC related to the Licensed Product in the
Licensed Field, and shall also use good faith efforts to cause any Third
Party(ies) controlling any such clinical data and regulatory filings to make
such access available.

3. STEERING COMMITTEES.

        3.1 (a) A Development Steering Committee (the "Development Steering
Committee") shall be established within thirty (30) days after the Effective
Date. During the period beginning on the Effective Date and ending on the
earlier of (i) the date on which all regulatory approvals have been obtained and
(ii) a date mutually agreed by the parties (the "Development Period"), the
Development Steering Committee shall consist of five (5) members, three (3)
individuals appointed by Corixa and two (2) individuals appointed by ZKC, and
shall be chaired by an individual from Corixa. During the Development Period,
the Development Steering Committee shall be responsible for, among other things,
regular coordination in the Territory of the supply of preclinical and clinical
grade test materials and the monitoring of clinical development activities in
the Territory. In addition, Corixa shall use good faith efforts to establish a
steering committee to monitor clinical development activities for the Licensed
Product in the Licensed Field worldwide (the "Global Steering Committee") to be
comprised of Corixa, ZKC and Corixa's additional partners for the development
and commercialization of the Licensed Product in the Licensed Field.

        (b) Following the Development Period and until the expiration or earlier
termination of this Agreement, a Commercialization Steering Committee (the
"Commercialization Steering Committee") shall be established. The
Commercialization Committee shall consist of five (5) members, three (3)
individuals appointed by ZKC and two (2) individuals appointed by Corixa, and
shall be chaired by an individual from ZKC. The Commercialization Steering
Committee shall be responsible for, among other things, regular coordination in
the Territory of reimbursement policies, product positioning and marketing and
such other related and ancillary activities as may be agreed.

        3.2 To facilitate coordination during the Development Period, the
parties shall share all reports and data generated under the Development and
Commercialization Program with each other on a prompt and regular basis at
meetings of the Development Steering Committee, which shall be every six (6)
months during meetings to be held alternatively in Seattle, Washington and
Tokyo, Japan, or at such other location as may be determined by the Development
Steering Committee. ZKC shall provide Corixa with written reports in a format
agreed by Corixa and ZKC on the progress in the Territory of the Development and
Commercialization Program, including clinical and regulatory progress,
premarketing activities, clinical development (including utilization of
preclinical and clinical grade test materials) and commercial launch of the
Licensed Product. All such reports and data shall be in sufficient detail to
enable Corixa to determine ZKC's compliance with its diligence obligations under
Section 8.1, and all such reports, data and information shall be subject to the
confidentiality provisions of Section 12 of this Agreement. In addition, Corixa
shall provide ZKC written reports during the course of the Development and
Commercialization Program in a format to be agreed by Corixa and ZKC which shall
contain clinical data related to the Licensed Product in the Field generated by
Corixa


                                       -6-
<PAGE>

outside of the Territory, and which shall be subject to the confidentiality
provisions of Section 12 of this Agreement. The Development Steering Committee
shall review the Development and Commercialization Program annually, implement
any mutually agreeable modifications and make recommendations related to
possible Development and Commercialization Program extensions and/or expansions
to the respective senior management teams of each party. All actions by the
Development Steering Committee shall require the approval by a majority of its
members, provided, however, that approval of any and all actions shall require
participation of a majority of all members of the Development Steering Committee
and approval by majority shall require the affirmative vote of at least one
member appointed by each of the parties.

        3.3 Commencing at the end of the Development Period, the
Commercialization Steering Committee shall meet at least once every twelve (12)
months at a mutually agreed location to review and discuss the commercialization
progress and plans with respect to the Licensed Product in the Territory. In
conjunction with the foregoing meetings, ZKC shall provide Corixa with annual
written summary reports on the progress of commercialization, including
activities and literature related to the marketing and the Commercial Launch of
the Licensed Product in the Territory. All such information shall be subject to
the confidentiality provisions of Section 12 of this Agreement. All actions by
the Commercialization Steering Committee shall require the approval by a
majority of its members, provided, however, that approval of any and all actions
shall require participation of a majority of all members of the
Commercialization Steering Committee and approval by majority shall require the
affirmative vote of at least one member appointed by each of the parties.

4. LICENSE GRANTS; RIGHTS OF FIRST NEGOTIATION

        4.1 License.

               (a) Subject to the terms and conditions of this Agreement,
including, without limitation, Section 5 hereof, Corixa hereby grants to ZKC an
exclusive license, with the right to grant sublicenses in the Territory to
practice under the Corixa Patents, the Joint Patents and Corixa Know-How, to use
any trademarks under Corixa's sole control in the Territory with regard to the
Licensed Product and to research, develop, use, have used, sell, offer for sale,
have sold, keep and import the Licensed Product solely in the Licensed Field in
the Territory. Corixa acknowledges that ZKC may, in its sole discretion,
register its exclusive license rights under this Agreement with applicable
governmental authorities in the Territory and Corixa agrees that, if requested
by ZKC, it shall cooperate with ZKC to register such license rights. All costs,
fees, and expenses associated with any such registration, whether incurred by
ZKC or Corixa, shall be borne by [*].

               (b) Subject to the terms and conditions of this Agreement, ZKC
hereby grants to Corixa during the term of this Agreement a non-exclusive, fully
paid-up (with the exception of Corixa's obligation to reimburse certain of ZKC's
patent expenses, as described in Section 11.1 in connection with ZKC Patents),
royalty-free, worldwide license (except within the Territory), with the right to
grant sublicenses worldwide (except within the Territory), to practice under the
ZKC Patents, the Joint Patents and ZKC Know-How, to the extent that ZKC has the
right to


--------
* Confidential treatment requested.

                                       -7-
<PAGE>

grant licenses thereunder on the terms and conditions of this Agreement.

               (c) If during the period commencing on the Effective Date and
ending on the third anniversary of the Effective Date Corixa or ZKC believes
that technology related to the subject matter hereof is controlled by a Third
Party ("Additional Technology"), which technology may be valuable or necessary
to the commercialization of the Licensed Product hereunder, Corixa or ZKC as
appropriate shall present such Additional Technology, along with a written
report with respect thereto, to the Development Steering Committee. The
Development Steering Committee shall then determine whether licenses to, and/or
acquisitions of, such Additional Technology should be made, the party that shall
approach and negotiate with any Third Party(ies) and the terms of any
agreement(s) with any Third Party(ies). All costs and expenses to be incurred in
connection with obtaining such a license shall be subject to approval of the
Development Steering Committee, irrespective of which party is selected to
negotiate with such Third Party(ies). No such Third Party license and/or
acquisition shall be effective with respect to ZKC or Corixa, as the case may
be, unless and until ZKC or Corixa, as the case may be, specifically agrees in
writing to abide by the applicable terms and conditions of any such license
and/or acquisition, and to make such payments and/or royalties as are mutually
agreed by the parties. Nothing set forth in this Section 4.1(c) shall limit the
ability of either party to procure technology for their own account or for
license to other parties, provided, however, that in the case of Additional
Technology the parties shall first have completed the determination set forth
above and determined that such Additional Technology shall not be acquired for
the benefit of commercialization of the Licensed Product hereunder.

               (d) To the extent that ZKC does not have the right to grant
licenses under any ZKC Patent or ZKC Know-How on the terms and conditions of
this Agreement, ZKC shall use good faith efforts to take measures to grant such
a license to Corixa at no additional cost to Corixa.

               (e) To the extent that Corixa does not have the right to grant
licenses under any Corixa Patent or Corixa Know-How on the terms and conditions
of this Agreement, Corixa shall use good faith efforts to take measures to grant
such a license to ZKC at no additional cost to ZKC.

