[Form 4] Xilio Therapeutics, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Xilio Therapeutics (XLO) reported insider equity activity for its Chief Financial Officer on a Form 4. The Board approved a new 2025 Stock Incentive Plan on October 8, 2025, and stockholders approved the plan on November 21, 2025.

Under this plan, the CFO received stock options to purchase 925,000 shares of common stock at an exercise price of $0.841 per share, expiring on October 7, 2035. These options vest in 36 equal monthly installments over three years beginning on December 21, 2025, contingent on continued service.

The filing also details a one-time option repricing effective November 21, 2025, that reduced the exercise price of several existing stock option grants to $1.50 per share, while keeping their original vesting and expiration terms. If any repriced option is exercised before November 21, 2026, the original, higher exercise price must be paid.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Frankenfield Christopher James

(Last) (First) (Middle)

828 WINTER STREET

SUITE 300

(Street)

WALTHAM MA 02451

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Xilio Therapeutics, Inc. [ XLO ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
11/21/2025

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Stock Option (right to buy)	$0.841	11/21/2025(1)		A		925,000		(2)	10/07/2035	Common Stock	925,000	$0	925,000	D
Stock Option (right to buy)	$6.65	11/21/2025		D			155,090	(3)	03/28/2031	Common Stock	155,090	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A			155,090	(3)	03/28/2031	Common Stock	155,090	(4)	155,090	D
Stock Option (right to buy)	$6.65	11/21/2025		D			23,786	(3)	03/31/2031	Common Stock	23,786	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		23,786		(3)	03/31/2031	Common Stock	23,786	(4)	23,786	D
Stock Option (right to buy)	$16	11/21/2025		D			37,296	(3)	10/20/2031	Common Stock	37,296	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		37,296		(3)	10/20/2031	Common Stock	37,296	(4)	37,296	D
Stock Option (right to buy)	$12.66	11/21/2025		D			45,000	(5)	02/21/2032	Common Stock	45,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		45,000		(5)	02/21/2032	Common Stock	45,000	(4)	45,000	D
Stock Option (right to buy)	$2.13	11/21/2025		D			20,000	(6)	08/31/2032	Common Stock	20,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		20,000		(6)	08/31/2032	Common Stock	20,000	(4)	20,000	D
Stock Option (right to buy)	$2.69	11/21/2025		D			117,000	(7)	12/31/2032	Common Stock	117,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		117,000		(7)	12/31/2032	Common Stock	117,000	(4)	117,000	D
Stock Option (right to buy)	$2.75	11/21/2025		D			150,000	(8)	08/02/2033	Common Stock	150,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		150,000		(8)	08/02/2033	Common Stock	150,000	(4)	150,000	D
Stock Option (right to buy)	$2.785	11/21/2025		D			300,000	(3)	08/15/2033	Common Stock	300,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		300,000		(3)	08/15/2033	Common Stock	300,000	(4)	300,000	D

Explanation of Responses:

1. On October 8, 2025, the Board of Directors (the "Board") approved the adoption of the Xilio Therapeutics, Inc. 2025 Stock Incentive Plan (the "2025 Plan"), subject to stockholder approval of the adoption of the 2025 Plan. On October 8, 2025, the Compensation Committee of the Board granted these options (referred to as "Tranche 1 Options" in the 2025 Plan) to the Reporting Person, subject to stockholder approval of the adoption of the 2025 Plan. The stockholders approved the adoption of the 2025 Plan on November 21, 2025.

2. The options vest in 36 equal monthly installments over the three-year period beginning on December 21, 2025, subject to the Reporting Person's continued service to the registrant through each applicable vesting date.

3. Immediately exercisable.

4. The transactions reported herein reflect a one-time option repricing, effective on November 21, 2025, which reduced the exercise price of each repriced option to $1.50 per share unless such repriced stock option is exercised prior to November 21, 2026, in which case the original exercise price must be paid (the "Option Repricing"). Except as modified by the Option Repricing, all other terms and conditions of the repriced options, including, without limitation, any provisions with respect to vesting and expiration, remain in full force and effect.

5. This option was granted on February 22, 2022. The shares underlying the option began vesting on March 1, 2022 and continue to vest in equal monthly installments thereafter through February 1, 2026.

6. This option was granted on September 1, 2022. The shares underlying the option began vesting on September 1, 2022 and continue to vest in equal monthly installments thereafter through August 1, 2026.

7. This option was granted on January 1, 2023. The shares underlying the option began vesting on February 1, 2023 and continue to vest in equal monthly installments thereafter through January 1, 2027.

8. This option was granted on August 3, 2023. The shares underlying the option began vesting on September 1, 2023 and continue to vest in equal monthly installments thereafter through August 1, 2027.

	/s/ Kevin Brennan, Attorney-in-Fact	11/25/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transaction did Xilio Therapeutics (XLO) disclose in this Form 4?

Xilio Therapeutics disclosed stock option grants and an option repricing for its Chief Financial Officer involving multiple option awards on its common stock.

How many new stock options did the XLO CFO receive and at what price?

The CFO received options to purchase 925,000 shares of Xilio common stock at an exercise price of $0.841 per share, expiring on October 7, 2035.

When do the new Xilio (XLO) CFO stock options vest?

The new options vest in 36 equal monthly installments over three years, starting on December 21, 2025, subject to the CFO’s continued service.

What is the Xilio Therapeutics 2025 Stock Incentive Plan mentioned in the Form 4?

The 2025 Stock Incentive Plan is a stock-based compensation plan approved by the Board on October 8, 2025 and by stockholders on November 21, 2025, under which the CFO’s new options (Tranche 1 Options) were granted.

What is the one-time option repricing for Xilio (XLO) options?

Effective November 21, 2025, certain existing options had their exercise price reduced to $1.50 per share, while all other terms, including vesting and expiration, remained the same.

Are there any special conditions on exercising the repriced Xilio (XLO) options?

Yes. If a repriced option is exercised before November 21, 2026, the holder must pay the original higher exercise price instead of $1.50 per share.

What prior grant dates are affected by Xilio’s option repricing?

The repricing affects options originally granted on February 22, 2022, September 1, 2022, January 1, 2023, and August 3, 2023, among others noted in the filing.