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CORRESP
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 CORRESP

 AGENUS INC.
 3 Forbes Road Lexington, MA 02421
 May 28, 2025 VIA EDGAR
 U.S. Securities and Exchange Commission Division of Corporation
Finance 100 F Street, N.W. Washington, D.C. 20549

 Attention:
   Joshua Gorsky

 Re:
 Agenus Inc.
 Registration Statement on Form S-3 (File No. 333-287197)
 Request for Acceleration Ladies and
Gentlemen: Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “ Company ”)
hereby requests that the Securities and Exchange Commission (the “ Commission ”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File No. 333-287197) (the “ Registration Statement ”), so that it will be declared effective at 4:00 p.m. Eastern Time on May 30, 2025, or as soon as possible thereafter. The Company hereby
authorizes Zachary Blume of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for acceleration.
 It would be appreciated if, as soon as the Registration Statement is declared effective, you would inform Zachary Blume of Ropes &
Gray LLP, counsel to the Company, at (617) 951-7663.

 Very truly yours,

 AGENUS INC.

 By:

 /s/ Christine M. Klaskin

 Christine M. Klaskin

 Vice President, Finance

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 May 15, 2025

Garo H. Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

 Re: Agenus Inc.
 Registration Statement on Form S-3
 Filed May 12, 2025
 File No. 333-287197
Dear Garo H. Armen:

 This is to advise you that we have not reviewed and will not review your
registration
statement.

 Please refer to Rules 460 and 461 regarding requests for acceleration.
We remind you
that the company and its management are responsible for the accuracy and
adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action
by the staff.

 Please contact Joshua Gorsky at 202-551-7836 with any questions.

 Sincerely,

 Division of
Corporation Finance
 Office of Life
Sciences
cc: Zachary Blume
</TEXT>
</DOCUMENT>

CORRESP
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CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 November 19, 2019

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.W.

 Washington, D.C. 20549

Attention:
 Mary Beth Breslin

Irene Paik

Re:
 Agenus Inc.

Registration Statement on Form S-3 (File No. 333-234333)

 Request for Acceleration

 Ladies
and Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”)
hereby requests that the Securities and Exchange Commission (the “Commission”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File No. 333-234333) (the “Registration Statement”), so that it will be declared effective at 4:00 p.m. Eastern Time on November 22, 2019, or as soon as possible thereafter. The Company hereby
authorizes Zachary Blume and Rachael Diament of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for acceleration.

It would be appreciated if, as soon as the Registration Statement is declared effective, you would inform Rachael Diament of Ropes &
Gray LLP, counsel to the Company, at (212) 596-9159.

 Very truly yours,

 AGENUS INC.

 By:

 /s/ Evan D. Kearns

Evan D. Kearns

VP & General Counsel

November 18, 2019
Garo H. Armen, Ph.D.
Chief Executive Officer
Agenus Inc.
3 Forbes Road
Lexington, Massachusetts 02421
Re:Agenus Inc.
Form 10-K for Fiscal Year Ended December 31, 2018
Filed March 18, 2019
File No. 000-29089
Dear Dr. Armen:
            We have completed our review of your filing.  We remind you that the company and its
management are responsible for the accuracy and adequacy of their disclosures, notwithstanding
any review, comments, action or absence of action by the staff.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Zachary R. Blume - Ropes & Gray LLP

CORRESP
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CORRESP

 ROPES & GRAY LLP

 PRUDENTIAL
TOWER

 800 BOYLSTON STREET

 BOSTON, MA 02199-3600

WWW.ROPESGRAY.COM

 November 8, 2019

VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F. Street, N.E.

Washington, D.C. 20549

Attention:

Mary Beth Breslin

Mary Mast

Irene Paik

Lisa Vanjoske

Re:

Agenus Inc.

Form 10-K for Fiscal Year Ended December 31, 2018

Response dated October 7, 2019

File No. 000-29089

 Ladies and Gentlemen:

 On behalf
of Agenus Inc. (the “Company” or “Agenus”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the Securities
and Exchange Commission, dated October 25, 2019 (the “Comment Letter”), with regard to the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018
(filed March 18, 2019). For the convenience of the Staff’s review, we have set forth the comments contained in the Comment Letter in italics followed by the responses of the Company.

Form 10-K for Fiscal Year Ended December 31, 2018

Item 1. Business

 Our Business, page 3

1. We note your response to our prior comment 2. However, terms such as
“best-in-class” and “first-in-class” suggest that the product
candidates are effective and likely to be approved. In future filings, please delete these references. If your use of these terms was intended to convey your belief that the products are based on a novel technology or approach and/or is further

Securities and Exchange Commission

 Division of Corporation Finance

November 8, 2019

along in the development process than a third party, you may discuss how your technology differs from existing antibodies and, if applicable, that you are not aware of competing products that are
further along in the development process. Statements such as these should be accompanied by cautionary language that the statements are not intended to give any indication that the product candidates have been proven effective or that they will
receive regulatory approval.

 Response:

 The
Company advises the Staff that it maintains that the applicable product candidates have the potential to be “best-in-class” and/or “first-in-class,” based on the preclinical and clinical data, and other information, provided to the Staff in response to comment 2 in the Company’s letter
dated October 7, 2019. In future filings, the Company will revise its disclosure to include cautionary language that such statements are not intended to give any indication that the product candidates have been proven effective or that they
will receive regulatory approval. The Company will also refer to these product candidates in a stage-appropriate way (i.e., preclinical or investigational) to clarify that such product candidates remain in preclinical or clinical trials and have not
yet been approved.

 Item 1A. Risk Factors

 Risks
Related to our Tokens, page 36

 2. We note your responses to our prior comments 4-10 that you are not
pursuing the offering of Tokens and will remove from future filings information regarding the Token offering. Please confirm that you will disclose in future filings, to the extent true, that you are not pursuing the offering of Tokens and have not
issued any Tokens.

 Response:

 The Company
acknowledges the Staff’s comment and confirms that in its most recent Quarterly Report on Form 10-Q for the quarter ended September 30, 2019 filed with the Securities and Exchange Commission on
November 7, 2019, the Company disclosed that it is not currently offering any Tokens at this time and that it has not issued any Tokens to date.

***

 2

 We hope that the foregoing has been responsive to the Staff’s comments. If you have any questions or
comments about this letter or need any further information, please call the undersigned at (617) 951-7663.

Very truly yours,

/s/ Zachary R. Blume

Zachary R. Blume

 cc: Evan
Kearns (Agenus Inc.)

November 3, 2019
Garo H. Armen, Ph.D.
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421
Re:Agenus Inc.
Registration Statement on Form S-3
Filed October 25, 2019
File No. 333-234333
Dear Dr. Armen:
            We have limited our review of your registration statement to those issues we have
addressed in our comment.
            Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe our comment applies 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 this comment, we may have additional comments.
Registration Statement on Form S-3 filed October 25, 2019
General
1.We note that there are outstanding comments on your Form 10-K for the fiscal year ended
December 31, 2018.  Please be advised that we will not be in a position to declare your
registration statement on Form S-3 effective until all comments on your Exchange Act
filing are resolved.
            We remind you that the company and its management are responsible for the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.
            Refer to Rules 460 and 461 regarding requests for acceleration.  Please allow adequate
time for us to review any amendment prior to the requested effective date of the registration
statement.

 FirstName LastNameGaro H. Armen, Ph.D.
 Comapany NameAgenus Inc.
 November 3, 2019 Page 2
 FirstName LastName
Garo H. Armen, Ph.D.
Agenus Inc.
November 3, 2019
Page 2
            Please contact Irene Paik at 202-551-6553 or Mary Beth Breslin at 202-551-3625 with
any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Zachary R. Blume - Ropes & Gray LLP

October 25, 2019
Garo H. Armen, Ph.D.
Chief Executive Officer
Agenus Inc.
3 Forbes Road
Lexington, Massachusetts 02421
Re:Agenus Inc.
Form 10-K for Fiscal Year Ended December 31, 2018
Response dated October 7, 2019
File No. 000-29089
Dear Dr. Armen:
            We have reviewed your October 7, 2019 response to our comment letter and have the
following 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 these comments within ten business days by providing the requested
information or advise us as soon as possible when you will respond.  If you do not believe our
comments apply to your facts and circumstances, please tell us why in your response.
            After reviewing your response to these comments, we may have additional
comments.  Unless we note otherwise, our references to prior comments are to comments in our
September 19, 2019 letter.
Form 10-K for Fiscal Year Ended December 31, 2018
Item 1. Business
Our Business, page 3
1.We note your response to our prior comment 2.  However, terms such as "best-in-class"
and "first-in-class" suggest that the product candidates are effective and likely to be
approved.  In future filings, please delete these references. If your use of these terms was
intended to convey your belief that the products are based on a novel technology or
approach and/or is further along in the development process than a third party, you may
discuss how your technology differs from existing antibodies and, if applicable, that you
are not aware of competing products that are further along in the development process.
Statements such as these should be accompanied by cautionary language that the

 FirstName LastNameGaro H. Armen, Ph.D.
 Comapany NameAgenus Inc.
 October 25, 2019 Page 2
 FirstName LastName
Garo H. Armen, Ph.D.
Agenus Inc.
October 25, 2019
Page 2
statements are not intended to give any indication that the product candidates have been
proven effective or that they will receive regulatory approval.
Item 1A. Risk Factors
Risks Related to our Tokens, page 36
2.We note your responses to our prior comments 4-10 that you are not pursuing the offering
of Tokens and will remove from future filings information regarding the Token offering.
Please confirm that you will disclose in future filings, to the extent true, that you are not
pursuing the offering of Tokens and have not issued any Tokens.
            You may contact Lisa Vanjoske at 202-551-3614 or Mary Mast at 202-551-3613 if
you have questions regarding comments on the financial statements and related matters.
Please contact Irene Paik at 202-551-6553 or Mary Beth Breslin at 202-551-3625 with any
other questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Zachary R. Blume - Ropes & Gray LLP

CORRESP
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CORRESP

 ROPES & GRAY LLP

 PRUDENTIAL TOWER

800 BOYLSTON STREET

 BOSTON, MA 02199-3600

WWW.ROPESGRAY.COM

 October 7, 2019

 VIA
EDGAR

 Securities and Exchange Commission

 Division
of Corporation Finance

 100 F. Street, N.E.

 Washington, D.C.
20549

Attention:

 Mary Beth Breslin

 Mary Mast

Irene Paik

 Lisa Vanjoske

Re:

 Agenus Inc.

 Annual Report on Form 10-K

 Filed March 18, 2019

File No. 000-29089

 Ladies and Gentlemen:

 On behalf
of Agenus Inc. (the “Company” or “Agenus”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the Securities
and Exchange Commission, dated September 19, 2019 (the “Comment Letter”), with regard to the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2018
(filed March 18, 2019). For the convenience of the Staff’s review, we have set forth the comments contained in the Comment Letter in italics followed by the responses of the Company.

Annual Report on Form 10-K filed March 18, 2019

Item 1. Business

 Our Business, page 3

1. In future filings, please revise your disclosure to include the royalty terms for your agreements with Gilead, Incyte, UVA, Ludwig and UConn. In
addition, with respect to the UConn agreement, please disclose the pipeline program or product candidate to which the agreement relates, the royalty rate and the “future payments” you are obligated to make under the March 2003 amendment.
With respect to the UVA agreement, please disclose when the last of the licensed patents is scheduled to expire.

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 Response:

The Company acknowledges the Staff’s comment and will revise its disclosure in future filings to include the royalty terms for its agreements with Gilead,
Incyte, UVA, Ludwig and UConn, as well as the additional information requested with respect to the UConn and UVA agreements.

 2. Please tell us why you
believe your assets, such as next generation anti-CTLA-4 (AGEN1181) and TIGIT (AGEN1307) as well as CD137 (AGEN2373) and bispecific antibodies that are partnered with Gilead are potentially “best-in-class and first-in-class” in light of your discussion of your competitors on
pages 11-12 and the early stages of development of these product candidates.

 Response:

The Company believes that these assets are potentially
“best-in-class,” because they have been specifically designed to overcome the limitations of existing antibodies, and the Company has demonstrated this ability
in preclinical studies, as well as an early clinical trial for AGEN1811. Current molecules targeting CTLA-4 (i.e., Yervoy®), TIGIT (i.e., CGEN-15137),
and CD137 (i.e., urelumab) are limited in the population of potential responders (CTLA-4; genomic restrictions Quesada, et al. 2018), they have suboptimal ability to stimulate important tumor killing cytokines
(like interferon gamma) (CTLA-4, TIGIT preclinical data), and they have off-target binding resulting in significant liver toxicity (CD137 BMY data). With respect to
AGEN1223 (a bispecific antibody) and AGEN1423 (a bifunctional antibody), Agenus believes these are potentially “first-in-class,” because they are designed to
address mechanisms that, to the Company’s knowledge, no third party is addressing. The following is more detailed information regarding each asset. If the Staff deems it appropriate, the Company is willing to include additional details in its
future filings to support these statements.

 Anti-CTLA-4 (AGEN1181)

AGEN1181 is engineered with important features that are required to optimize the immune attack against cancer and to expand the benefit to the majority of
patients who harbor a genetic polymorphism (FcyRIIIA) and do not respond to first generation anti-CTLA-4 antibodies (Quesada et al. 2018).

Specifically, in preclinical models, AGEN1181 has demonstrated enhanced binding to the FcyRIIIA receptor, which correlates with superior T cell priming and
activation and regulatory T cells (“Treg”) depletion, including enhanced potency, compared to competitor anti-CTLA-4 antibodies. In animal models, this enhanced binding reveals superior anti-tumor
immunity by a corresponding Fc-enhanced anti-CTLA-4 antibody that is not seen in other molecules, thus underscoring that AGEN1181 employs
best-in-class features and has preclinically demonstrated best-in-class outcomes.

 2

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 Importantly, approximately 60% of patients express a genetic polymorphism in FcyRIIIA. Clinical studies show
that patients with this polymorphism do not respond to currently available CTLA-4 antibodies. AGEN1181 is Fc-engineered to significantly enhance binding to FcyRIIIA to
broaden the efficacy of anti-CTLA-4 regardless of FcyRIIIA polymorphism. To Agenus’ knowledge, no other molecule is designed to address this problem.

Finally, in preclinical assays designed to measure T cell responsiveness, AGEN1181 has demonstrated superior combination potential with anti-PD-1 antibodies as compared to competitive antibodies.

 For the reasons set
forth above and the data available to date, Agenus believes that is has a reasonable basis to state that AGEN1181 has best-in-class potential.

Anti-TIGIT (AGEN1307)

 Similarly, Agenus’ pre-clinical anti-TIGIT antibody, AGEN1307, has best-in-class potential because of its design features that are not observed with
competitor TIGIT antibodies, including its (i) enhanced binding to the FcyRIIIA receptor, (ii) potential ability to treat a broader patient population than competitive antibodies and (iii) superior combination potential with anti-PD-1 antibodies.

 AGEN1307 is the only anti-TIGIT molecule designed as an
IgG1 Fc-engineered antibody known to us that has demonstrated (preclinically) the ability to promote superior binding to FcyRIIIA as compared to known competitor anti-TIGIT antibodies. Agenus’ primary in
vitro immune stimulation assays show that anti-TIGIT antibodies depend on FcyRIIIA binding to enhance T cell responsiveness as determined by IL-2 cytokine secretion. AGEN1307 is designed with this enhancement
and in preclinical studies demonstrated optimal in vitro immune stimulation compared to competitor molecules.

 Finally, AGEN1307 demonstrates superior
single agent activity and combination activity, with anti-PD-1, compared to known competitor anti-TIGIT antibodies.

AGEN1307 is designed to optimize anti-tumor immunity and has demonstrated the ability to do so in a manner that is superior to available anti-TIGIT molecules
in preclinical and in vitro assays.

 Anti-CD137 (AGEN2373)

CD137 is an important therapeutic pathway to promote antitumor immunity due to its ability to enhance T cell and natural killer (NK) cell proliferation,
cytokine secretion, and cellular cytotoxicity. The therapeutic development of CD137-targeting antibodies, such as Bristol Myers Squibb’s (“BMS”) urelumab, has been limited by on-target, off-site toxicity (i.e. liver tox) (Segal et al. 2017).

 3

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 AGEN2373 is a conditionally active CD137 antibody that selectively enhances T and NK cell activity
only during immune co-stimulation, in contrast to urelumab and Pfizer Inc.’s utomilumab. As a result, AGEN2373 is a unique and highly potent molecule that avoids the
on-target, off-site toxicity that has limited the use of urelumab.

AGEN1223 (Bispecific)

 Treg infiltration into tumors is
an important mechanism by which cancers escape immune surveillance. Agenus has developed a bispecific antibody that selectively and potently depletes intratumoral Tregs through the depletion of highly suppressive intratumoral Treg and co-stimulation of tumor-targeting effector T cells.

 Agenus believes this is a first-in-class approach because there are no known bispecific molecules designed to address this important tumor escape mechanism. Importantly, the pharmacology of AGEN1223 cannot be achieved by the
combination of monospecific antibodies targeting the same antigens. The bispecific approach of AGEN1223 takes advantage of the co-expression of the target antigens on intratumoral Tregs, whereas competitor
monospecific antibodies will also bind to target cells that only express one of the antigens, such as peripheral T cells.

 AGEN1423 (Bifunctional)

 AGEN1423 is a bifunctional antibody that is designed to condition the tumor microenvironment by addressing two potent immune suppressing mechanisms
that promote immune evasion. This is a first of its kind molecule in the class – therefore, Agenus’ believes that AGEN1423 is potentially a first-in-class
molecule despite its current stage of development.

 Intellectual Property Portfolio, page 9

3. Please expand your disclosure in future filings regarding your intellectual property portfolio to (i) clarify which patents are owned and which ones
are licensed, (ii) identify the product candidate or platform to which your patents and patent applications apply, and (iii) disclose the foreign jurisdictions where you have issued patents or pending patent applications, and the
corresponding expiration dates (or expected expiration dates).

 Response:

The Company acknowledges the Staff’s comment and will, in future filings, revise its disclosure regarding its intellectual property portfolio to
(i) clarify which patents are owned and which ones are licensed, (ii) identify the product candidate or platform to which the Company’s patents and patent applications apply, and (iii) disclose the foreign jurisdictions where the
Company has issued patents or pending patent applications, and the corresponding expiration dates (or expected expiration dates).

 4

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 Item 1A. Risk Factors

The sale of a significant number of shares could cause the market price of our stock to decline, page 35

4. We note your disclosure that if AGEN2034 is not approved for commercial sale by the FDA before December 31, 2021, Token holders will be permitted to
convert into shares of common stock, and that you retain the right to pay cash in lieu of delivering shares. Please clarify whether conversion will occur automatically or if holders will have the option to hold the Tokens indefinitely. Please also
clarify the conversion ratio if the price per share of the common stock is above $10, in particular how the amount of the “fraction” will be determined.

Response:

 The Company advises the Staff that at this
time the Company is not pursuing its previously announced offering of Biotech Electronic Security Tokens (“Tokens”) and has not issued any Tokens. As a result, the Company will remove from future filings information regarding the
conversion of Tokens, unless and until the Company commences a new offering of Tokens.

 Risks Related to our Tokens, page 36

5. We note your disclosure on page 37 that a “significant portion of the net sales of such product in the U.S. will be paid to Token holders until the
Token holders are paid the full amount to which they are entitled pursuant to their purchase agreement.” Please expand your disclosure in future filings to clarify what Token holders will be entitled to receive. For instance, describe how net
sales will be defined, who will calculate it, and whether it will be audited, the percentage of the net sales of AGEN2034 Token holders will receive, the defined multiple of the purchase price that must be earned prior to any distribution to Token
holders, and any caps on the amount that Token holders will receive. Please also clarify whether the amount Token holders are entitled to receive is correlated to the number of tokens sold or is fixed per Token.

