SecProbe.io

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 ​ May 6, 2025 VIA EDGAR SUBMISSION U.S. Securities and Exchange Commission Division of Corporation Finance, Office of Life Sciences 100 F Street, NE Washington, DC 20549 Attention: Alan Campbell Re: Xilio Therapeutics, Inc. Registration Statement on Form S-3 Filed March 11, 2025 File No. 333-285703 Request for Acceleration Ladies and Gentlemen: Pursuant to Rule 461 under the Securities Act of 1933, as amended, Xilio Therapeutics, Inc. hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-285703), so that it may become effective at 9:00 a.m., Eastern Time, on May 8, 2025, or as soon as practicable thereafter. Very truly yours, ​ XILIO THERAPEUTICS, Inc. ​ By: /s/ René Russo ​ ​ Name: René Russo Title: President and Chief Executive Officer ​

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 March 17, 2025

Ren Russo
President and Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street, Suite 300
Waltham, MA 02451

 Re: Xilio Therapeutics, Inc.
 Registration Statement on Form S-3
 Filed March 11, 2025
 File No. 333-285703
Dear Ren Russo:

 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 Alan Campbell at 202-551-4224 with any questions.

 Sincerely,

 Division of
Corporation Finance
 Office of Life
Sciences
cc: Molly W. Fox, Esq.
</TEXT>
</DOCUMENT>

United States securities and exchange commission logo
May 2, 2024
René Russo, Pharm.D.
President and Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street, Suite 300
Waltham, Massachusetts 02451
Re:Xilio Therapeutics, Inc.
Registration Statement on Form S-3
Filed April 30, 2024
File No. 333-279015
Dear René Russo:
            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 Tim Buchmiller at 202-551-3635 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Molly W. Fox, Esq.

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​

May 2, 2024

VIA EDGAR SUBMISSION

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, NE

Washington, DC 20549

Attention:  Tim Buchmiller

Re: Xilio Therapeutics, Inc.

 Registration Statement on Form S-3

 Filed April 30, 2024

File No. 333-279015

Request for Acceleration

Ladies and Gentlemen:

Pursuant to Rule 461 under the Securities Act of 1933, as amended, Xilio Therapeutics, Inc. (the “Registrant”) hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No. 333-279015), so that it may become effective at 4:00 p.m. Eastern time on May 6, 2024, or as soon thereafter as practicable, or at such later time as the Registrant or its counsel may orally request via telephone call to the staff of the U.S. Securities and Exchange Commission.

Very truly yours,

XILIO THERAPEUTICS, INC.

By:/s/ René Russo

René Russo

President and Chief Executive Officer

​

​

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Xilio Therapeutics, Inc.

828 Winter Street, Suite 300

Waltham, MA 02451

November 16, 2022

VIA EDGAR SUBMISSION

U.S. Securities and Exchange Commission

Division of Corporation Finance, Office of Life Sciences

100 F Street, N.E.

Washington, D.C. 20549

Attention: Christine Westbrook

 Re: Xilio Therapeutics, Inc.
Registration Statement on Form S-3
File No. 333-268264
Request for Acceleration

Ladies and Gentlemen:

Pursuant to Rule 461 under the Securities Act of 1933, as
amended, Xilio Therapeutics, Inc. hereby requests acceleration of the effective date of its Registration Statement on Form S-3 (File No.
333-268264), so that it may become effective at 4:00 p.m., Eastern time, on November 18, 2022, or as soon as practicable thereafter,
or at such later time as the Registrant or its counsel may orally request via telephone call to the staff.

    Very truly yours,

    Xilio Therapeutics, Inc.

    By:
    /s/ René Russo

    Name: René Russo

    Title: Chief Executive Officer

United States securities and exchange commission logo
November 15, 2022
Rene Russo
Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street, Suite 300
Waltham, MA 02451
Re:Xilio Therapeutics, Inc.
Registration Statement on Form S-3
Filed November 9, 2022
File No. 333-268264
Dear Rene Russo:
            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 Christine Westbrook at 202-551-5019 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Molly W. Fox, Esq.

