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                                                                   Exhibit 10.68

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

                               September 28, 2001



Mr. Takashi Kato
Member of the Board
Executive Vice President
Pharmaceutical Division
Japan Tobacco, Inc.
2-2-1 Toranomon
Minato-ku, Tokyo 105-8422
Japan

RE: LICENSE AND COLLABORATIVE RESEARCH AGREEMENT, DATED JUNE 15, 1999, BETWEEN
CORIXA CORPORATION ("CORIXA") AND JAPAN TOBACCO INC. ("JT") (THE "AGREEMENT")

Dear Mr. Kato:

This Letter Agreement sets forth our understanding regarding the Research
Program to be performed by Corixa during the third year of the Research Program
Term. All capitalized terms not otherwise defined herein shall have the
definitions given them in the Agreement.

Except as set forth herein or otherwise modified in accordance with the
Agreement, the Research Program during the third year of the Research Program
Term will be as set forth in the Year 3 Work Plan attached hereto as Exhibit A
and incorporated herein by this reference (the "Work Plan"). JT will be
responsible for [*]. Also, JT will be responsible for [*] of the Direct Costs
set forth therein. The parties acknowledge that Direct Costs are [*], and
subject to mutual agreement, [*]. In addition to the foregoing, the Research
Program during the third year of the Research Program Term will include [*] in
addition to those identified in the Work Plan (the "Additional [*]"). The
Additional [*] will also be in addition to the [*] pursuant to the Letter
Agreement, dated June 15, 1999, between Corixa and JT. The Additional [*] shall
perform lung cancer antigen [*] in keeping with the goal of validation of
additional antigens for [*]. Each Additional [*] shall be funded by JT at the
rate of [*]. Details of the research goal will be discussed and agreed upon
separately. Data generated as a result of JT funding of the Additional [*] shall
be provided to JT on a regular basis and shall be treated as "Confidential
Information" in keeping with the Agreement.


* Confidential Treatment Requested.
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Unless otherwise agreed between JT and Corixa, the Research Program Term shall
end on July 19, 2002.

If JT agrees to the foregoing, please have the enclosed duplicate original of
this letter executed as indicated below and returned to my attention.

                                            Sincerely,

                                            /s/ Steven Gillis

                                            Steven Gillis, Ph.D.
                                            Chairman, Chief Executive Officer


                                            Acknowledged and Accepted:

                                            JAPAN TOBACCO INC.


                                            /s/ Takashi Kato
                                            ------------------------------------
                                            By: Takashi Kato
                                            Member of the Board
                                            Executive Vice President
                                            Pharmaceutical Division