        4.2 Right of First Negotiation to Other Autoimmune Indications. In the
event that Corixa from time to time during the period beginning on the Effective
Date and ending on August 16, 2002, elects to undertake and completes, in
Corixa's reasonable scientific judgment, initial preclinical efficacy research
in animals regarding the Licensed Product related to any of the indications of
rheumatoid arthritis, scleroderma, lupus, multiple sclerosis, diabetes and/or
inflammatory bowel disease (in each case as defined in Exhibit D, the "Other
Autoimmune Indication(s)"), subject in the case of scleroderma, lupus and
inflammatory bowel disease to Corixa having exercised its option for a license
in such Other Autoimmune Indication(s) from Stanford Rook, Ltd., ZKC shall have
a first right of negotiation for an exclusive license to the Licensed Product in
the Territory for any or all of such Other Autoimmune Indication(s) solely in
accordance with the process described in this Section 4.2. In connection with
each of the Other Autoimmune Indications for which Corixa completes such
preclinical efficacy research in animals regarding the Licensed Product, Corixa
shall notify ZKC promptly after it finishes its first series of preclinical
efficacy experiments in animals related to such Other Autoimmune



                                       -8-
<PAGE>

Indication and shall provide ZKC with a summary of relevant data available to
Corixa with respect to such Other Autoimmune Indication. ZKC shall have one
opportunity to exercise its right of first negotiation in connection with such
Other Autoimmune Indication by providing Corixa an executed letter of intent to
enter into good faith negotiations for a license regarding the Licensed Product
related to such Other Autoimmune Indication within thirty (30) days of receipt
of such notice from Corixa. Thereafter, Corixa and ZKC shall have thirty (30)
days from Corixa's receipt of such letter of intent to negotiate and enter into
an agreement covering a license for such Other Autoimmune Indication. The terms
of any such license shall be negotiated in good faith for each parties' mutual
benefit, and shall reflect the fair market value with respect to such Other
Autoimmune Indication, taking into account factors such as market size, margins,
cost of manufacture and price comparables. In the event ZKC does not provide
such executed letter of intent within such thirty (30) day period, Corixa shall
be free to seek a Third Party partner in the Territory for the Other Autoimmune
Indication, provided, however, any agreement between Corixa and a Third Party
partner in the Territory for an Other Autoimmune Indication shall require that
the product licensed thereunder (i) be marketed and sold using a brand name
different from, and which may not reasonably be confused with, the brand name
under which the Licensed Product is then marketed and sold by ZKC in the
Territory and (ii) have specifications which are not identical to the
specifications set forth in Exhibit B.

5. PAYMENTS.

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

                      (This space intentionally left blank)



                                       -9-
<PAGE>

        5.1 Research and Development Funding. Research and development funding
payments in the following amounts on the dates set forth below:

<TABLE>
<CAPTION>
                                                              PAYMENT
                           PAYMENT DATE                     AMOUNT (US$)
               --------------------------------------     --------------
               <S>                                        <C>
               September 16, 1999                              187,500
               November 16, 1999                               187,500
               February 16, 2000                               187,500
               May 16, 2000                                    187,500
               August 16, 2000                                 750,000
               November 16, 2000                               750,000
               February 16, 2001                               750,000
               May 16, 2001                                    750,000
               August 16, 2001                                 500,000
               November 16, 2001                               500,000
               February 16, 2002                               500,000
               May 16, 2002                                    500,000
</TABLE>

        The payment amounts set forth above shall be guaranteed, non-refundable
and non-creditable and shall be paid directly to Corixa, provided, however, (1)
in the event that Corixa has not delivered to ZKC the data analysis of Corixa's
US Phase II clinical trial of Licensed Product in the Licensed Field on or
before August 2, 2000, ZKC's obligation to make the payment due under Section
5.1 on August 16, 2000 shall be delayed until two (2) weeks after ZKC's receipt
of such data analysis (2) in the event ZKC elects to terminate this Agreement
pursuant to Section 18.3 hereof, ZKC shall pay Corixa any and all amounts
payable and still outstanding under this Section 5.1 as of the date of such
termination, provided, however, that in the event such termination occurs after
August 16, 2000 due to Corixa's delay in providing ZKC with the data analysis of
Corixa's US Phase II clinical trial of Licensed Product in the Licensed Field,
ZKC shall have no obligation to make any of the payments that were otherwise due
under Section 5.1 on and after August 16, 2000 and (3) if ZKC shall elect to
terminate this Agreement pursuant to Section 18.4 hereof, ZKC shall (i) in the
event such termination occurs pursuant to Section 18.4(i), immediately pay
Corixa $[*], less the amount ZKC has paid to Corixa under this Section 5.1 from
August 16, 2000 up until that date and (ii) in the event such termination occurs
pursuant to Section 18.4(ii), immediately pay Corixa $[*], less the amount ZKC
has paid to Corixa under this Section 5.1 from August 16, 2001 up until that
date. In any of the aforementioned instances, ZKC shall not be required to pay
any amount that is due on a date

--------
* Confidential treatment requested.


                                      -10-
<PAGE>

after the termination notice is dispatched under this Section 5.1.

        5.2 License Fees.

        (a) On September 16, 1999, ZKC shall pay to Corixa a licensing fee of
US$[*].

        (b) Beginning on January 31, 2003, and on each January 31 and July 31
thereafter during the term of this Agreement until Commercial Launch of the
Licensed Product in the Territory, ZKC shall pay Corixa a license maintenance
fee equal to US$[*]. Subsequent to Commercial Launch of the Licensed Product in
the Territory, ZKC shall pay Corixa a minimum royalty equal to US$[*] on each
January 31 and July 31 thereafter, provided, however, that Corixa shall, during
the calendar year of Commercial Launch of the Licensed Product in the Territory
(even if such Commercial Launch takes place in the middle of such calendar year)
and for each calendar year thereafter, credit amounts paid under this Section
5.2(b) following Commercial Launch, on a non-cumulative basis, against royalties
due Corixa pursuant to Section 6.1. For purposes of clarification, in the event
Commercial Launch occurs during the six (6) month period following a payment
made hereunder, the portion of that payment that represents the pro rata portion
of such six (6) month period that follows Commercial Launch shall be creditable
on a non-cumulative basis, against royalties due Corixa pursuant to Section 6.1

        5.3 Milestone Payments. In addition to the amounts payable pursuant to
Sections 5.1 and 5.2 above, ZKC also agrees to pay Corixa the following
milestone payments, to be made via wire transfer of immediately available funds,
within thirty (30) days following (i) in the event such milestone is achieved
outside of the Territory, ZKC's receipt of a written notice as well as
documentary evidence of achievement of each of the following milestones and (ii)
in the event such milestone is achieved in the Territory, achievement of such
milestone:

<TABLE>
<CAPTION>
                    DEVELOPMENT MILESTONES                         PAYMENT (US$)
    --------------------------------------------------------      --------------
    <S>                                                           <C>
    (i)    [*] the Licensed Product in the Licensed Field               [*]
           [*].
    (ii)   [*] for the Licensed Product in the Licensed                 [*]
           Field.
    (iii)  [*] for the Licensed Product in the Licensed                 [*]
           Field.
    (iv)   [*] for the Licensed Product in the Licensed                 [*]
           Field.
    (v)    [*] the Licensed Product in the Licensed Field.              [*]
    (vi)   [*] the Licensed Product in the Licensed Field.              [*]
</TABLE>

--------
* Confidential treatment requested.


                                      -11-
<PAGE>

<TABLE>
<CAPTION>
                 COMMERCIALIZATION MILESTONES                      PAYMENT (US$)
    --------------------------------------------------------      --------------
    <S>                                                           <C>
    (i)    [*] Licensed Product in the Licensed Field [*].              [*]
    (ii)   [*] Licensed Product in the Licensed Field [*].              [*]
    (iii)  [*] Licensed Product in the Licensed Field [*].              [*]
</TABLE>

6. LICENSE AND ROYALTY PAYMENTS.

        6.1 Royalties for Licensed Product.

               Royalties on annual Net Sales of Licensed Product in the
Territory shall be paid to Corixa by ZKC as follows:

<TABLE>
<CAPTION>
                 ANNUAL NET SALES OF LICENSED
                  PRODUCT IN THE TERRITORY                              ROYALTY
              ------------------------------------------               -----------
              <S>                                                      <C>
              < US$[*] million                                            [*]%
              -
              > US$[*] million < US$[*] million                           [*]%
                               -
              > US$[*] million < US$[*] million                           [*]%
                               -
              > US$[*] million                                            [*]%
</TABLE>

               The royalty rates under Section 6.1 are incremental with respect
to the annual Net Sales of the Licensed Product sold in the Territory. For
example, by way of illustration, if annual Net Sales of Licensed Product in the
Territory is $35,000,000, ZKC will owe Corixa $[*], which is equal to: $[*]
multiplied by [*] plus $[*] multiplied by [*] plus $[*] multiplied by [*].

        6.2 Royalty Term. Subject to Section 6.5 of this Agreement, Royalties
shall be earned and paid to Corixa until the earlier to occur of (i) the date
the last Valid Claim under the patents with regard to the Corixa Patents and the
Joint Patents in connection with use in the Licensed Field in the Territory
expires and (ii) the date of expiration or earlier termination of this
Agreement. No royalties shall be payable on sales of the Licensed Product
between ZKC and any Affiliate of ZKC or between ZKC and any sublicensee of ZKC,
provided that such Affiliate or sub-licensee, as the case may be, is not an end
user of the Licensed Product.

        6.3 Currency. All amounts payable to Corixa under this Agreement shall
be payable in United States Dollars by wire transfer of immediately available
funds to a bank account designated by Corixa in accordance with Section 7.1. Net
Sales during a month shall be translated on a monthly basis from Japanese Yen to
U.S. Dollars by using an average rate of exchange of such month. This average
shall be computed using the closing Telegraphic Transfer Selling (TTS) Rate of
exchange quoted by the Tokyo-Mitsubishi Bank in Tokyo as of the end of such
month plus the rate as of the end of the prior month and dividing by two (2).

