SecProbe.io

CORRESP
 1
 filename1.htm

 CORRESP

 IO Biotech, Inc.
 Ole Maaløes Vej 3
 DK-2200 Copenhagen N
 Denmark July 29, 2025
 Via EDGAR U.S. Securities and Exchange Commission
 Division of Corporation Finance 100 F Street, N.E.
 Washington, D.C. 20549-3720

 Attention:

 Alan Campbell

 Re:

 IO Biotech, Inc. Registration Statement on Form
 S-3, as amended File No. 333-288936

 Acceleration Request

 Requested Date: July 31, 2025

 Requested Time: 4:00 P.M., Eastern Time
 Ladies and Gentlemen:
 Pursuant to Rule 461 under the Securities Act of 1933, as amended, IO Biotech, Inc. (the “ Company ”) hereby requests
that the effective date of the above-referenced Registration Statement on Form S-3, as amended (the “ Registration Statement ”), be accelerated so that the Registration Statement will
become effective at 4:00 P.M., Eastern Time, on July 31, 2025, or as soon thereafter as practicable or at such later time as the Company or its counsel may orally request via telephone call to the staff of the Division of Corporation Finance of
the U.S. Securities and Exchange Commission. Please contact Nick DeAngelis of Sidley Austin LLP at (214)
 969-3563 with any questions regarding the foregoing and to confirm the effectiveness of the Registration Statement.

 Very truly yours,

 /s/ Devin Smith

 Devin Smith

 General Counsel

 IO Biotech, Inc.

 cc:
 Mai-Britt Zocca, IO Biotech, Inc.
 Amy Sullivan, IO Biotech, Inc.
 Frank Rahmani, Sidley Austin LLP
 Istvan Hajdu, Sidley Austin LLP
 Nick DeAngelis, Sidley Austin LLP

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 July 29, 2025

Mai-Britt Zocca
President and Chief Executive Officer
IO Biotech, Inc.
Ole Maal es Vej 3
DK-2200 Copenhagen N
Denmark

 Re: IO Biotech, Inc.
 Registration Statement on Form S-3
 Filed July 24, 2025
 File No. 333-288936
Dear Mai-Britt Zocca:

 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: Istvan A. Hajdu, Esq.
</TEXT>
</DOCUMENT>

CORRESP
 1
 filename1.htm

 CORRESP

 IO Biotech, Inc.
 Ole Maaløes Vej 3
 DK-2200 Copenhagen N
 Denmark June 9, 2025
 Via EDGAR U.S. Securities and Exchange Commission
 Division of Corporation Finance 100 F Street, N.E.
 Washington, D.C. 20549-3720 Attention: Tim Buchmiller

 Re:
 IO Biotech, Inc.
 Registration Statement on Form S-3, as amended
 File No. 333-287554
 Acceleration Request
 Requested Date: June 11, 2025
 Requested Time: 4:00 P.M., Eastern Time
 Ladies and Gentlemen: Pursuant to Rule 461
under the Securities Act of 1933, as amended, IO Biotech, Inc. (the “ Company ”) hereby requests that the effective date of the above-referenced Registration Statement on Form S-3, as
amended (the “ Registration Statement ”), be accelerated so that the Registration Statement will become effective at 4:00 P.M., Eastern Time, on June 11, 2025, or as soon thereafter as practicable or at such later time as the
Company or its counsel may orally request via telephone call to the staff of the Division of Corporation Finance of the U.S. Securities and Exchange Commission.
 Please contact Nick DeAngelis of Sidley Austin LLP at (214) 969-3563 with any questions regarding the
foregoing and to confirm the effectiveness of the Registration Statement.