Response:

 As noted in response to Comment 4 above, at
this time the Company is not pursuing its offering of Tokens and has not issued any Tokens. As a result, the Company will remove from future filings information regarding what Token holders are entitled to receive, unless and until the Company
commences a new offering of Tokens.

 6. Please revise your disclosure in future filings to state whether you expect the proceeds from Token sales to
fund all of the costs to develop AGEN2034, including all research and development expenses, legal and professional fees, and other costs related obtaining regulatory approval and commercialization of AGEN2034. To the extent the company funds a
portion of such costs, please clarify whether such funding will affect the portion of the net sales to which Token holders will be entitled. Please also clarify whether the proceeds from sales of Tokens will be used to fund the combination therapy
of AGEN2034 with AGEN1884, or whether they will be used only to fund AGEN2034 as a monotherapy.

 5

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 Response:

As noted in response to Comment 4 above, at this time the Company is not pursuing its offering of Tokens and has not issued any Tokens. As a result, the
Company will remove from future filings information regarding the use of proceeds from Token sales, unless and until the Company commences a new offering of Tokens.

7. We note your disclosure in the Form 10-K filed on March 18, 2019 that the anticipated closing date of the
Token offering is March 2019 and that you plan to raise up to a maximum of $100 million in the offering. We also note that as of the date of the filing of your Form 10-Q on August 9, 2019, you had
not closed on the sale of any Tokens and that you no longer disclose the maximum aggregate offering amount. Please tell us the status of the offering.

Response:

 At this time the Company is not pursuing its
offering of Tokens and has not issued any Tokens.

 8. We note your disclosure on page 37 that you intend to transfer the record ownership of Tokens
from book-entry ledger to the blockchain following the holding period required by Rule 144. You also state that you have not yet selected which blockchain to utilize and that Tokens may “continue to be recorded in a book-entry ledger
indefinitely.” Given this disclosure, please tell us why you believe it is appropriate to identify the Tokens as “digital assets,” “digital securities” or “blockchain-based.”

Response:

 As noted in our response to Comment 4 above,
at this time the Company is not pursuing its offering of Tokens and has not issued any Tokens. If the Company commences a new offering for Tokens, it will evaluate the appropriate identification of such Tokens for use in future filings.

9. We note your disclosure that you have not identified all the persons that will need to provide services and functions critical to the maintenance of the
Tokens. Please tell us the services you will require to develop and maintain the Tokens and distributed ledger technology, the estimated cost of such development and maintenance, and the source of funds for the same.

Response:

 As noted in our response to Comment 4 above,
at this time the Company is not pursuing its offering of Tokens and has not issued any Tokens. If the Company commences a new offering of Tokens, it will provide in future filings additional information about the services required, the estimated
costs of such services, and the source of funds for the same.

 6

 Securities and Exchange Commission

Division of Corporation Finance

 October 7, 2019

 10. We note your disclosure that you do not expect to pay any dividends on the Tokens. Please clarify
whether distributions to Token holders will be considered dividends.

 Response:

As noted in our response to Comment 4 above, at this time the Company is not pursuing its offering of Tokens and has not issued any Tokens. As a result, the
Company will remove from future filings information regarding any distributions potentially payable

September 19, 2019
Garo H. Armen, Ph.D.
Chief Executive Officer
Agenus Inc.
3 Forbes Road
Lexington, Massachusetts 02421
Re:Agenus Inc.
Annual Report on Form 10-K
Filed March 18, 2019
File No. 000-29089
Dear Dr. Armen:
            We have reviewed your filing and have the following 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 these comments within ten business days by providing the requested
information or advise us as soon as possible when you will respond.  If you do not believe our
comments apply to your facts and circumstances, please tell us why in your response.
            After reviewing your response to these comments, we may have additional comments.
Annual Report on Form 10-K filed March 18, 2019
Item 1. Business
Our Business, page 3
1.In future filings, please revise your disclosure to include the royalty terms for your
agreements with Gilead, Incyte, UVA, Ludwig and UConn.  In addition, with respect to
the UConn agreement, please disclose the pipeline program or product candidate to which
the agreement relates, the royalty rate and the "future payments" you are obligated to
make under the March 2003 amendment. With respect to the UVA agreement, please
disclose when the last of the licensed patents is scheduled to expire.
2.Please tell us why you believe your assets, such as next generation anti-CTLA-4
(AGEN1181) and TIGIT (AGEN1307) as well as CD137 (AGEN2373) and bispecific
antibodies that are partnered with Gilead are potentially "best-in-class and first-in-class"
in light of your discussion of your competitors on pages 11-12 and the early stages of
development of these product candidates.

 FirstName LastNameGaro H. Armen, Ph.D.
 Comapany NameAgenus Inc.
 September 19, 2019 Page 2
 FirstName LastNameGaro H. Armen, Ph.D.
Agenus Inc.
September 19, 2019
Page 2
Intellectual Property Portfolio, page 9
3.Please expand your disclosure in future filings regarding your intellectual property
portfolio to (i) clarify which patents are owned and which ones are licensed, (ii) identify
the product candidate or platform to which your patents and patent applications apply, and
(iii) disclose the foreign jurisdictions where you have issued patents or pending patent
applications, and the corresponding expiration dates (or expected expiration dates).
Item 1A. Risk Factors
The sale of a significant number of shares could cause the market price of our stock to decline,
page 35
4.We note your disclosure that if AGEN2034 is not approved for commercial sale by the
FDA before December 31, 2021, Token holders will be permitted to convert into shares of
common stock, and that you retain the right to pay cash in lieu of delivering shares.
Please clarify whether conversion will occur automatically or if holders will have the
option to hold the Tokens indefinitely.  Please also clarify the conversion ratio if the price
per share of the common stock is above $10, in particular how the amount of the
“fraction” will be determined.
Risks Related to our Tokens, page 36
5.We note your disclosure on page 37 that a "significant portion of the net sales of such
product in the U.S. will be paid to Token holders until the Token holders are paid the full
amount to which they are entitled pursuant to their purchase agreement."  Please expand
your disclosure in future filings to clarify what Token holders will be entitled to receive.
For instance, describe how net sales will be defined, who will calculate it, and whether it
will be audited, the percentage of the net sales of AGEN2034 Token holders will
receive, the defined multiple of the purchase price that must be earned prior to any
distribution to Token holders, and any caps on the amount that Token holders will
receive.  Please also clarify whether the amount Token holders are entitled to receive is
correlated to the number of tokens sold or is fixed per Token.
6.Please revise your disclosure in future filings to state whether you expect the proceeds
from Token sales to fund all of the costs to develop AGEN2034, including all research
and development expenses, legal and professional fees, and other costs related obtaining
regulatory approval and commercialization of AGEN2034.  To the extent the company
funds a portion of such costs, please clarify whether such funding will affect the portion of
the net sales to which Token holders will be entitled.  Please also clarify whether the
proceeds from sales of Tokens will be used to fund the combination therapy of
AGEN2034 with AGEN1884, or whether they will be used only to fund AGEN2034 as a
monotherapy.
7.We note your disclosure in the Form 10-K filed on March 18, 2019 that the anticipated
closing date of the Token offering is March 2019 and that you plan to raise up to a

 FirstName LastNameGaro H. Armen, Ph.D.
 Comapany NameAgenus Inc.
 September 19, 2019 Page 3
 FirstName LastName
Garo H. Armen, Ph.D.
Agenus Inc.
September 19, 2019
Page 3
maximum of $100 million in the offering.  We also note that as of the date of the filing of
your Form 10-Q on August 9, 2019, you had not closed on the sale of any Tokens and that
you no longer disclose the maximum aggregate offering amount.  Please tell us the status
of the offering.
8.We note your disclosure on page 37 that you intend to transfer the record ownership of
Tokens from book-entry ledger to the blockchain following the holding period required by
Rule 144. You also state that you have not yet selected which blockchain to utilize and
that Tokens may "continue to be recorded in a  book-entry ledger indefinitely."  Given
this disclosure, please tell us why you believe it is appropriate to identify the Tokens as
"digital assets," "digital securities" or "blockchain-based."
9.We note your disclosure that you have not identified all the persons that will need to
provide services and functions critical to the maintenance of the Tokens.  Please tell us the
services you will require to develop and maintain the Tokens and distributed ledger
technology, the estimated cost of such development and maintenance, and the source of
funds for the same.
10.We note your disclosure that you do not expect to pay any dividends on the
Tokens.  Please clarify whether distributions to Token holders will be considered
dividends.
Item 15. Exhibits and Financial Statement Schedules, page 101
11.In future filings, please include your bylaws as an exhibit.  See Item 601(b)(3) of
Regulation S-K.
            We remind you that the company and its management are responsible for the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.
            You may contact Lisa Vanjoske at 202-551-3614 or Mary Mast at 202-551-3613 if you
have questions regarding comments on the financial statements and related matters.  Please
contact Irene Paik at 202-551-6553 or Mary Beth Breslin at 202-551-3625 with any other
questions.
Sincerely,
Division of Corporation Finance
Office of Healthcare & Insurance
cc:       Zachary R. Blume - Ropes & Gray LLP

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 December 7, 2018

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Attention: Irene Paik

Re:
 Agenus Inc.

 Registration Statement on Form S-3 (File
No. 333-228273)

 Request for Acceleration

Ladies and Gentlemen:

 Pursuant to Rule 461
promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”) hereby requests that its Registration Statement on Form S-3 (File
No. 333-228273) (the “Registration Statement”), be declared effective at 4:00 p.m., Washington, D.C. time, on December 10, 2018, or as soon thereafter as practicable. The Company
hereby authorizes Zachary Blume and Jessica Tracy of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for acceleration.

It would be appreciated if, as soon as the Registration Statement is declared effective, you would inform Jessica Tracy of Ropes &
Gray LLP, counsel to the Company, at (212) 596-9237.

[Signature page follows]

 Very truly yours,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 VP,
Finance

Signature Page to Acceleration Request

January 17, 2018
Christine Klaskin
VP, Finance and Principal Financial Officer
Agenus Inc.
3 Forbes Road
Lexington, MA   02421
Agenus Inc.
Form 10-K for the Fiscal Year Ended December 31, 2016
Filed March 16, 2017
File No. 000-29089Re:
Dear Ms. Klaskin:
            We have completed our review of your filings.  We remind you that the company and its
management are responsible for the accuracy and adequacy of their disclosures, notwithstanding
any review, comments, action or absence by the staff.
Division of Corporation Finance
Office of Healthcare & Insurance

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 January 17, 2018

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 450 Fifth Street, N.W.

 Washington, D.C. 20549

Attention:
Mary Beth Breslin

Dorrie Yale

Re:
Agenus Inc.

Registration Statement on Form S-3 (File No. 333-221465)

Request for Acceleration

 Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”) hereby requests
that the Securities and Exchange Commission (the “Commission”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File
No. 333-221465) (the “Registration Statement”), so that it will be declared effective at 4:00 p.m. Eastern Time on January 19, 2018, or as soon as possible thereafter. The Company
hereby authorizes Zachary Blume and Stephen Hall of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for acceleration.

It would be appreciated if, as soon as the Registration Statement is declared effective, you would inform Stephen Hall of Ropes &
Gray LLP, counsel to the Company, at (617) 235-4684.

 Very truly yours,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 VP,
Finance

CORRESP
1
filename1.htm

CORRESP

 ROPES & GRAY LLP

 PRUDENTIAL
TOWER

 800 BOYLSTON STREET

 BOSTON, MA 02199-3600

WWW.ROPESGRAY.COM

 December 18, 2017

VIA EDGAR

Securities and Exchange Commission

 Division of Corporation
Finance

 100 F. Street, N.E.

 Washington, D.C. 20549

Attention:

 Angela Connell

 Ibolya Ignat

Re:

 Agenus Inc.

 Form 10-K for the Fiscal Year Ended December 31, 2016

 Filed March 16, 2017

Form 10-Q for the Quarterly Period Ended September 30, 2017

Filed November 7, 2017

 File
No. 000-29089

 Ladies and Gentlemen:

 On
behalf of Agenus Inc. (“Agenus” or the “Company”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the
Securities and Exchange Commission, dated November 30, 2017 (the “Comment Letter”), with regard to the Company’s Form 10-K for the fiscal year ended December 31, 2016 (filed
March 16, 2017), and Form 10-Q for the quarterly period ended September 30, 2017 (filed November 7, 2017), File No. 000-29089. For the convenience of
the Staff’s review, we have set forth the comment contained in the Comment Letter in italics followed by the response of the Company. The letter previously filed on December 14, 2017 in response to the Comment Letter (the “December 14th Letter”) inadvertently omitted a portion of the response letter. This letter is intended to replace the December 14th Letter.

Form 10-Q for the Quarterly Period Ended September 30, 2017

Notes to Unaudited Condensed Consolidated Financial Statements

Note H - Collaboration Agreement, page 10

 1. Please
provide us a full accounting analysis with reference to authoritative literature of your February 14, 2017 transactions with Incyte Corporation. Include the following in your analysis.

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

•

With respect to the amendment to your January 9, 2015 License, Development and Commercialization Agreement, explain the basis for your accounting treatment of the $20 million in
accelerated milestone payments as revenue during the nine months ended September 30, 2017. In this regard, discuss your consideration of whether the amendment should be evaluated with the remaining performance obligations from the
original agreement as one arrangement.

•

With respect to the Stock Purchase Agreement also entered into on February 14, 2017, tell us what consideration was given to the fact that the agreements were entered into contemporaneously and how
you accounted for the amount received over the fair value of the shares issued.

 Response:

SUMMARY OF ACCOUNTING CONCLUSIONS

•

The License, Development and Commercialization Agreement, dated January 9, 2015, by and among Company, Agenus Switzerland Inc. (as successor to 4-Antibody AG), Incyte
Corporation (“Incyte”) and Incyte Europe Sarl (the “Collaboration Agreement”) was considered a collaboration arrangement and the First Amendment to the License, Development and Commercialization Agreement, dated
February 14, 2017, by and among (the “Amendment”) was considered a modification and not a new arrangement.

•

The Company recognized $20.0 million as revenue in Q1’17 related to milestones for the GITR and OX-40 projects. Prior to the Amendment, all work required by Agenus had
been performed on these projects and there were no further performance obligations related to them. The milestone payment was considered imminent without the Amendment, however the Amendment caused the amount to be paid earlier than originally
contemplated.

•

The Stock Purchase Agreement, dated February 14, 2017, between the Company and Incyte (the “SPA”) was separate from the Amendment and (1) the consideration received for the purchase of shares
under the SPA was determined to be fair value in accordance with ASC 820 Fair Value Measurements, and (2) the transaction was recorded to equity at the fair value of the consideration exchanged.

Please see below for a detailed analysis of the accounting considerations of the Amendment and the SPA, as well as a summary of key points from the
Collaboration Agreement, which we have included to provide background on the Amendment accounting conclusions.

 2

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

 ORIGINAL AGREEMENT

The following sections relate to the Collaboration Agreement and are included to provide general background information on the Collaboration Agreement and
associated accounting.

 Summary of Original Agreement

On January 9, 2015, Agenus entered into the Collaboration Agreement with Incyte, effective February 19, 2015, pursuant to which Agenus granted Incyte
an exclusive royalty bearing, non-transferable license or sublicense, as applicable, under Agenus intellectual property to develop, manufacture and commercialize four antibody products (targeting GITR, OX-40, TIM-3 and LAG-3) (each, a “Licensed Antibody”) worldwide in hematology and oncology. Incyte granted to Agenus a
non-exclusive, royalty-free, non-transferable license or sublicense, as applicable, under Incyte intellectual property solely to the extent necessary to permit Agenus to
exercise rights to perform their obligations under the Collaboration Agreement and a non-exclusive, fully paid-up sublicensable license or sublicense, as applicable, to
develop, manufacture and commercialize the Licensed Antibodies worldwide outside of hematology and oncology. In accordance with the terms and conditions of the Collaboration Agreement, in November 2015, Agenus and Incyte added three undisclosed
checkpoint modulator (“CPM”) targets into the collaboration.

 Scoping & Related Party Considerations

At the time the Company entered into the Collaboration Agreement, management determined the arrangement met the US GAAP definition of a collaboration
arrangement under ASC 808 as both parties were (a) active participants and (b) exposed to the significant risks and rewards dependent on the commercial success of the activity. Under the Collaboration Agreement, both parties have
the right to participate in a Joint Steering Committee (“JSC”) which directs the activities to be carried out through the antibody programs.

ASC 808-10-45-3 and 45-4 state that the income classification of payments between parties in a collaboration agreement shall be in accordance with other authoritative accounting literature to the extent the income classification
applies based on analogy to such other accounting literature. Based on the nature of the research and development activities to be performed under the Collaboration Agreement, management considered the application of ASC 730-20 Research and Development Arrangements.

 ASC 730-20-25-3 states that if an entity is obligated to repay any of the funds provided regardless of the outcome of the research and development, the entity shall
recognize a liability. The guidance states that repayment may be in the form of cash, securities, or other means. ASC
730-20-25-4 states that an entity may conclude that a liability does not exist when the transfer of the financial risk
involved with the research and development from the entity to the other party is substantive and genuine. Management has determined that the Company is not obligated to re-pay any of the funds received under
the Collaboration Agreement regardless of the outcome of the research and development.

 3

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

 Management also considered ASC
730-20-S99 and ASC 730-20-25-6 regarding
significant related party relationships. It evaluated whether Incyte’s position as a related party of the Company creates an obligation of the Company to repay the upfront payments and concluded there is no liability for the amounts received
because (1) the performance obligations under the arrangement that trigger payment are similar to other non-related party relationships, (2) the Collaboration Agreement that provides an obligation
for us to pay Incyte for development is also consistent with market development agreements, (3) there is no future obligation to pay Incyte royalties, and (4) there is no linkage between product development and additional equity or option
purchase. We therefore concluded that the conditions to overcome the presumption that there is an obligation to repay the funds received under the Collaboration Agreement were met.

Accounting for the Agreement under ASC 605

Units of Account

 The following chart summarizes
the units of account identified based on ASC 605-25 separation criteria:

 Unit of
Account

 Description

1

Perpetual license of IP to GITR antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

2

Perpetual license of IP to OX-40 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

3

Perpetual license of IP to TIM-3 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

4

Perpetual license of IP to LAG-3 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

5

Access to Discovery Projects (as defined in the Collaboration Agreement) during the Discovery Period (as defined in the Collaboration Agreement).

 Participation in the JSC was not determined to be a unit of account as participation is optional and non-participation would not be considered a breach of contract or result in a penalty. We believe this is consistent with the accounting literature with consideration of the SEC Staff comments on Joint Steering
Committees at the 2007 AICPA National Conference on Current SEC and PCAOB Developments.

 4

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

 Management reviewed the guidance of ASC 605-25-25-1 Multiple Element Arrangements, which indicates an entity must determine whether the components of an agreement represent an individual unit of accounting and, if so, the fair value of
the respective units must be determined. The total consideration is then, based on the relative fair value of each unit of accounting, allocated to the respective unit.

As all payments in the Collaboration Agreement are non-refundable and there are no rights of return on any good or
service, the separation criterion in ASC 605-25-25-5(b) is met for all units of account.