        6.4 Currency Transfer Restrictions. If payment or transfer of funds out
of the Territory shall be prohibited by law or regulation, the parties hereto
shall confer regarding the terms and conditions on which the Licensed Product
shall be sold in the Territory, including the

--------
* Confidential treatment requested.


                                      -12-
<PAGE>

possibility of payment of royalties to Corixa in local currency to a bank
account in the Territory or the renegotiation of royalties for such sales, and
in the absence of any other agreement by the parties, such funds payable to
Corixa shall be deposited in whatever currency is allowable by ZKC in an
accredited bank in that country that is acceptable to Corixa.

        6.5 Royalty Payments Upon Termination. Notwithstanding anything
contained herein to the contrary, if this Agreement is terminated in accordance
with Section 18, ZKC shall pay to Corixa all amounts payable pursuant to this
Section 6 prior to the date on which such termination shall become effective,
and shall also pay Corixa royalty amounts earned thereafter as a result of sales
of residual inventory of the Licensed Product.

        6.6 Withholding Tax. All payments made by ZKC under this Agreement shall
be made to Corixa with the deduction of withholding tax (if any) imposed upon
such payment. If requested by Corixa, ZKC shall cooperate with Corixa regarding
the characterization of payments so that it may take advantage of any and all
benefits under any Japan-US Tax Treaty and any filing fees or other governmental
fees shall be at the cost and expense of Corixa.

7. REPORTS, PAYMENTS AND ACCOUNTING.

        7.1 Payments and Reports.


               (a) ZKC agrees to make written reports (in a format, if any,
reasonably specified by Corixa), and the payments set forth in Section 6 to
Corixa within forty-five (45) days after the close of each calendar quarter
during the term of this Agreement. These reports shall show for such calendar
quarter sales by ZKC, its Affiliates and sublicensees of Licensed Product,
details of the gross invoices from sales, trade discounts allowed and taken, Net
Sales and the royalties due to Corixa pursuant to Section 6. Concurrently with
the making of each such report, ZKC shall make payment to Corixa of (i) amounts
payable under Section 6 for the period covered by such report and (ii) all other
amounts accrued under this Agreement which have not been previously reimbursed
as required, unless otherwise provided hereunder. All payments due to Corixa by
ZKC under this Agreement that are subject to withholding tax under the laws of
Japan shall, in accordance with Section 6.6, be made net of Japanese withholding
tax.

               (b) Corixa agrees to submit a detailed statement of account to
ZKC within thirty (30) days after the close of each calendar quarter for any
costs or expenses incurred during such calendar quarter related to patents and
other expenses agreed to be paid or reimbursed by ZKC. The costs and expenses of
patent filings shall be as set forth in Section 11.

        7.2 Termination Report. ZKC also agrees to make a written report (in a
format, if any, reasonably specified by Corixa) within ninety (90) days after
the date on which ZKC, its Affiliates or sublicensees sell the last Licensed
Product stating in such report the same information required for quarterly
reports provided under Section 7.1 hereof.

        7.3 Accounting. ZKC agrees to keep clear, accurate and complete records,
all in a format, if any, reasonably specified by Corixa, for a period of at
least three (3) years (or such longer period as may correspond to ZKC's internal
records retention policy) for each reporting period in which sales of Licensed
Product occur showing the manufacturing, if any, sales, use and other
disposition thereof in sufficient detail to determine amounts payable pursuant
to



                                      -13-
<PAGE>

Section 6 hereof. ZKC further agrees to permit its books and records to be
examined from time to time (but not more than once a year) by an independent
accounting firm selected and paid by Corixa and reasonably satisfactory to ZKC.
Such examination shall occur only on reasonable notice during regular business
hours during the term of 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 ZKC. In the event the report demonstrates that ZKC has underpaid
Corixa, ZKC shall pay the amount of such underpayment immediately upon request
of Corixa and to the extent such underpayment is more than five percent (5%) of
the royalty payments otherwise due for the audited period, ZKC shall reimburse
Corixa for the expense of the audit.

        7.4 Confidentiality of Reports. Each party agrees that the information
set forth in (i) the reports required by Sections 7.1 and 7.2 and (ii) the
records subject to examination under Section 7.3, shall be subject to Section 12
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.

8. COMMERCIAL DEVELOPMENT.

        8.1 Diligence by ZKC. ZKC will use efforts equivalent to a ZKC priority
development program, and will use at least the same level of diligence as ZKC
currently uses or in the past has used with respect to its own commercially
successful products on which ZKC places or has placed a priority, such that if
after discussions with the Japanese Ministry of Health it shall be determined
that (i) ZKC shall be required to file an IND and perform one or more clinical
trials with respect to the Licensed Product, then such IND shall be filed by the
later of (a) completion of Corixa's U.S. Phase II clinical trial with respect to
the Licensed Product and (b) December 31, 2001 or (ii) ZKC shall be required to
conduct a bridging study only with respect to the Licensed Product, then such
bridging study shall commence by the later of (a) the date that is three months
following completion of Corixa's US Phase III clinical trial with respect to the
Licensed Product and (b) June 30, 2002. ZKC shall also use its commercially
reasonable efforts consistent with industry standards in the Territory to
prevent the use of Licensed Product outside of the Licensed Field.

        8.2 Diligence by Corixa. Corixa undertakes to use commercial best
efforts to materially perform its obligations under the Development and
Commercialization Program, and will use at least the same level of diligence as
Corixa currently uses or in the past has used with respect to its own
commercially successful products on which Corixa has placed a priority.

9. SUPPLY; DISTRIBUTION OF SAMPLE PRODUCT.

        9.1 Corixa shall provide ZKC with Licensed Product pursuant to the terms
and conditions of a Supply Agreement in the form attached hereto as Exhibit E
(the "Supply Agreement") and in compliance with all applicable foreign, federal,
state or local laws and


                                      -14-
<PAGE>

regulations. ZKC shall use all materials provided to ZKC by Corixa hereunder or
under the Supply Agreement in compliance with all applicable foreign, federal,
state or local laws and regulations.

        9.2 ZKC may only transfer Licensed Product to a Third Party in the
Territory without consideration subject to the approval of the Development
Steering Committee or the Commercialization Steering Committee, as applicable,
and according to the following.

        (a) Prior to Commercial Launch, ZKC may request that Corixa transfer
reasonable amounts of Licensed Product to academic researchers in connection
with the performance of the Development and Commercialization Program. In the
event that the Development Steering Committee determines that such transfer is
in the best interests of the performance of the Development and
Commercialization Program, the parties shall negotiate a materials transfer with
such academic researcher as follows. ZKC shall present such academic researcher
with Corixa's standard form of Special Biological Materials Transfer Agreement
for execution by such academic researcher. In the event that such academic
researcher requests any modifications to Corixa's standard form of Special
Biological Materials Transfer Agreement, ZKC shall communicate such requested
modifications to Corixa. ZKC shall thereafter facilitate any further
negotiations between Corixa and such academic researcher related to the
execution by Corixa and such academic researcher of the Special Biological
Materials Transfer Agreement. Corixa shall cooperate with ZKC in good faith the
effect the collaborations contemplated by this Section 9.2(a); provided,
however, that Corixa shall have the sole discretion in determining whether to
agree to any particular modifications to the Special Biological Materials
Transfer Agreement.

        (b) Prior to Commercial Launch, ZKC may transfer Licensed Product for
use in clinical trials in the Licensed Field in the Territory only in reasonable
amounts.

        (c) Following final regulatory approval of commercial sales in the
Territory, ZKC may transfer reasonable amounts of Licensed Product for the sole
purpose of promoting the commercial sale of Licensed Product for use in the
Licensed Field in the Territory

10. INVENTIONS.

        Inventions, discoveries and technology(ies) related to the Licensed
Product that arise from the performance of the Development and Commercialization
Program and that are made by Corixa solely or jointly other than with an
employee or agent of ZKC shall be owned by Corixa. Inventions, discoveries and
technology(ies) which are made jointly by employees or agents of Corixa and ZKC
during the term of this Agreement shall be jointly owned by Corixa and ZKC and
treated as joint inventions (collectively, "Joint Inventions"). Inventions,
discoveries and technology(ies) which arise from the performance of the
Development and Commercialization Program and that are made by an employee or
agent of ZKC during the term hereof, solely or jointly other than with an
employee or agent of Corixa, shall be owned by ZKC (collectively, "ZKC
Inventions"). Except as otherwise set forth in this Agreement, ZKC and Corixa
shall retain their respective unrestricted rights to make, have made, use and
sell all such inventions and discoveries that are owned by them.