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Xilio Therapeutics, Inc.

828 Winter Street, Suite 300

Waltham, Massachusetts 02451

October 19, 2021

VIA EDGAR

U.S. Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549

    Re:
    Xilio Therapeutics, Inc.

Registration Statement on Form S-1

File No. 333-259973

Request for Acceleration

Ladies and Gentlemen:

Pursuant to Rule 461 promulgated under the Securities Act of 1933,
as amended, Xilio Therapeutics, Inc. (the “Company”) hereby requests acceleration of the effective date of its Registration
Statement on Form S-1 (File No. 333-259973), as amended, so that it may become effective at 4:00 p.m. Eastern
time on October 21, 2021, or as soon thereafter as practicable, or at such later time as the Company or its counsel may orally request
by telephone call to the staff of the U.S. Securities and Exchange Commission. Please contact Cynthia T. Mazareas of Wilmer Cutler Pickering
Hale and Dorr LLP, counsel to the Company, at (617) 526-6393, or in her absence, Molly W. Fox at (617) 526-6812, to provide
notice of effectiveness, or if you have any other questions regarding this matter.

[Remainder of Page Intentionally Left Blank]

    Very truly yours,

    XILIO THERAPEUTICS, INC.

    By:
    /s/ René Russo

    Name:
    René Russo, Pharm.D.

    Title:
    President and Chief Executive Officer

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October 19, 2021

U.S. Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, D.C. 20549

    Attention:
    Ada Sarmento

    Tim Buchmiller

    Re:

    Xilio Therapeutics, Inc.

    Registration Statement
on Form S-1 (File No. 333-259973)

    Request for Acceleration

Ladies and Gentlemen:

Pursuant to Rule 460 of the General Rules and
Regulations under the Securities Act of 1933, as amended, we wish to advise that as of the date hereof, approximately 2,103 copies of
the Preliminary Prospectus dated October 18, 2021 were distributed to prospective underwriters, institutional investors and prospective
dealers in connection with the above-captioned Registration Statement.

We wish to advise you that the participating underwriters
have informed us that they have complied and will continue to comply with the requirements of Rule 15c2-8 under the Securities Exchange
Act of 1934, as amended.

We hereby join in the request of the registrant
that the effectiveness of the above-captioned Registration Statement, as amended, be accelerated to 4:00 p.m. Eastern Time, on October 21,
2021 or as soon thereafter as practicable.

[Signature page follows]

Very truly yours,

MORGAN STANLEY & CO. LLC

COWEN AND COMPANY, LLC

GUGGENHEIM SECURITIES, LLC

As representatives of the Underwriters

MORGAN STANLEY & CO. LLC

    By:

    /s/ Chirag D. Surti

    Name:
    Chirag D. Surti

    Title:
    Vice President

COWEN AND COMPANY, LLC

    By:

    /s/ Bill Follis

    Name:
    Bill Follis

    Title:
    Managing Director

GUGGENHEIM SECURITIES, LLC

    By:

    /s/ Thomas Burkly

    Name:
    Thomas Burkly

    Title:
    Senior Managing Director

[Signature
Page to Xilio Therapeutics, Inc. Acceleration Request]

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October 18, 2021

    +1 617 526 6000 (t)

    +1 617 526 5000 (f)

    wilmerhale.com

By Electronic Submission

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, DC 20549

Attention: Ada Sarmento

 Re: Xilio Therapeutics, Inc.

                                            Registration Statement on Form S-1

                                            Filed October 1, 2021

                                            File No. 333-259973

Ladies and Gentlemen:

On behalf of Xilio Therapeutics, Inc. (the “Company”),
we are responding to the comment contained in a letter, dated October 13, 2021 (the “Letter”) from the Staff
(the “Staff”) of the Office of Life Sciences of the Division of Corporation Finance of the Securities and Exchange
Commission (the “Commission”) to René Russo, Pharm.D., the Company’s President and Chief Executive Officer,
relating to the above referenced Registration Statement on Form S-1.