Allocation of Consideration

 The allocation
guidance of ASC 605-25-25-1 and 25-2 state that the total arrangement
consideration, which is comprised of the fixed and determinable fees, is to be allocated based on the relative selling price method. The consideration under the Collaboration Agreement was comprised of $25 million in fixed upfront payments and
contingent payments based on research and development services to be delivered and various milestones, and sales-based royalties.

 5

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

 The Company determined that due to the unique and proprietary nature of each deliverable, neither
vendor-specific objective evidence, nor third party evidence of selling price exists for the deliverables. As a result, the best estimate of selling price was used to perform the allocation under the relative selling price method. The fixed and
determinable consideration is comprised of the upfront payments that have been allocated to the deliverables identified above as follows:

 Unit of Account

 Deliverables

Total Fixed
and
Determinable
Consideration

 Additional consideration

 1

GITR antibody program and associated R&D

$
4,000,000

R&D Services, Reimbursements and potential future milestones

 2

OX-40 antibody program and associated R&D

$
3,000,000

R&D Services, Reimbursements and potential future milestones

 3

LAG-3 antibody program and associated R&D

$
1,500,000

R&D Services, Reimbursements and potential future milestones

 4

TIM-3 antibody program and associated R&D

$
1,500,000

R&D Services, Reimbursements and potential future milestones

 5

Discovery Project Access

$
15,000,000

Total

$
25,000,000

 Consistent with ASC
605-25-30-5, the allocation of consideration is limited to amounts that are not contingent.

Recognition

 Units of Account 1-4:

 Antibody Programs (GITR, OX-40,
LAG-3, and TIM-3)

 The upfront consideration allocated to each of the
respective antibody programs was deferred and recognized over the estimated period of service delivered by the Company, as the Company is required to perform pre-clinical R&D services for each Licensed
Antibody until an investigational new drug application (an “IND”) is filed. Subsequent to the IND filing date, Incyte is responsible for all clinical research and development and commercialization activities. The Company is
responsible for all manufacturing activities.

 R&D Services

For all Licensed Antibody programs, the Company provides Incyte with full time equivalent (“FTE”) research and development personnel, at a
rate of $275,000 per FTE per year. The consideration related to R&D services is recognized in the month the service is performed as revenue (not as a reduction of costs).

R&D Services Reimbursements

 For all Licensed
Antibody programs, the Company is reimbursed by Incyte for certain costs incurred during the performance of research and development activities.

 6

 Securities and Exchange Commission

Division of Corporation Finance

 December 18, 2017

 Under the Collaboration Agreement, some of the programs were designated as profit-share programs and others
were designated as royalty-bearing programs.

 Profit Share Programs

Prior to the Amendment, for certain Licensed Antibody programs, Agenus and Incyte split the profit and loss as earned, on a 50/50 basis,
related to the R&D, manufacturing and commercialization of the related product. The amount of consideration is based on the profit or loss in a particular period. Agenus recognized profit share payments as revenue/expense in the period in which
the services were provided as that was the time at which the fee became fixed and determinable.

 Royalty-bearing Programs

On all other programs, Agenus is compensated for 100% of its R&D services and will earn royalties on sales of the related product. The
amount of the royalty is based on the agreed upon tiered royalty schedule in the Collaboration Agreement. Agenus recognizes consideration related to royalty-bearing programs as revenue in the period in which the services are provided as that is the
time at which the fee becomes fixed and determinable. Sales-based royalties will be recognized as revenue at the time the sale of the related product is communicated to Agenus as that is the time at which the fee becomes fixed and determinable.

Milestone Payments

 For all Licensed Antibody programs,
the Collaboration Agreement includes various milestones contingent on the initiation/completion of clinical trials, receipt of regulatory approvals, and certain sales thresholds. These milestones were evaluated and (1) determined to meet the
criteria to be substantive milestones and (2) the fee paid at each milestone represented the relative selling price. Accordingly, the Company has elected the milestone method in ASC 605-28. As a
result, milestones are recognized as revenue in their entirety in the period in which achieved.

 Unit of Account 5:

Discovery Project Access

 Incyte has access to certain
additional targets (“Discovery Projects”) during the Discovery Period, a period of approximately five years, commencing upon the effective date of the agreement (February 19, 2015) and terminating on December 31, 2019. At the
mutual agreement of the parties, the Discovery Period can be extended for an additional three yea

CORRESP
1
filename1.htm

CORRESP

 ROPES & GRAY LLP

 PRUDENTIAL
TOWER

 800 BOYLSTON STREET

 BOSTON, MA 02199-3600

WWW.ROPESGRAY.COM

 December 14, 2017

VIA EDGAR

Securities and Exchange Commission

 Division of Corporation
Finance

 100 F. Street, N.E.

 Washington, D.C. 20549

Attention:

 Angela Connell

 Ibolya Ignat

Re:

 Agenus Inc.

 Form 10-K for the Fiscal Year Ended December 31, 2016

 Filed March 16, 2017

Form 10-Q for the Quarterly Period Ended September 30, 2017

Filed November 7, 2017

 File
No. 000-29089

 Ladies and Gentlemen:

 On
behalf of Agenus Inc. (“Agenus” or the “Company”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the
Securities and Exchange Commission, dated November 30, 2017 (the “Comment Letter”), with regard to the Company’s Form 10-K for the fiscal year ended December 31, 2016 (filed
March 16, 2017), and Form 10-Q for the quarterly period ended September 30, 2017 (filed November 7, 2017), File No. 000-29089. For the convenience of
the Staff’s review, we have set forth the comment contained in the Comment Letter in italics followed by the response of the Company.

 Form 10-Q for the Quarterly Period Ended September 30, 2017

 Notes to Unaudited Condensed Consolidated Financial
Statements

 Note H - Collaboration Agreement, page 10

1. Please provide us a full accounting analysis with reference to authoritative literature of your February 14, 2017 transactions with Incyte
Corporation. Include the following in your analysis.

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

•

With respect to the amendment to your January 9, 2015 License, Development and Commercialization Agreement, explain the basis for your accounting treatment of the $20 million in
accelerated milestone payments as revenue during the nine months ended September 30, 2017. In this regard, discuss your consideration of whether the amendment should be evaluated with the remaining performance obligations from the
original agreement as one arrangement.

•

With respect to the Stock Purchase Agreement also entered into on February 14, 2017, tell us what consideration was given to the fact that the agreements were entered into contemporaneously and how
you accounted for the amount received over the fair value of the shares issued.

 Response:

SUMMARY OF ACCOUNTING CONCLUSIONS

•

The License, Development and Commercialization Agreement, dated January 9, 2015, by and among Company, Agenus Switzerland Inc. (as successor to 4-Antibody AG), Incyte
Corporation (“Incyte”) and Incyte Europe Sarl (the “Collaboration Agreement”) was considered a collaboration arrangement and the First Amendment to the License, Development and Commercialization Agreement, dated
February 14, 2017, by and among (the “Amendment”) was considered a modification and not a new arrangement.

•

The Company recognized $20.0 million as revenue in Q1’17 related to milestones for the GITR and OX-40 projects. Prior to the Amendment, all work required by Agenus had
been performed on these projects and there were no further performance obligations related to them. The milestone payment was considered imminent without the Amendment, however the Amendment caused the amount to be paid earlier than originally
contemplated.

•

The Stock Purchase Agreement, dated February 14, 2017, between the Company and Incyte (the “SPA”) was separate from the Amendment and (1) the consideration received for the purchase of shares
under the SPA was determined to be fair value in accordance with ASC 820 Fair Value Measurements, and (2) the transaction was recorded to equity at the fair value of the consideration exchanged.

Please see below for a detailed analysis of the accounting considerations of the Amendment and the SPA, as well as a summary of key points from the
Collaboration Agreement, which we have included to provide background on the Amendment accounting conclusions.

 2

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

 ORIGINAL AGREEMENT

The following sections relate to the Collaboration Agreement and are included to provide general background information on the Collaboration Agreement and
associated accounting.

 Summary of Original Agreement

On January 9, 2015, Agenus entered into the Collaboration Agreement with Incyte, effective February 19, 2015, pursuant to which Agenus granted Incyte
an exclusive royalty bearing, non-transferable license or sublicense, as applicable, under Agenus intellectual property to develop, manufacture and commercialize four antibody products (targeting GITR, OX-40, TIM-3 and LAG-3) (each, a “Licensed Antibody”) worldwide in hematology and oncology. Incyte granted to Agenus a
non-exclusive, royalty-free, non-transferable license or sublicense, as applicable, under Incyte intellectual property solely to the extent necessary to permit Agenus to
exercise rights to perform their obligations under the Collaboration Agreement and a non-exclusive, fully paid-up sublicensable license or sublicense, as applicable, to
develop, manufacture and commercialize the Licensed Antibodies worldwide outside of hematology and oncology. In accordance with the terms and conditions of the Collaboration Agreement, in November 2015, Agenus and Incyte added three undisclosed
checkpoint modulator (“CPM”) targets into the collaboration.

 Scoping & Related Party Considerations

At the time the Company entered into the Collaboration Agreement, management determined the arrangement met the US GAAP definition of a collaboration
arrangement under ASC 808 as both parties were (a) active participants and (b) exposed to the significant risks and rewards dependent on the commercial success of the activity. Under the Collaboration Agreement, both parties have
the right to participate in a Joint Steering Committee (“JSC”) which directs the activities to be carried out through the antibody programs.

ASC 808-10-45-3 and 45-4 state that the income classification of payments between parties in a collaboration agreement shall be in accordance with other authoritative accounting literature to the extent the income classification
applies based on analogy to such other accounting literature. Based on the nature of the research and development activities to be performed under the Collaboration Agreement, management considered the application of ASC 730-20 Research and Development Arrangements.

 ASC 730-20-25-3 states that if an entity is obligated to repay any of the funds provided regardless of the outcome of the research and development, the entity shall
recognize a liability. The guidance states that repayment may be in the form of cash, securities, or other means. ASC
730-20-25-4 states that an entity may conclude that a liability does not exist when the transfer of the financial risk
involved with the research and development from the entity to the other party is substantive and genuine. Management has determined that the Company is not obligated to re-pay any of the funds received under
the Collaboration Agreement regardless of the outcome of the research and development.

 3

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

 Management also considered ASC
730-20-S99 and ASC 730-20-25-6 regarding
significant related party relationships. It evaluated whether Incyte’s position as a related party of the Company creates an obligation of the Company to repay the upfront payments and concluded there is no liability for the amounts received
because (1) the performance obligations under the arrangement that trigger payment are similar to other non-related party relationships, (2) the Collaboration Agreement that provides an obligation
for us to pay Incyte for development is also consistent with market development agreements, (3) there is no future obligation to pay Incyte royalties, and (4) there is no linkage between product development and additional equity or option
purchase. We therefore concluded that the conditions to overcome the presumption that there is an obligation to repay the funds received under the Collaboration Agreement were met.

Accounting for the Agreement under ASC 605

Units of Account

 The following chart summarizes
the units of account identified based on ASC 605-25 separation criteria:

 Unit of
Account

 Description

1

Perpetual license of IP to GITR antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

2

Perpetual license of IP to OX-40 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

3

Perpetual license of IP to TIM-3 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

4

Perpetual license of IP to LAG-3 antibodies and products and the related services to research and develop these licenses with the intent to manufacture and commercialize

5

Access to Discovery Projects (as defined in the Collaboration Agreement) during the Discovery Period (as defined in the Collaboration Agreement).

 Participation in the JSC was not determined to be a unit of account as participation is optional and non-participation would not be considered a breach of contract or result in a penalty. We believe this is consistent with the accounting literature with consideration of the SEC Staff comments on Joint Steering
Committees at the 2007 AICPA National Conference on Current SEC and PCAOB Developments.

 4

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

 Management reviewed the guidance of ASC 605-25-25-1 Multiple Element Arrangements, which indicates an entity must determine whether the components of an agreement represent an individual unit of accounting and, if so, the fair value of
the respective units must be determined. The total consideration is then, based on the relative fair value of each unit of accounting, allocated to the respective unit.

As all payments in the Collaboration Agreement are non-refundable and there are no rights of return on any good or
service, the separation criterion in ASC 605-25-25-5(b) is met for all units of account.

Allocation of Consideration

 The allocation
guidance of ASC 605-25-25-1 and 25-2 state that the total arrangement
consideration, which is comprised of the fixed and determinable fees, is to be allocated based on the relative selling price method. The consideration under the Collaboration Agreement was comprised of $25 million in fixed upfront payments and
contingent payments based on research and development services to be delivered and various milestones, and sales-based royalties.

 5

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

 The Company determined that due to the unique and proprietary nature of each deliverable, neither
vendor-specific objective evidence, nor third party evidence of selling price exists for the deliverables. As a result, the best estimate of selling price was used to perform the allocation under the relative selling price method. The fixed and
determinable consideration is comprised of the upfront payments that have been allocated to the deliverables identified above as follows:

 Unit of Account

 Deliverables

Total Fixed
and
Determinable
Consideration

 Additional consideration

 1

GITR antibody program and associated R&D

$
4,000,000

R&D Services, Reimbursements and potential future milestones

 2

OX-40 antibody program and associated R&D

$
3,000,000

R&D Services, Reimbursements and potential future milestones

 3

LAG-3 antibody program and associated R&D

$
1,500,000

R&D Services, Reimbursements and potential future milestones

 4

TIM-3 antibody program and associated R&D

$
1,500,000

R&D Services, Reimbursements and potential future milestones

 5

Discovery Project Access

$
15,000,000

Total

$
25,000,000

 Consistent with ASC
605-25-30-5, the allocation of consideration is limited to amounts that are not contingent.

Recognition

 Units of Account 1-4:

 Antibody Programs (GITR, OX-40,
LAG-3, and TIM-3)

 The upfront consideration allocated to each of the
respective antibody programs was deferred and recognized over the estimated period of service delivered by the Company, as the Company is required to perform pre-clinical R&D services for each Licensed
Antibody until an investigational new drug application (an “IND”) is filed. Subsequent to the IND filing date, Incyte is responsible for all clinical research and development and commercialization activities. The Company is
responsible for all manufacturing activities.

 R&D Services

For all Licensed Antibody programs, the Company provides Incyte with full time equivalent (“FTE”) research and development personnel, at a
rate of $275,000 per FTE per year. The consideration related to R&D services is recognized in the month the service is performed as revenue (not as a reduction of costs).

R&D Services Reimbursements

 For all Licensed
Antibody programs, the Company is reimbursed by Incyte for certain costs incurred during the performance of research and development activities.

 6

 Securities and Exchange Commission

Division of Corporation Finance

 December 14, 2017

 Under the Collaboration Agreement, some of the programs were designated as profit-share programs and others
were designated as royalty-bearing programs.

 Profit Share Programs

Prior to the Amendment, for certain Licensed Antibody programs, Agenus and Incyte split the profit and loss as earned, on a 50/50 basis,
related to the R&D, manufacturing and commercialization of the related product. The amount of consideration is based on the profit or loss in a particular period. Agenus recognized profit share payments as revenue/expense in the period in which
the services were provided as that was the time at which the fee became fixed and determinable.

 Royalty-bearing Programs

On all other programs, Agenus is compensated for 100% of its R&D services and will earn royalties on sales of the related product. The
amount of the royalty is based on the agreed upon tiered royalty schedule in the Collaboration Agreement. Agenus recognizes consideration related to royalty-bearing programs as revenue in the period in which the services are provided as that is the
time at which the fee becomes fixed and determinable. Sales-based royalties will be recognized as revenue at the time the sale of the related product is communicated to Agenus as that is the time at which the fee becomes fixed and determinable.

Milestone Payments

 For all Licensed Antibody programs,
the Collaboration Agreement includes various milestones contingent on the initiation/completion of clinical trials, receipt of regulatory approvals, and certain sales thresholds. These milestones were evaluated and (1) determined to meet the
criteria to be substantive milestones and (2) the fee paid at each milestone represented the relative selling price. Accordingly, the Company has elected the milestone method in ASC 605-28. As a
result, milestones are recognized as revenue in their entirety in the period in which achieved.

 Unit of Account 5:

Discovery Project Access

 Incyte has access to certain
additional targets (“Discovery Projects”) during the Discovery Period, a period of approximately five years, commencing upon the effective date of the agreement (February 19, 2015) and terminating on December 31, 2019. At the
mutual agreement of the parties, the Discovery Period can be extended for an additional three years with no additional consideration given. Despite the uncertainty associated with the option to extend, given the three-year extension is at no
additional consideration to Incyte, management included the presumed extension in

CORRESP
1
filename1.htm

CORRESP

 December 12, 2017

VIA EDGAR

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F. Street, N.E.

Washington, D.C. 20549

Attention:

Mary Beth Breslin

Dorrie Yale

Re:

Agenus Inc.

Registration Statement on Form S-3, filed November 9, 2017

File No. 333-221465

 Ladies and Gentlemen:

 On behalf
of Agenus Inc. (the “Company”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the Securities and Exchange Commission, dated
December 1, 2017 (the “Comment Letter”), with regard to the Company’s above-referenced Registration Statement on Form S-3 (the “Registration Statement”). For the
convenience of the Staff’s review, we have set forth the comment contained in the Comment Letter in italics followed by the response of the Company.

General

 1. We note that there is an
outstanding comment on your 10-K for the fiscal year ended December 31, 2016 filed March 16, 2017, and on your Form 10-Q for the quarterly period ended
September 30, 2017 filed on November 7, 2017. Please be advised that we will not be in a position to declare your registration statement effective until all comments on your Exchange Act filings are resolved.

Response:

 The Company acknowledges the Staff’s
comment that the Staff will not be in a position to declare the Company’s Registration Statement effective until all comments concerning the Company’s Exchange Act filings are resolved.

We hope that the foregoing has been responsive to the Staff’s comments. If you have any questions or comments about this letter or need any further
information, please call the undersigned at (617) 951-7663.

 Very truly yours,

 /s/ Zachary R. Blume

Zachary R. Blume

cc:
Evan Kearns (Agenus Inc.)

December 1, 2017
Garo Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421
Re:Agenus Inc.
Registration Statement on Form S-3
Filed November 9, 2017
File No. 333-221465
Dear Dr. Armen:
            We have limited our review of your registration statement to those issues we have
addressed in our comment.
            Please respond to this letter by amending your registration statement and providing the
requested information.  If you do not believe our comment applies 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 the comment, we may have additional comments.
Registration Statement on Form S-3
General
1.We note that there is an outstanding comment on your 10-K for the fiscal year ended
December 31, 2016 filed March 16, 2017, and on your Form 10-Q for the quarterly
period ended September 30, 2017 filed on November 7, 2017.  Please be advised that we
will not be in a position to declare your registration statement effective until all
comments on your Exchange Act filings are resolved.
            We remind you that the company and its management are responsible for the accuracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

 FirstName LastNameGaro Armen
 Comapany NameAgenus Inc.
 June 16, 2017 Page 2
 FirstName LastName
Garo Armen
Agenus Inc.
December 1, 2017
Page 2
            Refer to Rules 460 and 461 regarding requests for acceleration.  Please allow adequate
time for us to review any amendment prior to the requested effective date of the registration
statement.
            Please contact Dorrie Yale at 202-551-8776 or Mary Beth Breslin at 202-551-3625 with
any questions.
Division of Corporation Finance
Office of Healthcare & Insurance
cc: Zachary Blume, Esq.

