Xilio Therapeutics Form 4 details new CMO grant and repricing

Rhea-AI Filing Summary

Xilio Therapeutics (XLO)November 21, 2025, the officer received a stock option for 625,000 shares at an exercise price of $0.841 per share. These options vest in 36 equal monthly installments starting December 21, 2025, so the grant is earned gradually over three years.

The filing also records a one-time option repricing effective November 21, 2025. Several existing stock options with higher exercise prices, including grants for 44,210 and 106,000 shares, were modified so that the exercise price is reduced to $1.50 per share. If any repriced option is exercised before November 21, 2026, the original, higher exercise price still applies, while all other vesting and expiration terms remain unchanged.

11/25/2025 - 04:10 PM

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

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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^*

Luptakova Katarina

(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 MEDICAL 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		625,000		(2)	10/07/2035	Common Stock	625,000	$0	625,000	D
Stock Option (right to buy)	$9.69	11/21/2025		D			44,210	(3)	12/06/2031	Common Stock	44,210	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		44,210		(3)	12/06/2031	Common Stock	44,210	(4)	44,210	D
Stock Option (right to buy)	$2.37	11/21/2025		D			15,000	(5)	10/31/2032	Common Stock	15,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		15,000		(5)	10/31/2032	Common Stock	15,000	(4)	15,000	D
Stock Option (right to buy)	$2.69	11/21/2025		D			35,000	(6)	12/31/2032	Common Stock	35,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		35,000		(6)	12/31/2032	Common Stock	35,000	(4)	35,000	D
Stock Option (right to buy)	$2.785	11/21/2025		D			25,000	(7)	08/15/2033	Common Stock	25,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		25,000		(7)	08/15/2033	Common Stock	25,000	(4)	25,000	D
Stock Option (right to buy)	$2.79	11/21/2025		D			106,000	(8)	09/04/2033	Common Stock	106,000	(4)	0	D
Stock Option (right to buy)	$1.5	11/21/2025		A		106,000		(8)	09/04/2033	Common Stock	106,000	(4)	106,000	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. This option was granted on December 7, 2021 and vested on December 2, 2022 with respect to 25% of the shares of common stock underlying the stock option. The remaining 75% of the shares of common stock underlying the stock option continues to vest in 36 equal monthly installments thereafter through December 2, 2025.

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 November 1, 2022. The shares underlying the option began vesting on December 1, 2022 and continue to vest in equal monthly installments thereafter through November 1, 2026.

6. 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.

7. Immediately exercisable.

8. This option was granted on September 5, 2023. The shares underlying the option began vesting on October 1, 2023 and continue to vest in equal monthly installments thereafter through September 1, 2027.

	/s/ Kevin Brennan, Attorney-in-Fact	11/25/2025
	** Signature of Reporting Person	Date
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FAQ

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

The filing reports a new stock option grant and a one-time repricing of existing stock options held by the company’s chief medical officer, reflecting changes in their equity compensation.

How many new stock options were granted to the XLO chief medical officer and at what price?

The chief medical officer received a stock option covering 625,000 shares of common stock with an exercise price of $0.841 per share, granted under the 2025 Stock Incentive Plan.

When do the newly granted XLO options start vesting and over what period?

The new options begin vesting on December 21, 2025 and vest in 36 equal monthly installments over three years, subject to continued service.

What is the 2025 Stock Incentive Plan mentioned by Xilio Therapeutics (XLO)?

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 new 625,000-share option was granted.

What are the key terms of the option repricing for Xilio Therapeutics (XLO) options?

Effective November 21, 2025, certain existing options had their exercise price reduced to $1.50 per share. If any of these repriced options are exercised before November 21, 2026, the original higher exercise price must be paid; vesting and expiration dates were not changed.

Which existing XLO option grants were affected by the repricing?

The repricing applied to multiple prior grants, including options originally priced at $9.69, $2.37, $2.69, $2.785, and $2.79 per share, covering tranches such as 44,210, 15,000, 35,000, 25,000, and 106,000 shares.