 Very truly yours,

 /s/ Devin Smith

 Devin Smith

 General Counsel

 IO Biotech, Inc.

 cc:
 Mai-Britt Zocca, IO Biotech, Inc.
 Amy Sullivan, IO Biotech, Inc.
 Frank Rahmani, Sidley Austin LLP
 Istvan Hajdu, Sidley Austin LLP
 Nick DeAngelis, Sidley Austin LLP

<DOCUMENT>
<TYPE>TEXT-EXTRACT
<SEQUENCE>2
<FILENAME>filename2.txt
<TEXT>
 May 29, 2025

Devin Smith, Esq.
General Counsel
IO Biotech, Inc.
Ole Maal es Vej 3
DK-2200 Copenhagen N
Denmark

 Re: IO Biotech, Inc.
 Registration Statement on Form S-3
 Filed May 23, 2025
 File No. 333-287554
Dear Devin Smith Esq.:

 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: Istvan A. Hajdu, Esq.
</TEXT>
</DOCUMENT>

August 13, 2024
Amy Sullivan
Chief Financial Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Form 10-K for the fiscal year ended December 31, 2023
Filed March 5, 2024
File No. 001-41008
Dear Amy Sullivan:
            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

CORRESP
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filename1.htm

CORRESP

 IO Biotech, Inc.

 Ole
Maaløes Vej 3

 DK-2200 Copenhagen N

Denmark

 August 9, 2024

U.S. Securities and Exchange Commission

Division of Corporation Finance

 Office of Life
Sciences

 100 F Street, N.E.

 Washington, D.C. 20549

Attention: Vanessa Robertson, Kevin Vaughn

 Re:
IO Biotech, Inc.

 Form 10-K for the fiscal year ended December 31, 2023

Filed March 5, 2024

 File No. 001-41008

 Dear Ms. Robertson and Mr. Vaughn:

This letter sets forth the response of IO Biotech, Inc., a Delaware corporation (the “Company”), to the comment issued by the staff of
the Division of Corporation Finance (the “Staff”) of the U.S. Securities and Exchange Commission in a letter dated July 30, 2024 regarding the Company’s Form 10-K for the
fiscal year ended December 31, 2023. For the Staff’s convenience, we have incorporated your comment into this response letter in italics.

Form 10-K for the Fiscal year Ended December 31, 2023

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

Results of Operations

 Research and Development
Expense, page 130

1.
 We note your disclosure on page 128 that you generally have not tracked your research and development
expenses on a program-by-program basis and that substantially all of your direct research and development expenses in the years ended December 31, 2023 and 2022
were on IO102-IO103 and consisted primarily of external costs. For the amounts you do track by product candidate and/or indication, please provide revised disclosure to be included in future filings to break out research and development expenses by
product candidate and by indication. In addition, please disaggregate the first line item in your table on page 130 between preclinical and clinical. If you cannot disaggregate these amounts, please disclose that fact and explain why not.

 Response: The Company respectfully acknowledges the Staff’s comment and advises the Staff that the Company does not
track research and development expenses by product candidate or indication, but the Company does track expenses associated with clinical trial-related activities separately from expenses associated with preclinical studies and activities. The
Company has one clinical stage product candidate, IO102-IO103. This product candidate is used in all the Company’s current clinical trials and targets multiple oncology indications.

 Accordingly, to address the Staff’s comment, the Company has prepared the proposed disclosure below as
well as the pro forma tables attached hereto as Appendix A to show the expenses associated with clinical trial related activities separately from preclinical studies and activities. The Company plans to include the proposed format
in the section titled “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in each of its periodic reports on a go-forward basis, beginning with the Form 10-Q that the Company will file for the fiscal period ended September 30, 2024:

 We use our
personnel and infrastructure resources across multiple research and development programs directed toward identifying and developing product candidates. We have not tracked our research and development expenses on a program-by-program basis, as our only program in clinical trials, IO102-IO103, is used in each of our three ongoing clinical trials across all target oncology indications that we are researching.
Substantially all of our direct research and development expenses in the years ended December 31, 2023 and 2022 and in the three- and nine-months ended September 30, 2024 were on IO102-IO103 and consisted primarily of external costs, such
as consultants, third-party contract organizations that conduct research and development activities on our behalf, costs related to production of preclinical and clinical materials, including fees paid to contract manufacturers, and laboratory and
vendor expenses related to the execution of our ongoing and planned preclinical studies and clinical trials.

 Please do not hesitate to contact the
undersigned with any questions or comments regarding this letter.

Sincerely,

 /s/ Amy Sullivan

 Amy Sullivan

 Chief Financial
Officer

 IO Biotech, Inc.