                                      -15-
<PAGE>

11. PATENTS; PROSECUTION AND LITIGATION.

        11.1 Corixa shall have the right and the obligation to prosecute and
maintain all Corixa Patents and Joint Patents as provided in this Section 11 and
shall do so in a timely manner. Corixa shall disclose in writing at least once
per year to ZKC the complete texts of all Corixa Patents and Joint Patents as
well as all information received concerning the institution or possible
institution of any interference, opposition, re-examination, reissue,
revocation, nullification or any official proceeding involving any patent
licensed herein. Corixa agrees to keep ZKC promptly and fully informed of the
course of patent prosecution or other proceedings including by providing ZKC
with copies of substantive communications, search reports and Third Party
observations submitted to or received from patent offices. ZKC shall have the
right to review all such pending applications, patents, substantive
communications and other proceedings and make recommendations to Corixa
concerning them and their conduct in the Territory. ZKC shall hold all
information disclosed to it under this Section 11 as confidential information
under Section 12. ZKC shall reimburse Corixa for all prior reasonable and
documented costs for the filing, prosecution and maintenance of the Corixa
Patents and Joint Patents in the Licensed Field in the Territory that contain
claim(s) directed to the Licensed Product in the Licensed Field and reasonable
and documented costs for the filing, prosecution and maintenance of the Corixa
Patents and Joint Patents in the Licensed Field incurred by Corixa during the
term of this Agreement in the Territory that contain claim(s) directed to the
Licensed Product in the Licensed Field. The amount payable by ZKC on the
Effective Date for such prior costs shall be $12,982. All expenses to be paid or
reimbursed by ZKC 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. In the event Corixa sublicenses its
rights under Section 4.1(b) to one or more Third Party(ies), Corixa shall
reimburse [*] of all reasonable and documented costs incurred prior to the
effective date of such sublicense agreement for the filing, prosecution and
maintenance solely in the territory that is the subject of such sublicense(s) of
the ZKC Patents in the Licensed Field that contain claim(s) directed to the
Licensed Product in the Licensed Field and reasonable and documented costs for
the filing, prosecution and maintenance solely in the territory that is the
subject of such sublicense(s)of the ZKC Patents in the Licensed Field incurred
after the effective date of such sublicense agreement and during the term of
this Agreement that contain claim(s) directed to the Licensed Product in the
Licensed Field. In addition, in the event Corixa directly markets Licensed
Product in the Licensed Field, Corixa shall reimburse [*] of all reasonable and
documented costs incurred prior to Corixa's commercial launch of Licensed
Product in the Licensed Field for the filing, prosecution and maintenance solely
in the territory in which Corixa is directly marketing Licensed Product in the
Licensed Field of the ZKC Patents in the Licensed Field that contain claim(s)
directed to the Licensed Product in the Licensed Field and reasonable and
documented costs for the filing, prosecution and maintenance solely in the
territory that is the subject of such sublicense(s) of the ZKC Patents in the
Licensed Field incurred after Corixa's commercial launch of Licensed Product in
the Licensed Field and during the term of this Agreement that contain claim(s)
directed to the Licensed Product in the Licensed Field.

        11.2 In the event Corixa finally abandons any patent or any part of a
patent (including Corixa Patents) covered by this Agreement, it shall notify ZKC
and ZKC shall have the right at


--------
* Confidential treatment requested.


                                      -16-
<PAGE>

its own expense to assume all rights to any such patent or part thereof in the
Territory, provided, however, ZKC's rights under this Section 11.2 shall in all
respects be subject to the rights of Corixa's Third Party licensor(s) of such
abandoned patent or part of a patent.

        11.3 In the event of the initiation of any suit by a Third Party against
Corixa Corporation, Zenyaku Kogyo Co., Ltd. or any Affiliate of either for
patent infringement with respect to Corixa Patents, Joint Patents or ZKC Patents
in the License Field and involving the manufacture, use, sale, distribution or
marketing of the Licensed Product in the License Field in the Territory, the
party sued shall promptly notify the other party in writing. Corixa and/or, at
Corixa's sole discretion, Corixa's Third Party licensor with respect to the
Corixa Patents, or ZKC with respect to the ZKC Patents, that are the subject of
such suit, shall have the obligation to defend such suit at its own expense. ZKC
shall assist and cooperate with Corixa or such Third Party licensor, and Corixa
or such Third Party licensor, as applicable, shall assist and cooperate with
ZKC, as applicable, in any such litigation at Corixa's and/or such Third Party
licensor's, or ZKC's request and expense, as applicable. Neither Corixa nor such
Third Party licensor may enter into any settlement with respect to such suit
without ZKC's written consent, which consent shall not be unreasonably withheld
or delayed, and ZKC shall not enter into any settlement with respect to such
suit without Corixa's and/or the Third Party licensor's consent, which consent
shall not be unreasonably withheld.

        11.4 (a) In the event that Corixa or ZKC becomes aware of actual or
threatened infringement of a patent covered by this Agreement with respect to
the Licensed Product in the Licensed Field in the Territory, that party shall
promptly notify the other party in writing. In connection with any such actual
or threatened infringement in the Territory, Corixa and/or, at Corixa's sole
discretion, Corixa's Third Party licensor with respect to the Corixa Patents or
the Joint Patents, or ZKC with respect to the ZKC Patents, that are the subject
of such actual or threatened infringement shall have the first right but not the
obligation to bring an infringement action against any alleged infringer at its
sole cost and expense. The party conducting such action shall have full control
over its conduct, provided that it may not enter into any settlement related to
infringement in the Territory without ZKC's written consent which consent shall
not be unreasonably withheld or delayed. ZKC shall assist and cooperate with
Corixa or such Third Party licensor, as applicable, in any such action at
Corixa's and/or such Third Party licensor's request and expense. In the event
that ZKC and/or, at ZKC's sole discretion, ZKC's Third Party licensor with
respect to the ZKC Patents that are the subject of such actual or threatened
infringement bring an infringement action against any alleged infringer, Corixa
shall assist and cooperate with ZKC or such Third Party licensor, as applicable,
in any such action at ZKC's and/or such Third Party licensor's request and
expense. The party conducting such action shall have full control over its
conduct, provided that it may not enter into any settlement related to
infringement in the Territory without Corixa's prior written consent, which
consent shall not be unreasonably withheld or delayed.

        (b) In the event that Corixa or ZKC becomes aware of actual or
threatened infringement of a patent covered by this Agreement with respect to
the Licensed Product in the Licensed Field outside the Territory, that party
shall promptly notify the other party in writing. In connection with any such
actual or threatened infringement outside the Territory, ZKC and/or, at ZKC's
sole discretion, ZKC's Third Party licensor with respect to the ZKC Patents,
that are the subject of such actual or threatened infringement shall have the
first right but not the


                                      -17-
<PAGE>

obligation to bring an infringement action against any alleged infringer at its
sole cost and expense. The party conducting such action shall have full control
over its conduct, provided that it may not enter into any settlement related to
infringement in the Territory without Corixa's written consent which consent
shall not be unreasonably withheld or delayed. Corixa shall assist and cooperate
with ZKC or such Third Party licensor, as applicable, in any such action at
ZKC's and/or such Third Party licensor's request and expense. Notwithstanding
the foregoing, in the event such actual or threatened infringement of any ZKC
Patent(s) is in the territory of a sublicense under such ZKC Patent(s) granted
by Corixa to a sublicensee hereunder, such sublicensee shall have the right but
not the obligation to bring an infringement action against the alleged infringer
at its sole cost and expense. Such sublicensee shall have full control over
conduct of such action, provided that it may not enter into any settlement
related to such infringement without ZKC's written consent, which consent shall
not be unreasonably withheld or delayed. ZKC shall assist and cooperate with
such sublicensee, in any such action at such sublicensee's request and expense.

        11.5 Any recovery by Corixa and/or, at Corixa's sole discretion,
Corixa's Third Party licensor with respect to the Corixa Patents or the Joint
Patents that are the subject of an action pursuant to Section 11.3 or Section
11.4, in an amount in excess of expenses and related to an action involving
activities in the Territory shall be retained by Corixa, provided, however, that
in the event ZKC contributes [*] of such expenses, any such excess recovery
shall be shared between ZKC and Corixa, with ZKC receiving [*] and Corixa
receiving [*] of such excess, and provided further that any recovery by ZKC with
respect to the ZKC Patents that are the subject of an action pursuant to Section
11.3 or Section 11.4, in an amount in excess of expenses and related to an
action involving activities in the Territory shall be retained by ZKC, provided,
however, that in the event Corixa and/or the Third Party licensor contributes
[*] of such expenses, any such excess recovery shall be shared between Corixa,
and ZKC with Corixa and/or the Third Party licensor receiving an aggregate of
[*] and ZKC receiving [*] of such excess.

        11.6 The parties shall keep one another informed of the status of their
respective activities regarding any litigation or settlement thereof concerning
the Licensed Product.

