EXHIBIT 3.1

                AMENDED AND RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                                 ANTIGENICS INC.

         The undersigned, for the purpose of amending and restating the
Certificate of Incorporation of Antigenics Inc. under the laws of the State of
Delaware, hereby certifies as follows:

         1. The name of the corporation is Antigenics Inc. and the date that the
corporation's original Certificate of Incorporation was filed with the Secretary
of State of the State of Delaware was November 10, 1999.

         2. Pursuant to a meeting of the Board of Directors of Antigenics Inc.,
a resolution was duly adopted, pursuant to Sections 141, 242 and 245 of the
General Corporation Law of the State of Delaware, setting forth this Amended and
Restated Certificate of Incorporation and declaring the adoption of this Amended
and Restated Certificate of Incorporation to be advisable. The stockholders of
Antigenics Inc. duly approved this Amended and Restated Certificate of
Incorporation pursuant to a meeting in accordance with Sections 212, 242 and 245
of the General Corporation Law of the State of Delaware.

         3. This Amended and Restated Certificate of Incorporation amends and
restates the Certificate of Incorporation of Antigenics Inc. in its entirety as
follows:

         FIRST: The name of the corporation is Antigenics Inc. (the
"Corporation").

         SECOND: The address of the registered office of the Corporation in the
State of Delaware is 1209 Orange Street, in the City of Wilmington, New Castle
County, Delaware. The name of its registered agent at such address is The
Corporation Trust Company.

         THIRD: The purpose of the corporation is to engage in any lawful act or
activity for which corporations may be organized under the General Corporation
Law of Delaware.

         FOURTH: The Corporation shall be authorized to issue one hundred
twenty-five million (125,000,000) shares of capital stock, which shall be
divided into one hundred million (100,000,000) shares of Common Stock, par value
$0.01 per share, and twenty-five million (25,000,000) shares of Preferred Stock,
par value $0.01 per share.

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         The following is a statement of the designations, preferences, voting
powers, qualifications, special or relative rights and privileges in respect of
the authorized capital stock of the Corporation.

                                 PREFERRED STOCK

         The Board of Directors is authorized, subject to limitations prescribed
by law and the provisions of this Article FOURTH, to provide by resolution for
the issuance of the shares of Preferred Stock in one or more series, and by
filing a certificate pursuant to the applicable law of the State of Delaware, to
establish from time to time the number of shares to be included in each such
series, and to fix the designations, powers, preferences and rights of the
shares of each such series and the qualifications, limitations or restrictions
thereof.

         The authority of the Board with respect to each series shall include,
but shall not be limited to, determination of the following:

         (a) The number of shares constituting that series and the distinctive
designation of that series;

         (b) The dividend rate, if any, on the shares of that series, whether
dividends shall be cumulative, and if so, from which date or dates, and the
relative rights of priority, if any, of payment of dividends on shares of the
series;

         (c) Whether that series shall have voting rights, in addition to the
voting rights provided by law, and, if so, the terms of such voting rights;

         (d) Whether that series shall have conversion privileges, and, if so,
the terms and conditions of such conversion, including provision for adjustment
of the conversion rate in such events as the Board of Directors shall determine;

         (e) Whether or not the shares of that series shall be redeemable, and
if so, the terms and conditions of such redemption, including the date or dates
upon or after which they shall be redeemable, and the amount per share payable
in case of redemption, which amount may vary under different conditions and at
different redemption dates;

         (f) Whether that series shall have a sinking fund for the redemption or
purchase of shares of that series, and if so, the terms and amount of such
sinking fund;

         (g) The rights of the shares of that series in the event of voluntary
or involuntary liquidation, dissolution or winding up of the Corporation, and
the relative rights of priority, if any, of payment of shares of that series;

         (h)  Any other relative rights, preferences and limitations of that
series.

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                                  COMMON STOCK

         The Common Stock is subject to the rights and preferences of the
Preferred Stock as hereinbefore set forth or authorized.

         Subject to the provisions of any applicable law or of the by-laws of
the Corporation, as from time to time amended, with respect to the fixing of a
record date for the determination of stockholders entitled to vote, and except
as otherwise provided herein or by law or by the resolution or resolutions
providing for the issue of any series of Preferred Stock, the holders of
outstanding shares of Common Stock shall have exclusive voting rights for the
election of directors and for all other purposes, each holder of record of
shares of Common Stock being entitled to one vote for each share of Common Stock
standing in his name on the books of the Corporation.

         Subject to the rights of any one or more series of Preferred Stock, the
holders of Common Stock shall be entitled to receive such dividends from time to
time as may be declared by the Board of Directors out of any funds of the
Corporation legally available for the payment of such dividends.

         In the event of the liquidation, dissolution, or winding up of the
Corporation, whether voluntary or involuntary, after payment shall have been
made to the holders of the Preferred Stock of the full amount to which they are
entitled, the holders of Common Stock shall be entitled to share ratably
according to the number of shares of Common Stock held by them in all remaining
assets of the Corporation available for distribution to its stockholders.

ISSUANCE

         Subject to the provisions of this Certificate of Incorporation and
except as otherwise provided by law, the shares of stock of the Corporation,
regardless of class, may be issued for such consideration and for such corporate
purposes as the Board of Directors may from time to time determine.