CC:
 Mai-Britt Zocca, IO Biotech, Inc.

Devin Smith, IO Biotech, Inc.

Brian Burkavage, IO Biotech, Inc.

Frank Rahmani, Sidley Austin LLP

Istvan Hajdu, Sidley Austin LLP

 Appendix A:

Research and Development Expenses

 Research and
development expenses comprised:

For the Three Months
Ended September 30,

Change

2024

2023

Amount

Percent

(in thousands)

 Preclinical studies and activities

$

 Clinical trial-related activities

 Chemistry, manufacturing and control

 Personnel

 Consultants and other costs

 Total research and development expenses

$

For the Nine Months
Ended September 30,

Change

2024

2023

Amount

Percent

(in thousands)

 Preclinical studies and activities

$

 Clinical trial-related activities

 Chemistry, manufacturing and control

 Personnel

 Consultants and other costs

 Total research and development expenses

$

July 30, 2024
Amy Sullivan
Chief Financial Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Form 10-K for the fiscal year ended December 31, 2023
Filed March 5, 2024
File No. 001-41008
Dear Amy Sullivan:
            We have limited our review of your filing to the financial statements and related
disclosures and have the following comment.
            Please respond to this letter 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 a
comment applies to your facts and circumstances, please tell us why in your response.
            After reviewing your response to this letter, we may have additional comments.
Form 10-K for the fiscal year ended December 31, 2023
Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations
Results of Operations
Research and Development Expenses, page 130
1.We note your disclosure on page 128 that you generally have not tracked your research
and development expenses on a program-by-program basis and that substantially all of
your direct research and development expenses in the years ended December 31, 2023 and
2022 were on IO102-IO103 and consisted primarily of external costs. For the amounts
you do track by product candidate and/or indication, please provide revised disclosure to
be included in future filings to break out research and development expenses by product
candidate and by indication.  In addition, please disaggregate the first line item in your
table on page 130 between preclinical and clinical. If you cannot disaggregate these
amounts, please disclose that fact and explain why not.

July 30, 2024
Page 2
            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.
            Please contact Vanessa Robertson at 202-551-3649 or Kevin Vaughn at 202-551-3494
with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences

CORRESP
1
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CORRESP

 IO Biotech, Inc.

Ole Maaløes Vej 3

DK-2200 Copenhagen N

Denmark

 September 6, 2023

Via EDGAR

 U.S. Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549-3720

Attention:
     Cindy Polynice

Re:
 IO Biotech, Inc.

Registration Statement on Form S-3, as amended

File No. 333-274267

Acceleration Request

Requested Date: September 8, 2023

Requested Time: 4:00 P.M., Eastern Time

Ladies and Gentlemen:

 Pursuant to Rule 461
under the Securities Act of 1933, as amended, IO Biotech, Inc. (the “Company”) hereby requests that the effective date of the above-referenced Registration Statement on Form S-3, as
amended (the “Registration Statement”), be accelerated so that the Registration Statement will become effective at 4:00 P.M., Eastern Time, on September 8, 2023, or as soon thereafter as practicable or at such later time as
the Company or its counsel may orally request via telephone call to the staff of the Division of Corporation Finance of the U.S. Securities and Exchange Commission.

Please contact Nick DeAngelis of Sidley Austin LLP at (214) 969-3563 with any questions regarding the
foregoing and to confirm the effectiveness of the Registration Statement.

Very truly yours,

/s/ Devin Smith

Devin Smith

General Counsel

IO Biotech, Inc.

cc:
 Mai-Britt Zocca, IO Biotech, Inc.

Amy Sullivan, IO Biotech, Inc.

Frank Rahmani, Sidley Austin LLP

Istvan Hajdu, Sidley Austin LLP

Nick DeAngelis, Sidley Austin LLP

United States securities and exchange commission logo
September 6, 2023
Dr. Mai-Britt Zocca
President and Chief Executive Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Registration Statement on Form S-3
Filed August 30, 2023
File No. 333-274267
Dear Dr. Mai-Britt Zocca:
            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 Cindy Polynice at 202-551-8707 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Istvan A. Hajdu, Esq.