The Company also is filing Amendment No. 1 to the Registration
Statement on Form S-1 (the “Registration Statement”), relating to the registration under the Securities Act of
1933, as amended (the “Securities Act”), of common stock of the Company.

Set forth below is the Company’s response to the Staff’s
comment. The response is based upon information provided to Wilmer Cutler Pickering Hale and Dorr LLP by the Company. The response is
keyed to the numbering of the comment and the heading used in the Letter. Where appropriate, the Company has responded to the Staff’s
comment by making changes to the disclosure in the Registration Statement. Page numbers referred to in the response reference the
applicable page numbers in the Registration Statement.

October 18, 2021

Page 2

Registration Statement on Form S-1

Our History and Team, page 8

 1. We note your revisions in response to prior comment 2 but your response
                                            and revised disclosure do not appear to address all of the concerns raised in our prior comment.
                                            As such, we continue to believe the identification of the pre-IPO investors is inappropriate
                                            in the prospectus summary. Please provide us with a more detailed response addressing the
                                            concerns raised in our prior comment or revise your disclosure as appropriate.

 Response: In
                                            response to the Staff’s comment, the Company has revised the disclosure on pages 8
                                            and 113 of the Registration Statement.

If you have any further questions or comments, or if you require any
additional information, please contact the undersigned by telephone at (617) 526-6393 or e-mail at cynthia.mazareas@wilmerhale.com. Thank
you for your assistance.

    Very truly yours,

    /s/ Cynthia T. Mazareas

    Cynthia T. Mazareas

 cc: René Russo, Pharm.D., Xilio Therapeutics, Inc.

Salvatore Giovine, Xilio Therapeutics, Inc.

Chris Frankenfield, Xilio Therapeutics, Inc.

Molly W. Fox, Wilmer Cutler Pickering Hale and Dorr LLP

Divakar Gupta, Cooley LLP

Richard C. Segal, Cooley LLP

United States securities and exchange commission logo
October 13, 2021
René Russo, Pharm.D.
President and Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street
Waltham, Massachusetts 02451
Re:Xilio Therapeutics, Inc.
Registration Statement on Form S-1
Filed October 1, 2021
File No. 333-259973
Dear Dr. Russo:
            We have reviewed your registration statement 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 this letter by amending your registration statement and providing the
requested information.  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 registration statement and the information you
provide in response to these comments, we may have additional comments.
Registration Statement on Form S-1
Our History and Team, page 8
1.We note your revisions in response to prior comment 2 but your response and revised
disclosure do not appear to address all of the concerns raised in our prior comment.  As
such, we continue to believe the identification of the pre-IPO investors is inappropriate in
the prospectus summary.  Please provide us with a more detailed response addressing the
concerns raised in our prior comment or revise your disclosure as appropriate.
            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

 FirstName LastNameRené Russo, Pharm.D.
 Comapany NameXilio Therapeutics, Inc.
 October 13, 2021 Page 2
 FirstName LastName
René Russo, Pharm.D.
Xilio Therapeutics, Inc.
October 13, 2021
Page 2
time for us to review any amendment prior to the requested effective date of the registration
statement.
            You may contact Michael Fay at 202-551-3812 or Vanessa Robertson at 202-551-3649 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Ada D. Sarmento at 202-551-3798 or Tim Buchmiller at 202-551-3635 with any other
questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Cynthia T. Mazareas, Esq.

CORRESP
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October 1, 2021

    +1 617
    526 6000 (t)

    +1 617
    526 5000 (f)

    wilmerhale.com

By Electronic Submission

Securities and Exchange Commission

Division of Corporation Finance

100 F Street, N.E.

Washington, DC 20549

Attention: Ada Sarmento

 Re: Xilio Therapeutics, Inc.