November 30, 2017
Christine Klaskin
VP, Finance and Principal Financial Officer
Agenus Inc.
3 Forbes Road
Lexington, MA 02421
Re:AGENUS INC
Form 10-K for the Fiscal Year Ended December 31, 2016
Filed March 16, 2017
Form 10-Q for the Quarterly Period Ended September 30, 2017
Filed November 7, 2017
File No. 000-29089
Dear Ms. Klaskin:
            We have limited our review of your filings to the financial statements and related
disclosures and have the following comment.  In our comment we may ask you to provide us
with information so we may better understand your disclosure.
            Please respond to the comment within ten business days by providing the requested
information or advise us as soon as possible when you will respond.  If you do not believe our
comment applies to your facts and circumstances, please tell us why in your response.
            After reviewing your response, we may have additional comments.
Form 10-Q for the Quarterly Period Ended September 30, 2017
Notes to Unaudited Condensed Consolidated Financial Statements
Note H - Collaboration Agreement, page 10
1.Please provide us a full accounting analysis with reference to authoritative literature of
your February 14, 2017 transactions with Incyte Corporation.  Include the following in
your analysis:

•With respect to the amendment to your January 9, 2015 License, Development and
Commercialization Agreement, explain the basis for your accounting treatment of the
$20 million in accelerated milestone payments as revenue during the nine months

 FirstName LastNameChristine Klaskin
 Comapany NameAgenus Inc.
 June 16, 2017 Page 2
 FirstName LastName
Christine Klaskin
Agenus Inc.
November 30, 2017
Page 2
ended September 30, 2017.  In this regard, discuss your consideration of whether the
amendment should be evaluated with the remaining performance obligations from the
original agreement as one arrangement.
•With respect to the Stock Purchase Agreement also entered into on February 14,
2017, tell us what consideration was given to the fact that the agreements were
entered into contemporaneously and how you accounted for the amount received over
the fair value of the shares issued.
            In closing, we remind you that the company and its management are responsible for the
accuracy and adequacy of their disclosures, notwithstanding any review, comments, action or
absence of action by the staff.
            You may contact Ibolya Ignat at (202) 551-3636 or Angela Connell at (202) 551-3426
with any questions.
Division of Corporation Finance
Office of Healthcare & Insurance

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 October 26, 2017

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 450 Fifth Street, N.W.

 Washington, D.C. 20549

Attention:
Jeffrey Gabor

Re:
Agenus Inc.

Registration Statement on Form S-3 (File No. 333-221008)

Request for Acceleration

 Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”) hereby requests
that the Securities and Exchange Commission (the “Commission”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File
No. 333-221008) (the “Registration Statement”), so that it will be declared effective at 4:00 p.m. Eastern Time on October 30, 2017, or as soon as possible thereafter. The Company
hereby authorizes Zachary Blume and Stephen Hall of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for acceleration.

It would be appreciated if, as soon as the Registration Statement is declared effective, you would inform Stephen Hall of Ropes &
Gray LLP, counsel to the Company, at (617) 235-4684.

 Very truly yours,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 VP,
Finance

October 25, 2017
Garo Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421
Agenus Inc.
Registration Statement on Form S-3
Filed October 18, 2017
File No. 333-221008Re:
Dear Mr. Armen:
            This is to advise you that we have not reviewed and will not review your registration
statement.
            Please refer to Rules 460 and 461 regarding requests for acceleration.  We remind you that
the company and its management are responsible for the accuracy and adequacy of their
disclosures, notwithstanding any review, comments, action or absence of action by the staff.
            Please contact Jeffrey Gabor at 202-551-2544 with any questions.
Division of Corporation Finance
Office of Healthcare & Insurance
cc: Zachary Blume

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 March 30, 2017

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Attention:     Jeffrey Gabor, Joseph McCann

Re:
Agenus Inc.

 Registration Statement on Form S-3 (File No. 333-215640)

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”)
hereby requests that the Securities and Exchange Commission (the “Commission”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File No. 333-215640), so that it will be declared effective
at 4:30 p.m. Eastern Time on March 31, 2017, or as soon as possible thereafter. The Company hereby authorizes Zachary Blume and Jessica Unger of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for
acceleration.

 Should you have any questions or comments, please do not hesitate to contact Jessica Unger of Ropes & Gray LLP at
(212) 596-9237.

 Very truly yours,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 VP,
Finance

CORRESP
1
filename1.htm

CORRESP

 February 23, 2017

VIA EDGAR

 United States Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street,
N.E.

 Washington, D.C. 20549

 Attn: Jeffrey Gabor

Re:
Agenus Inc.

 Registration Statement on Form S-3 (File No. 333-215640)

Request for Acceleration

 Ladies and Gentlemen:

 On behalf of Agenus Inc. (the “Company”), we hereby confirm in writing our request that the Securities and Exchange Commission
accept the Company’s withdrawal of our acceleration request filed on February 22, 2017 (which requested effectiveness of the Company’s Registration Statement on Form S-3 at 4:30 p.m. Eastern Time on February 23, 2017).

Should you have any questions or comments, please do not hesitate to contact Jessica Unger of Ropes & Gray LLP at
(212) 596-9237.

Very truly yours,

/s/ Jessica R. Unger

 Jessica R. Unger

Cc:
Christine M. Klaskin (Agenus Inc.)

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 February 22, 2017

 VIA EDGAR

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Attention:     Jeffrey Gabor

Re:
Agenus Inc.

 Registration Statement on Form S-3 (File No. 333-215640)

Request for Acceleration

 Ladies and
Gentlemen:

 Pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, Agenus Inc. (the “Company”)
hereby requests that the Securities and Exchange Commission (the “Commission”) accelerate the effective date of the Company’s Registration Statement on Form S-3 (File No. 333-215640), so that it will be declared effective
at 4:30 p.m. Eastern Time on February 23, 2017, or as soon as possible thereafter. The Company hereby authorizes Zachary Blume and Jessica Unger of Ropes & Gray LLP, counsel to the Company, to orally modify or withdraw this request for
acceleration.

 Should you have any questions or comments, please do not hesitate to contact Jessica Unger of Ropes & Gray LLP at
(212) 596-9237.

 Very truly yours,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 VP,
Finance

CORRESP
1
filename1.htm

CORRESP

 January 26, 2017

VIA EDGAR

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F. Street, N.E.

Washington, D.C. 20549

Attention:

Jeffrey Gabor

Suzanne Hayes

Re:

Agenus Inc.

Registration Statement on Form S-3, filed January 20, 2017

File No. 333-215640

 Ladies and Gentlemen:

 On behalf
of Agenus Inc. (the “Company”), we submit via EDGAR this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the Securities and Exchange Commission (the
“SEC”), dated January 25, 2017 (the “Comment Letter”), with regard to the Company’s above-referenced Registration Statement on Form S-3 (the “Registration Statement”). For the convenience
of the Staff’s review, we have set forth the comments contained in the Comment Letter in italics followed by the response of the Company.

General

 1. We note that you have a pending
request for confidential treatment. Please be advised that we will not be in a position to declare your registration statement effective until we resolve any issues concerning the confidential treatment request.

Response:

 The Company acknowledges the Staff’s
comment that the Staff will not be in a position to declare the Company’s Registration Statement effective until any issues concerning the confidential treatment request are resolved.

 Securities and Exchange Commission

Division of Corporation Finance

 January 26, 2017

 We hope that the foregoing has been responsive to the Staff’s comments. If you have any questions or
comments about this letter or need any further information, please call the undersigned at (617) 951- 7663.

 Very
truly yours,

 /s/ Zachary R. Blume

Zachary R. Blume

cc:
Evan Kearns (Agenus Inc.)

 2

Mail Stop 4546

 January 25, 201 7

Garo H. Armen
Chief Executive Officer  and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
  Registration Statement on Form S-3
Filed  January 20,  2017
  File No.  333-215640

Dear  Mr. Armen :

We have limited our review of your registration statement to those issues we have
addressed in our comment.

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

After reviewing any amendment to your registration statement and the information you
provide in response to th is comment, we may have additional comments.

General

1. We note that you have a pending request for confidential treatment . Please be advised
that we will not be in a position to declare your registration statement effective until we
resolve any issues concerning the confidential treatment request.

We remind you that the company and its management are responsible for the acc uracy
and adequacy of their disclosures, notwithstanding any review, comments, action or absence of
action by the staff.

Refer to Rules 460 and 461 regarding requests for acceleration.  Please allow adequate
time for us to review any amendment prior to the requested effective date of the registration
statement.

Garo H. Armen
Agenus Inc.
January 25 , 2017
Page 2

  Please contact Jeffrey Gabor at (202) 551 -2544 or Suzanne Hayes  at (202) 551 -3675 with
any questions.

Sincerely,

 /s/ Suzanne Hayes

Suzanne Hayes
Assistant Director
Office of Healthcare and Insurance

cc: Zachary Blume , Esq.
 Ropes & Gray  LLP

June 1 5, 2016

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

Re: Agenus Inc.
 Preliminary Proxy Statement on Schedule 14A
Filed April 15, 2016
File No. 000 -29089

Dear Mr. Armen :

We completed our review of your filing on April 26, 2016.   We remind you that our
comments or changes to disclosure in response to our comments do not foreclose  the
Commission from taking any action with respect to the company or the filing and the company
may not assert staff comments as a defense in any proceeding initiated by the Commission or any
person under the federal securities laws of the United States.  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 Exchange Act of 1934 and all applicable rules
require.

Sincerely,

 /s/ Mary Beth Breslin for

Suzanne Haye s
Assistant Director
Office of Healthcare and Insurance

cc: Zachary R. Blume
Ropes & Gray LLP

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 May 16, 2016

VIA EDGAR

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549

Re:
Agenus Inc.

S-3 Registration Statement, File No. 333-209941

 Ladies and Gentlemen:

The undersigned registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the effective
date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern Time, on Tuesday, May 17, 2016 or as soon thereafter as practicable.

The Company acknowledges that:

•

should the Securities and Exchange Commission (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 for 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.

 Sincerely,

AGENUS INC.

By:

/s/ C. Evan Ballantyne

 C. Evan Ballantyne

 Chief Financial
Officer

Cc:
John R. Pitfield, Esq. (Choate, Hall & Stewart LLP)

CORRESP
1
filename1.htm

CORRESP

 VIA EDGAR AND FACSIMILE

April 27, 2016

 United States Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street,
N.E.

 Washington, DC 20549-4720

 Attention: Suzanne Hayes,
Assistant Director

Re:
Agenus Inc.

Acceleration Request for Registration Statement on Form S-3

File No. 333-209749

 Dear Ms. Hayes:

Pursuant to Rule 461 under the Securities Act of 1933, as amended (the “Act”), Agenus Inc. (the “Company”) hereby requests
that the effective date of the above-referenced registration statement (the “Registration Statement”) be accelerated to Thursday, April 28, 2016 at 4:30 p.m., Eastern time, or as soon thereafter as practicable. In making this
acceleration request, the Company acknowledges that it is aware of its responsibilities under the Act. Once the Registration Statement is effective, please orally confirm the event with our counsel, Goodwin Procter LLP by calling Arthur R. McGivern
at (617) 570-1971. We also respectfully request that a copy of the written order from the Securities and Exchange Commission (the “Commission”) verifying the effective time and date of the Registration Statement be sent to our
counsel, Goodwin Procter LLP, Attention: Arthur R. McGivern, by facsimile to (617) 801-8626.

 In connection with the foregoing, the Company hereby
acknowledges the following:

•

should the Commission or the staff of the Commission, acting pursuant to delegated authority, declare the Registration Statement effective, it does not foreclose the Commission from taking any action with respect to the
Registration Statement;

•

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

 If you have any questions regarding this request, please contact Arthur R. McGivern of Goodwin Procter LLP at
(617) 570-1971.

 Sincerely,

AGENUS, INC.

/s/ C. Evan
Ballantyne

 C. Evan Ballantyne

Chief Financial Officer

cc:
Alla Berenshteyn (United States Securities and Exchange Commission)

 Mary Beth Breslin (United
States Securities and Exchange Commission)

 Evan Kearns (Agenus Inc.)

Arthur M. McGivern, Esq. (Goodwin Procter LLP)

CORRESP
1
filename1.htm

CORRESP

 VIA EDGAR AND FACSIMILE

April 27, 2016

 United States Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street,
N.E.

 Washington, DC 20549-4720

 Attention: Suzanne Hayes,
Assistant Director

Re:
Agenus Inc.

 Acceleration Request for Registration Statement on Form S-3

 File No. 333-208890

 Dear
Ms. Hayes:

 Pursuant to Rule 461 under the Securities Act of 1933, as amended (the “Act”), Agenus Inc. (the
“Company”) hereby requests that the effective date of the above-referenced registration statement (the “Registration Statement”) be accelerated to Thursday, April 28, 2016 at 4:30 p.m., Eastern time, or as soon thereafter as
practicable. In making this acceleration request, the Company acknowledges that it is aware of its responsibilities under the Act. Once the Registration Statement is effective, please orally confirm the event with our counsel, Goodwin Procter LLP by
calling Arthur R. McGivern at (617) 570-1971. We also respectfully request that a copy of the written order from the Securities and Exchange Commission (the “Commission”) verifying the effective time and date of the Registration
Statement be sent to our counsel, Goodwin Procter LLP, Attention: Arthur R. McGivern, by facsimile to (617) 801-8626.

 In connection with the
foregoing, the Company hereby acknowledges the following:

•

should the Commission or the staff of the Commission, acting pursuant to delegated authority, declare the Registration Statement effective, it does not foreclose the Commission from taking any action with respect to the
Registration Statement;

•

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

 If you have any questions regarding this request, please contact Arthur R. McGivern of Goodwin Procter LLP at (617) 570-1971.

Sincerely,

AGENUS INC.

 /s/ C. Evan Ballantyne

C. Evan Ballantyne

Chief Financial Officer

cc:
Alla Berenshteyn (United States Securities and Exchange Commission)

 Mary Beth Breslin (United
States Securities and Exchange Commission)

 Evan Kearns (Agenus Inc.)

Arthur M. McGivern, Esq. (Goodwin Procter LLP)

CORRESP
1
filename1.htm

CORRESP

 April 26, 2016

VIA EDGAR

 United States Securities and Exchange
Commission

 Division of Corporation Finance

 100 F Street
N.E.

 Washington, D.C.20549

 Attention:

Mary Beth Breslin

 Alla Berenshteyn

 Suzanne Hayes

Re:

Agenus Inc.

Preliminary Proxy Statement on Schedule 14A

Filed April 15, 2016

File No. 000-29089

 Ladies and Gentlemen:

 Agenus
Inc. (the “Company”) is submitting this letter in response to the written comments of the staff (the “Staff”) of the Division of Corporation Finance of the Securities and Exchange Commission (the
“Commission”), dated April 25, 2016 (the “Comment Letter”), with regards to the Company’s Preliminary Proxy Statement on Schedule 14A, filed with the Commission on April 15, 2016.

For the convenience of the Staff’s review, we have set forth the comment contained in the Comment Letter in italics followed by the response of the
Company.

 Proposal 2, page 53

1.
We note that you have proposed an amendment to your certificate of incorporation that would increase the number of authorized shares of your common stock. Please revise your disclosure to describe any specific plans,
arrangements or understandings to issue any of the shares that will be newly available for issuance following shareholder approval of the increase. If you have no such plans, please revise your disclosure to so state. If such plans exist, please
provide the disclosures required per Note A of Schedule 14A.

 Response:

In response to the Staff’s comment, we will revise the disclosure on page 53 of the Company’s Definitive Proxy Statement on Schedule 14A to state
that the Company has no specific plans, arrangements or understandings to issue any of the shares that will be newly available for issuance following shareholder approval of the increase.

 United States Securities and Exchange Commission

April 26, 2016

 Page 2

 The Company hereby acknowledges that:

•

it 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 comments as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

If the Staff has any questions concerning this letter or requires further information, please do not hesitate to contact me at (781) 674-4433 or Zachary
R. Blume, Ropes & Gray LLP, at (617) 951-7663.

 Sincerely,

 /s/ Karen H. Valentine

 Karen H. Valentine

 Chief Legal Officer and General Counsel

 Agenus Inc.

cc:

Via E-Mail

 Garo H. Armen (Agenus Inc.)

 Paul Kinsella (Ropes & Gray LLP)

April 25, 2016

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

Re: Agenus Inc.
 Preliminary Proxy Statement on Schedule 14A
Filed April 15, 2016
File No. 000 -29089

Dear Mr. Armen :

We have limited our review of  your filing to those issues we have addressed in our
comment .

Please respond to this comment  within ten busine ss days by providing the requested
information or advis e us as soon as possible when you will respond.  If you do not believe our
comment  applies to your facts and circumstances, please tell us why in your response.

After reviewing your response and any amendment you may fi le in response to this
comment , we may have  additional comments.

Proposal 2, page 53

1. We note that you have proposed an amendment to your certificate of incorporation that
would increase the number of authorized shares of your common stock. Please revise
your disclosure to describe a ny specific plans, arrangements or understandings  to issue
any of the shares that will be newly available for issuance  following shareholder approval
of the increase .  If you have no such plans, p lease revise your disclosure to so state.  If
such plans exist, please provide the disclosures required per Note A of Schedule 14A .

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 Exchange Act of
1934 and all applicable Exchange 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 accurac y
and adequacy of the disclosures they have made.

Garo H. Armen
Agenus Inc.
April 25, 2016
Page 2

  In responding to our comments, please provide  a written statement from the company
acknowledging that:

 the company is responsible for the adequacy and accuracy of the disclosure in the filing;

 staff c omments 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 comments as a defense in any proceeding initiated by
the Commission or a ny person under the federal securities laws of the United States.

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: Zachary R. Blume
Ropes & Gray  LLP

Mail Stop 4720
March 10 , 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  March 4 , 2016
  File No.  333-209941

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 fiscal year ended December 31, 2015 which, in turn,
incorporates by reference the Part III information to be included in yo ur 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 Disc losure Interpretation
123.01, available on the Commission’s website.

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 proce ssing your confidential treatment request.

Garo H. Armen
Agenus Inc.
March 10, 2016
Page 2

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 Securiti es 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 eve nt you request acceleration 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 t o 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 and the declaration of effect iveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceler ation of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration 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: John R. Pitfield
Choate, Hall & Stewart LLP

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

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  January  6, 2016
  File No.  333-208890

Dear Mr. Armen:

This is to advise you that we have not  reviewed and will not review your registration
statement .

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.

In the event you request acceleration of the effective date of the pending regist ration
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 wit h 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 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.

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

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

 of the fact that those requesting acceleration 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 registered securities .

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

Sincerely,

 /s/ Mary Beth Breslin for

Suzanne Hayes
Assistant Director
Office of Healthcare and Insurance

cc: Arthur McGivern
Goodwin Procter  LLP

CORRESP
1
filename1.htm

Acceleration Request

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 January 4, 2016

 VIA EDGAR

 Securities and Exchange Commission

 Division of
Corporation Finance

 100 F Street, N.E.

 Washington, D.C.
20549

Re:
Agenus Inc.

S-3 Registration Statement, File No. 333-208135

 Ladies and Gentlemen:

The undersigned registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the effective
date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern Time, on Tuesday, January 5, 2016 or as soon thereafter as practicable.

The Company acknowledges that:

•

should the Securities and Exchange Commission (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 for 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.

 Sincerely,

AGENUS INC.

By:

/s/ C. Evan Ballantyne

 C. Evan Ballantyne

 Chief Financial
Officer

Cc:
John R. Pitfield, Esq. (Choate, Hall & Stewart LLP)

Mail Stop 4720
December 1, 2015

Via E -mail
Garo H. Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
  Registration Statement on Form S-3
Filed  November 20, 2015
  File No.  333- 208135

Dear Mr. Armen :

This is to advise you that we have not  reviewed and will not review your registration
statement .