         FIFTH: The following provisions are inserted for the management of the
business and for the conduct of the affairs of the Corporation:

         1. The number of directors that shall constitute the whole Board of
Directors shall be fixed by resolution of the Board of Directors but in no event
shall be less than one or more than fifteen.

         2. The directors shall be divided into three classes, as nearly equal
in number as the then total number of directors constituting the entire Board
permits, with the term of office of one class expiring each year. The initial
Class I directors elected by the stockholders of the Corporation shall hold
office for a term expiring at the 2000 annual meeting of stockholders; the
initial Class II directors elected by the stockholders of the Corporation shall
hold office for a term expiring at the 2001 annual meeting of stockholders; and
the initial Class III directors elected by the stockholders of the Corporation
shall hold office for a term expiring at the 2002 annual meeting of

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stockholders. At each such annual meeting of stockholders and at each annual
meeting thereafter, successors to the class of directors whose term expires at
that meeting shall be elected for a term expiring at the third annual meeting
following their election and until their successors shall be elected and
qualified, subject to prior death, resignation, retirement or removal. If the
number of directors is changed, any increase or decrease shall be apportioned
among the classes so as to maintain the number of directors in each class as
nearly equal as possible, but in no event will a decrease in the number of
directors shorten the term of any incumbent director. Notwithstanding the
foregoing, and except as otherwise required by law, whenever the holders of any
one or more series of Preferred Stock shall have the right, voting separately as
a class, to elect one or more directors of the Corporation, the election, terms
of office and other features of such directorships shall be governed by the
terms of the vote establishing such series, and such directors so elected shall
not be divided into classes pursuant to this Article FIFTH unless expressly
provided by such terms. This Section 2 of Article FIFTH may not be amended,
revised or revoked, in whole or in part, except by the affirmative vote of the
holders of 80% of the voting power of the shares of all classes of stock of the
Corporation entitled to vote for the election of directors, considered for the
purposes of this Article FIFTH as one class of stock.

         3. Each director chosen to fill a vacancy in the Board of Directors
shall be elected to complete the term of office of the director who is being
succeeded. In the case of any election of a new director to fill a directorship
created by an enlargement of the Board, the Board shall in such election assign
the class of directors to which such additional director is being elected, and
each director so elected shall hold office for the same term as the other
members of the class to which the director is assigned.

         4. Except as otherwise determined by the Board of Directors in
establishing a series of Preferred Stock as to directors elected by holders of
such series, at any special meeting of the stockholders called at least in part
for the purpose, any director or directors may, by the affirmative vote of the
holders of at least a majority of the stock entitled to vote for the election of
directors, be removed from office for cause. The provisions of this subsection
shall be the exclusive method for the removal of directors. This Section 4 of
Article FIFTH may not be amended, revised or revoked, in whole or in part,
except by the affirmative vote of the holders of 80% of the voting power of the
shares of all classes of stock of the Corporation entitled to vote for the
election of directors, considered for the purposes of this Article FIFTH as one
class of stock.

         5. Elections of directors need not be by ballot.

         6. The Board of Directors of the Corporation is expressly authorized to
adopt, amend or repeal the by-laws of the Corporation.

         7. A director of the Corporation shall not be personally liable to the
Corporation or its stockholders for monetary damages for breach of fiduciary
duty as a director, except for liability (i) for any breach of the director's
duty of loyalty to the Corporation or its stockholders, (ii) for acts or
omissions not in good faith or that involve intentional misconduct or a knowing
violation of law, (iii) under Section 174 of the

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Delaware General Corporation Law, or (iv) for any transaction from which the
director derived an improper personal benefit. If the Delaware General
Corporation Law is amended after approval by the stockholders of this Article
FIFTH to authorize corporate action further eliminating or limiting the personal
liability of directors, then the liability of a director of the Corporation
shall be eliminated or limited to the fullest extent permitted by the Delaware
General Corporation Law, as so amended from time to time.

         Any repeal or modification of this Article FIFTH shall not increase the
personal liability of any director of this Corporation for any act or occurrence
taking place before such repeal or modification, nor otherwise adversely affect
any right or protection of a director of the Corporation existing at the time of
such repeal or modification.

         8. Meetings of stockholders may be held anywhere within or without the
State of Delaware. The books of the Corporation may be kept 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 by-laws of the Corporation.

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

         This Article SIXTH may not be amended, revised or revoked, in whole or
in part, except by the affirmative vote of the holders of 80% of the voting
power of the shares of all classes of stock of the Corporation entitled to vote
for the election of directors, considered for the purposes of this Article SIXTH
as one class of stock.

         SEVENTH: The Corporation reserves the right to amend, alter, change or
repeal any provisions contained in this Restated Certificate of Incorporation in
the manner now or hereafter prescribed by statute, and all rights conferred upon
stockholders are granted subject to this reservation.


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         IN WITNESS WHEREOF, the undersigned has duly executed this Amended and
Restated Certificate of Incorporation in the name and on behalf of Antigenics
Inc. on the 7th day of June, 2002.


                                               /s/  Garo H. Armen
                                               ---------------------------------
                                               Garo H. Armen, Chief Executive
                                               Officer



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