CORRESP
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CORRESP

 IO Biotech, Inc.

Ole Maaløes Vej 3

DK-2200 Copenhagen N

Denmark

 February 9, 2023

Via EDGAR

 U.S. Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549-3720

Attention:        Tyler Howes

Re:                   IO Biotech, Inc.

Registration Statement on Form S-3, as amended

                         File No. 333-269569

Acceleration Request

               Requested Date:     February 10, 2023

               Requested Time:    4:00 P.M., Eastern Time

Ladies and Gentlemen:

 Pursuant to
Rule 461 under the Securities Act of 1933, as amended, IO Biotech, Inc. (the “Company”), hereby requests that the effective date of the above-referenced Registration Statement
on Form S-3, as amended (the “Registration Statement”), be accelerated so that the Registration Statement will become effective at 4:00 P.M., Eastern Time, on
February 10, 2023, or as soon thereafter as practicable or at such later time as the Company or its counsel may orally request via telephone call to the staff of the Division of Corporation Finance of the U.S. Securities and Exchange
Commission.

 Please contact Nick DeAngelis of Sidley Austin LLP at (214) 969-3563 with any
questions regarding the foregoing and to confirm the effectiveness of the Registration Statement.

Very truly yours,

 /s/ Devin Smith

Devin Smith

General Counsel

IO Biotech, Inc.

cc:
 Mai-Britt Zocca, IO Biotech, Inc.

Amy Sullivan, IO Biotech, Inc.

Frank Rahmani, Sidley Austin LLP

Istvan Hajdu, Sidley Austin LLP

Nick DeAngelis, Sidley Austin LLP

United States securities and exchange commission logo
February 8, 2023
Mai-Britt Zocca, Ph.D.
President and Chief Executive Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Registration Statement on Form S-3
Filed February 3, 2023
File No. 333-269569
Dear Mai-Britt Zocca:
            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 Tyler Howes at 202-551-3370 with any questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Frank Rahmani, Esq.

CORRESP
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CORRESP

 November 2, 2021

Via EDGAR

 U.S. Securities and Exchange Commission

Division of Corporation Finance

 100 F Street, N.E.

Washington, D.C. 20549-3720

Attention:

 Celeste Murphy

 Daniel Crawford

David Burton

 Al Pavot

Re:

 IO Biotech, Inc.

 Registration Statement on Form
S-1

 File No. 333-260301

Acceleration Request

 Requested Date: November 4, 2021

 Requested Time: 3:00 P.M., Eastern Time

 Ladies and Gentlemen:

Pursuant to Rule 461 under the Securities Act of 1933, as amended, IO Biotech, Inc. (the “Company”), hereby
requests that the effective date of the Company’s Registration Statement on Form S-1, Registration Number 333-260301 (the
“Registration Statement”) be accelerated so that the Company’s Registration Statement will become effective at 3:00 P.M., Eastern Time, on November 4, 2021, or as soon thereafter as practicable or at such later time
as the Company or its counsel may orally request via telephone call to the staff of the Division of Corporation Finance of the U.S. Securities and Exchange Commission.

We would appreciate it if, as soon as the Registration Statement is declared effective, you would so inform Istvan A. Hajdu of Sidley
Austin LLP at (212) 839-5651.

Very truly yours,

 /s/ Mai-Britt Zocca

Mai-Britt Zocca

Chief Executive Officer

IO Biotech, Inc.

cc:
 Keith Vendola, IO Biotech, Inc.

Frank F. Rahmani, Sidley Austin LLP

Istvan A. Hajdu, Sidley Austin LLP

Nick D. DeAngelis, Sidley Austin LLP

Nathan Ajiashvili, Latham & Watkins LLP

Alison Haggerty, Latham & Watkins LLP

CORRESP
1
filename1.htm

CORRESP

 November 2, 2021

U.S. Securities and Exchange Commission

 Division of Corporation
Finance

 100 F Street, N.E.

 Washington, D.C. 20549

Attention:
 Celeste Murphy

Daniel Crawford

David Burton

Al Pavot

Re:
 IO Biotech, Inc.