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.

In the event you request acceleration of the effective date of the pending regist ration
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 t o 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 and the declaration of effect iveness 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.
December 1, 2015
Page 2

 Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceler ation of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration 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 registered securities .

Please contact Christina Thomas  at (202) 551 -3577 or me at (202) 551 -3675  with any
questions.

Sincerely,

 /s/ Suzanne Hayes

 Suzanne Hayes
Assistant Director
Office of Healthcare and Insurance
cc: Via E-mail
John R. Pitfield, Esq.
Choate, Hall & Stewart LLP
Two International Place
Boston, MA 02110

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

September 9, 2015

 VIA EDGAR

Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Re:
Agenus Inc.

 S-3 Registration Statement, File No. 333-206513

Ladies and Gentlemen:

 The undersigned
registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the effective date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern
Time, on Thursday, September 10, 2015 or as soon thereafter as practicable.

 The Company acknowledges that:

•

should the Securities and Exchange Commission (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 for 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.

Sincerely,

AGENUS INC.

By:

 /s/ Garo H. Armen, PhD

Garo H. Armen, PhD

Chief Executive Officer

Cc:
John R. Pitfield (Choate, Hall & Stewart LLP)

Mail Stop 4720

August 28 , 2015

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

Re: Agenus, Inc.
  Registration Statement on Form S-3
Filed  August 21 , 2015
  File No.  333-206513

Dear Mr. Armen :

This is to advise you that we have not  reviewed and will not review your registration
statement .

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.

In the event you request acceleration of the effective date of the pending regist ration
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 t o 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 and the declaration of effect iveness 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.
August 28 , 2015
Page 2

 Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceler ation of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration 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 registered securities .

 Please  contact Johnny Gharib  at (202) 551 -3170 or me at (202) 551 -3715  with any
questions.

Sincerely,

 /s/ Jeffrey P. Riedler

Jeffrey P. Riedler
Assistant Director
Office of Healthcare and Insurance

cc: Via E-mail
 John R. Pitfield, Esq.
 Choate, Hall & Stewart LLP

CORRESP
1
filename1.htm

Acceleration Request

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 June 5, 2015

 VIA EDGAR

Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Re:
Agenus Inc.

 S-3 Registration Statement, File No. 333-203807

Ladies and Gentlemen:

 The undersigned
registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the effective date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern
Time, on Monday, June 8, 2015 or as soon thereafter as practicable.

 The Company acknowledges that:

•

should the Securities and Exchange Commission (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 for 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.

Sincerely,

AGENUS INC.

By:

 /s/ Christine M. Klaskin

Christine M. Klaskin

Vice President, Finance

(Principal Financial and Principal Accounting Officer)

Cc:
William B. Asher, Jr. (Choate, Hall & Stewart LLP)

May 6, 2015

Via E -mail
Garo H. Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
  Registration Statement on Form S-3
Filed May 1, 2015
  File No. 333-203807

Dear Mr. Armen :

We have reviewed your registration statement  and have the following comment.  If you
do not believe this comment applies to your facts and circumstances, please tell us why in your
response.

After reviewing any information you provide in response to this comment, we may have
additional comments.

1. We have limited our review of your registration statement to the resolution of your
pending confidential treatment request.  Please be advised that we will not be in a
position to declare your registration statement effective until all outstanding comments , if
any, on your request for confidential treatment have been cleared.

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.

Notwithstand ing our comments, in the event you request acceleration of the effective date
of the pending regist ration statement please provide  a written statement from the company
acknowledging that:

 should the Commission or the staff, acting pursuant to delegated au thority, declare the
filing effective, it does not foreclose the Commission from taking any action with respect
to the filing;

Garo H. Armen
Agenus Inc.
May 6, 2015
Page 2

  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 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.

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 acceleration 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 i n 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 Tara Keating Brooks  at (202) 551 -8336 , Daniel Greenspan at (202) 551 -
3623 or me at (202) 551 -3715  with any other questions.

Sincerely,

 /s/ Daniel  Greenspan for

Jeffrey P. Riedler
Assistant Director

cc: Via E -mail
Gerald E. Quirk, Esq.
Choate, Hall & Stewart LLP

CORRESP
1
filename1.htm

CORRESP

 AGENUS INC.

3 Forbes Road

 Lexington, MA 02421

 June 17, 2014

 VIA
EDGAR

 Securities and Exchange Commission

 Division
of Corporation Finance

 100 F Street, N.E.

 Washington, D.C.
20549

Re:
Agenus Inc.

 S-3 Registration Statement, File No. 333-195852

 Ladies and Gentlemen:

 The undersigned
registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the effective date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern
Time, on Wednesday, June 18, 2014 or as soon thereafter as practicable.

 The Company acknowledges that:

•

should the Securities and Exchange Commission (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 for 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.

 Sincerely,

AGENUS INC.

By:

/s/ Christine M. Klaskin

 Christine M. Klaskin

 Vice President,
Finance

 (Principal Financial and Principal Accounting Officer)

Cc:
Gerald E. Quirk (Choate, Hall & Stewart LLP)

May 21 , 2014

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

Re: Agenus, Inc.
  Registration Statement on Form S-3
Filed  May 9 , 2014
  File No.  333-195852

Dear Mr. Armen :

We have limited our review of your registration statement to the resolution of your
pending confidential treatment request .  Please be advised that we will not be in a position to
declare your registration statement effective until all outstanding comments, if any, on your request
for confidential treatment have been cleared.

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 comment , in the event you request acceleration of the effective d ate
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 Commissio n 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 accur acy 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.
May 21 , 2014
Page 2

 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 acceleration are aware of thei r 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 rev iew any amendment prior to the requested effective date of the
registration statement.

Please co ntact J ohnny Gharib at (202) 551 -3170 or me at (202) 551 -3715 with any
questions.

Sincerely,

 /s/ Daniel  Greenspan  for

 Jeffrey P. Riedler
Assistant Director

cc: Via E -mail
Gerald E. Quirk, Esq.
Choate, Hall & Stewart LLP

March 10, 2014

Via E -mail
Mr. Garo Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
 Preliminary Proxy Statement on Form PRE14A
Filed February 27, 2014
File No. 000 -29089

Dear  Mr. Armen :

We have completed our review of your filing .  We remind you that our comments or
changes to disclosure in response to our comments do not foreclose the Commission from taking
any action with respect to the company or the filing and the company may not assert staff
comments as a defense in any proceeding initiated by the Commission or any person under the
federal securities laws of the United States.  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 Exchange Act of 1934 and all applicable rules require.

Sincerely,

 /s/ Daniel Greenspan for

 Jeffrey P. Riedler
Assistant Direc tor

cc:  Gerald Quirk
Choate, Hall & Stewart LLP
Two International Place
Boston, MA 02110

March 6, 2014

Via E -mail
Mr. Garo Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
 Preliminary Proxy Statement on Form PRE14A
Filed February 27 , 2014
File No. 000-29089

Dear  Mr. Armen :

We have reviewed your filing an d have the following comment .  Please respond to this
letter within ten business days by amending your filing, by providing the requested information,
or by advising us when you will provide the requested response.   If you do not believe our
comments 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 filing and the information you provide in
response to this comment , we may have  additional comments.

Preliminary Proxy Statement on Form PRE14A

1. Please disclose whether you currently have, or do not have, any plans to issue any of the
authorized but unissued shares that would be available as a result of the approval of the
amendment to your Amended and R estated Certificate of Incorporation to increase the
number of shares of common stock authorized for issuance from 70 million to 140
million.  Your current disclosure indicates that you will use the additional authorized but
unissued shares to satisfy cert ain equity awards, and for general business and financial
purposes.  Your amended disclosure should describe any specific plans that may fall
under the category of general business and financial purposes, such as any current
agreements or commitments for t he issuance of these shares.

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 Exchange Act of
1934 and all applicable Exchange Act r ules 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.

Mr. Garo Armen
Agenus Inc.
March 6, 2014
Page 2

  In responding to our comments, please provide  a written 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 t aking any action with respect to the filing; and

 the company may not assert staff comments as a defense in any proceeding initiated by
the Commission or any person under the federal securities laws of the United States.

You may contact Rose Zukin at (202) 551 -3239 with any questions.

Sincerely,

 /s/ Daniel  Greenspan for

 Jeffrey P. Riedler
Assistant Director

cc:  Gerald Quirk
Choate, Hall & Stewart LLP
Two International Place
Boston, MA 02110

CORRESP
1
filename1.htm

CORRESP

 March 6, 2014

 Jeffrey
P. Riedler, Assistant Director

 Division of Corporation Finance

United States Securities and Exchange Commission

 100 F Street,
N.E.

 Washington, DC 20549-3628

Re:

Agenus Inc.

Preliminary Proxy Statement on Form PRE14A

Filed February 27, 2014

(File No. 000-29089)

 Dear Mr. Riedler:

On behalf of Agenus Inc. (the “Company”), we are transmitting for electronic filing via EDGAR pursuant to the Securities Act
of 1933, as amended, proposed revisions to the language of the above-referenced proxy statement (the “Proxy Statement”), as originally filed with the Securities and Exchange Commission (the “Commission”) on
February 27, 2014. Set forth below is the Company’s response to the comment of the staff of the Securities and Exchange Commission (the “Staff”) in its letter dated March 6, 2014 with respect to the Proxy Statement.
For your convenience, the text of the Staff’s comment is set forth in bold below, followed by the Company’s response.

 Preliminary Proxy
Statement on Form PRE14A

 1. Please disclose whether you currently have, or do not have, any plans to issue any of the
authorized but unissued shares that would be available as a result of the approval of the amendment to your Amended and Restated Certificate of Incorporation to increase the number of shares of common stock authorized for issuance from
70 million to 140 million. Your current disclosure indicates that you will use the additional authorized but unissued shares to satisfy certain equity awards, and for general business and financial purposes. Your amended disclosure should
describe any specific plans that may fall under the category of general business and financial purposes, such as any current agreements or commitments for the issuance of these shares.

Based on the Staff’s comment, the Company has revised the Proxy Statement to state that the Company currently has no specific plans,
arrangements or understandings relating to the issuance of any of the Company’s common stock that may fall under the category of general business or financial purposes. The Company has added the following language to the disclosure provided in
Proposal 2 at the end of the third paragraph on page 49 of the Proxy Statement:

 Other than issuances pursuant to our 2009 Equity
Incentive Plan, as of the date of this Proxy Statement we have no plans, arrangements or understandings regarding the issuance of additional shares that would be authorized pursuant to this Proposal 2.

* * *

 In addition, please note
that the Company has authorized us to inform you that it acknowledges that it is responsible for the adequacy and accuracy of the disclosure in the Proxy Statement; that Staff comments or

Securities and Exchange Commission

 March 6, 2014

 Page
 2

changes to the disclosure in response to Staff comments in the Proxy Statement do not foreclose the Commission from taking any action with respect to the Proxy Statement, and the Company may not
assert Staff comments as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

If the proposed changes to the Proxy Statement are acceptable to the Staff, we expect to file the definitive Proxy Statement on Form DEF14A
once the comments are cleared or the Staff indicates that we may do so. If the Staff has any questions concerning this letter or requires further information, please do not hesitate to contact Gerald E. Quirk at (617) 248-4817 or Daniel P.
Riley at (617) 248-4754.

Sincerely,

/s/ Gerald E. Quirk

Gerald E. Quirk

cc:

Garo H. Armen, Ph.D.

Chairman and Chief Executive Officer

Agenus Inc.

Karen H. Valentine, Esq.

Vice President and General Counsel

Agenus Inc.

CORRESP
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Acceleration Request

 Agenus Inc.

 3 Forbes Road

 Lexington, MA 02421

January 10, 2013

 VIA EDGAR

 Securities and Exchange Commission

Division of Corporation Finance

 100 F Street,
N.E.

 Washington, D.C. 20549

 Attn:
Jeffrey P. Riedler

Re:
Agenus Inc. (the “Company”)

 S-3 Registration Statement, File No. 333-185657

 Ladies and Gentlemen:

The undersigned registrant hereby requests, pursuant to Rule 461 promulgated under the Securities Act of 1933, as amended, that the
effective date of the above-referenced Registration Statement be accelerated so that it may become effective as of 4:00 p.m., Eastern Time, on Thursday, January 10, 2013 or as soon thereafter as practicable.

The Company acknowledges that:

•

 should the Securities and Exchange Commission (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 for 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.

Sincerely,

AGENUS INC.

By:

 /s/ Christine M. Klaskin

Christine M. Klaskin

Vice President, Finance (Principal Accounting Officer and Principal Financial Officer)

January 3, 2013

Via E -mail
Mr. Garo H. Armen
Chief Executive Officer and Chairman of the Board
Agenus Inc.
3 Forbes Road
Lexington, MA 02421

Re: Agenus Inc.
  Registration Statement on Form S-3
Filed  December 21, 2012
  File No.  333-185657

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 .  Where you do not believe our comments 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 , we may have  additional comments.

Registration Statement on Form S -3

1. Please refer to the third prospectus in this registration statement relating to the issuance
and sale, by the company, of up to 766,036 shares of common stock issuable upon the
conve rsion of 3,105 shares of Series B2 Convertible Preferred Stock.  It appears that
these shares of common stock were included in the number of common shares to be
registered in the Secondary Offering portion of the registration statement fee table.
Please r evise the fee table to reduce the number of shares being registered for the
Secondary Offering by the 766,036 shares issuable upon conversion of Series B2
Convertible Preferred Stock.  These shares represent a portion of the shares being
registered in the Primary Offering.

2. Please refer to the second prospectus in this registration statement relating to the issuance
and sale of up to 10 million shares of common stock through your sales agent, MLV&

Mr. Garo H. Armen
Agenus Inc.
January 3, 2013
Page 2

 Co. LLC.  Please revise the Prospectus Cover Page and Plan o f Distribution in the second
prospectus to identify MLV as an underwriter in this offering.

3. Please refer to the legal opinion filed as Exhibit 5.1.  The third paragraph in the legal
opinion refers to the 3,384,152 shares of common stock issuable upon the  exercise of
certain warrants, which are held by certain selling stockholders.  This amount is not
consistent with information in the fourth and fifth prospectuses in this registration
statement, relating to an aggregate of 2,618,116 shares of common stock  issuable upon
the exercise of certain warrants held by selling shareholders.  Please revise the legal
opinion accordingly.

In addition, it does not appear that counsel has opined as to the legality of the 766,036
shares of common stock issuable by the Company upon the conversion of 3,105 shares of
Series B2 Convertible Preferred Stock.  Please revise the legal opinion accordingly.  For
guidance, please refer to Section II.B of Staff Legal Bulletin No. 19 (Oct. 14, 2011).

We urge all persons who are r esponsible 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
possess ion 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 acceleration of the effective date
of the pending registrat ion 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 for
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.

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 acceleration 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.

Mr. Garo H. Armen
Agenus Inc.
January 3, 2013
Page 3

 You may contact Rose Zukin at (202) 551 -3239 or me at (202) 551 -3710 with any
questions.

Sincerely,

 /s/ Jeffrey P. Riedler

 Jeffrey P. Riedler
Assistant Director

cc: William B. Asher, Esquire
Choate, Hall & Stewart LLP
Two Internationa l Place
Boston, MA 02110

CORRESP
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Correspondence

 Antigenics Inc.

 162 Fifth Avenue, Suite 900

 New York, New York
10010

 March 18, 2010

 VIA EDGAR

 Mr. Jeffrey Riedler

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F Street, N.E.

 Washington, D.C. 20549

 Re: Securities and Exchange Commission (“SEC”) Comment Letter dated March 17, 2010 with respect to the Preliminary
Proxy Statement (File No. 000-29089) (the “Preliminary Proxy Statement”) filed by Antigenics Inc. (the “Company”) with the SEC on March 15, 2010.

 Dear Mr. Riedler:

 This letter responds to the staff’s comments on the above referenced
Preliminary Proxy Statement. For convenience, we have repeated the text of the staff’s comments by number and in bold. Our response is denoted with an “R.” Underlines denote additions.

 Preliminary Proxy Statement filed March 15, 2010

 1. Please disclose any plans or commitments your company has to issue the newly authorized shares of common stock that will become available for issuance as a result of the reverse stock split.

 R. The definitive proxy statement will be revised to reflect this comment by adding a new sentence after the second sentence of the first
bullet under the heading “Possible Effects of the Reverse Stock Split” in proposal 2. The bullet will read as follows:

•

 Immediately after the reverse stock split is implemented, Company common stockholders will own fewer shares than they currently own. By reducing the
number of shares outstanding without a corresponding reduction in the number of shares authorized but unissued common stock, the reverse stock split will have the effect of increasing the number of authorized but unissued shares. The Company does
not currently have any plans to issue any of the authorized but unissued shares of common stock that would become available for issuance if the reverse stock split of our outstanding shares of common stock is approved by our stockholders and
subsequently effected by the Board. Any outstanding options or warrants would also be adjusted by the same split ratio. The following table shows the number of shares that would be (a) issued and outstanding, (b) authorized and
reserved for issuance upon the exercise of outstanding capital stock options and warrants, vesting of nonvested.

 We
acknowledge that we are responsible for the adequacy and accuracy of the disclosure in the filing, that the staff comments or changes to disclosure in response to staff comments do not foreclose the SEC from taking any action with respect to the
filing, and we may not assert staff comments as a defense in any proceeding initiated by the SEC or any person under the federal securities laws of the United States.

 Please call the undersigned at (212) 994-8200 with any questions regarding this letter.

Very truly yours,

ANTIGENICS INC.

By:

 /S/ Shalini Sharp

Name:

Shalini Sharp

Title:

Chief Financial Officer

 -2-

Mail Stop 4720          March 18, 2010  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.
 Preliminary Proxy Statement on Schedule 14A
Filed March 15, 2010      Supplemental Response filed March 18, 2010
 File No. 000-29089

Dear Dr. Armen:
  We have completed our review of  your preliminary proxy statement on
Schedule 14A and have no further comments at this time.
Sincerely,

        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
 Fax: 617-235-0822

Mail Stop 4720          March 17, 2010  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.
 Preliminary Proxy Statement on Schedule 14A
Filed March 15, 2010
 File No. 000-29089

Dear Dr. Armen:
 We have reviewed your filing and have the following comments.  Where
indicated, we think you should re vise your document in response to these comments.  If
you disagree, we will consider your explanation as to why our comment is inapplicable or
a revision is unnecessary.  Please be as deta iled as necessary in your explanation.  In
some of our comments, we may ask you to provi de us with information so we may better
understand your disclosure.  After reviewing th is 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.
 General

1. Please disclose any plans or commitments your company has to issue the newly
authorized shares of common stock that will become available for issuance as a
result of the reverse stock split.

* * *

 As appropriate, please amend your filing and respond to these comments within
10 business days or tell us when you will provid e us with a response.  You may wish to
provide us with marked copies of the amendm ent to expedite our review.  Please furnish
a cover letter with your amendment that keys your responses to our comments and

Garo H. Armen, Ph.D.
Antigenics Inc.
March 17, 2010
Page 2 of 2
provides any requested information.  Detailed co ver letters greatly faci litate our review.
Please understand that we may have addi tional comments after reviewing your
amendment and responses to our comments.    We urge all persons who are responsi ble for the accuracy an d 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 comments, please provide, in writing, 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 comments 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 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 comments on your filing.
Please contact Mike Rosenthall at  (202) 551-3674 with any questions.
         S i n c e r e l y ,             J e f f r e y  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
 Fax: 617-235-0822

Via Facsimile and U.S. Mail Mail Stop 4720                                                                                                    October 15, 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 completed our review of your Form 10-K and related filings and
have no further comments at this time.

