SecProbe.io

Mail Stop 6010       January 8, 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
  Registration Statement on Form S-1
  File Number: 333-156556   Filed: January 2, 2009

Dear Dr. Armen:   We have limited our review of your filing to those issues we have addressed in
our comments.  Where indicated, we think you should revise your document in response
to these comments.  If you disagree, we w ill consider your explanation as to why our
comment is inapplicable or a revision is unneces sary.  Please be as detailed as necessary
in your explanation.  In some of our comme nts, we may ask you to provide us with
information so we may better understand your  disclosure.  After reviewing this
information, we may raise additional comments.

 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 any other aspect of our
review.  Feel free to call us at the telephone numbers listed at the end of this letter.
 Form S-1

 General

1. We note that that you have filed a conf idential treatment request on December 19,
2008.  We will not be in a position to  accelerate the effectiveness of your
registration statement until we have completed processing your confidential treatment request.

Garo H. Armen, Ph.D.
Antigenics Inc.  January 8, 2009 Page 2

Plan of Distribution, page 2

2. Please revise your plan of di stribution to describe the secondary offering of the
shares of common stock underlying your c onvertible preferred stock.  Please
provide a discussion of how the shares will be distributed and subsequently resold by the selling shareholders.

* * *
  As appropriate, please amend your regist ration statement in response to these
comments.  You may wish to provide us w ith marked copies of the amendment to
expedite our review.  Please furnish a cove r letter with your amendment that keys your
responses to our comments and provides any requested information.  Detailed cover
letters greatly facilitate our review.  Please understand that we may have additional comments after reviewing your amendmen t and responses to our comments.
  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 Act of 1933 and that they have  provided all information investors require
for an informed investment decision.  Since the company and its management are in possession of all facts relating to a company’ s disclosure, they are responsible for the
accuracy and adequacy of the disclosures they have made.       Notwithstanding our comments, in the ev ent the company requests acceleration of
the effective date of the pending registration statement, it should furnish a letter, at the
time of such request , acknowledging that:

• should the Commission or the staff, acting purs uant to delegated authority, declare the
filing effective, it does not foreclose th e Commission from taking any action with
respect to the filing;

• the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective,  does not relieve the company from its full responsibility
for the adequacy and accuracy of the disclosure in the filing; and

• the company may not assert staff comments a nd the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the
federal securities laws of the United States.
  In addition, please be advi sed that the Division of En forcement has access to all
information you provide to the staff of the Di vision of Corporation Finance in connection
with our review of your filing or in response to our comments on your filing.

Garo H. Armen, Ph.D.
Antigenics Inc.  January 8, 2009 Page 3
 We will consider a written request for acceleration of the effective date of the
registration statement as conf irmation of the fact that t hose requesting acceleration are
aware of their respective re sponsibilities under the S ecurities Act of 1933 and the
Securities Exchange Act of 1934 as they rela te to the proposed public offering of the
securities specified in the above registration statement.  We will act  on the request and,
pursuant to delegated authority, grant acce leration of the effective date.
  We direct your attention to Rules 460 and 461 regarding requesting acceleration
of a registration statement.  Please allow ad equate time after the filing of any amendment
for further review before submitting a request for acceleration.  Please provide this request at least two business days in a dvance of the requested effective date.
  Please contact Bryan Pitko at (202) 551-3203 or me at (202) 551-3715 with any
questions.          S i n c e r e l y ,             J e f f r e y  P .  R i e d l e r          A s s i s t a n t  D i r e c t o r    cc: Paul M. Kinsella
Ropes & Gray LLP  One International Place
Boston, MA 02110-2624