Registration Statement on Form S-1

File No. 333-260301

Acceleration Request

Requested Date:     November 4, 2021

Requested Time:     3:00 p.m., Eastern Standard Time

Ladies and Gentlemen:

In accordance with Rule 461 under the Securities Act of 1933, as amended (the “Act”), Morgan Stanley & Co.
LLC, Cowen and Company, LLC and Jefferies LLC, as representatives of the several underwriters, hereby joins IO Biotech, Inc. in requesting that the Securities and Exchange Commission take appropriate action to cause the Registration Statement on
Form S-1 (File No. 333-260301) (the “Registration Statement”) to become effective on November 4, 2021, at 3:00 p.m., Eastern Standard
Time, or as soon as practicable thereafter.

 Pursuant to Rule 460 under the Act, please be advised that we will take reasonable steps to
secure adequate distribution of the preliminary prospectus, to underwriters, dealers, institutions and others, prior to the requested effective time of the Registration Statement.

We have been informed by the participating underwriters that they will comply with the requirements of Rule
15c2-8 under the Securities Exchange Act of 1934, as amended, to the extent applicable.

[Signature Page Follows]

Very truly yours,

MORGAN STANLEY & CO LLC

By:

 /s/ Chirag Suri

Name:

Chirag Suri

Title:

Vice President

COWEN AND COMPANY, LLC

By:

 /s/ Bill Follis

Name:

Bill Follis

Title:

Managing Director

JEFFERIES LLC

By:

 /s/ Matthew Kim

Name:

Matthew Kim

Title:

Managing Director

cc:
 Mai-Britt Zocca, IO Biotech, Inc.

Frank F. Rahmani, Sidley Austin LLP

Mehdi Khodadad, Sidley Austin LLP

Istvan A. Hajdu, Sidley Austin LLP

Nick D. DeAngelis, Sidley Austin LLP

Nathan Ajiashvili, Latham & Watkins LLP

Alison Haggerty, Latham & Watkins LLP

[Signature Page to Acceleration Request]

United States securities and exchange commission logo
August 31, 2021
Mai-Britt Zocca, Ph.D.
Chief Executive Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Amendment No. 1 to Draft Registration Statement on Form S-1
Submitted August 9, 2021
CIK No. 0001865494
Dear Dr. Zocca:
            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 submitted August 9, 2021
Overview, page 1
1.We note your revisions in response to prior comment 1 and reissue the comment in part. It
remains unclear whether the results/observations in your a single-arm Phase 1/2 clinical
trial of 30 patients are statistically significant.  Also, it does not appear that you have
addressed the final sentence of the prior comment by telling us whether you were able to
evaluate and determine the contributions of IO102-IO103 as compared to those of the
combination therapy.  Please revise or advise.

 FirstName LastNameMai-Britt Zocca, Ph.D.
 Comapany NameIO Biotech, Inc.
 August 31, 2021 Page 2
 FirstName LastName
Mai-Britt Zocca, Ph.D.
IO Biotech, Inc.
August 31, 2021
Page 2
            You may contact Al Pavot at (202) 551-3738 if you have questions regarding comments
on the financial statements and related matters. Please contact Joe McCann at (202) 551-6262
with any other questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Frank Rahmani, Esq.

United States securities and exchange commission logo
July 3, 2021
Mai-Britt Zocca, Ph.D.
Chief Executive Officer
IO Biotech, Inc.
Ole Maaløes Vej 3
DK-2200 Copenhagen N
Denmark
Re:IO Biotech, Inc.
Draft Registration Statement on Form S-1
Submitted June 3, 2021
CIK No. 0001865494
Dear Dr. Zocca:
            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 submitted June 3, 2021
Overview, page 1
1.Please balance your discussion of the Phase 1/2 clinical trial results/observations
concerning efficacy by explaining the purpose of the trial and any material limitations to
the reported results/observations.  In this regard, we note that it is unclear whether
clinical endpoints were established with respect to tumor regression and durability of
antitumor response and it is also unclear whether these results/observations are
statistically significant.  With reference to your disclosure at the bottom of page 23, also
tell us whether you were able to evaluate and determine the contributions of IO102-IO103
as compared to those of the combination therapy.