Sincerely,

 Jeffrey Riedler,  Assistant Director

CORRESP
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SEC Response Letter

 October 7, 2009

 VIA EDGAR

 Mr. Jeffrey Riedler

 Division of Corporation Finance

 United States
Securities and Exchange Commission

 100 F Street, N.E.

 Washington, D.C. 20549

Re:
Antigenics Inc.

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

 Filed March 16, 2009

 File Number 000-29089

 Dear
Mr. Riedler:

 This letter responds to the comments from the Staff (the “Staff”) of the Securities and Exchange
Commission (the “Commission”), dated September 24, 2009, regarding the above-referenced Form 10-K of Antigenics Inc. (the “Company”, “we”, “our” or “us”). We have repeated the text of the
comments by number and in bold. Where requested to provide proposed disclosure for our 2009 Form 10-K, we have underlined the additions and struck through deletions of the disclosure in our Form 10-K for the year ended December 31, 2008.

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

 Business, page 11

 1. We note your response to Comment 1 and your statement that you
have been granted confidential treatment in relation to the information requested in our comment. Please note that we do not grant confidential treatment for aggregate amounts. As such, please revise the proposed disclosure for your agreements with
GSK and Elan to disclose the aggregate potential milestone payments and the percentage range of royalties (for example: royalties between 10% and 15% of net sales or low single digit royalties).

 In addition, it appears that the confidential treatment requests that you refer to were not subject to review. Please note that we
reserve the right to reconsider our confidential treatment determinations.

 Below is our currently proposed disclosure for our 2009 Form
10-K:

 GSK. In July 2006, we entered into a license agreement and a supply agreement with GSK for the use of QS-21. On
July 20, 2007, we executed a letter of intent with GSK amending the supply agreement to accelerate GSK’s commercial-grade QS-21 manufacturing rights.

Accordingly, from the effective date, Pursuant to the terms of the letter agreement, GSK obtained the right to manufacture all of its requirements of commercial
grade QS-21 and, upon our election, is obligated to supply us (or our affiliates, licensees, or customers) certain quantities of commercial grade QS-21 for a stated period of time. On January 16, 2009, we entered into an Amended and Restated
Manufacturing Technology Transfer and Supply Agreement (the “Amended GSK supply agreement”) reflecting the provisions of the July 20, 2007 letter agreement. To date we have received $8.8 million of a potential $15.3 million in upfront
and milestone payments related to these agreements. Furthermore, under both the license and the supply agreements, we are entitled to receive low single-digit royalties on net sales of resulting products for a period of at least 10 years after the
first commercial sale. The agreements may be terminated by either party upon a material breach if the breach is not cured within the time specified in the agreement. The termination or expiration of the GSK license agreement does not relieve either
party from any obligation which accrued prior to the termination or expiration. Among other provisions, the milestone payment obligations survive termination or expiration for any reason, and the license rights granted to GSK survive expiration of
the GSK license agreement. The license rights and payment obligations of GSK under the Amended GSK supply agreement survive termination or expiration, except that GSK’s license rights and future royalty obligations do not survive if we
terminate due to GSK’s material breach unless we elect otherwise.

 We understand that QS-21 is a key component
included in several of GSK’s proprietary adjuvant systems and that a number of GSK’s vaccine candidates currently under development are formulated using adjuvant systems containing QS-21. GSK has initiated a Phase 3 study evaluating its
investigational MAGE-A3 Antigen-Specific Cancer Immunotherapeutic containing QS-21 in non-small cell lung cancer. GSK and its research partners have also released data from Phase 2 studies of its malaria vaccine candidate in African infants and
young children. GSK has indicated that it intends to proceed into late stage trials of what could be the first malaria vaccine for infants and young children in Africa. We will receive royalties on net sales for a period of at least 10 years
after the first commercial sale under the GSK supply agreement.

 Elan/Janssen Alzheimer’s Immunotherapy.
In November 1999 we entered into license and supply agreements (the “Prior Agreements”) with granted Elan a commercial license for the use of QS-21 in research and commercialization of
products. Under the terms of the Prior Agreements, Elan had the right to develop, make, have made, use, sell, offer for sale, import, and have sold Elan’s Alzheimer’s disease vaccine that contains QS-21 (“Licensed Product”),
and we had the exclusive right and obligation to supply Elan with QS-21 for use in the Licensed Product. In addition, under the terms of the Prior Agreements, we were entitled to receive future milestone payments and product
royalties in the event of the successful development of the Licensed Product for a period of at least 10 years after the first commercial sale of such product, if any. In 2007, Elan initiated a Phase 2 study of its vaccine. To date we have
received $3 million in upfront and milestone payments related to the license agreement.

 Effective September 14,
2009, we entered into an Amended and Restated License Agreement (“Amended license agreement”) with Elan. On September 17, 2009, the Amended license agreement was assigned to Janssen Alzheimer’s Immunotherapy, a subsidiary of
Johnson & Johnson. Under the terms of the Amended license agreement assigned to Janssen Alzheimer Immunotherapy, they will have the right to develop, make, have made, use, sell, offer for sale, import, and have sold, the Licensed Product.
In addition, pursuant to the terms of the Amended license agreement, Janssen Alzheimer Immunotherapy has the right to manufacture all of its

requirements of QS-21 for use in the Licensed Product and we have no further supply obligations. Assuming all benchmarks are met under this agreement, we could receive up to $11.5 million in
future milestone payments. Furthermore, under the terms of the Amended license agreement, we are entitled to receive middle single-digit royalties on net sales of Licensed Product for a period of at least 10 years after the first commercial sale of
such product, if any. Pursuant to the terms of the supply agreement between the parties, we (directly or through a third-party manufacturer) are Elan’s exclusive supplier of QS-21 Expiration or termination of the Amended
license agreement is without prejudice to any rights that accrued to the benefit of the parties prior to the date of such expiration or termination. Upon expiration of the Amended license agreement, Janssen Alzheimer Immunotherapy will have a
royalty-free license. Upon early termination of the Amended license agreement, Janssen Alzheimer Immunotherapy’s license rights terminate and future payment obligations do not accrue.

 Executive Compensation

 Annual
Incentive Bonuses, page 108

 2. We note your response to Comment 3 and Comments 4. Please provide proposed disclosure to be included
in your 2009 Form 10-K, which identifies how the level of achievement with regard to the Company goals impacts the actual bonuses to be paid to your NEOs. For example, your 2008 disclosure should have described the level of achievement of each of
the Company goals and indicated how the respective levels of achievement contributed to the Compensation Committee’s decision to provide bonus payouts at 60% of target. Your proposed disclosure for the 2009 Form 10-K should clearly indicate how
the achievement of your Company goals will contribute to the Compensation Committee’s determination of the total bonus payout for 2009. If there is a specific formula relating achievement to award levels and/or weightings for your Company
goals, this information should be provided. In the alternative, if there is no such formula or weighting for the Company goals, your proposed disclosure should describe how the Compensation Committee will make its bonus payout determination. Please
confirm that you will disclose how the compensation committee made its bonus payout determination.

 Please also confirm
that you will discuss the degree of achievement of corporate goals and the NEO’s individual performance and the level of adjustment in the event that the Compensation Committee adjusts an individual NEO’s bonus payout based on individual
performance.

 Below is the proposed disclosure to be included in our 2009 Form 10-K, which will identify how the level of
achievement of Company goals impacts the actual bonuses paid to our NEOs.

 The Company’s annual goals and objectives are
set at the beginning of each fiscal year and are reviewed and approved by the Board of Directors. At the end of the fiscal year our executive management prepares a status report outlining the extent to which the goals and objectives were achieved
and presents that to the Compensation Committee along with a recommendation on the percentage funding level for the NEOs’ target bonus awards. The Compensation Committee evaluates the report, along with any relevant supporting documentation and
considers it in the context of any change in facts or circumstances that could have impacted goal attainment throughout the year. Based on this evaluation, as well as the

Company’s available financial resources, the Compensation Committee determines the appropriate funding level for the NEOs’ target bonus payout. There is no quantifiable formula or
weighting of goals. As a result, the Compensation Committee exercises discretion in establishing the funding level of the NEOs’ target bonus payout, taking into account the level of achievement of the Company goals as a whole. Once determined,
the recommended bonus payout level is applied to each NEO’s target bonus percentage to establish the individual target award. The Compensation Committee may exercise further discretion to adjust the actual bonus paid to the individual NEO to
recognize an extraordinary personal contribution or performance disappointment that impacted the Company’s overall performance. When exercising discretion to establish funding levels and individual awards, the Compensation Committee members
apply the same standards of good faith and fiduciary duty they apply to their general responsibilities as a Committee of the Board of Directors and as individual directors.

 2009 Company goals included the following:

 Oncophage

•

 Obtain export license from Russia for tissue shipment

•

 Generate Oncophage revenues in Russia

•

 Pursue conditional approval in renal cell carcinoma (RCC) in Europe

•

 Complete the analysis of the survival registry for the RCC trial and determine U.S. approval pathway

•

 Work with clinical investigators to advance Oncophage development in glioma with minimal or no expense to Antigenics

 QS-21

•

 Continue to support and optimize existing QS-21 partnerships and monitor use of QS-21 by third parties to maximize proprietary position and franchise
value

 General Finance and Administration

•

 Reduce our net cash burn rate and optimize our existing financial and human resources

•

 Generate $20 million in cash through partnership, product sales and/or financing activities

•

 Work toward achieving liquidity of our common stock in the wake of the NASDAQ delisting

•

 Strategically and cost effectively advance our IP position for Oncophage, our HSP technology, QS-21 and other assets

 We confirm that our 2009 Form 10-K will disclose how the Compensation Committee made its bonus determination, the degree of achievement of corporate goals
and the NEOs’ individual performance and the level of adjustment in the event that the Compensation Committee adjusts an individual NEO’s bonus payout based on individual performance.

 We acknowledge that we are responsible for the adequacy and accuracy of the disclosure in
the filing, that the 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 we may not assert Staff comments as a defense in any proceeding
initiated by the Commission or any person under the federal securities laws of the United States.

 We hope that this letter
fully responds to your concerns.

 Please call the undersigned at (212) 994-8200 with any questions regarding this letter.

 Sincerely,

 /s/ Shalini Sharp

 Shalini Sharp

 Chief Financial Officer

Cc:
Garo Armen, Chairman and CEO

 Paul Kinsella, Ropes & Gray LLP

Via Facsimile and U.S. Mail Mail Stop 4720                                                                                                   September 24, 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 supplemental response and have the following additional comments.   In our comments, we ask you to provide us with information to better understand your disclosure. Where it requests yo u to revise disclosure, the information
you provide should show us what the revised disclosure will look like and identify the
annual or quarterly filing, as applicable, in which you intend to first include it. If you do
not believe that revised disc losure is necessary, explain the reason in your response.
After reviewing the information provided, we may raise additional 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

Business, page 11

1. We note your response to Comment 1 a nd your statement that you have been
granted confidential treatment in relation to the information requested in our comment.  Please note that we do not gr ant confidential treatment for aggregate
amounts.  As such, please revise the propos ed disclosure for your agreements with
GSK and Elan to disclose the aggregate potential milestone payments and the percentage range of royalties  (for example: royalties between 10% and 15% of net
sales or low single digit royalties).

Garo H. Armen, Ph.D.
Antigenics Inc.  September 24, 2009 Page 2

In addition, it appears that the confidential tr eatment requests that you refer to
were not subject to review.  Please note th at we reserve the right to reconsider our
confidential treatment determinations.

Executive Compensation

 Annual Incentive Bonuses, page 108

2. We note your response to Comment 3 a nd Comments 4.  Please provide proposed
disclosure to be included  in your 2009 Form 10-K, which identifies how the level
of achievement with regard to the Comp any goals impacts the actual bonuses to
be paid to your NEOs.  For example, your 2008 disclosure should have described
the level of achievement of each of th e Company goals and indicated how the
respective levels of achie vement contributed to the Compensation Committee’s
decision to provide bonus payout s at 60% of target.  Your  proposed disclosure for
the 2009 Form 10-K should clearly indi cate how the achievement of your
Company goals will contribute to th e Compensation Committee’s determination
of the total bonus payout for 2009.  If there is a specific formula relating
achievement to award levels and/or we ightings for your Company goals, this
information should be provided.  In the alte rnative, if there is  no such formula or
weighting for the Company goals, your pr oposed disclosure should describe how
the Compensation Committee will make its  bonus payout determination.  Please
confirm that you will disclose how the compensation committee made its bonus payout determination.    Please also confirm that you will discuss the degree of achievement of corporate
goals and the NEO’s individual performan ce and the level of adjustment in the
event that the Compensation Committ ee adjusts an individual NEO’s bonus
payout based on individual performance.

*    *    *    *
 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.

Garo H. Armen, Ph.D.
Antigenics Inc.  September 24, 2009 Page 3
  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

CORRESP
1
filename1.htm

SEC RESPONSE LETTER

 September 14, 2009

 VIA EDGAR

 Mr. Jeffrey Riedler

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F Street, N.E.

 Washington, D.C. 20549

Re:
Antigenics Inc.

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

Filed March 16, 2009

File Number 000-29089

 Dear Mr. Riedler:

 This letter responds to the comments from the Staff (the “Staff”) of the Securities and Exchange Commission (the “Commission”), dated
August 31, 2009, regarding the above-referenced Form 10-K of Antigenics Inc. (the “Company”, “we”, “our” or “us”). We have repeated the text of the comments by number and in bold. Where requested to
provide proposed disclosure for our 2009 Form 10-K, we have underlined the additions and struck through deletions of the disclosure in our Form 10-K for the year ended December 31, 2008.

 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:

•

 The amounts paid to date;

•

 The aggregate potential milestone payments;

•

 The percentage range of royalties; and,

•

 Termination provisions

 We note that the
Staff has requested additional information pertaining to amounts paid to date, the aggregate potential milestone payments and the percentage range of royalties under each of these agreements. We have not included most of this information in our
proposed disclosure below because we have been previously granted confidential treatment of such information by

the Staff. We believe that the requested information, if disclosed, would cause substantial competitive injury through the disclosure of confidential
commercial or financial information. We respectfully refer the Staff to our requests dated, May 11, 2009 pertaining to the Amended GSK supply agreement, August 3, 2006 pertaining to the GSK license agreement, and November 8, 2007
pertaining to the license and supply agreements with Elan. Below is our currently proposed disclosure for our 2009 Form 10-K:

 GSK.
In July 2006, we entered into a license agreement and a supply agreement with GSK for the use of QS-21. On July 20, 2007, we executed a letter of intent with GSK amending the supply agreement to accelerate GSK’s commercial grade QS-21
manufacturing rights. Pursuant to the terms of the letter agreement, GSK obtained the right to manufacture all of its requirements of commercial grade QS-21 and, upon our election, is obligated to supply us (or our affiliates, licensees, or
customers) certain quantities of commercial grade QS-21 for a stated period of time. On January 16, 2009, we entered into an Amended and Restated Manufacturing Technology Transfer and Supply Agreement (the “Amended GSK supply
agreement”) reflecting the provisions of the July 20, 2007 letter agreement. To date we have received $8.8 million in up-front and milestone payments related to these agreements. In addition, for manufacturing profits that were anticipated
to have otherwise been payable under the 2006 GSK supply agreement, GSK agreed to pay us $1.75 million on or before December 31, 2008 and fixed additional amounts thereafter. Furthermore, under both the license and the supply agreements, we are
entitled to receive milestone payments upon the achievement of certain benchmarks and royalties on net sales of resulting product for a period of at least 10 years after the first commercial sale. The agreements may be terminated by either party
upon a material breach if the breach is not cured within the time specified in the agreement. The termination or expiration of the GSK license agreement does not relieve either party from any obligation which accrued prior to the termination or
expiration. Among other provisions, the milestone payment obligations survive termination or expiration for any reason, and the license rights granted to GSK survive expiration of the GSK license agreement. The license rights and payment obligations
of GSK under the Amended GSK supply agreement survive termination or expiration, except that GSK’s license rights and future royalty obligations do not survive if we terminate due to GSK’s material breach unless we elect otherwise.

 We understand that QS-21 is a key component included in several of GSK’s proprietary adjuvant systems and that a number of GSK’s
vaccine candidates currently under development are formulated using adjuvant systems containing QS-21. GSK has initiated a Phase 3 study evaluating its investigational MAGE-A3 Antigen-Specific Cancer Immunotherapeutic containing QS-21 in non-small
cell lung cancer. GSK and its research partners have also released data from Phase 2 studies of its malaria vaccine candidate in African infants and young children. GSK has indicated that it intends to proceed into late stage trials of what could be
the first malaria vaccine for infants and young children in Africa. We will receive royalties on net sales for a period of at least 10 years after the first commercial sale under the GSK supply agreement.

 Elan. We granted Elan a commercial license for the use of QS-21 in research and commercialization of products. Under the terms of the agreement,
we are entitled to receive future milestone payments and product royalties in the event of the successful development of Elan’s Alzheimer’s disease vaccine that contains QS-21 for at least 10 years after the first commercial sale of
such product. In 2007, Elan initiated a Phase 2 study of their vaccine. To date we have received $3 million in up-front and milestone payments related to this license agreement. Pursuant to the terms of the supply agreement between the
parties, we (directly or

through a third-party manufacturer) are Elan’s exclusive supplier of QS-21 and receive payments for manufacturing clinical materials supplied at the
request of Elan. Expiration or termination of the license agreement is without prejudice to any rights that accrued to the benefit of the parties prior to the date of such expiration or termination. Upon expiration of the license agreement, Elan
will have a royalty-free license. Upon early termination of the license agreement, Elan’s license rights terminate and future payment obligations do not accrue, provided that if Elan terminates early without cause, and we have made irrevocable
commitments for the establishment of capacity to meet Elan’s supply needs, the parties shall negotiate a termination payment to us.

 2. We
note your disclosure that on November 30, 2008, you entered into a patent assignment assigning all rights, title, and interest 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 December 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.

 On November 30, 2008, we
assigned patent applications PCT/US2002/40910, US 10/499890, AU2002357359A, JP2003556090T and CA2471092A, each entitled “Compositions comprising immunoreactive reagents and saponins, and methods of use thereof”, and all substitutions,
continuations, continuations-in-part, divisionals, supplementary protection certificates, renewals, all letters patent granted thereon, all reissues, reexaminations, extensions, confirmations, utility models, registrations and patents of addition
thereof, which have been or may be filed in the United States or elsewhere in the world (the “Patent Applications”) to CSL Limited, an Australian corporation. Prior to our entering into the assignment arrangement, in the ordinary course of
strategic planning, we had made the decision not to pursue the Patent Applications ourselves, as they were not material to our business. Subsequently, we were approached by, and agreed to assign the Patent Applications to, CSL Limited. Pursuant to
the terms of the agreement, CSL Limited agreed to pay us $4,750,000 with $2,000,000 due and payable upon signing. At December 31, 2008 our cash balance was $34,463,000 and we projected a net cash spend of $25 million during the year ending
December 31, 2009, therefore we were not substantially dependent on this agreement for our liquidity. We note that the Staff has indicated that the $2 million dollar payment in 2008 represented a substantial portion of our revenues for the year
ended December 31, 2008. However, the $2 million was not included as revenues in our Statement of Operations for the year ended December 31, 2008, rather it was classified as Other Income. The total consideration to be received under the
agreement represented approximately 8% of our total assets at December 31, 2008. There are no further payments owing under this agreement. We therefore determined that the assignment of the Patent Applications was a disposition of an
insignificant amount of assets and that the agreement provided no material rights to, or obligations of, the Company. Accordingly, we do not believe we are required to file the agreement.

