POWER OF ATTORNEY
        For Obtaining EDGAR Access Codes and Executing Forms 3, 4 and 5

      Know all by these presents, that the undersigned hereby constitutes and
appoints each of Garo H. Armen, Christine M. Klaskin, Evan D. Kearns and
Jennifer Coffin signing singly, his/her true and lawful attorney-in-fact to:

      (1)  execute for and on behalf of the undersigned all forms necessary to
           revive or obtain new EDGAR Access Codes for the undersigned,
           including without limitation, PMAC, CCC and passwords necessary to
           enable the undersigned to make filings in the United States
           Securities and Exchange Commission's EDGAR system;

      (2)  execute for and on behalf of the undersigned Forms 3, 4 and 5 in
           accordance with Section 16(a) of the Securities Exchange Act of 1934
           and the rules thereunder, and any other forms or reports the
           undersigned may be required to file, in connection with the
           undersigned's ownership, acquisition, or disposition of securities of
           Agenus Inc., a Delaware corporation;

      (3)  do and perform any and all acts for and on behalf of the undersigned
           which may be necessary or desirable to complete the execution of any
           such Form 3, 4 and 5, or other form or report, complete and execute
           any amendment or amendments thereto, and the timely filing of such
           form with the United States Securities and Exchange Commission and
           any other authority; and

      (4)  take any other action of any type whatsoever in connection with the
           foregoing which, in the opinion of such attorney-in-fact, may be of
           benefit to, in the best interest of, or legally required by, the
           undersigned, it being understood that the documents executed by such
           attorney-in-fact on behalf of the undersigned pursuant to this Power
           of Attorney shall be in such form and shall contain such terms and
           conditions as such attorney-in-fact may approve in his/her
           discretion.

      The undersigned hereby grants to each such attorney-in-fact full power and
authority to do and perform all and every act and thing whatsoever requisite,
necessary and proper to be done in the exercise of any of the rights and powers
herein granted, as fully to all intents and purposes as such attorney-in-fact
might or could do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-in-fact, or
his/her substitute or substitutes, shall lawfully do or cause to be done by
virtue of this power of attorney and the rights and powers herein granted.  The
undersigned acknowledges that the foregoing attorneys-in-fact, in serving in
such capacity at the request of the undersigned, are not assuming any of the
undersigned's responsibilities to comply with Section 16 of the Securities
Exchange Act of 1934.

      This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file Forms 3, 4, and 5 with respect to the
undersigned's holdings of and transactions in securities issued by Agenus Inc.,
unless earlier revoked by the undersigned in a signed writing delivered to the
foregoing attorneys-in-fact.

      IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of this 8th day of February, 2021.


/s/Steven O'Day
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Steven O'Day