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Via Facsimile and U.S. Mail Mail Stop 4720                                                                                                   August 31, 2009 Garo H. Armen, Ph.D.  President and Chief Executive Officer  Antigenics Inc.  162 Fifth Avenue, Suite 900  New York, New York 10010

 Re: Antigenics Inc.
Form 10-K for the Fiscal Year Ended December 31, 2008 Filed March 16, 2009 File Number 000-29089

Dear Dr. Armen:
  We have reviewed your filing and have the following comments.   In our comments, we ask you to provide us with  information to better understand your
disclosure. Where it requests you to revise disclosure, the information you provide should
show us what the revised di sclosure will look like and iden tify the annual or quarterly
filing, as applicable, in which you intend to first include it. If you do not believe that
revised disclosure is necessary, explain the r eason in your response.  After reviewing the
information provided, we may raise additiona l comments and/or request that you amend
your filing.   Please understand that the purpose of our re view process is to assist you in your
compliance with the applicable disclosure  requirements and to  enhance the overall
disclosure in your filing.  We look forward to  working with you in these respects.  We
welcome any questions you may have about our  comments or on any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.

Form 10-K for the Fiscal Year Ended December 31, 2008

Form 10-K
 Business, page 11

1. We note you have entered into license agreements with Glaxo Smith Kline and
Elan in relation to the right to use QS-21 for the development of vaccines.  Please
provide proposed disclosure for your 2009 Form 10-K which includes the
following information in relation to each of these agreements:

Garo H. Armen, Ph.D.
Antigenics Inc.  August 31, 2009 Page 2
 • The amounts paid to date;
• The aggregate potential milestone payments;
• The percentage range of royalties; and,
• Termination provisions

2. We note your disclosure that on Novemb er 30, 2008, you entered into a patent
assignment assigning all rights, title, and inte rest in certain patent applications in
return for an up-front payment and a future payment.  Please identify the entity and patents that you are referring to.  It appears that you are substantially
dependent on this agreement for liquidity  and it amounted to a substantial portion
of your revenue for the year ended Decem ber 31, 2008.   In addition, please file
this agreement as an exhibit to your filing or provide us with your analysis as to
why you are not required to file it.
 Executive Compensation

 Annual Incentive Bonuses, page 108

3. Your Compensation Discussi on and Analysis does not disclose the “company’s
annual goals and objectives and functiona l area goals, as well as individual
performance objectives” that provide th e basis for your NEO’s annual incentive
bonuses.  Please provide us with draft disclosure for your 2009 Form 10-K which provides the following:

• The company, functional area, and in dividual goals and objectives; and
• A discussion of how the level of achie vement will affect the actual bonuses
to be paid.

Additionally, confirm that you will discu ss the achievement of these objectives.
To the extent that the objectives ar e quantified, the disc ussion in your proxy
statement should also be quantified.
4. We note your statement on page 119, that the funding for the target incentive
awards is based on the extent of achieveme nt of a predetermine d set of corporate
objectives and milestones.  Please provide us with draft disclosure for your 2009
Form 10-K which provides the following:

• The predetermined corporate ob jectives and milestones; and,
• A discussion of how the level of achie vement will affect the funding of the
target incentive awards.

Additionally, confirm that you will discu ss the extent to which objectives and
milestones are achieved. To the extent that the objectives are quantified, the discussion in your proxy statem ent should also be quantified.

Garo H. Armen, Ph.D.
Antigenics Inc.  August 31, 2009 Page 3

Exhibits, Financial Statement Schedules, page 135

5. Please file the change of control agre ement you have entered into with Ms.
Klaskin as an exhibit to your filing.

*    *    *    *
 Please respond to these comments within  10 business days or tell us when you
will provide us with a response.  Please furnish a cover letter that keys your responses to
our comments and provide any requested inform ation.  Detailed letter s greatly facilitate
our review.  Please file y our letter on EDGAR under the form type label CORRESP.
  We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filing to be certain that the filing includes all in formation required under
the Securities Exchange Act of 1934 and th at they have provided all information
investors require for an informed invest ment decision.  Since the company and its
management are in possession of all facts re lating to a company’s disclosure, they are
responsible for the accuracy and adequacy of the disclosures they have made.

 In connection with responding to our co mments, please provide, in your letter, a
statement from the company acknowledging that:
• the company is responsible for the adequacy  and accuracy of the disclosure in the
filing;
• staff comments or changes to disclosure  in response to staff comments do not
foreclose the Commission from taking any action with respect to the filing; and
• the company may not assert staff comme nts as a defense in any proceeding
initiated by the Commission or any person under the federal secu rities laws of the
United States.

In addition, please be advise d that the Division of Enfo rcement has access to all
information you provide to the staff of the Divi sion of Corporation Fi nance in our review
of your filing or in response to our comment on your filing.
Please contact Bryan Pitko at  (202) 551-3203 with any quest ions.  In this regard,
please feel free to cont act me at (202) 551-3715.

Sincerely,

  Jeffrey Riedler,  Assistant Director