 Executive Compensation

 Annual Incentive Bonuses, page 108

 3. Your Compensation Discussion and Analysis does not disclose the “company’s annual
goals and objectives and functional area goals, as well as individual performance objectives” that provide the 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 individual goals and objectives; and

•

 A discussion of how the level of achievement will affect the actual bonuses to be paid.

 Additionally, confirm that you will discuss the achievement of these objectives. To the extent that the objectives are quantified, the discussion in your proxy
statement should also be quantified.

 The Company’s annual goals and objectives are outlined on page 107 of our 2008 Form 10-K. Due to the
Company’s small size and limited organizational complexity Named Executive Officers, or NEOs, are expected to perform and contribute cross-functionally and the annual incentive bonus is designed to reward the achievement of overall company
goals and objectives. Little if any distinction is made in annual bonuses paid to NEOs based on functional or individual goals except as they relate to the achievement of overall company goals and objectives. We believe that disclosing functional
and individual goals in addition to Company goals would be duplicative.

 The Company’s annual goals and objectives are set at the beginning of each
fiscal year and are reviewed and approved by the Board of Directors. At the end of the fiscal year our executive management prepares a status report outlining the extent to which the goals and objectives were achieved and presents that to the
Compensation Committee along with a recommendation on the percentage funding level for the NEO’s target bonus awards. The Compensation Committee approves and/or adjusts that recommendation based on their assessment of the Company’s
performance vis-à-vis its annual goals and objectives and the available resources. Once approved, the recommended bonus payout level is applied to each NEO’s target bonus percentage to determine the actual bonus paid. While adjustments
can be made to the individual NEO’s actual bonus paid, those adjustments occur infrequently and are limited in size.

 In our 2009 Form 10-K
disclosure, we will remove references to individual and functional area goals and objectives to avoid confusion, but respectfully request the Staff to accept no additional changes to our existing disclosures.

 4. We note your statement on page 119, that the funding for the target incentive awards is based on the extent of achievement of a predetermined 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 objectives and milestones; and,

•

 A discussion of how the level of achievement will affect the funding of the target incentive awards.

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

 The predetermined corporate objectives and milestones for 2008 are set forth on page 107 of our 2008 Form 10-K and will
similarly be disclosed for 2009. Because awards are determined based on a qualitative review of the facts and circumstances related to the Company, we cannot meaningfully quantify how the level of achievement will affect the funding of the target
incentive awards beyond what we have provided on page 109 of our 2008 Form 10-K. In our 2009 Form 10-K, we will discuss the extent to which objectives and milestones have been achieved for the year, as applicable.

 Exhibits, Financial Statement Schedules, page 135

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

 Ms. Klaskin is not party to
a change in control agreement but is covered under our change of control plan as noted on pages 111 and 123 of our filing. Our executive change of control plan is filed as Exhibit 10.26 to our annual report on Form 10-K for the year ended
December 31, 2008.

 We acknowledge that we are responsible for the adequacy and accuracy of the disclosure in the filing, that the
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 we may not assert Staff comments as a defense in any proceeding initiated by the Commission
or any person under the federal securities laws of the United States.

 We hope that this letter fully responds to your concerns.

 Please call the undersigned at (212) 994-8200 with any questions regarding this letter.

Sincerely,

 /s/ Shalini Sharp

Shalini Sharp

Chief Financial Officer

Cc:
Garo Armen, Chairman and CEO

 Paul Kinsella,
Ropes & Gray LLP

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

Via Facsimile and U.S. Mail
Mail Stop 6010
         April 27, 2009   Dr. Garo H. Armen, Ph.D.  Chairman and Chief Executive Officer  Antigenics, Inc.  3 Forbes Road  Lexington, MA 02421

Re: Antigenics, Inc.
 Preliminary Proxy Statement on Schedule 14A  Filed April 9, 2009  File Number 000-29089

Dear Dr. Armen:
  We have completed our review of the above listed filing and have no further
comments at this time.

Sincerely,

Jeff Riedler Assistant Director

CORRESP
1
filename1.htm

SEC RESPONSE LETTER

 Antigenics Inc.

 3 Forbes Road

 Lexington, MA 02421

 April 20, 2009

 VIA EDGAR

 Ms. Rose Zukin

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F. Street, N.E.

 Washington, D.C. 20549

Re:
Securities and Exchange Commission (“SEC”) Comment Letter dated April 16, 2009 with respect to the Preliminary Proxy Statement (File No. 000-29089) (the
“Preliminary Proxy Statement”) filed by Antigenics Inc. (the “Company”) with the SEC on April 9, 2009.

 Dear Ms. Zukin:

 This letter responds to the staff’s comments on the above-referenced Preliminary Proxy Statement. For convenience, we
have repeated the text of the staff’s comments by number and in bold. Our response is denoted with an “R.”

 Preliminary Proxy
Statement filed April 9, 2009

 1. Please disclose whether you currently have, or do not have, any plans to issue any of the authorized but
unissued shares that would be available as a result of the approval of the amendment to the Amended and Restated Certificate of Incorporation to effect a reverse stock split of your outstanding shares of common stock.

 1R. The definitive proxy statement will be revised to reflect this comment by adding a new sentence to the end of the second paragraph under the heading “Effects of
the Reverse Stock Split on Outstanding Capital Stock” in proposal 4. The sentence will state the following: “The Company does not currently have any plans to issue any of the authorized but unissued shares that would be available as a
result of the increased “headroom” created if the reverse stock split of our outstanding shares of common stock is approved by our stockholders and subsequently effected by the Board.”

 We acknowledge that we are responsible for the adequacy and accuracy of the disclosure in the filing, that the staff comments or changes to disclosure in response to
staff comments do not foreclose the SEC from taking any action with respect to the filing, and we may not assert staff comments as a defense in any proceeding initiated by the SEC or any person under the federal securities laws of the United States.

 Please call the undersigned at (212) 994-8200 with any questions regarding this letter.

 Very truly yours,

ANTIGENICS INC.

By:

/s/    Shalini Sharp

 Name: Shalini Sharp

 Title: Chief Financial Officer

Mail Stop 6010          April 16, 2009  Dr. Garo H. Armen, Ph.D.  Chairman and Chief Executive Officer  Antigenics, Inc.  3 Forbes Road  Lexington, MA 02421

Re: Antigenics, Inc.
 Preliminary Proxy Statement on Schedule 14A  Filed April 9, 2009  File Number 000-29089

Dear Dr. Armen:

We have limited our review of your filing to the issue we have addressed in our
comment below.  Where indicated, we think you should revise your document in response to this comment.  If you disagree, we  will consider your e xplanation as to why
our comment is inapplicable or a revision is unnecessary.  Please be as detailed as
necessary in your explanations.     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 comment or any other aspect of our review.  Feel free to call us at the telephone numbers listed at the end of this letter.
 Preliminary Proxy Statement filed April 9, 2009

1. Please disclose whether you currently have, or do not have, any plans to issue any
of the authorized but unissued shares th at would be available as a result of the
approval of the amendment to the Am ended and Restated Certificate of
Incorporation to effect a reverse stock split of your outstanding shares of common stock.

* * * * *

Dr. Garo H. Armen, Ph.D.
Antigenics, Inc.  April 16, 2009 Page 2   As appropriate, please amend your filing and respond to this comment within 10
business days or tell us when you will provide  us with a response.  You may wish to
provide us with marked copies of the amendm ent to expedite our review.  Please furnish
a cover letter with your amendment that keys your response to our comment and provides any requested information.  Detailed cover lett ers greatly facilitate our review.  Please
understand that we may have additional comm ents after reviewing your amendment and
response to our comment.   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.
  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 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 for the adequacy  and accuracy of the disclosure in the filing; and

• the company may not assert this action as  a defense in any proceeding initiated by
the Commission or any person under the fe deral 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 Divi sion of Corporation Fi nance in our review
of your filing or in response to our comments on your filing.    Please contact Rose Zukin at (202) 551-3239 or me at (202) 551-3710 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

CORRESP
1
filename1.htm

SEC Letter

 March 16, 2009

 VIA EDGAR

 Mr. Bryan Pitko

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F Street, N.E.

 Washington, D.C. 20549-0306

Re:
Antigenics Inc.

 Registration Statement on Form
S-1, filed on January 2, 2009, as amended on January 27, 2009 and March 16, 2009 (File No. 333-156556)

 Post-Effective
Amendment on Form S-1 to the Registration Statement on Form S-3, filed on January 2, 2009, as amended on March 16, 2009 (File No. 333-149116)

 Post-Effective Amendment on Form S-1 to the Registration Statement on Form S-3, filed on January 2, 2009, as amended on March 16, 2009 (File No. 333-150326)

 Dear Mr. Pitko,

 In connection with the above
referenced registration statement and post-effective amendments (collectively, the “Registration Statements”), Antigenics Inc. (the “Company”) hereby acknowledges that (i) should the Securities and Exchange
Commission (the “Commission”) or the staff, acting pursuant to delegated authority, declare the filings effective, it does not foreclose the Commission from taking any action with respect to the filings, (ii) the action of the
Commission or the staff pursuant to delegated authority, in declaring the filings effective, does not relieve the Company from its full responsibility for the adequacy and accuracy of the disclosure in the filings, and (iii) the Company may not
assert the declaration of effectiveness as defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

 The Company requests effectiveness of each Registration Statement at 9:00 AM on March 18, 2009, or as soon thereafter as practicable.

 Please call the undersigned at (781) 674-4400 as soon as the Registration Statements have been declared effective.

 Best regards,

 /s/    Karen Higgins
Valentine

 Karen
Higgins Valentine

 Vice President and General Counsel

Cc:
Garo Armen, Chairman and CEO

 Paul Kinsella,
Ropes & Gray LLP

CORRESP
1
filename1.htm

Effectiveness Request

 ANTIGENICS INC.

 February 3, 2009

 VIA EDGAR

 Bryan Pitko

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F. Street, N.E.

 Washington, D.C. 20549

Re:
Antigenics Inc.

 Pre-Effective Amendment No. 1
to the Registration Statement on Form S-1, filed on January 27, 2009 (File No. 333-156556)

 Post-Effective Amendment on Form S-1
to the Registration Statement on Form S-3, filed on January 2, 2009 (File No. 333-149116)

 Post-Effective Amendment on Form S-1 to
the Registration Statement on Form S-3, filed on January 2, 2009 (File No. 333-150326)

 Dear Mr. Pitko,

 On January 2, 2009, Antigenics Inc. (the “Company”) filed (i) a Registration Statement on Form S-1 (File No. 333-156556), which was
subsequently amended by Pre-Effective Amendment No. 1 filed on January 27, 2009; (ii) a Post-Effective Amendment on Form S-1 to the Registration Statement on Form S-3 (File No. 333-149116); and (iii) a Post-Effective
Amendment on Form S-1 to the Registration Statement on Form S-3 (File No. 333-150326) (collectively, the “January Filings”) with the Securities and Exchange Commission (the “Commission”). In order to satisfy
its contractual obligations with certain holders of the Company’s common stock, par value $0.01 per share, and the Company’s Series B2 Convertible Preferred Stock, par value $0.01 per share, the Company made the January Filings.

 Pursuant to Rule 461 of the Securities Act of 1933, as amended (the “Securities Act”), the Company requests effectiveness of each of
the January Filings on March 9, 2009 at 4:00 p.m., or as soon thereafter as practicable.

 On or before March 16, 2009, the Company plans to
file its Annual Report on Form 10-K for the year ended December 31, 2008. Immediately thereafter, and assuming that the Commission has granted the Company’s requests for acceleration of effectiveness of each of the January Filings, the
Company plans to file a post-effective amendment to each of the January Filings (collectively, the “March Filings”), with the purpose of incorporating the Company’s Annual Report on Form 10-K for the year ended
December 31, 2008 into each of the registration

statements. The Company, in light of potential penalties related to the aforementioned contractual obligations, expects to seek Commission accommodation on a
request for immediate acceleration of effectiveness of each of the March Filings pursuant to Rule 461 of the Securities Act.

 In connection with the
January Filings and the March Filings, the Company hereby acknowledges that (i) should the Commission or the staff, acting pursuant to delegated authority, declare any filing effective, it does not foreclose the Commission from taking any
action with respect to such filing; (ii) the action of the Commission or the staff, acting pursuant to delegated authority, in declaring any filing effective, does not relieve the Company from its full responsibility for the adequacy and
accuracy of the disclosure in such filing; and (iii) the Company may not assert the declaration of effectiveness as defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

 Please contact the undersigned at 781-674-4678 if you have any questions regarding this letter or, alternatively, as soon as the above-referenced filings
have become effective.

Best regards,

ANTIGENICS INC.

 /s/ Karen Higgins Valentine

Karen Higgins Valentine

Vice President and General Counsel

Cc:
Garo Armen, Chairman and CEO

 Paul Kinsella,
Ropes & Gray LLP

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

CORRESP
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Letter to the SEC

 January 2, 2009

 VIA EDGAR

 Securities and Exchange Commission

 Division of Corporation Finance

 100 F Street, N.E.

 Washington, DC 20549

Re:
Antigenics Inc.

 Registration
Statement on Form S-1, filed on January 2, 2009

 Post-Effective Amendment on Form S-1 to the Registration Statement on

 Form S-3, filed on January 2, 2009 (File No. 333-149116)

 Post-Effective Amendment on Form S-1 to the Registration Statement on

 Form S-3, filed on January 2, 2009 (File No. 333-150326)

 Ladies and Gentlemen:

 On January 2, 2009, Antigenics Inc. (the “Company”) filed
(i) a Registration Statement on Form S-1; (ii) a Post-Effective Amendment on Form S-1 to the Registration Statement on Form S-3 (File No. 333-149116) and (iii) a Post-Effective Amendment on Form S-1 to the Registration Statement
on Form S-3 (File No. 333-150326) (collectively, the “January 2 Filings”) with the Securities and Exchange Commission (the “Commission”). The following is a brief explanation of the January 2 Filings.

 In the third quarter of 2008, the Company failed to file a Form 8-K disclosing the adoption of an amendment to the Company’s by-laws
dated September 11, 2008. On November 10, 2008, the Company disclosed the amendment to its by-laws in an amendment to its Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2008. Based upon the foregoing and
the Commission’s interpretation of Rule 401(b) of the Securities Act of 1933, as amended (the “Securities Act”), the Company will cease to be eligible to register shares of its capital stock on Form S-3 upon the Company filing
its Annual Report on Form 10-K for the year ended December 31, 2008. In order to satisfy its contractual obligations with certain holders of the Company’s common stock, par value $0.01 per share, and the Company’s Series B2
Convertible Preferred Stock, par value $0.01 per share, the Company made the January 2

Filings. Pending the Commission’s review of the January 2 Filings, the Company plans to request acceleration of effectiveness of each of the
January 2 Filings pursuant to Rule 461 of the Securities Act prior to the Company filing its Annual Report on Form 10-K for the year ended December 31, 2008.

 On or before March 16, 2009, the Company plans to file its Annual Report on Form 10-K for the year ended December 31, 2008. Immediately thereafter and assuming that the Commission has granted the
Company’s requests for acceleration of effectiveness of the January 2 Filings, the Company plans to file a post-effective amendment to each of the January 2 Filings (collectively, the “March Filings”), with the
purpose of the March Filings to incorporate the Company’s Annual Report on Form 10-K for the year ended December 31, 2008 into each of the registration statements. The Company, in light of potential penalties related to the aforementioned
contractual obligations, expects to seek Commission accommodation on a request for immediate acceleration of effectiveness of each of the March Filings pursuant to Rule 461 of the Securities Act.

 In connection with the January 2 Filings and the March Filings, the Company hereby acknowledges that (i) should the Commission or the staff,
acting pursuant to delegated authority, declare any filing effective, it does not foreclose the Commission from taking any action with respect to such filing, (ii) the action of the Commission or the staff, acting pursuant to delegated
authority, in declaring any filing effective, does not relieve the Company from its full responsibility for the adequacy and accuracy of the disclosure in such filing, and (iii) the Company may not assert the declaration of effectiveness as
defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United States.

 Please call
the undersigned at (781) 674-4678 with any questions regarding this letter.

 Best regards,

 /s/ Karen Higgins Valentine

 Karen Higgins Valentine

 Vice President and General Counsel

Cc:
Garo Armen, Chairman and CEO

 Paul Kinsella,
Ropes & Gray LLP

 -2-

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Acceleration Request

 Antigenics Inc.

 162 Fifth Avenue, Suite 900

 New York, New York 10010

 June 23, 2008

 VIA EDGAR

 Mr. Bryan Pitko

 Division of Corporation Finance

 United States Securities and Exchange Commission

 100 F. Street, N.E.

 Washington, D.C. 20549

Re:
Registration Statement on Form S-3 filed by Antigenics Inc. with the Securities and

Exchange Commission (the “Commission”) on May 29, 2008 (File No. 333-151244)

(the “Registration Statement”)

 Dear Mr. Pitko,

 In connection with the above-referenced filing, Antigenics Inc. (the “Company”) hereby acknowledges that (i) should
the Securities and Exchange Commission (the “Commission”) or the staff, acting pursuant to delegated authority, declare the Registration Statement effective, it does not foreclose the Commission from taking any action with respect
to the Registration Statement, (ii) the action of the Commission or the staff pursuant to delegated authority, in declaring the Registration Statement effective, does not relieve the Company from its full responsibility for the adequacy and
accuracy of the disclosure in the Registration Statement, and (iii) the Company may not assert the declaration of effectiveness as defense in any proceeding initiated by the Commission or any person under the federal securities laws of the
United States.

 Pursuant to Rule 461 under the Securities Act of 1933, as amended, the Company requests effectiveness of the above
referenced Registration Statement at 4:45 PM EST on June 25, 2008, or as soon thereafter as practicable.

 Please call the undersigned at
(212) 994-8200 as soon as the above-referenced filing has become effective.

 Very truly yours,

ANTIGENICS INC.

By:

/s/ Garo H. Armen

 Name: Garo H. Armen

 Title: Chief Financial Officer

Mail Stop 6010        June 5, 2008  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-3
  Filed May 29, 2008
  File No. 333-151244

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.
 General

1. We note that that you have filed a co nfidential treatment request on May 12,
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.

2. We note that you disclose the termination of the offering initially registered on
Form S-3 on August 12, 2004 in a footnote to  the calculation of your registration
fee.  Please note that you will need to file a post-effective amendment to the
earlier registration statemen t on Form S-3 in order to properly de-register any
unsold securities.

Dr. Garo H. Armen
Antigenics, Inc.
June 5, 2008 Page 2
* * *
  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.     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.

Dr. Garo H. Armen
Antigenics, Inc.
June 5, 2008 Page 3
 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

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Acceleration Request

 ANTIGENICS INC.

 162 Fifth Avenue, Suite 900

 New York, New York 10010

 May 6, 2008

 Securities and Exchange Commission

 100 F Street, N.E.

 Washington, D.C. 20549

Re:
Antigenics Inc.— Registration Statement on Form S-3, File No. 333-150326

 Ladies and Gentlemen:

 Pursuant to Rule 461 under the Securities Act of 1933, as amended, Antigenics Inc. hereby
respectfully requests that the effective time of the above-captioned Registration Statement be accelerated to May 7, 2008 at 4:30 p.m. or as soon thereafter as practicable.

 The cooperation of the staff in meeting the timetable described above is very much appreciated.

