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                                                                  EXHIBIT 10.29


                                OPTION AGREEMENT

        This OPTION AGREEMENT (together with the exhibits hereto the
"Agreement") is entered into the 1st day of March, 1997 (the "Effective Date")
by and between CORIXA CORPORATION, a Delaware corporation with its principal
place of business located at 1124 Columbia Street, Suite 200, Seattle,
Washington 98104 ("Corixa") and SmithKline Beecham Biologicals Manufacturing
S.A., a Belgian corporation with its principal place of business at Rue de
l'Institut 89, B-1330 Rixensart, Belgium ("SB").


                              W I T N E S S E T H:

        WHEREAS, Corixa and SB are parties to a Prostate Cancer Collaboration
and License Agreement (the "Prostate Cancer Agreement") and a Breast Cancer
Collaboration and License Agreement (the "Breast Cancer Agreement") both of even
date herewith (each, the "Collaboration Agreement") whereby the parties have
agreed to collaborate in the research, development and license of antigens for
vaccine products for the prevention and/or treatment of prostate and breast
cancers, respectively;

        WHEREAS, SB desires to acquire from Corixa an option to enter into
additional agreements for antigens for vaccine products for the prevention
and/or treatment of colon and/or ovarian cancers that take the form of the
Collaboration Agreements with appropriate revisions to reflect a modification of
the subject matter to cover colon and/or ovarian cancers.

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

        1. DEFINITIONS

           "Colon Collaboration Agreement" shall have the meaning assigned
thereto in Section 2(a).

           "Colon Field" shall mean any and all in vivo administered
prophylactic and/or therapeutic colon cancer Vaccines (as defined in the
Collaboration Agreements) for use in humans.

           "Colon Option" means the option granted by Corixa to SB pursuant to
Section 2 hereof.

           "Colon Option Period" means the period commencing on the Effective
Date and continuing until the last day of the eighteenth (18th) month following
the Effective Date, as such Colon Option Period may be extended pursuant to
Section 2(c) hereof.


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           "National Exchange" shall mean the Nasdaq National Market or any
other national exchange on which the Common Stock of Corixa is listed.

           "Ovarian Collaboration Agreement" shall have the meaning assigned
thereto in Section 3(a).

           "Ovarian Field" shall mean any and all in vivo administered
prophylactic and/or therapeutic ovarian cancer Vaccines as defined in the
Collaboration Agreement for use in humans.

           "Ovarian Option" means the option granted by Corixa to SB pursuant to
Section 3 hereof.

           "Ovarian Option Period" means the period commencing on the Effective
Date and continuing until the last day of the twelfth (12th) month following the
Effective Date, as such Ovarian Option Period may be extended pursuant to
Section 3(c) hereof.

        2. GRANT OF OPTION FOR COLON FIELD

           (a) Grant of Option

               Subject to the provisions of this Agreement, Corixa hereby grants
to SB an option, exercisable during the Colon Option Period, to enter into a
collaboration and license agreement to cover the Colon Field (the "Colon
Option"), on substantially the same terms and conditions set forth in the
Collaboration Agreement; provided, that the parties acknowledge and agree that
the amounts allocated to research funding and other modifications that reflect
the nature of the disease target may be required (the "Colon Collaboration
Agreement"). SB may exercise the Colon Option at any time on or before the
expiration of the Colon Option Period (i) by providing written notice of
exercise to Corixa prior to the expiration of the Colon Option Period, and (ii)
paying to Corixa a lump sum payment of Five Hundred Thousand United States
Dollars (U.S.$500,000) by wire transfer of immediately available funds, which
payment shall be subject to credit or conversion as set forth in Section 4
below; provided, however, that Corixa may begin discussing possible
collaborations with parties other than SB at any time after ninety (90) days
prior to the expiration of the Colon Option Period; such discussions shall be
terminated forthwith by Corixa if and when SB exercises the Colon Option or
extends the Colon Option Period pursuant to Section 2(c) hereof.

           (b) Initial Option Fee

               Upon execution and delivery of this Agreement, SB shall pay to
Corixa a lump sum payment of One Million Five Hundred Thousand United States
Dollars (US$1,500,000) by wire transfer of immediately available funds, which
payment shall be subject to credit, conversion or repayment as set forth in
Section 4 below.



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           (c) Extension of the Option Period

               SB will have the right to extend the Colon Option Period for one
(1) additional twelve (12) month period by (i) providing written notice to
Corixa of SB's intention to extend the Colon Option Period prior to the
expiration of the initial Colon Option Period, and (ii) making the payment set
forth in Section 2(d) below.

           (d) Option Extension Fee

               If SB elects to extend the Colon Option Period pursuant to
Section 2(c) above, on or before the expiration of the initial Colon Option
Period, SB shall pay to Corixa a lump sum payment of Two Million United States
Dollars (US$2,000,000) by wire transfer of immediately available funds, which
payment shall be subject to credit, conversion or repayment as set forth in
Section 4 below.