Draft Registration Statement on Form S-1

Submitted September 14, 2021

CIK No. 0001840233

Ladies and Gentlemen:

On behalf of Xilio Therapeutics, Inc. (the “Company”),
we are responding to the comments contained in a letter, dated September 23, 2021 (the “Letter”) from the Staff
(the “Staff”) of the Office of Life Sciences of the Division of Corporation Finance of the Securities and Exchange
Commission (the “Commission”) to René Russo, Pharm.D., the Company’s President and Chief Executive Officer,
relating to the above referenced Draft Registration Statement on Form S-1.

The Company also is filing a Registration Statement on Form S-1
(the “Registration Statement”), relating to the registration under the Securities Act of 1933, as amended (the “Securities
Act”), of common stock of the Company.

Set forth below are the Company’s responses to the Staff’s
comments. The responses are based upon information provided to Wilmer Cutler Pickering Hale and Dorr LLP by the Company. The responses
are keyed to the numbering of the comments and the headings used in the Letter. Where appropriate, the Company has responded to the Staff’s
comment by making changes to the disclosure in the Registration Statement. Page numbers referred to in the responses reference the
applicable page numbers in the Registration Statement.

October 1, 2021

Page 2

Amendment No. 1 to Draft Registration Statement on Form S-1

Prospectus Summary

Our Pipeline, page 4

 1. Please revise your pipeline table to remove your targeted cytokine program. Given the early stage of development of this program, it
does not appear to be sufficiently material to your business to warrant inclusion in your pipeline
table.

 Response: In response to the Staff’s comment, the Company has revised the disclosure on pages 5 and 118 of the Registration Statement.

Our History and Team, page 8

 2. We note your response to prior comment 4. The identification of past life science investors appears to suggest that potential investors
may consider investments made by these investors as a factor in making their investment decisions
without knowing the amount of their investment in total or on a per share basis, their investment strategies or whether these investors continue to hold their
shares. Additionally, as these shareholders are not subject to the reporting requirements of
Section 16, investors will not know when they decide to sell their shares. Therefore, we
continue to believe the disclosure is inappropriate for the registration statement and
ask that it be removed.

 Response: In response to the Staff’s comment, the Company has revised the disclosure on pages 8 and 112 of the Registration Statement.

Our Strategy, page 8

 3. We note your disclosure that your strategy is to enable a rapid transition to randomized registration-enabling trials in a range of solid tumor indications
for XTX101. Please revise this statement and any similar disclosure to remove any implication that you will be successful in advancing
your product candidates in a rapid or accelerated manner as such statements are speculative.

Response:
In response to the Staff’s comment, the Company has revised the disclosure on pages 9 and 112 of the Registration
Statement.

If you have any further questions or comments, or if you require any
additional information, please contact the undersigned by telephone at (617) 526-6393 or e-mail at cynthia.mazareas@wilmerhale.com. Thank
you for your assistance.

    Very truly yours,

    /s/ Cynthia T. Mazareas

    Cynthia T. Mazareas

October 1, 2021

Page 3

 cc: René Russo, Pharm.D., Xilio Therapeutics, Inc.

Salvatore Giovine, Xilio Therapeutics, Inc.

Chris Frankenfield, Xilio Therapeutics, Inc.

Molly W. Fox, Wilmer Cutler Pickering Hale and Dorr LLP

Divakar Gupta, Cooley LLP

Richard C. Segal, Cooley LLP

United States securities and exchange commission logo
September 23, 2021
René Russo, Pharm.D.
President and Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street
Waltham, Massachusetts 02451
Re:Xilio Therapeutics, Inc.
Amendment No. 1 to Draft Registration Statement on Form S-1
Submitted September 14, 2021
CIK No. 0001840233
Dear Dr. Russo:
            We have reviewed your amended draft registration statement 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 this letter by providing the requested information and either submitting
an amended draft registration statement or publicly filing your registration statement on
EDGAR.  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 the information you provide in response to these comments and your
amended draft registration statement or filed registration statement, we may have additional
comments.
Amendment No. 1 to Draft Registration Statement on Form S-1
Prospectus Summary
Our Pipeline, page 4
1.Please revise your pipeline table to remove your targeted cytokine program.  Given the
early stage of development of this program, it does not appear to be sufficiently material
to your business to warrant inclusion in your pipeline table.
Our History and Team, page 8
2.We note your response to prior comment 4.  The identification of past life science
investors appears to suggest that potential investors may consider investments made by
these investors as a factor in making their investment decisions without knowing the

