SecProbe.io

Mail Stop 4720
March 7 , 2016

Garo H. Armen
Chief Executive Officer
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
Registration Statement on Form S -3
Filed  February 26 , 2016
  File No.  333-209749

Dear Mr. Armen:

We have limited our review of your registration statement to those issues we have
addressed in our comments.  In  some of our comments, we may ask you to provide us with
information so we may better understand your disclosure.

Please respond to this letter by amending your registration statement and providing the
requested information .  If you do not believe our com ments apply to your facts and
circumstances or do not believe an amendment is appropriate, please tell us why in your
response.

After reviewing any amendment to your registration statement and the information you
provide in response to these  comments, w e may have additional comments.

General

1. Please note that we will not be in a position to take your filing effective until you have
include d audited financial statements for the year ended December 31, 2015  pursuant to
Article 3 -01 of Regulation S -X. Please be advised that if you choose to incorporate by
reference your Form 10 -K for the fis cal year ended December 31, 2015  which, in turn,
incorporates by reference the Part III informatio n to be included in your 2016  definitive
proxy statement, such Part III information would be required to be filed prior to
effectiveness of your registration statement.  For guidance, please refer to the Division of
Corporation Finance’s Securities Act Forms Compliance and Disclosure Interpretation
123.01, available on the Commission’s website.

Garo H. Armen
Agenus Inc.
March 7 , 2016
Page 2

 2. We note that you have a pending confidential treatment request.  We will not be in a
position to accelerate the effectiveness of your registration statement until we have
completed processing your confidential t reatment request.

Exhibit 5.1

3. It is not appropriate for counsel to include in its opinion assumptions that are overly
broad, assume away the relevant issue, or assume the material facts underlying the
opinion. For example, counsel should not assume that  the registrant has sufficient
authorized shares . Please obtain from counsel and file a revised legal opinion which
retains no such assumptions. For guidance, please see Staff Legal Bulletin No. 19 at
Section II.B.3.a, available on the Commission’s website .

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 the information the Securities Act of 193 3 and
all applicable Securities  Act rules require.   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 event you request accelera tion of the effective date
of the pending registration statement , please provide a written statement from the company
acknowledging that:

 should the Commission or the staff, acting pursuant to delegated authority, declare the
filing effective, it does not  foreclose the 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 f or
the adequacy and accuracy of the disclosure in the filing; and

 the company may not assert staff comments and 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.

Garo H. Armen
Agenus Inc.
March 7 , 2016
Page 3

 Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceler ation are aware of their respective responsibilities under
the Securities Act of 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the securities specified in the above registration statement.  Please allow
adequate time  for us to review any amendment prior to the requested effective date of the
registration statement.

Please contact Alla Berenshteyn at (202) 551 -4325 or Mary Beth Breslin  at (202) 551 -
3625 with any other questions.

Sincerely,

 /s/ Mary Beth Breslin  for

Suzanne  Hayes
Assistant Director
Office of Healthcare and Insurance

cc: Arthur McGivern
Goodwin Procter LLP