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                                                                     Exhibit 3.1
                           FIFTH AMENDED AND RESTATED
                          CERTIFICATE OF INCORPORATION
                                       OF
                               CORIXA CORPORATION

                             A Delaware corporation

                        (Pursuant to Sections 242 and 245
                    of the Delaware General Corporation Law)

     CORIXA CORPORATION, a corporation organized and existing under and by
virtue of the General Corporation Law of the State of Delaware, hereby certifies
as follows:

     FIRST: That the name of the corporation is Corixa Corporation and that the
corporation was originally incorporated as WWE Corporation on September 8, 1994
pursuant to the General Corporation Law.

     SECOND: An Amended and Restated Certificate of Incorporation of this
corporation was originally filed with the Secretary of State of Delaware on
September 23, 1994.

     THIRD: An Amended and Restated Certificate of Incorporation of this
corporation was originally filed with the Secretary of State of Delaware on
December 2, 1994.

     FOURTH: An Amended and Restated Certificate of Incorporation of this
corporation was originally filed with the Secretary of State of Delaware on May
10, 1996.

     FIFTH: An Amended and Restated Certificate of Incorporation of this
corporation was originally filed with the Secretary of State of Delaware on
September 24, 1997 and as corrected by that certain Certificate of Correction
filled with the Secretary of State of Delaware on September 26, 1997.

     SIXTH: The Amended and Restated Certificate of Incorporation of this
corporation shall be restated to read in full as follows:

                                   "ARTICLE I

     The name of this corporation is Corixa Corporation.

                                   ARTICLE II

     The address of the registered office of this corporation in the State of
Delaware is 1013 Centre Road, City of Wilmington, County of New Castle, Delaware
19805. The name of its registered agent at such address is Corporation Service
Company.

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                                   ARTICLE III

     The nature of the business or purposes to be conducted or promoted is to
engage in any lawful act or activity for which corporations may be organized
under the General Corporation Law of Delaware.

                                   ARTICLE IV

     This corporation is authorized to issue two classes of stock to be
designated common stock ("Common Stock") and preferred stock ("Preferred
Stock"). The total number of shares which the Corporation is authorized to issue
is Fifty Million (50,000,000) shares. The number of shares of Common Stock
authorized to be issued is Forty Million (40,000,000), par value $0.001 per
share, and the number of shares of Preferred Stock authorized to be issued is
Ten Million (10,000,000), par value $0.001 per share.

     The Preferred Stock may be issued from time to time in one or more series,
without further stockholder approval. The Board of Directors is hereby
authorized, in the resolution or resolutions adopted by the Board of Directors
providing for the issuance of any wholly unissued series of Preferred Stock,
within the limitations and restrictions stated in this Amended and Restated
Certificate of Incorporation, to fix or alter the dividend rights, dividend
rate, conversion rights, voting rights, rights and terms of redemption
(including sinking fund provisions), the redemption price or prices, and the
liquidation preferences of any wholly unissued series of Preferred Stock, and
the number of shares constituting any such series and the designation thereof,
or any of them, and to increase or decrease the number of shares of any series
subsequent to the issue of shares of that series, but not below the number of
shares of such series then outstanding. In case the number of shares of any
series shall be so decreased, the shares constituting such decrease shall resume
the status that they had prior to the adoption of the resolution originally
fixing the number of shares of such series.

                                    ARTICLE V

     Except as otherwise provided in this Amended and Restated Certificate of
Incorporation, in furtherance and not in limitation of the powers conferred by
statute, the Board of Directors is expressly authorized to make, repeal, alter,
amend, and rescind any or all of the Bylaws of this corporation.

                                   ARTICLE VI

     The number of directors of this corporation shall be fixed from time to
time by a bylaw or amendment thereof duly adopted by at least 66-2/3% of the
Board of Directors.

                                   ARTICLE VII

     Elections of directors need not be by written ballot unless the Bylaws of
this corporation shall so provide.