 FirstName LastNameRené Russo, Pharm.D.
 Comapany NameXilio Therapeutics, Inc.
 September 23, 2021 Page 2
 FirstName LastName
René Russo, Pharm.D.
Xilio Therapeutics, Inc.
September 23, 2021
Page 2
amount of their investment in total or on a per share basis, their investment strategies or
whether these investors continue to hold their shares. Additionally, as these shareholders
are not subject to the reporting requirements of Section 16, investors will not know when
they decide to sell their shares. Therefore, we continue to believe the disclosure is
inappropriate for the registration statement and ask that it be removed.
Our Strategy, page 8
3.We note your disclosure that your strategy is to enable a rapid transition to randomized
registration-enabling trials in a range of solid tumor indications for XTX101. Please revise
this statement and any similar disclosure to remove any implication that you will be
successful in advancing your product candidates in a rapid or accelerated manner as such
statements are speculative.
            You may contact Michael Fay at 202-551-3812 or Vanessa Robertson at 202-551-3649 if
you have questions regarding comments on the financial statements and related matters.  Please
contact Ada D. Sarmento at 202-551-3798 or Tim Buchmiller at 202-551-3635 with any other
questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Cynthia T. Mazareas, Esq.

United States securities and exchange commission logo
June 20, 2021
René Russo, Pharm.D.
President and Chief Executive Officer
Xilio Therapeutics, Inc.
828 Winter Street
Waltham, Massachusetts 02451
Re:Xilio Therapeutics, Inc.
Draft Registration Statement on Form S-1
Submitted May 24, 2021
CIK No. 0001840233
Dear Dr. Russo:
            We have reviewed your draft registration statement 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 this letter by providing the requested information and either submitting
an amended draft registration statement or publicly filing your registration statement on
EDGAR.  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 the information you provide in response to these comments and your
amended draft registration statement or filed registration statement, we may have additional
comments.
Draft Registration Statement on Form S-1
Our Pipeline, page 4
1.Please include the indication for each program in the pipeline table here and on page 117.
Overview, page 4
2.We note your disclosure that cytokines have demonstrated the ability to generate sustained
complete responses. If this disclosure is based on the data in the chart presented on page
112, please balance your disclosure to indicate, if true, that only a small subset of patients
who received high-dose IL-2 achieved a complete response, or tell us the basis for this
disclosure. Please also disclose the nature of the “compelling clinical efficacy”
demonstrated by cytokines in certain tumors.

 FirstName LastNameRené Russo, Pharm.D.
 Comapany NameXilio Therapeutics, Inc.
 June 20, 2021 Page 2
 FirstName LastName
René Russo, Pharm.D.
Xilio Therapeutics, Inc.
June 20, 2021
Page 2
Our GPS Platform, page 6
3.We note your disclosure that your engineered molecules are designed to be turned on
selectively in the TME, thereby reducing potential toxicities and improving their
therapeutic index. We note, however, that some of your statements in this section and
elsewhere indicate less activity outside of the TME and some statements indicate no
activity. For example, we note your disclosure in this section that MMPs are
“preferentially active” in the TME by comparison to non-tumor organs or tissues, and that
your GPS-enabled cytokines minimize or reduce the risk of activity outside of the TME
and, therefore, the risk of toxicity. Given those disclosures, please tell us why your
disclosure in this section that MMP activity can be leveraged to activate molecules within
the TME that "remain inactive outside of the TME", and that the features of your GPS-
enabled molecules work in concert to enable your molecules’ potential ability to induce
tumor selective biological activity and tumor growth inhibition "without toxicity outside
of the TME," are appropriate, or revise your disclosure as necessary.
Our History and Team, page 7
4.We note that you identify certain entities as investors in your company here and on page
107. However, certain of these entities do not appear to be among your principal
stockholders as disclosed on page 186. If material, please expand your disclosure to
describe the nature of each such entity's investment in you and explain to us why
including this information is appropriate. Please also explain in the response your plans to
update investors about any changes these entities make with respect to their investments in
your company.
Our Strategy, page 8
5.We note your disclosure here and throughout the prospectus comparing XTX202
to aldesleukin, and XTX101 to an ipilimumab analog. Please clarify, if true, that these
observations were made in mouse models and may not be replicated in clinical trials.
Risk Factors, page 16
6.Given the length of your risk factor section, please revise to comply with Regulation S-K
Item 105 by relocating risks that could generically apply to any registrant or offering to
the end of the section under the caption "General Risk Factors."
Some intellectual property that we have in-licensed may have been discovered through
government funded programs, page 52
7.Please revise to identify the product candidates that are or may be subject to march-
in rights.