        3. GRANT OF OPTION FOR OVARIAN FIELD

           (a) Grant of Option

               Subject to the provisions of this Agreement, Corixa hereby grants
to SB an option, exercisable during the Ovarian Option Period, to enter into a
collaboration and license agreement to cover the Ovarian Field (the "Ovarian
Option"), on substantially the same terms and conditions set forth in the
Collaboration Agreement, provided, that the parties acknowledge and agree that
the amounts allocated to research funding and other modifications that reflect
the nature of the disease target may be required (the "Ovarian Collaboration
Agreement"). SB may exercise the Ovarian Option at any time on or before the
expiration of the Ovarian Option Period (i) by providing written notice of
exercise to Corixa prior to the expiration of the Ovarian Option Period and (b)
paying to Corixa a lump sum payment of Five Hundred Thousand United States
Dollars (U.S.$500,000) by wire transfer of immediately available funds, which
payment shall be subject to credit or conversion as set forth in Section 4
below; provided, however, that Corixa may begin discussing possible
collaborations with parties other than SB at any time after ninety (90) days
prior to the expiration of the Ovarian Option Period. Said discussions shall be
terminated forthwith by Corixa if and when SB exercises the Ovarian Option or
extends the Ovarian Option Period pursuant to Section 3(c) hereof.

           (b) Initial Option Fee

               Upon execution and delivery of this Agreement, SB shall pay to
Corixa a lump sum payment of One Million Five Hundred Thousand United States
Dollars (US$1,500,000) by wire transfer of immediately available funds, which
payment shall be subject to credit, conversion or repayment as set forth in
Section 4 below.

           (c) Extension of the Option Period



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               SB will have the right to extend the Ovarian Option Period for
one (1) additional eighteen (18) month period by (i) providing written notice to
Corixa of SB's intention to extend the initial Ovarian Option Period prior to
the expiration of the initial Ovarian Option Period, and (ii) making the payment
set forth in Section 3(d) below.

           (d) Option Extension Fee

               If SB elects to extend the Ovarian Option Period pursuant to
Section 3(c) above, on or before the expiration of the initial Ovarian Option
Period, SB shall pay to Corixa a lump sum payment of Two Million United States
Dollars (US$2,000,000) by wire transfer of immediately available funds, which
payment shall be subject to credit, conversion or repayment as set forth in
Section 4 below.

        4. OPTION PAYMENTS. All payments made by SB to Corixa pursuant to
Sections 2 and 3 above shall be subject to the following terms and conditions:

           (a) Colon Option Payments. If SB exercises the Colon Option, then all
payments made by SB to Corixa pursuant to Section 2 shall be, at the election of
SB, either (i) credited against future milestones in the Colon Collaboration
Agreement in accordance with Section 4(c) below or (ii) if Corixa's Common Stock
is listed on a National Exchange and Corixa has a market capitalization of not
less than US$128 million (assuming exercise or conversion of all outstanding
options, warrants and other securities exercisable for or convertible into
Corixa's Common Stock), converted into Corixa's Common Stock in accordance with
Section 4(d) below. If SB does not exercise the Colon Option, then all payments
made by SB to Corixa pursuant to Section 2 shall be repaid by Corixa in
accordance with Section 4(e) below.

           (b) Ovarian Option Payments. If SB exercises the Ovarian Option, then
all payments made by SB to Corixa pursuant to Section 3 shall be, at the
election of SB, either (i) credited against future milestones in the Ovarian
Collaboration Agreement in accordance with Section 4(c) below or (ii) if
Corixa's Common Stock is listed on a National Exchange and Corixa has a market
capitalization of not less than US$128 million (assuming exercise or conversion
of all outstanding options, warrants and other securities exercisable for or
convertible into Corixa's Common Stock), converted into shares of Corixa's
Common Stock in accordance with Section 4(d) below. If SB does not exercise the
Ovarian Option, then all payments made by SB to Corixa pursuant to Section 3
shall be repaid by Corixa in accordance with Section 4(e) below.

           (c) Credit Against Milestones. From and after receipt of written
notice from SB to Corixa (the "Credit Notice") of SB's intent to credit payments
made by it pursuant to Section 2 and/or Section 3 of this Agreement, as
applicable (the "Credit Amount"), which Credit Notice shall be made within
fifteen (15) days of the exercise of the Colon Option and/or the Ovarian Option,
as applicable, Corixa shall repay the Credit Amount by applying such Credit
Amount against future milestones that become payable by SB to Corixa in
accordance with the terms of the Colon Collaboration Agreement



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and/or the Ovarian Collaboration Agreement, as applicable, during the period
beginning the date of the Credit Notice(s) and ending on the fifth anniversary
date of the Credit Notice(s). On the fifth anniversary date of the Credit
Notice, Corixa shall pay to SB the balance, if any, of the Credit Amount not
credited against such milestones pursuant to this Section 4(c). However, the
entire Credit Amount or any portion thereof may be prepaid by Corixa at any time
in its sole discretion.