 FirstName LastNameMai-Britt Zocca, Ph.D.
 Comapany NameIO Biotech, Inc.
 July 3, 2021 Page 2
 FirstName LastName
Mai-Britt Zocca, Ph.D.
IO Biotech, Inc.
July 3, 2021
Page 2
2.With reference to your regulatory discussion on pages 146-147, please tell us your basis
for identifying this trial as "Phase 1/2" and your planned trial as a potentially
"registrational Phase 3 trial."  Also, revise the disclosure on page 1 to explain the term
"basket trials". Revise your regulatory discussion in the Business section to discuss these
three terms.
3.We note your statement on page 2 that your IO102-IO103 product candidate in
combination with nivolumab demonstrated a "manageable tolerability profile" and your
disclosure on page 107 identifying tolerability as an advantage of your T-win Technology
Platform.  Please balance these disclosures by addressing the occurrence of serious, high-
grade adverse events in your MM1636 trial as disclosed on pages 20 and 112.  Also, tell
us why there does not appear to be any discussion concerning dosage tolerability in your
discussions of the ongoing phase 1/2 trial or the planned phase 3 trial.
4.Revise the Summary to explain why your plan is to use pembrolizumab as the
combination product for your next trial as opposed to nivolumab.
Our Immunotherapy Pipeline, page 2
5.We note your statement on page 99 that the you plan to move into a Phase1/2 trial for
IO112 in combination with IO102 and IO103 and your disclosure on page 23 that "it is
expected that our product candidates, if approved, would be used in combination with
third-party drugs or biologics." Please clearly indicate such in the pipeline table on pages
2 and 98.
Our Strategy, page 4
6.We note your disclosure here and in the Business section that your strategy is to
"rapidly advance" 1O102-IO103 toward approval in combination with anti-PD-1 therapy
in first-line treatment of metastatic melanoma. We also note your risk factor disclosure
that, "[b]reakthrough therapy designation by the FDA for any product candidate may not
lead to a faster development or regulatory review." Please revise/balance this disclosure to
remove the implication that you will be successful in commercializing your product
candidates in a rapid or accelerated manner as such statements are speculative.
Some data for product candidates comes from clinical trials conducted outside the United
States..., page 21
7.Please revise to explain whether the phase 1/2 trial you reference was representative of the
population that you intend to label the product candidate in the United States.

 FirstName LastNameMai-Britt Zocca, Ph.D.
 Comapany NameIO Biotech, Inc.
 July 3, 2021 Page 3
 FirstName LastName
Mai-Britt Zocca, Ph.D.
IO Biotech, Inc.
July 3, 2021
Page 3
Use of Proceeds, page 78
8.We note your statement that the use of proceeds is to fund the development and regulatory
activities relating to your product candidates. Please revise your disclosure to allocate the
amount of proceeds you expect to use for each of your programs and specify how far in
the clinical development of your product candidates you expect to reach with the net
proceeds. If any material amounts of other funds are necessary to accomplish the specified
purposes for which the proceeds are to be obtained, state the amounts and sources of such
other funds needed for each such specified purpose and the sources thereof. Refer to
Instruction 3 of Item 504 of Regulation S-K.
9.We note your disclosure on page 94 that you will be obligated to pay Herlev a fee upon
the completion of this offering. To the extent the offering proceeds will be used to pay this
obligation, please disclose the fee owed to Herlev here.
Dual Epitope IO102-IO103, page 107
10.Please clarify your disclosure in this section to make clear that your planned Phase 3 trial
for IO102-IO103 is a combination trial with an anti-PD-1 monoclonal antibody therapy,
consistent with your disclosure throughout your registration statement.
Preclinical Development, page 108
11.We note your disclosure that, "[t]here have been no health impairments in the two non-
clinical toxicity studies performed with IO102 and IO103." Please clarify here if the
studies performed evaluated your combination product IO102-IO103 or if the studies
evaluated each product candidate individually.
Development of Dual Epitope IO102-IO103 in the First-line Setting, page 111
12.We note your disclosure that the results from the MM1636 trial have a cut-off date of
February 22, 2021 and that the prior cut-off date was in January 2021.  With a view to
disclosure, please tell us whether you are receiving updated data from this cohort and
whether a more recent cut-off date will be used in future amendments.
Additional Trials in Other First-Line Indications and Neo-Adjuvant and Adjuvant Settings, page
120
13.We note that Table 5 on page 121 depicts a summary of adverse events of various
investigator completed trials with IO101, IO102 and IO103 and Table 6 and Table 7
depict ongoing and planned trials. Please provide narrative disclosure to accompany Table
5 to specifically discuss any material serious adverse events occurring in your trials. In
addition, include narrative disclosure for Table 6 and Table 7 to clarify the specific trials
designs and their status, including planned or actual initiation dates and planned
completion dates.