 Per your letter to the
Company dated April 29, 2008, the Company hereby acknowledges 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 for the adequacy and accuracy of the disclosure in the filing; and

•

 the Company may not assert this action as a defense in any proceeding initiated by the Commission or any person under the federal securities laws of the United
States.

 Any questions should be addressed to Paul Kinsella at Ropes & Gray LLP, One International Place, Boston, Massachusetts
02110, telephone (617) 951-7921.

 Very truly yours,

 ANTIGENICS INC.

 By:  /s/    Shalini
Sharp

         Shalini Sharp

         Chief Financial Officer

Mail Stop 6010
April 29, 2008
 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-3
Filed April 18, 2008
  File No. 333-150326

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.
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.
 General

1. We note that there is a pending confidential treatment request currently under
review.  Please note that we will not be able to consider your request for
acceleration of the effective da te of the registration statement until any issues that
arise during our examination of th e request have been satisfied.
 Selling Stockholders, page 21

 2. Please revise your selling stockholder table to disclose the name(s) of the natural
person(s) who have voting or investment  control over the shares of Antigenics
owned by the selling stockholders.

* * *

Garo H. Armen, Ph.D.
Antigenics Inc.
April 29, 2008 Page 2

As appropriate, please amend your regist ration statement in response to these
comments.  You may wish to provide us with 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 even t 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.
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 46 0 and 461 regarding requesting acceleration
of a registration statement.  Please allow ad equate time after the filing of any amendment

Garo H. Armen, Ph.D.
Antigenics Inc. April 29, 2008 Page 3

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 Sebastian Gomez Abero at (202) 551-3578 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

Via Facsimile and U.S. Mail
Mail Stop 6010
        January 8, 2007

Garo H. Armen, Ph.D.
Chief Executive Officer and Chairman of the Board
Antigenics Inc.
630 Fifth Avenue
Suite 2100
New York, NY  10111

Re: Antigenics Inc.
 Form 10-K for Fiscal Year Ended December 31, 2005
 File No. 0-29089

Dear Dr. Armen:

 We have completed our review of your Form 10-K and have no further comments
at this time.

        S i n c e r e l y ,

Kevin Woody
        B r a n c h  C h i e f

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Correspondence Letter

 December 15, 2006

 VIA FEDERAL EXPRESS

 Mr. Jim B. Rosenberg

 Division of Corporation Finance

 United States Securities and Exchange Commission

 450 Fifth Street, N.W.

 Washington, D.C. 20549-0306

Re:
Form 10-K for Fiscal Year Ended December 31, 2005 (the “10-K”) of Antigenics Inc. (the “Company”)

 Dear Mr. Rosenberg:

 This letter responds to the
comments from the Staff of the Securities and Exchange Commission (the “Commission”), dated November 3, 2006, regarding the above-referenced 10-K. We have repeated the text of the comments by number and in bold. Where requested to
provide disclosure-type language, we have underlined the changes to our December 31, 2005 disclosures that we would propose to make in future filings based on the facts at the time.

 Management’s Discussion and Analysis of Financial Condition and Results of Operation

 Critical Accounting Policies and
Estimates

 Research and Development, page 68

 1. You
disclose how you determine your accruals for research and development expenses and you indicate that you subsequently adjust your accruals as you become aware of actual costs. You also indicate that these adjustments could be material. Please
provide us, in a disclosure-type format, a revised discussion that quantifies:

•

the effect that changes in estimates have had on the financial statements for each period presented; and

•

the effect that reasonably likely changes in the key assumptions underlying these estimates as of the latest balance sheet may have on the financial statements.

 Research and Development – Clinical Study Accruals

 Research and development costs are expensed as incurred and were $47,080,000, $41,718,000, and $46,264,000 for the years ended December 31, 2005, 2004, and 2003,
respectively.

 1

 Research and development expenses include the costs associated with our internal research and development activities,
including salaries and benefits, occupancy costs, clinical manufacturing costs, related administrative costs, and research and development conducted for us by outside advisors, such as sponsored university-based research partners, and clinical study
partners. We account for our clinical study costs by estimating the total cost to treat a patient in each clinical trial and recognizing this cost based on estimates of when the patient receives treatment, beginning when the patient enrolls in the
trial. This estimated cost includes patient-related costs, including laboratory costs, related to the conduct of the trial. Cost per patient varies based on the type of clinical trial, the site of the clinical trial and length of treatment period.
As we become aware of the actual study costs, we adjust our accrual; such a change in estimate may be a material change in our clinical study accrual, which could also materially affect our results of operations. There were no changes to our
estimates during the year ended December 31, 2005. During the year ended December 31, 2004, two of our phase 3 trials were closed to enrollment and an analysis of the assumptions used in our clinical study accruals, primarily the number of
patients in the study as well as the estimated length of the study, resulted in a reduction in our accruals in the amount of $401,000. During the year ended December 31, 2003, we reviewed our budgeted per patient costs which resulted in a
reduction of our clinical study accrual in the amount of $203,000. Clinical study costs included in accrued liabilities on our consolidated balance sheets were $2,608,000 and $3,219,000 at December 31, 2005 and 2004, respectively. Clinical
study costs that are subject to estimation and included in research and development expenses were $1,909,000, $3,534,000 and $5,291,000 for the years ended December 31, 2005, 2004, and 2003, respectively. We believe the effects of reasonably
likely changes in the key assumptions underlying the clinical study cost estimates would not likely have a material effect on the consolidated financial statements.

 Financial Statements and Supplementary Data

 Notes to Consolidated Financial Statements

 Note 15: Debt, page 100

 2. You disclose that the conversion price is
subject to adjustment and that notes surrendered for conversion in connection with certain fundamental changes may in certain circumstances be entitled to an increase in the conversion rate of the notes. You also disclose that you are obligated to
keep effective a shelf registration statement for the shares underlying the conversion of your notes. It appears from your January 25, 2005 indenture agreement that the fundamental changes include a change of control and the termination of
trading; both events that appear to be outside of your control. Please explain to us why you apparently have not bifurcated the embedded conversion feature under EITF 00-19. In your response please address all the requirements of paragraphs 12
through 32 of that consensus. In addition, please provide us, in a disclosure-type format, revised disclosure that clearly indicates:

•

how the initial conversion rate of $10.76 can be adjusted;

•

the nature of the fundamental changes outlined in your indenture agreement;

 2

•

the circumstances that could increase the conversion rate of the notes when a fundamental change exists; and

•

your consideration for the separate derivative accounting for the conversion feature of the notes.

 Our Consideration of the Guidance in Paragraphs 12-32 of EITF 00-19:

 We reviewed Statement of Financial Accounting Standards No. 133, Accounting for Derivative Instruments and Hedging Activities (“SFAS No. 133”), to determine whether the notes issued by us
contain embedded derivative features that require bifurcation and separate accounting as derivatives.

 In accordance with paragraph 199 of
SFAS No. 133, the conversion feature is essentially a call option on our stock. Under the provisions of SFAS No. 133, our accounting depends on whether a separate instrument with the same terms as the embedded written option would be a
derivative instrument pursuant to paragraphs 6–11 of SFAS No. 133. Paragraph 11(a) of SFAS No. 133 states that if the contract is both (1) indexed to a company’s own stock and (2) classified in stockholders’
equity, then it will not be considered an embedded derivative that requires bifurcation under SFAS No. 133. EITF Issue No. 01-6, The Meaning of “Indexed to a Company’s Own Stock” (“EITF 01-6”), provides
guidance on the meaning of “indexed to a company’s own stock” and applies to instruments for which “settlement is based on changes in the issuing company’s stock price and one or more defined contingencies provided that once
the contingencies have occurred, the instrument’s settlement amount is based solely on the issuing company’s stock.” Instruments within the scope of EITF 01-6 are considered indexed to a company’s own stock within the meaning of
EITF Issue No. 00-19, Accounting for Derivative Financial Instruments Indexed to, and Potentially Settled in, a Company’s Own Stock (“EITF 00-19”), and paragraph 11(a) of SFAS No. 133 provided that (1) the contingency
provisions are not based on an observable market, other than the market for the issuer’s stock (if applicable), or an observable index, other than those calculated or measured solely by reference to the issuer’s own operations, and
(2) once the contingent events have occurred, the instrument’s settlement amount is based solely on the issuer’s stock. In this case, it appears that the settlement of the conversion feature is based on our stock price and other
defined contingencies. Therefore, it appears that EITF 01-6 applies, and the option would be considered to be indexed to our own stock. EITF 00-19 provides guidance on determining if the contract should be classified as equity.

 We considered the conversion feature in light of the guidance under paragraphs 12 - 32 of EITF 00-19 in determining whether or not the feature would be
classified in equity if it were freestanding as follows:

 EITF 00-19
Paragraph

 00-19 Paragraph

 Our Analysis

12

An instrument that includes any provision that could require net-cash settlement cannot be accounted for as equity (except in those limited circumstances in which holders of the underlying
shares also would receive cash-e.g., liquidation).

No such net-cash settlement provisions are included in the agreement. We have the option to settle the conversion premium in either cash or

 3

For SEC registrants, any provision that could require physical settlement by a cash payment to the counterparty in exchange for the company's shares cannot be accounted for as permanent equity
(temporary equity classification is required).

shares. We believe this condition is satisfied.

13-18

In order to be equity classified, an instrument must permit the company to settle in unregistered shares. Related considerations: 1) the contract permits a company to net-share settle by
delivery of unregistered shares, 2) if (a) a derivative contract requires physical or net-share settlement by delivery of registered shares and does not specify any circumstances under which net-cash settlement would be permitted or required and (b)
the contract does not specify how the contract would be settled in the event that the company is unable to deliver registered shares, then net-cash settlement is assumed if the company is unable to deliver registered shares and the instruments fails
equity classification, 3) if a settlement alternative includes a penalty that would be avoided by a company under other settlement alternatives, the uneconomic settlement alternative should be disregarded in classifying the contract, and 4) if an
instrument involves delivery of shares at settlement that are registered at inception of the transaction and there are no further timely filing or registration requirements, share delivery is within the control of the company.

Section 2.17 of the Indenture states that each Global Security (i.e., the securities issued) are to bear the Private Placement Legend. Upon conversion of such securities bearing this legend, the
Common Stock issued upon conversion is also to bear this legend (i.e., if the note bears the legend, the Common Stock must also bear the legend). This legend explicitly states that neither the Global Security nor the Common Stock have been
registered under the Securities Act of 1933. See discussion below of the liquidated damages provisions.

19

The company must have sufficient authorized and unissued shares available to settle the contract after considering all other commitments that may require the issuance of stock during the maximum
period the derivative contract could remain outstanding. If a company could be required to obtain shareholder approval to increase the company's authorized shares in order to net-share or physically settle a contract, share settlement is not
controlled by the company and asset or liability classification is required.

 Per section 10.05 of the Indenture, we are required to reserve sufficient authorized and unissued shares to cover the number of shares issuable under
all contracts that require issuance of stock. We have sufficient authorized and unissued shares to cover the number of shares issuable under all contracts that require issuance of stock.

 We have 54.4 million shares authorized and unissued as of December 31, 2005.
The

 4

 maximum number of shares that may need to be issued upon the occurrence of a make-whole fundamental change is approximately 1.98 million shares. This
is derived as follows for illustrative purposes only:

 Initial
conversion rate - 92.9023 shares

 Maximum additional shares when the stock price is $8.97 per share

 Make-whole conversion rate per $1,000 principal amount - 39.53 shares

 Multiply by total number of convertible notes issued - 50,000

 Total conversion value in shares
6,621,615

 Multiply by applicable share price $10.7640

 Total conversion value $71,275,000

 Less: Principal amount to be settled in cash only
$50,000,000

 Conversion premium $21,275,000

 Divide by applicable share price $10.7640

 Maximum shares represented by make-whole premium
1,976,500

 We are not currently aware of any other commitments that would require the
issuance of the Company’s authorized and unissued shares, except for approximately 8.1 million shares issuable upon the exercise of outstanding stock options and warrants, conversion of our preferred stock and those that will be issued in
accordance with our Directors Deferred Compensation Plan.

 5

20-24

An instrument must contain an explicit limit on the number of shares to be delivered in a share settlement. For certain contracts, the number of shares that could be required to be delivered
upon net-share settlement is essentially indeterminate. If the number of shares that could be required to be delivered to net-share settle the contract is indeterminate, a company will be unable to conclude that it has sufficient available
authorized and unissued shares and, therefore, net-share settlement is not within the control of the company. If a contract limits or caps the number of shares to be delivered upon expiration of the contract to a fixed number, that fixed maximum
number can be compared to the available authorized and unissued shares to determine if net-share settlement is within the control of the company.

Pages 2 and A-6 of the Indenture state that each $1,000 principal amount of securities is convertible into 92.9023 shares. Therefore, a cap is inherent in the conversion
formula.

25

An instrument must not require cash payment to the counterparty in the event the company fails to make timely filings with the SEC, as this is not within the control of the company. Accordingly,
if a contract permits share settlement but requires net-cash settlement in the event that the company does not make timely filings with the SEC, that contract must be classified as an asset or a liability.

There are no explicit references in the Indenture to additional cash payments required if we fail to make timely filings with the SEC. Page 88 of the Offering Memorandum indicates, however, that
if a registration default (as defined) occurs, additional interest at an annual rate of .25% will accrue for the first 90 days and at an annual rate of .5% thereafter until the registration default is cured. We computed the present value of the
maximum potential payment under this provision for the life of the notes. Using the approximate risk free interest rate (4% and 5% were used to provide a sensitivity analysis), we computed the present value of

 6

a maximum possible payment to be made under this provision to be between $3.1 million and $3.4 million. This represents a maximum additional return to the holders of between 6.2% and 6.8%, which
is not considered to be onerous (i.e., the present value of the additional interest does not appear to represent an unreasonable estimate of the difference in fair value between registered and unregistered shares). Additionally, this provision does
not result in a net-cash settlement, as described in paragraph 25 of EITF 00-19. Therefore, this liquidated damages provision does not appear to affect equity classification.

26

An instrument cannot require cash payments to the counterparty if the shares initially delivered upon settlement of the conversion are subsequently sold and the sales proceeds are insufficient
to provide the counterparty with full return of the amount due (that is, there are no cash settled “top-off” or “make-whole” provisions). Top-off or make-whole provisions that are net share settled and are also subject to the
share cap would not preclude equity classification.

No such provisions noted.

27-28

An instrument may require net cash settlement in specific circumstances in which the holders of the shares underlying the contract also would receive cash.

No such provis

CORRESP
1
filename1.htm

Correspondence Letter

 November 29, 2006

 VIA EDGAR

 Mr. Mark Brunhofer

 Division of Corporation Finance

 United States Securities and Exchange Commission

 450 Fifth Street, N.W.

 Washington, D.C. 20549-0306

Re:

 Form 10-K for Fiscal Year Ended December 31, 2005 (the “10-K”) of

 Antigenics Inc. (the “Company”)

 Dear Mr. Brunhofer:

 On November 16, 2006 the Company communicated to you that in order to fully respond to the Comment Letter, the Company believed it needed until November 30, 2006 and that as that day approached, if the
Company believed it would require additional time, it would contact you. At this time the Company believes it will need until December 15, 2006 but plans to file its response as soon as it is completed. The Company appreciates the Staff’s
willingness to allow for the additional time.

 Please call the undersigned at (212) 994-8218 if you have any questions regarding this
letter.

 Best regards,

 /s/ Christine M. Klaskin

Christine M. Klaskin

VP, Finance and Principal Accounting Officer

CORRESP
1
filename1.htm

Correspondence Letter

 November 16, 2006

 VIA EDGAR

 Mr. Mark Brunhofer

 Division of Corporation Finance

 United States Securities and Exchange Commission

 450 Fifth Street, N.W.

 Washington, D.C. 20549-0306

Re:
Form 10-K for Fiscal Year Ended December 31, 2005 (the “10-K”) of

 Antigenics Inc. (the “Company”)

 Dear Mr. Brunhofer:

 The Company confirms that it is in receipt of a comment letter (the “Comment Letter) from the Staff of the Securities and Exchange Commission, dated
November 3, 2006, regarding the above-referenced 10-K. The Comment Letter requests that Company respond within 10 business days or tell the Staff when the Company will respond. In order to fully respond to the Comment Letter, the Company
believes it will need until November 30, 2006. If, as that date draws closer, the Company believes it requires additional time, it will contact you. The Company appreciates the Staff’s willingness to allow for the additional time.

 Please call the undersigned at (212) 994-8218 if you have any questions regarding this letter.

 Best regards,

 /s/ Christine M. Klaskin

Christine M. Klaskin

VP, Finance and Principal Accounting Officer

Via Facsimile and U.S. Mail
Mail Stop 6010
        November 3, 2006

Garo H. Armen, Ph.D.
Chief Executive Officer and Chairman of the Board
Antigenics Inc.
630 Fifth Avenue
Suite 2100
New York, NY  10111

Re: Antigenics Inc.
 Form 10-K for Fiscal Year Ended December 31, 2005
 File No. 0-29089

Dear Dr. Armen:

We have limited our review of your filing to  the issues we have addressed in our
comments.  In our comments, we ask you to pr ovide us with more information so we may
better understand your disclosure.  After re viewing 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 filings.  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 10-K for the Year Ended December 31, 2005

Management’s Discussion and Analysis of Fi nancial Condition and Results of Operations

Critical Accounting Policies and Estimates

Research and Development, page 68
1. You disclose how you determine your acc ruals for research and development
expenses and you indicate that you subs equently adjust your accruals as you
become aware of actual costs.   You also indicate that these adjustments could be
material.  Please provide us, in a disclosu re-type format, a revised discussion that
quantifies:
• the effect that changes in estimates ha ve had on the financial statements for
each period presented; and

Garo H. Armen, Ph.D.
Antigenics Inc.
November 3, 2006 Page 2
• the effect that reasonably likely cha nges in the key assumptions underlying
these estimates as of the latest ba lance sheet may have on the financial
statements.

Financial Statements and Supplementary Data

Notes to Consolidated Financial Statements

Note 15: Debt, page 100
2. You disclose that the conversion price is  subject to adjustment and that notes
surrendered for conversion in connection with certain fundamental changes may in certain circumstances be entitled to an  increase in the conversion rate of the
notes.  You also disclose that you are obligated to keep effective a shelf
registration statement for the shares unde rlying the conversion of your notes.  It
appears from your January 25, 2005 indenture agreement that the fundamental changes include a change of control and th e termination of trad ing; both events
that appear to be outside your control.  Please explain to us why you apparently
have not bifurcated the embedded conversion feature under EITF 00-19.  In your response please address all the requiremen ts of paragraphs 12 through 32 of that
consensus.  In addition, please provide us , in a disclosure-type format, revised
disclosure that clearly indicates:
• how the initial conversion rate  of $10.76 can be adjusted;
• the nature of the fundamental change s outlined in your indenture agreement;
• the circumstances that could increase th e conversion rate of the notes when a
fundamental change exists; and
• your consideration for the separate de rivative accounting for the conversion
feature of the notes.

Please respond to these comments within  10 business days or tell us when you
will provide us with a response.  Please furnish a letter that keys your responses to our comments and provides the requested information.  Detailed letters greatly facilitate our
review.  Please furnish your 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:

Garo H. Armen, Ph.D.
Antigenics Inc.
November 3, 2006 Page 3
‚ 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 comments 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 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 comments on your filing.

 If you have any questions, please co ntact Mark Brunhofer , Senior Staff
Accountant, at (202) 551-3638.  In  this regard, do not hesita te to contact me, at (202)
551-3679.

Sincerely,

Jim B. Rosenberg
Senior Assistant Chief Accountant