        11.7 TO THE EXTENT PERMITTED BY APPLICABLE LAW, CORIXA MAKES NO
REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, OTHER THAN THOSE EXPRESSLY
SET FORTH IN SECTION 17 BELOW, WITH RESPECT TO THE CORIXA PATENTS, THE JOINT
PATENTS OR CORIXA KNOW-HOW AND THE LICENSED PRODUCT RELATED THERETO, INCLUDING
WITHOUT LIMITATION ANY WARRANTY OF NONINFRINGEMENT, PATENTABILITY,
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.

        11.8 ZKC MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED,
OTHER THAN THOSE EXPRESSLY SET FORTH IN SECTION 17 BELOW.

12. CONFIDENTIALITY; PUBLICITY; PUBLICATIONS.

        12.1 Disclosure of Inventions. During the term of this Agreement, Corixa
shall promptly disclose, and shall use good faith efforts to cause any Third
Party(ies) that are Corixa's


--------
* Confidential treatment requested.


                                      -18-
<PAGE>

partner(s) for the development and commercialization of Licensed Product in the
Licensed Field (the "Third Party Partner(s)") to promptly disclose, to ZKC
and/or supply ZKC in a timely fashion with all documented Corixa Know-How, all
Corixa Patents and all relevant patent applications filed and/or controlled by
Corixa or the Third Party Partner(s) and all inventions controlled by Corixa or
the Third Party Partner(s) related to the Licensed Product in the Licensed Field
arising from the performance of the Development and Commercialization Program.
During the term of this Agreement, ZKC shall promptly disclose to Corixa and/or
supply Corixa in a timely fashion with all documented know-how owned or
controlled by ZKC related to the Licensed Product in the Licensed Field, all ZKC
Patents and all relevant patent applications filed and/or controlled by ZKC in
the Territory, and all inventions controlled by ZKC related to the Licensed
Product in the Licensed Field arising from the performance of Development and
Commercialization Program. In addition, each party shall provide the other party
with all information that is reasonably necessary or useful for achieving the
goals of the Development and Commercialization Program. All such reports shall
comply with all applicable requirements of appropriate regulatory agencies in
any country which is or is anticipated to be a significant market for such
Licensed Product.

        12.2 Adverse Drug Events. The parties recognize that each may be
required to submit information and file reports to various governmental agencies
on compounds under clinical investigation, compounds proposed for marketing, or
marketed drugs. In this regard, information must be submitted at the time of
initial filing for investigational use in humans and at the time of a request
for market approval of a new drug. In addition, supplemental information must be
provided on compounds at periodic intervals and adverse drug experiences must be
reported at more frequent intervals depending on the severity of the experience.
Consequently, each party agrees to:

        (a) provide to the other party for initial and/or periodic submission to
government agencies significant information on the Licensed Product from
preclinical laboratory, animal toxicology and pharmacology studies, as well as
adverse drug experience reports from clinical trials and commercial experiences
with the Licensed Product;

        (b) in connection with investigational use of the Licensed Product,
report to the other party within five (5) business days of the initial receipt
of a report of any unexpected Grade 3 or 4 adverse event or serious adverse
event with the Licensed Product or concurrently with the reporting of such
experience to a regulatory agency, if sooner than five (5) business days, or
sooner if required for any party to comply with regulatory requirements; and

        (c) in connection with commercial use of the Licensed Product, report to
the other party within five (5) business days of the initial receipt of a report
of any adverse experience with the Licensed Product that is serious and
unexpected or sooner if required for any party to comply with regulatory
requirements. Serious adverse experiences mean any experience that suggests a
significant hazard, contraindication side-effect or precaution, or any
experience that is fatal or life-threatening, is permanently disabling, requires
or prolongs inpatient hospitalization, or is a congenital anomaly, cancer or
overdose. An unexpected adverse experience is one not identified in nature,
specificity, severity or frequency in the current investigator brochure or the
United States labeling for the Licensed Product. Each party also agrees that if
it contracts with a third party for research to be performed by such third party
on the Licensed Product, that party


                                      -19-
<PAGE>

agrees to require such third party to report to the contracting party the
information set forth in subparagraphs (a), (b) and (c) above, and such
contracting party shall provide this information to the other party.

        12.3 Confidential Information. During the term of this Agreement and for
five (5) years thereafter, irrespective of any termination earlier than the
expiration of the term of this Agreement, Corixa and ZKC shall not use or reveal
or disclose to any Third Party any proprietary or confidential information
received from the other party or otherwise developed by either party in the
performance of activities in furtherance of this Agreement that by its nature or
content, or the context of disclosure, might reasonably be expected to be
confidential ("Confidential Information"), 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 investigating, developing, manufacturing,
selling or marketing the Licensed Product or for securing essential or desirable
authorizations, privileges or rights from governmental agencies, or is required
to be disclosed to a governmental agency, or is necessary to file or prosecute
patent applications concerning the Licensed Product or to carry out any
litigation concerning the Licensed Product or is otherwise required by
applicable law and/or regulations. This confidentiality obligation shall not
apply to such Confidential 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.

        12.4 Permitted Disclosures. Nothing herein shall be construed as
preventing ZKC from disclosing any information received from Corixa to any ZKC
Affiliate, or sublicensee or distributor of ZKC, provided such Affiliate is
bound by similar confidentiality obligations and such sublicensee or distributor
has undertaken in writing a similar obligation of confidentiality with respect
to the confidential information, with Corixa stated as a third-party beneficiary
thereof. In addition, notwithstanding anything herein to the contrary, Corixa
shall have the right to disclose all confidential information related to the
Development and Commercialization Program, the Corixa Patents and the Joint
Patents to Corixa's additional partners for the development and
commercialization of Licensed Product in the Licensed Field outside of the
Territory.

        12.5 Bankruptcy Procedures. 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 or any other similar insolvency event with respect
to 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.


                                      -20-
<PAGE>

        12.6 Publicity.

        (a) The parties to this Agreement may disclose the nature and general
terms of the Agreement in a press release following signature after due
consultation with the other party. The wording of any press release must be
agreed by both parties in advance of its release; provided that such agreement
is not unreasonably withheld by either party. 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.

        (b) Neither party shall publish or provide public disclosure of
information or inventions arising from the performance of the Development and
Commercialization Program (a "Dissemination") without at least sixty (60) 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 detrimental to its intellectual property position, the disseminating party
shall delay such publication for a period sufficient, but in no event greater
than an additional sixty (60) days, 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 ZKC 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, and ZKC shall have the right to disclose information
immediately and without prior consent of Corixa if such disclosure is required
by the rules and regulations of regulatory authorities in Japan, as determined
in good faith by ZKC.

13. GOVERNING LAW; ARBITRATION.

        This Agreement shall be governed by the laws of the State of Washington,
without regard to conflicts of law principles. 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 most senior executive officer having the right
to represent the respective parties shall attempt for a period of not less than
sixty (60) days to resolve such Dispute. Any Dispute that cannot be settled
amicably by agreement of the parties pursuant to the preceding sentence, shall
be finally settled by arbitration in accordance with the arbitration rules of
the American Arbitration Association ("AAA"), 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.
The language of the arbitration shall be in English, and the place of
arbitration shall be Seattle, Washington, USA if arbitration is initiated by ZKC
and Tokyo, Japan if initiated by Corixa. 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. The arbitrators in such proceeding may
expressly consider the amounts paid or payable pursuant to this Agreement in
considering any claim of damages. 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


                                      -21-
<PAGE>

any other proprietary rights. 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.

14. MISCELLANEOUS.

        14.1 Trademarks. Corixa shall be responsible for the selection,
registration and maintenance of all trademarks which are employed in connection
with the Licensed Product in the Territory and Corixa shall own and/or control
any such trademarks and shall use commercially reasonable efforts to ensure that
such trademarks and use thereof by ZKC in the Territory does not infringe any
rights of Third Parties, provided that prior to selection of such trademarks,
Corixa shall provide ZKC an opportunity to review and comment on any such
trademark together with the results of Corixa's non-infringement searches and
analysis related to such trademark and Corixa shall, in good faith and a
commercially reasonable manner, take ZKC's comments into consideration in
Corixa's selection of such trademarks.

        14.2 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.

        14.3 Severability.

               (a) 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.

               (b) 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.

        14.4 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 as of January 18, 1998, as amended December
18, 1998, shall remain 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
amend this Agreement by written instruments specifically referring to and
executed in the same manner as this Agreement.


                                      -22-
<PAGE>

15. NOTICES.

        15.1 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) 754-5711
               Facsimile: (206) 754-5994

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

               IF TO ZKC:
               Zenyaku Kogyo Co., Ltd.
               6-15 Otsuka, 5-Chome
               Bunkyo-Ku, Tokyo 112-8650 Japan
               Attention: Product Development Department
               Telephone: 813-3946-1113
               Facsimile:  813-3947-0520

        15.2 Any notice required or permitted to be given pursuant to this
Agreement shall be effective upon receipt by Corixa or ZKC, as the case may be.