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                                  ARTICLE VIII

     Meetings of stockholders may be held within or without the State of
Delaware, as the Bylaws may provide. The books of this corporation may be kept
(subject to any provision contained in the statutes) outside the State of
Delaware at such place or places as may be designated from time to time by the
Board of Directors or in the Bylaws of this corporation.

                                   ARTICLE IX

     A director of this corporation shall, to the full extent permitted by the
Delaware General Corporation Law as it now exists or as it may hereafter be
amended, not be liable to this corporation or its stockholders for monetary
damages for breach of fiduciary duty as a director. Neither any amendment nor
repeal of this Article, nor the adoption of any provision of this Amended and
Restated Certificate of Incorporation inconsistent with this Article, shall
eliminate or reduce the effect of this Article in respect of any matter
occurring, or any cause of action, suit or claim that, but for this Article,
would accrue or arise, prior to such amendment, repeal or adoption of an
inconsistent provision.

                                    ARTICLE X

     No action required to be taken or that may be taken at any annual or
special meeting of the stockholders of this corporation may be taken without a
meeting, and the power of stockholders to consent in writing, without a meeting,
to the taking of any action is specifically denied.

                                   ARTICLE XI

     To the fullest extent permitted by applicable law, this corporation is
authorized to provide indemnification of (and advancement of expenses to) its
agents (and any other persons to which Delaware law permits this corporation to
provide indemnification) through Bylaw provisions, agreement with such agents or
other persons, vote of stockholders or disinterested directors or otherwise, in
excess of the indemnification and advancement otherwise permitted by Section 145
of the Delaware General Corporation Law, subject only to limits created by
applicable Delaware law (statutory and non-statutory), with respect to actions
for breach of duty to this corporation, its stockholders, and others.

     Any repeal or modification of any of the foregoing provisions of this
Article shall not adversely affect any right or protection of a director,
officer, agent or other person existing at the time of, or increase the
liability of any director of this corporation with respect to any acts or
omissions of such director, officer, agent or other person occurring prior to
such repeal or modification.

                                   ARTICLE XII

     In the election of directors, each holder of shares of any class or series
of capital stock of the Corporation shall be entitled to one vote for each share
held. No stockholder will be permitted to cumulate votes at any election of
directors.


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                                  ARTICLE XIII

     The Board of Directors of the Corporation is expressly authorized to make,
alter or repeal Bylaws of the Corporation. In addition to any requirements of
law and any other provisions hereof (and notwithstanding the fact that approval
by a lesser vote may be permitted by law or any other provision hereof), the
affirmative vote of the holders of at least 66-2/3 percent of the voting power
of the then outstanding shares of stock of all classes and all series of the
Corporation entitled to vote generally in the election of directors, voting
together as a single class, shall be required to amend, alter, repeal, or adopt
any provision inconsistent with this Article XIII or Article VI hereof.

                                   ARTICLE XIV

     This corporation reserves the right to amend, alter, change or repeal any
provision contained in this Amended and Restated Certificate of Incorporation,
in the manner now or hereafter prescribed by statute, and all rights conferred
upon stockholders herein are granted subject to this reservation."

                                     * * * *


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     SEVENTH: That thereafter said amendment and restatement was duly adopted in
accordance with the provisions of Section 242 and Section 245 of the Delaware
General Corporation Law by obtaining a majority vote of each of the Common Stock
and Preferred Stock, in favor of said amendment and restatement in the manner
set forth in Section 228 of the Delaware General Corporation Law.

     IN WITNESS WHEREOF, CORIXA CORPORATION has caused this Amended and Restated
Certificate of Incorporation to be signed by its President and attested to by
its Secretary this 21st day of October, 1997.

                                          CORIXA CORPORATION



                                          /s/ Steven Gillis
                                          --------------------------------------
                                          Steven Gillis, Ph.D.
                                          President and Chief Executive Officer



ATTEST

/s/ William W. Ericson
---------------------------------
William W. Ericson, Secretary


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