 FirstName LastNameMai-Britt Zocca, Ph.D.
 Comapany NameIO Biotech, Inc.
 July 3, 2021 Page 4
 FirstName LastNameMai-Britt Zocca, Ph.D.
IO Biotech, Inc.
July 3, 2021
Page 4
Collaborations
Agreements with Herlev Hospital, page 139
14.We note your disclosure that the Company entered into a Framework Assignment
Agreement and an Assignment Agreement in January 2017 and December 2018 with
Herlev, for certain rights related to your lead product candidates. Please file such
agreements as an exhibit pursuant to Item 601(b)(10) of Regulation S-K or tell us why you
believe such filing is not required. In addition, we note your disclosure that you obtained
assignments and licenses related to each of your lead product candidates, IO102, IO103
and IO112. However, you appear to only discuss two Assignment Agreements
that cover (i) the PD-L1 technology and (ii) the Arginase technology. Please describe or
otherwise advise if a separate agreement covers your IDO target (IDO102).
15.We note your disclosure here that your agreement with Herlev covers "cancer vaccines"
and your Merck Collaboration Agreement disclosure also references a "peptide vaccine."
Please update your disclosure in your business section or otherwise advise if you are
currently developing cancer vaccines or peptide vaccines referenced here.
Patents, page 144
16.We note your disclosure that the, "[g]rant is imminent in China" for your patents related to
IO103 and that your TDO patent family is also "(grant imminent)" for the EPO. Given
that the grant of a patent in these jurisdictions appear to be outside of your control, please
provide your basis that the patents will be imminently granted in these jurisdictions or
otherwise advise.
17.We note that you have multiple types of patents (composition of matter and methods of
use) granted in multiple jurisdictions for your product candidates. Please revise
and expand your disclosure to clearly state the patent expiration date for each material
jurisdiction. In addition, please disaggregate and clarify the patent expiration dates for
your different types of patents (composition of matter and methods of use).
General
18.Please 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.
19.We note several graphics where the text is not legible. For example only, we note figure 2
and 3 on page 105, figure 4 on page 106 and figure 13 and 14 on page 119, where the text
is not clear or legible. Please modify your graphics throughout your filing as necessary to
ensure that all text is legible.
20.At first use, please define abbreviations. For example only, we note that "CI" on page 109
and "LDH"  and "DMSO" on page 111 are not defined at first use.

 FirstName LastNameMai-Britt Zocca, Ph.D.
 Comapany NameIO Biotech, Inc.
 July 3, 2021 Page 5
 FirstName LastName
Mai-Britt Zocca, Ph.D.
IO Biotech, Inc.
July 3, 2021
Page 5
21.We note your disclosure here to various sources where the description is not clear. For
example only, we note references to Ascierto (2019), Robert (2019), Larkin (2019), Maio
(2015) and Garbe (2011). If you funded or were otherwise affiliated with any of the
studies or reports you cite, please disclose such information. In addition, please confirm
that these sources are widely available to the public and update your disclosure
accordingly to provide additional details regarding the studies you appear to reference so
the disclosure clearly identifies the specific sources.
            You may contact David Burton at (202) 551-3626 or Al Pavot at (202) 551-3738 if you
have questions regarding comments on the financial statements and related matters.  Please
contact Jason Drory at (202) 551-8342 or Joe McCann at (202) 551-6262 with any other
questions.
Sincerely,
Division of Corporation Finance
Office of Life Sciences
cc:       Frank Rahmani, Esq.