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): October 2, 2025

Xilio Therapeutics, Inc.

(Exact Name of Registrant as Specified in Charter)

Delaware

001-40925

85-1623397

(State or Other Jurisdiction

of Incorporation)

(Commission

File Number)

(IRS Employer

Identification No.)

828 Winter Street, Suite 300

Waltham, Massachusetts

02451

(Address of Principal Executive Offices)

(Zip Code)

Registrant’s telephone number, including area code: (857) 524-2466

Not applicable

(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 (see General Instruction A.2. below):

☐	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, par value $0.0001 per share

XLO

Nasdaq Global Select Market

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 October 2, 2025, Xilio Therapeutics, Inc. (the “Company”) received approval from the Listing Qualifications Department (the “Staff”) of the Nasdaq Stock Market LLC (“Nasdaq”) to transfer the listing of the Company’s common stock from The Nasdaq Global Select Market to The Nasdaq Capital Market. Effective as of the opening of business on October 6, 2025, the Company’s common stock will be transferred to The Nasdaq Capital Market and will continue to trade under the symbol “XLO.” The Nasdaq Capital Market is a continuous trading market that operates in substantially the same manner as The Nasdaq Global Select Market. All companies listed on The Nasdaq Capital Market must meet certain financial requirements and adhere to Nasdaq’s corporate governance standards.

As previously disclosed on April 8, 2025, the Company received a letter from the Staff of Nasdaq notifying the Company of its failure to maintain the $1.00 minimum bid price required for continued listing on The Nasdaq Global Select Market under Nasdaq Listing Rule 5450(a)(1) (the “Minimum Bid Price Requirement”). In connection with the transfer to The Nasdaq Capital Market, Nasdaq granted the Company an additional 180 calendar day period, or until March 30, 2026, to regain compliance with the Minimum Bid Price Requirement.

During the additional 180 calendar day grace period, the Company’s common stock must close at $1.00 or more for at least 10 consecutive business days to regain compliance with the Minimum Bid Price Requirement, unless the Staff exercises its discretion to extend this 10-day period pursuant to Nasdaq Listing Rule 5810(c)(3)(H).

The Company is continuing to evaluate available options to regain compliance with the Minimum Bid Requirement.

SIGNATURES

Pursuant to the requirements 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 hereunto duly authorized.

XILIO THERAPEUTICS, INC.

Date: October 3, 2025

/s/ Caroline Hensley

Caroline Hensley

Chief Legal Officer

Xilio Therapeutics, Inc. 8-K