8-K

IO Biotech, Inc.

Date: December 19, 2025

/s/ Mai-Britt Zocca

Mai-Britt Zocca, Ph.D.

Chief Executive Officer

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): December 17, 2025

IO Biotech, Inc.

(Exact name of Registrant as Specified in Its Charter)

Delaware

001-41008

87-0909276

(State or Other Jurisdiction

of Incorporation)

(Commission
File Number)

(IRS Employer

Identification No.)

Ole Maaløes Vej 3

DK-2200 Copenhagen N

Denmark

(Address of Principal Executive Offices) (Zip Code)

Registrant’s Telephone Number, Including Area Code: +45 7070 2980

N/A

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐	Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐	Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐	Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐	Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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, $0.001 par value per share

IOBT

The Nasdaq Stock Market LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

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. ☐

Item 3.01. Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing

On December 17, 2025, IO Biotech, Inc. (the “Company”) received notice (the “Notice”) from the Listing Qualifications staff of The Nasdaq Stock Market LLC (“Nasdaq”) that, because the closing bid price for the Company’s common stock had fallen below $1.00 per share for 30 consecutive trading days, the Company no longer complies with the minimum bid price requirement for continued listing on the Nasdaq Global Select Market under Nasdaq Listing Rule 5450(a)(1). The Notice has no immediate effect on the listing of the Company’s common stock on the Nasdaq Global Select Market, and the Company’s common stock will continue to trade on the Nasdaq Global Select Market. Pursuant to Nasdaq Listing Rule 5810(c)(3)(A), the Company has been provided an initial compliance period of 180 calendar days, or until June 16, 2026, to regain compliance with the minimum bid price requirement. To regain compliance, the closing bid price of the Company’s common stock must meet or exceed $1.00 per share for a minimum of 10 consecutive trading days prior to June 16, 2026.

If the Company does not regain compliance by June 16, 2025, the Company may be eligible for an additional 180 calendar day compliance period if it applies to transfer the listing of its common stock from the Nasdaq Global Select Market to the Nasdaq Capital Market. To qualify, the Company would be required to meet the continued listing requirement for the market value of its publicly held shares and all other initial listing standards for the Nasdaq Capital Market, with the exception of the minimum bid price requirement, and provide written notice of its intention to cure the minimum bid price deficiency during the second compliance period. As part of its review process, Nasdaq will make a determination as to whether it believes the Company will be able to cure this deficiency. If Nasdaq staff determines that the Company will not be able to cure the deficiency, or if the Company is otherwise not eligible for such additional compliance period, Nasdaq will provide notice that the Company’s common stock will be subject to delisting. Upon receipt of such notice, the Company would have the right to appeal any determination to delist its common stock, and the common stock would remain listed on the Nasdaq Global Select Market until completion of the appeal process.

There can be no assurance that the Company will be able to regain compliance with the minimum bid price requirement or will otherwise be in compliance with other applicable Nasdaq listing rules.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

SEC Form 8-K filed by IO Biotech Inc.