UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K/A

(Amendment No. 1)

(Mark One)

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2023

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM      TO     

Commission File Number 001-41008

IO BIOTECH, INC.

(Exact name of Registrant as specified in its Charter)

Delaware	87-0909276
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
Ole Maaløes Vej 3 DK-2200 Copenhagen N Denmark	NA
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: +45 7070 2980

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
Common stock, par value $0.001 per share	IOBT	The Nasdaq Stock Market LLC

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the Registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes ☐ No ☒

Indicate by check mark if the Registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ☐ No ☒

Indicate by check mark whether the Registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the Registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ☒ No ☐

Indicate by check mark whether the Registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the Registrant was required to submit such files). Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	Smaller reporting company	☒
		Emerging growth company	☒

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark whether the Registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

As of June 30, 2023, the last day of the registrant’s most recently completed second fiscal quarter, the aggregate market value of the Common Stock held by non-affiliates of the registrant was approximately $31.1 million.

The number of shares of Registrant’s Common Stock, par value $0.001 per share, outstanding as of February 28, 2024 was 65,880,914.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of the registrant’s proxy statement relating to its 2024 Annual Meeting of Stockholders have been incorporated by reference herein in response to Part III, as specifically set forth in Part III.

EXPLANATORY NOTE

This Amendment No. 1 on Form 10-K/A (the “Amendment”) of IO Biotech, Inc. (the “Company”) amends the Company’s Annual Report on Form 10-K for the year ended December 31, 2023, originally filed with the Securities and Exchange Commission on March 5, 2024 (the “Original Report”). This Amendment is being filed solely for the purpose of inserting the conformed signature of the current Principal Accounting Officer, which was inadvertently omitted from the Original Report.

This Amendment speaks as of the original filing date of the Form 10-K, does not reflect events that may have occurred after the filing date of the Original Report, and does not modify or update in any way the Company’s financial statements or any other disclosures made in the Original Report. No other changes have been made to the Original Report.

As required by Rule 12b-15 of the Securities Exchange Act of 1934, as amended, this Amendment contains new certifications by the Company’s principal executive officer and principal financial officer, which are being filed as exhibits to the Amendment. Because the Amendment includes no financial statements, the Company is not including certifications pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

EXHIBITS INDEX

Exhibit Number	Description
31.1+	Certification of Principal Executive Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.2+	Certification of Principal Financial Officer Pursuant to Rules 13a-14(a) and 15d-14(a) under the Securities Exchange Act of 1934, as Adopted Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
101.INS	Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because XBRL tags are embedded within the Inline XBRL document.
101.SCH	Inline XBRL Taxonomy Extension Schema Document
104	Cover Page Interactive Data File (embedded within the Inline XBRL document)

* Previously filed.

+ Filed herewith.

† Indicates a management contract or compensatory plan or arrangement.

# Portions of the exhibit have been or will be excluded because it is both not material and is the type of information that the registrant treats as private or confidential.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, as amended, the Registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

	IO Biotech, Inc.
Date: March 22, 2024	By:	/s/ Mai-Britt Zocca
		Mai-Britt Zocca, Ph.D.
		Chief Executive Officer and Director (Principal Executive Officer)

Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, this report has been signed below by the following persons on behalf of the Registrant in the capacities and on the dates indicated.

Name	Title	Date
/s/ Mai-Britt Zocca, Ph.D. Mai-Britt Zocca, Ph.D.	Chief Executive Officer and Director (Principal Executive Officer)	March 22, 2024
/s/ Amy Sullivan, M.B.A. Amy Sullivan, M.B.A.	Chief Financial Officer (Principal Financial Officer)	March 22, 2024
/s/ Brian Burkavage Brian Burkavage	Vice President of Finance (Principal Accounting Officer)	March 22, 2024
/s/ Peter Hirth, Ph.D.*	Chairman of the Board	March 5, 2024
Peter Hirth, Ph.D.
/s/ Kathleen Sereda Glaub, M.B.A.*	Director	March 5, 2024
Kathleen Sereda Glaub, M.B.A.
/s/ Christian Elling, Ph.D.*	Director	March 5, 2024
Christian Elling, Ph.D.
/s/ Helen Collins, MD*	Director	March 5, 2024
Helen Collins, MD
/s/ Jack B. Nielsen*	Director	March 5, 2024
Jack B. Nielsen
/s/ Heidi Hunter*	Director	March 5, 2024
Heidi Hunter
/s/ David V. Smith, M.B.A.*	Director	March 5, 2024
David Smith, M.B.A.

* Previously signed.