           (d) Conversion to Common Stock. Within thirty (30) days (the
"Conversion Date") following the Corixa's receipt of a written notice from SB
(the "Conversion Notice Date") of SB's intent to convert payments made by it
pursuant to Section 2 and/or Section 3 of this Agreement as applicable into
shares of Corixa's Common Stock, (the "Conversion Amount"), Corixa shall issue
to SB the number of shares of Corixa's Common Stock equal to the Conversion
Amount divided by the "Common Stock Price." For purposes of this Section 4(d),
the "Common Stock Price" shall equal 111.25% of the average closing price for
Corixa's Common Stock during the period beginning six (6) trading days prior to
the Conversion Notice Date and ending on the trading day prior to the date of
the Conversion Notice Date, as reported on the National Exchange.

           (e) Repayment. Within thirty (30) days following expiration of the
Colon Option Period, or the Ovarian Option Period, as the case may be (the "Note
Issuance Date"), to the extent SB has not exercised the Colon Option, or the
Ovarian Option, as applicable, Corixa shall issue to SB an interest-free
promissory note in principal amount equal to the payments made by SB pursuant to
Section 2 in the case of the Colon Option and Section 3 in the case of the
Ovarian Option, which will not bear interest, payable in three (3) equal annual
payments on the third, fourth and fifth anniversaries of the date of this
Agreement

        5. MISCELLANEOUS

           (a) Development Efforts. Upon exercise of the Colon Option and/or
Ovarian Option, the parties will collaborate in the discovery and development of
Antigens for use in Vaccine(s) for the prevention and/or treatment of colon
cancer and/or ovarian cancer, as applicable, by using commercially reasonable
efforts to conduct the activities set forth in a research program plan to be
prepared in good faith jointly by the parties as soon as practicable after the
exercise of the Colon Option and/or Ovarian Option.

           (b) Entire Agreement. This Agreement, entered into as of the date
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 Non Disclosure Agreements dated 17 February 1995
and 10 August 1995, the Tuberculosis Collaboration and License Agreement dated
October 6, 1995 between Corixa Corporation and SmithKline Beecham Biologicals
S.A., the Prostate Cancer



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Collaboration and License Agreement of even date herewith and the Breast Cancer
Collaboration and License Agreement of even date herewith 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.

           (c) Notices. 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
                             Attention: Chief Operating Officer
                             Telephone: (206) 667-5711
                             Telecopy:  (206) 667-5715

           with a copy to:   Venture Law Group
                             4750 Carillon Point
                             Kirkland, Washington 98033
                             Attention: William W. Ericson
                             Telephone: (206) 739-8700
                             Telecopy:  (206) 739-8750

           If to SB:         SmithKline Beecham Biologicals
                             Manufacturing S.A.
                             Rue de l'Institut 89
                             1330 Rixensart, Belgium
                             Attention: Senior Vice President,
                             General Manager
                             Telephone: 32-2-6568250
                             Telecopy:  32-2-6568025

Any notice required or permitted to be given concerning this Agreement shall be
effective upon receipt by the party to whom it is addressed.

           (d) Assignment. Subject to the other provisions of this Section 5(d),
this Agreement and the Options herein granted shall be binding upon and inure to
the benefit of the successors in interest of the respective parties. 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 to any corporation or other entity with which it may
merge or consolidate, and/or to any corporation or other entity to which it may
transfer all or substantially all of its assets,



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without obtaining the consent of the other party; provided that the consent of
the non-transferring party (including, without limitation, by transfer of
assets, merger or consolidation or otherwise) shall be required for any transfer
of all or substantially all assets that materially alters the rights of such
non-transferring party under this Section 5(d).

           (e) Governing Law; Arbitration. This Agreement will be governed by
the laws of the State of Washington, USA. Any dispute, controversy or claim
arising out of or in relation to this Agreement or the breach, termination or
invalidity thereof, that cannot be settled amicably by agreement of the parties
hereto, 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
bio-pharmaceutical industry; provided further, however, that arbitration
proceedings may not be instituted until the party alleging breach of this
Agreement by the other party has given the other party not less than sixty (60)
days notice to remedy any alleged breach and the other party has failed to do
so. The place of arbitration shall be Seattle, Washington, USA if arbitration is
initiated by SB and New York, New York if initiated by Corixa. The award
rendered shall be final and binding upon both parties. The judgment rendered by
the arbitrator shall include costs of arbitration, reasonable attorneys' fees
and reasonable costs for any expert and other witnesses. The arbitration in such
proceeding may expressly consider the amounts paid pursuant to Sections 2 and 3
hereof 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 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.

           (f) Severability; Waiver If any provision of this Agreement is
finally held to be invalid, illegal or unenforceable by a court of competent
jurisdiction, the validity, legality and enforceability of the remaining
provisions shall not be affected or impaired in any way. Any delay in enforcing
a party's rights under this Agreement or any waiver as to a particular default
or other matter shall not constitute a waiver of a party's right to the future
enforcement of its rights under this Agreement.

           (g) [Intentionally omitted.]



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

Agreed to and accepted by:                     Agreed to and accepted by:
CORIXA CORPORATION                             SMITHKLINE BEECHAM BIOLOGICALS
MANUFACTURING S.A.


/s/  STEVEN GILLIS                             /s/  JEAN STEPHENNE
------------------------------                 ------------------------------
Steven Gillis                                  Jean Stephenne
President and CEO                              Senior Vice President and
                                               General Manager






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