16. ASSIGNMENT.

        Neither this Agreement nor any interest hereunder shall be assignable by
either party without the written consent of the other, provided, however, that
either party may assign this Agreement and all patents related to this Agreement
to any of such party's Affiliates or to any corporation or other entity with
which such party may merge or consolidate, and/or to any corporation or other
entity to which such party may transfer all or substantially all of such party's
assets, without obtaining the consent of other party. Transfer in contravention
of this Section 16 shall be considered a material breach of this Agreement
pursuant to Section 18.5 below. Subject to other provisions of this Section 16,
all rights and obligations under 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. Any assignment in violation of the foregoing shall be
null and void.


                                      -23-
<PAGE>

17. WARRANTIES, REPRESENTATIONS AND COVENANTS.

        17.1 Each party warrants that it has the right to enter into this
Agreement, and that this Agreement is a legal and valid obligation binding upon
such party and enforceable in accordance with its terms.

        17.2 Based on its commercially reasonable diligence, Corixa warrants
that to the best of its knowledge as of the Effective Date (i) Corixa Patents
existing as of the date hereof are valid and enforceable, (ii) Corixa owns or
has the right to license to ZKC on the terms and conditions of this Agreement
the Corixa Patents free and clear of any liens, restriction on use or
encumbrances of any nature whatsoever, (iii) no Third Party, including, without
limitation, Genesis and Stanford Rook, Ltd., has any right to research, develop,
use, have used, sell, offer for sale, have sold, keep and import the Licensed
Product solely for use in the Licensed Field in the Territory, (iv) the Licensed
Product, the distribution, sale, marketing and import of the Licensed Product by
ZKC, the Corixa Patents and the Corixa Know-How does not infringe any rights,
including patent rights, of Third Parties and (v) there are no pending actions,
either actual or threatened, relating to the Licensed Products, Corixa Patents
or Corixa Know-How.

        17.3 ZKC acknowledges that the licenses granted to ZKC herein include
sublicenses under technology that has been licensed by Corixa from certain Third
Parties (the "Corixa Third Party Agreements") attached as Exhibit F, and ZKC
covenants that it shall comply with all terms and conditions of such Corixa
Third Party Agreements that are applicable and relevant to ZKC's sublicense
thereunder. Notwithstanding anything herein to the contrary, the foregoing
covenant shall not be deemed to have the effect of limiting Corixa's
representation and warranty set forth in Section 17.2.

        17.4 LIMITED 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.

18. TERM AND TERMINATION.

        18.1 This Agreement may not be terminated by either party except in
accordance with this Section 18.

        18.2 Unless otherwise terminated, this Agreement shall expire upon the
later of (i) the fifteenth anniversary of the Effective Date and (ii) the
expiration, lapse or invalidation of the last to expire of the Corixa Patents
and the Joint Patents in the Territory. If ZKC requests, upon expiration of this
Agreement under this Section 18.2, that any agreement should be entered into
between the parties hereto in connection with the subject hereof, Corixa shall
enter into good faith negotiations with ZKC for such purpose.

        18.3 If on the later of the first anniversary of the Effective Date and
the date that is two


                                      -24-
<PAGE>

(2) weeks after the date Corixa delivers to ZKC the data analysis of Corixa's US
Phase II clinical study, both Corixa and ZKC shall have determined not to
conduct a future Phase III clinical trial in respect of the Licensed Product,
this Agreement may be terminated by the mutual consent of the parties, in which
event without further action on the part of either party, (i) all rights and
licenses granted to ZKC pursuant to this Agreement with respect to the Licensed
Product, including, without limitation, rights and licenses granted to ZKC to
all Corixa Patents, Joint Patents and Corixa Know-How, shall revert to Corixa
and ZKC shall retain no license rights therein, (ii) Corixa shall have an
exclusive, fully paid-up, royalty-free, worldwide license, with the right to
grant sublicenses worldwide, under all of ZKC's rights, title and interest in
the Joint Patents and, with the exception of the ZKC Patents, all technical
information, materials, know-how and clinical information owned or controlled by
ZKC related to the Licensed Products in the Licensed Field to the extent that
ZKC has the right to grant licenses thereunder on the terms and conditions of
this Agreement, (iii) subject to Corixa's payment of all expenses for the
filing, prosecution and maintenance of the ZKC Patents, Corixa shall have an
exclusive, fully paid-up, royalty-free, worldwide license, with the right to
grant sublicenses worldwide, under all of ZKC's rights, title and interest in
the ZKC Patents to the extent that ZKC has the right to grant licenses
thereunder on the terms and conditions of this Agreement, and (iv) each party
shall retain its respective rights in all Joint Inventions not covered by the
Joint Patents without obligation to the other party, except as provided for by
applicable law, provided that the parties agree to cooperate with each other
with respect to any patenting activities related to such Joint Inventions. In
the event either party wants to obtain a license to the other party's interest
in such Joint Inventions, the parties agree to negotiate the terms of such
license in good faith at such time. In addition, ZKC hereby agrees that in the
event of any such termination, unless Corixa shall otherwise be in breach hereof
or ZKC shall obtain any right to the Licensed Products, ZKC will (a) not assert
any claims against Corixa or its sublicensees with respect to Corixa's or such
sublicensee's practice, use, licensing, manufacturing, marketing, sale or
distribution of the Licensed Product and (b) promptly disclose in physical or
other tangible form to Corixa all materials, technology and data necessary to
allow Corixa to exercise the licenses granted pursuant to this Section 18.3.
Following termination pursuant to this Section 18.3, Corixa shall be responsible
for any and all costs and liabilities in connection with its or its
sublicensee's holding and/or exercise of the licenses granted pursuant to this
Section 18.3.

        18.4 ZKC may terminate this Agreement at its option, without any charge
to, or obligation of indemnification by, ZKC in connection with any Damages
arising on or after the date of such termination, by providing written notice at
any time (i) during the two (2) month period that ends six (6) months following
the first anniversary of the Effective Date and (ii) during the two (2) month
period that ends six (6) months following the second anniversary of the
Effective Date, solely in the event that ZKC determines in good faith for bona
fide scientific or clinical reasons, not to proceed with development of the
Licensed Product. In addition, ZKC may terminate this Agreement at its option,
without any charge to, or obligation of indemnification by, ZKC in connection
with any Damages arising on or after the date of such termination upon three (3)
months prior written notice at any time after Commercial Launch of the Licensed
Product in the Territory, in the event (x) ZKC determines in good faith at such
time through reasonable commercial means the unprofitability of the Licensed
Product in the Territory during a period of six (6) months or (y) ZKC receives a
governmental order to stop selling Licensed Product. In the event ZKC terminates
this Agreement pursuant to this Section 18.4, then (i) all rights and licenses
granted to ZKC pursuant to this Agreement with respect to


                                      -25-
<PAGE>

the Licensed Product, including, without limitation, rights and licenses granted
to ZKC to all Corixa Patents, Joint Patents and Corixa Know-How, shall revert to
Corixa and ZKC shall retain no license rights therein, (ii) Corixa shall have an
exclusive, fully paid-up, royalty-free, worldwide license, with the right to
grant sublicenses worldwide, under all of ZKC's rights, title and interest in
the Joint Patents and, with the exception of the ZKC Patents, all technical
information, materials, know-how and clinical information owned or controlled by
ZKC related to the Licensed Products in the Licensed Field to the extent that
ZKC has the right to grant licenses thereunder on the terms and conditions of
this Agreement, and ZKC shall use good faith efforts and cooperate with Corixa
to transfer ZKC's product registration rights to Corixa, (iii) subject to
Corixa's payment of all expenses for the filing, prosecution and maintenance of
the ZKC Patents, Corixa shall have an exclusive, fully paid-up, royalty-free,
worldwide license, with the right to grant sublicenses worldwide, under all of
ZKC's rights, title and interest in the ZKC Patents to the extent that ZKC has
the right to grant licenses thereunder on the terms and conditions of this
Agreement, and (iv) each party shall retain its respective rights in all Joint
Inventions not covered by the Joint Patents without obligation to the other
party, except as provided for by applicable law, provided that the parties agree
to cooperate with each other with respect to any patenting activities related to
such Joint Inventions. In the event either party wants to obtain a license to
the other party's interest in such Joint Inventions, the parties agree to
negotiate the terms of such license in good faith at such time. In addition, ZKC
hereby agrees that in the event of any such termination, unless Corixa shall
otherwise be in breach hereof or ZKC shall obtain any right to the Licensed
Products, ZKC will (a) not assert any claims against Corixa or its sublicensees
with respect to Corixa's or such sublicensee's practice, use, licensing,
manufacturing, marketing, sale or distribution of the Licensed Product and (b)
promptly disclose in physical or other tangible form to Corixa all materials,
technology, data, regulatory filings and product licenses necessary to allow
Corixa to exercise the licenses granted pursuant to this Section 18.4. Following
termination pursuant to this Section 18.4, Corixa shall be responsible for any
and all costs and liabilities in connection with its or its sublicensee's
holding and/or exercise of the licenses granted pursuant to this Section 18.4.