 FirstName LastNameRené Russo, Pharm.D.
 Comapany NameXilio Therapeutics, Inc.
 June 20, 2021 Page 3
 FirstName LastName
René Russo, Pharm.D.
Xilio Therapeutics, Inc.
June 20, 2021
Page 3
Capitalization, page 82
8.Please revise to reflect the convertible preferred stock outside of permanent equity
consistent with your interim balance sheet on page F-40.
Dilution, page 84
9.Please revise your disclosure to clarify that historical net tangible book value (deficit)
excludes convertible preferred stock classified outside of equity.
Management's Discussion and Analysis of Financial Condition and Results of Operations
Critical Accounting Policies and Use of Estimates
Determination of Fair Value of Common Units and Common Stock, page 104
10.Please disclose the actual specific factors underlying the increase in the May 2021
common stock valuation to $1.06.
Business
Key Features of Our GPS-Enabled Cytokines, page 114
11.We note your disclosure on pages 115 and 116 that you have validated your GPS platform
through your preclinical studies with XTX202 and by your tumor-selective anti-CTLA-4
antibody. Please revise to explain what you mean by validated given the current stage of
development of your product candidates.
Cytokine programs, page 117
12.We note your disclosure on page 27 that you rely on matrix metalloproteases to activate
your molecules within the tumor microenvironment and that if MMP activity in human
tumors is not sufficient to cleave the masking protein domain, the potential efficacy of
your product candidates would be limited. For each of your cytokine programs, please
clarify whether you have observed that the MMPs native to human cells are sufficient to
cleave the masking domain.
Measured PK Parameters (1 mg/kg dose), page 123
13.We note your statement that you expect XTX202 to achieve monotherapy activity in
clinical trials and have a better tolerability profile than aldesleukin based on your
preclinical data. Given the unpredictability of drug development, please remove this
statement and any similar statements as such statements would appear to be speculative.
Principal Stockholders, page 186
14.Please revise your disclosure to identify all of the natural person or persons who have
voting and investment control of the shares held by the entities affiliated with Atlas
Ventures, F-Prime Capital Partners Healthcare Fund IV LP and affiliates, Takeda
Ventures, Inc. and SV7 Impact Medicine Fund LP.

 FirstName LastNameRené Russo, Pharm.D.
 Comapany NameXilio Therapeutics, Inc.
 June 20, 2021 Page 4
 FirstName LastName
René Russo, Pharm.D.
Xilio Therapeutics, Inc.
June 20, 2021
Page 4
General
15.Please supplementally provide us with copies of all written communications, as defined in
Rule 405 under the Securities Act, that you, or anyone authorized to do so on your behalf,
present to potential investors in reliance on Section 5(d) of the Securities Act, whether or
not they retain copies of the communications.
            You may contact Michael Fay at (202) 551-3812 or Vanessa Robertson at (202) 551-
3649 if you have questions regarding comments on the financial statements and related matters.
Please contact Ada Sarmento at (202) 551-3798 or Tim Buchmiller at (202) 551-3635 with any
other questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Cynthia T. Mazareas, Esq.