XLO

8-K

false000184023300018402332026-01-082026-01-08

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): January 6, 2026

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 Capital 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 2.02 Results of Operations and Financial Condition.

On January 8, 2026, Xilio Therapeutics, Inc. (the “Company”) issued a press release announcing corporate updates and upcoming milestones, including that the Company estimates that it had cash and cash equivalents of approximately $137.5 million as of December 31, 2025. A copy of the press release is furnished as Exhibit 99.1 to this Current Report on Form 8-K.

The information contained in this Item 2.02 regarding the Company’s estimated cash balance above is based on preliminary, unaudited information and management estimates for the year ended December 31, 2025, is not a comprehensive statement of the Company’s financial results as of and for the fiscal year ended December 31, 2025 and may change. This estimate also does not present all information necessary for an understanding of the Company’s financial condition as of December 31, 2025 and its results of operations for the fourth quarter and year ended December 31, 2025. Xilio’s independent registered public accounting firm has not conducted an audit or review of, and does not express an opinion or any other form of assurance with respect to, this preliminary estimate. Accordingly, undue reliance should not be placed on this preliminary estimate.

The information in this Item 2.02 of this Current Report on Form 8-K, including Exhibit 99.1, is being furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Exchange Act or the Securities Act of 1933, as amended, except as expressly set forth by specific reference in such a filing.

Item 5.02. Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On January 8, 2026, the Company announced the appointment of Sara M. Bonstein as chair of the Board. Ms. Bonstein succeeds Paul Clancy, who notified the Company of his decision to retire from the Board on January 6, 2026, effective as of such date. Mr. Clancy’s retirement did not result from any disagreement with the Company or its management.

Item 9.01. Financial Statements and Exhibits. (d) Exhibits.

Exhibit Number

Description

99.1

Press release issued by Xilio Therapeutics, Inc. on January 8, 2026

104

Cover Page Interactive Data File (formatted as Inline XBRL with applicable taxonomy extension information contained in Exhibits 101)

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: January 8, 2026

By:

/s/ Caroline H

8-K

false000184023300018402332025-11-122025-11-12

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): November 13, 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 Capital 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 2.02 Results of Operations and Financial Condition.

On November 13, 2025, Xilio Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended September 30, 2025 and other business highlights. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein.

The information in this Current Report on Form 8-K, including Exhibit 99.1, is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

The following exhibit relating to Item 2.02 of this Current Report on Form 8-K shall be deemed to be furnished and not filed.

Exhibit No.

Description

99.1

Press release issued by Xilio Therapeutics, Inc. on November 13, 2025

104

Cover Page Interactive Data File (embedded within the Inline XBRL document and incorporated as Exhibit 101)

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: November 13, 2025

By:

/s/ Caroline Hensley

Caroline Hensley

Chief Legal Officer

0001840233false00018402332025-08-142025-08-14 ​

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): August 14, 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 2.02 Results of Operations and Financial Condition. ​ On August 14, 2025, Xilio Therapeutics, Inc. (the “Company”) announced its financial results for the quarter ended June 30, 2025 and other business highlights. The full text of the press release issued in connection with the announcement is furnished as Exhibit 99.1 to this Current Report on Form 8-K and is incorporated by reference herein. ​ The information in this Current Report on Form 8-K, including Exhibit 99.1, is intended to be furnished and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as expressly set forth by specific reference in such filing. ​ Item 9.01 Financial Statements and Exhibits. ​ (d) Exhibits. ​ The following exhibit relating to Item 2.02 of this Current Report on Form 8-K shall be deemed to be furnished and not filed. ​ ​

​

​

Exhibit No. ​ Description

99.1 ​ Press release issued by Xilio Therapeutics, Inc. on August 14, 2025

104 ​ Cover Page Interactive Data File (embedded within the Inline XBRL document and incorporated as Exhibit 101)

​ ​

​

​

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: August 14, 2025 By: /s/ Caroline Hensley

Caroline Hensley

Chief Legal Officer

​ ​ ​ ​

​