        18.5

        (a) If either party is in material breach of any material provision of
this Agreement and if such breach is not cured within thirty (30) days (or in
the case of non-payment, fourteen (14) days) 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. The parties agree and acknowledge that any breach by ZKC or Corixa of
Section 8 shall be deemed to be a material breach of a material provision of
this Agreement. ZKC shall also have the right to terminate this Agreement by
giving written notice to Corixa in the event of Corixa's material breach of the
Supply Agreement due to Corixa's failure to supply Materials for ZKC's clinical
trials or commercial use, provided that such termination shall not be effective
if Corixa has cured such material breach within the forty-five (45) day cure
period provided in Section 6.2 of the Supply Agreement.

        (b) In the event ZKC terminates this Agreement pursuant to this Section
18.5 as a result of Corixa's uncured material breach, then if (x) ZKC determines
to continue to use and/or sell the Licensed Products in the Territory, (i) all
rights and licenses granted to ZKC pursuant to Section 4.1(a) of this Agreement
with respect to the Corixa Patents shall remain in effect and


                                      -26-
<PAGE>
 ZKC shall continue to have the obligation to pay royalties in accordance with
Section 5 with respect to Licensed Product thereafter commercialized provided,
however, that the applicable royalty rate(s) set forth in Section 5 shall
thereafter be reduced by [*], (ii) all rights and licenses granted to ZKC
pursuant to Section 4.1(a) of this Agreement with respect to the Joint Patents
shall remain in effect, provided, however, that solely to the extent that any
Licensed Products that are thereafter commercialized are covered by one or more
Valid Claim(s) of at least one Joint Patent but are not covered by any Valid
Claim(s) of any Corixa Patents, the sale of such Licensed Products shall be [*]
(iii) subject to maintenance on their terms and conditions of all Third Party
sublicenses that Corixa has granted as of the effective date of any termination
pursuant to this Section 18.5, all rights and licenses granted to Corixa
pursuant to Section 4.1(b) shall revert to ZKC and (iv) each party shall retain
its respective rights in all Joint Inventions not covered by the Joint Patents
without obligation to the other party, except as provided for by applicable law,
provided that the parties agree to cooperate with each other with respect to any
patenting activities related to such Joint Inventions and, (y) ZKC determines
not to continue to use or sell the Licensed Products in the Territory, (i) ZKC
shall be released from any and all obligations hereunder arising after such
termination, (ii) all rights and licenses granted to ZKC pursuant to this
Agreement with respect to the Licensed Product, including, without limitation,
rights and licenses granted to ZKC to all Corixa Patents, Joint Patents and
Corixa Know-How, shall revert to Corixa and ZKC shall retain no license rights
therein, (iii) subject to maintenance on their terms and conditions of all Third
Party sublicenses that Corixa has granted as of the effective date of any
termination pursuant to this Section 18.5, all rights and licenses granted to
Corixa pursuant to Section 4.1(b) shall revert to ZKC and (iv) each party shall
retain its respective rights in all Joint Inventions not covered by the Joint
Patents without obligation to the other party, except as provided for by
applicable law, provided that the parties agree to cooperate with each other
with respect to any patenting activities related to such Joint Inventions. In
the event either party wants to obtain a license to the other party's interest
in such Joint Inventions, the parties agree to negotiate the terms of such
license in good faith at such time.

        (c) In the event Corixa terminates this Agreement pursuant to this
Section 18.5 as a result of ZKC's uncured material breach, then (i) all rights
and licenses granted to ZKC pursuant to this Agreement with respect to the
Licensed Product, including, without limitation, rights and licenses granted to
ZKC to all Corixa Patents, Joint Patents and Corixa Know-How, shall revert to
Corixa and ZKC shall retain no license rights therein, (ii) Corixa shall have an
exclusive, fully paid-up, royalty-free, worldwide license, with the right to
grant sublicenses worldwide, under all of ZKC's rights, title and interest in
the Joint Patents and, with the exception of the ZKC Patents, all technical
information, materials, know-how and clinical information owned or controlled by
ZKC related to the Licensed Products in the Licensed Field to the extent that
ZKC has the right to grant licenses thereunder on the terms and conditions of
this Agreement, and ZKC shall use good faith efforts and cooperate with Corixa
to transfer ZKC's product registration rights to Corixa, (iii) subject to
Corixa's payment of all expenses for the filing, prosecution and maintenance of
the ZKC Patents, Corixa shall have an exclusive, fully paid-up, royalty-free,
worldwide license, with the right to grant sublicenses worldwide, under all of
ZKC's rights, title and interest in the ZKC Patents to the extent that ZKC has
the right to grant licenses thereunder on the terms and conditions of this
Agreement, and (iv) each party shall retain its respective rights in all Joint
Inventions not covered by the Joint Patents without obligation to the other


--------
* Confidential treatment requested.


                                      -27-
<PAGE>

party, except as provided for by applicable law, provided that the parties agree
to cooperate with each other with respect to any patenting activities related to
such Joint Inventions. In the event either party wants to obtain a license to
the other party's interest in such Joint Inventions, the parties agree to
negotiate the terms of such license in good faith at such time. In addition, ZKC
hereby agrees that in the event of any such termination, unless Corixa shall
otherwise be in breach hereof or ZKC shall obtain any right to the Licensed
Products, ZKC will (a) not assert any claims against Corixa or its sublicensees
with respect to Corixa's or such sublicensee's practice, use, licensing,
manufacturing, marketing, sale or distribution of the Licensed Product and (b)
promptly disclose in physical or other tangible form to Corixa all materials,
technology, data, regulatory filings and product licenses necessary to allow
Corixa to exercise the licenses granted pursuant to this Section 18.5. Following
termination pursuant to this Section 18.5, Corixa shall be responsible for any
and all costs and liabilities in connection with its or its sublicensee's
holding and/or exercise of the licenses granted pursuant to this Section 18.5.

        18.6

        (a) 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 for any
other similar proceedings, 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 of such 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, or if the other party's license, registration,
approval or the like granted by any official or governmental agency is
rescinded, canceled or suspended.

        (b) In the event ZKC terminates this Agreement pursuant to this Section
18.6, then, subject to all bankruptcy laws and regulations applicable to
licensing arrangements, then if (x) ZKC determines to continue to use and/or
sell the Licensed Products in the Territory, (i) all rights and licenses granted
to ZKC pursuant to Section 4.1(a) of this Agreement with respect to the Corixa
Patents shall remain in effect and ZKC shall continue to have the obligation to
pay royalties in accordance with Section 5 with respect to Licensed Product
thereafter commercialized provided, however, that the applicable royalty rate(s)
set forth in Section 5 shall thereafter be reduced by [*], (ii) all rights and
licenses granted to ZKC pursuant to Section 4.1(a) of this Agreement with
respect to the Joint Patents shall remain in effect, provided, however, that
solely to the extent that any Licensed Products that are thereafter
commercialized are covered by one or more Valid Claim(s) of at least one Joint
Patent but are not covered by any Valid Claim(s) of any Corixa Patents, the sale
of such Licensed Products shall be [*] (iii) subject to maintenance on their
terms and conditions of all Third Party sublicenses that Corixa has granted as
of the effective date of any termination pursuant to this Section 18.6, all
rights and licenses granted to Corixa pursuant to Section 4.1(b) shall revert to
ZKC, and (iv) each party shall retain its respective rights in all Joint
Inventions not covered by the Joint Patents without obligation to the other
party, except as provided for by applicable law, provided that the parties agree
to cooperate

--------
* Confidential treatment requested.


                                      -28-
<PAGE>

with each other with respect to any patenting activities related to such Joint
Inventions and, (y) ZKC determines not to continue to use or sell the Licensed
Products in the Territory, (i) ZKC shall be released from any and all
obligations hereunder arising after such termination, (ii) all rights and
licenses granted to ZKC pursuant to this Agreement with respect to the Licensed
Product, including, without limitation, rights and licenses granted to ZKC to
all Corixa Patents, Joint Patents and Corixa Know-How, shall revert to Corixa
and ZKC shall retain no license rights therein, (iii) subject to maintenance on
their terms and conditions of all Third Party sublicenses that Corixa has
granted as of the effective date of any termination pursuant to this Section
18.6, all rights and licenses granted to Corixa pursuant to Section 4.1(b) shall
revert to ZKC, and (iv) each party shall retain its respective rights in all
Joint Inventions not covered by the Joint Patents without obligation to the
other party, except as provided for by applicable law, provided that the parties
agree to cooperate with each other with respect to any patenting activities
related to such Joint Inventions. In the event either party wants to obtain a
license to the other party's interest in such Joint Inventions, the parties
agree to negotiate the terms of such license in good faith at such time.

        (c) In the event Corixa terminates this Agreement pursuant to this
Section 18.6 then, subject to all bankruptcy laws and regulations applicable to
licensing arrangements, then (i) all rights and licenses granted to ZKC pursuant
to this Agreement with respect to the Licensed Product, including, without
limitation, rights and licenses granted to ZKC to all Corixa Patents, Joint
Patents and Corixa Know-How, shall revert to Corixa and ZKC shall retain no
license rights therein, (ii) Corixa shall have an exclusive, fully paid-up,
royalty-free, worldwide license, with the right to grant sublicenses worldwide,
under all of ZKC's rights, title and interest in the Joint Patents and, with the
exception of the ZKC Patents, all technical information, materials, know-how and
clinical information owned or controlled by ZKC related to the Licensed Products
in the Licensed Field to the extent that ZKC has the right to grant licenses
thereunder on the terms and conditions of this Agreement, and ZKC shall use good
faith efforts and cooperate with Corixa to transfer ZKC's product registration
rights to Corixa, (iii) subject to Corixa's payment of all expenses for the
filing, prosecution and maintenance of the ZKC Patents, Corixa shall have an
exclusive, fully paid-up, royalty-free, worldwide license, with the right to
grant sublicenses worldwide, under all of ZKC's rights, title and interest in
the ZKC Patents to the extent that ZKC has the right to grant licenses
thereunder on the terms and conditions of this Agreement, and ZKC shall use good
faith efforts and cooperate with Corixa to transfer ZKC's product registration
rights to Corixa, and (iv) each party shall retain its respective rights in all
Joint Inventions not covered by the Joint Patents without obligation to the
other party, except as provided for by applicable law, provided that the parties
agree to cooperate with each other with respect to any patenting activities
related to such Joint Inventions. In the event either party wants to obtain a
license to the other party's interest in such Joint Inventions, the parties
agree to negotiate the terms of such license in good faith at such time. In
addition, ZKC hereby agrees that in the event of any such termination, unless
Corixa shall otherwise be in breach hereof or ZKC shall obtain any right to the
Licensed Products, ZKC will (a) not assert any claims against Corixa or its
sublicensees with respect to Corixa's or such sublicensee's practice, use,
licensing, manufacturing, marketing, sale or distribution of the Licensed
Product and (b) promptly disclose in physical or other tangible form to Corixa
all materials, technology, data, regulatory filings and product licenses
necessary to allow Corixa to exercise the licenses granted pursuant to this
Section 18.6. Following termination pursuant to this Section 18.6, Corixa shall
be responsible for any and all costs and liabilities in connection with its or
its sublicensee's holding and/or


                                      -29-
<PAGE>

exercise of the licenses granted pursuant to this Section 18.6.

        18.7 The termination of this Agreement pursuant to Section 18.5 or 18.6
does not release the Indemnifying Party (as defined in Section 20.2) from any
obligation of indemnity under Section 20.1.

19. RIGHTS AND DUTIES UPON TERMINATION.

        19.1 Upon termination of this Agreement, Corixa shall have the right to
retain any sums already paid by ZKC hereunder, and ZKC shall pay all sums
accrued hereunder which are due as of the date of termination. For the avoidance
of doubt, as of the date of termination ZKC shall not be liable for any sums
that would have been due and payable under this Agreement after the date of
termination, except for those provided under this Agreement.

        19.2 Upon termination of this Agreement, ZKC shall notify Corixa of the
amount of Licensed Product ZKC and its Affiliates, sublicensees and distributors
then have on hand, the sale of which would be subject to royalty, and ZKC and
its Affiliates, sublicensees and distributors shall thereupon be permitted at
Corixa's sole discretion, the right to sell that amount of Licensed Product,
provided that ZKC shall pay to Corixa the amounts payable thereon at the time
herein provided for.

        19.3 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 1, 7, 11.3, 11.5 through 11.8, 12.3 through
12.6, 14 through 16, 17.4, 18.3, 18.4, 19 and 20, shall survive any expiration
or early termination of this Agreement.

20. INDEMNIFICATION.

        20.1 Subject to Section 20.2 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, sublicensees 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 (i) any breach or violation of, or
failure to properly perform, any covenant or agreement made by such Indemnifying
Party (as defined in Section 20.2) in this Agreement, unless waived in writing
by the Indemnified Party (as defined in Section 20.2); (ii) any breach of any of
the representations or warranties made by such Indemnifying Party in this
Agreement; or (iii) the gross negligence or willful misconduct of the
Indemnifying Party; provided, however, that this subsection (iii) shall not
apply to the extent such Damages are attributable to the gross negligence or
willful misconduct of the Indemnified Party.

        20.2 If either ZKC or Corixa, or any Affiliate of ZKC 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 ZKC, 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


                                      -30-
<PAGE>

Indemnifying Party as contemplated hereby shall not release the Indemnifying
Party from any liability to the Indemnified Party other than any liabilities
caused by such failure. 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.

        20.3 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.

        20.4 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]



                                      -31-
<PAGE>

        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.


<TABLE>
<S>                                             <C>
CORIXA CORPORATION                              ZENYAKU KOGYO CO., LTD.



By:                                             By:
   ---------------------------------------         -------------------------------------
     Mark McDade                                   Kazuhiro Hashimoto
     President and Chief Operating Officer         President and Representative Director
</TABLE>


         SIGNATURE PAGE TO THE ZENYAKU DEVELOPMENT AND LICENSE AGREEMENT


                                      -32-
<PAGE>

                                    EXHIBIT A

                                 PATENT EXHIBIT

                                 CORIXA PATENTS

<TABLE>
<CAPTION>
       COUNTRY           APPLICATION NO.       FILING DATE       PATENT NO.        ISSUE DATE
       -------           ---------------       -----------       ----------        ----------
       <S>               <C>                   <C>               <C>               <C>
        Japan               512187/90          Aug 24, 1990        5501870         Apr 8, 1993
        Japan               10-511516          Aug 28, 1997
         PCT              PCT/NZ98/00189       Dec 23, 1998
</TABLE>


                                       -1-
<PAGE>

                                    EXHIBIT B

                               PVAC SPECIFICATIONS

PVAC is delipidated, deglycolipidated heat-killed Mycobacterium vaccae. Further
specifications for PVAC shall be developed by the parties pursuant to the Supply
Agreement.


                                       -1-
<PAGE>

                                    EXHIBIT C

                    DEVELOPMENT AND COMMERCIALIZATION PROGRAM

                       PROJECT ROLES AND RESPONSIBILITIES:

<TABLE>
<S>                                                                          <C>
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
[*]                                                                          [*]
</TABLE>

--------
* Confidential treatment requested.


                                       -1-
<PAGE>

                                    EXHIBIT D

                          OTHER AUTOIMMUNE INDICATIONS

        AUTOIMMUNE DISEASES COVERED UNDER THE FIRST RIGHT OF NEGOTIATION

Under Exclusive License from SR Pharma, Ltd. to Corixa Corporation:

-   Diabetes
-   Multiple Sclerosis
-   Rheumatoid Arthritis

Under Exclusive Option from SR Pharma, Ltd. to Corixa Corporation (Option Period
Effective Until December 16, 2001)

-   Inflammatory Bowel Disease
-   Lupus
-   Scleroderma

ICD-9 CODES FOR DISEASES UNDER LICENSE TO CORIXA FROM SR PHARMA, LTD.

               Psoriasis

-   Psora NEC 696.1
-   Psoriasis 696.1
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]
        [*]

--------
* Confidential treatment requested.


                                       -2-
<PAGE>

                      Diabetes

-   [*]
               [*]
               [*]
               [*]
               [*]
               [*]

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


                      Multiple Sclerosis

-   Sclerosis, sclerotic
        [*]
        [*]
-   Myelitis [*]
        [*]
-   Neuritis
        [*]


                      Rheumatoid Arthritis

-   rheumatic 714.0
        [*]
        [*]
        [*]
-   rheumatoid (nodular) 714.0
        with
               [*]
               [*]
        [*]
        [*]

--------
* Confidential treatment requested.


                                       -3-
<PAGE>

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


ICD-9 CODES FOR DISEASES UNDER OPTION TO CORIXA FROM SR PHARMA, LTD.

                      Lupus

-   Lupus 710.0
        [*]
        [*]
        [*]
        [*]
               [*]
               [*]
               [*]
                      [*]
                             [*]
                             [*]
                      [*]
        [*]
               [*]
               [*]

                      Inflammatory Bowel Disease

-   Inflammation, inflamed, inflammatory (with exudation)
        [*]
-   Enteritis [*]
               [*]
                      [*]
                             [*]
                                    [*]
                             [*]
                                    [*]
-   Enterocolitis -- see also Enteritis
               [*]
-   Colitis [*]
               [*]
               [*]
                      [*]

--------
* Confidential treatment requested.


                                       -4-
<PAGE>

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

                      Scleroderma

-   Scleroderma, sclerodermia [*]
        [*]
        [*]
        [*]
        [*]


                                       -5-