Kevin Brennan - 21 Nov 2025 Form 4 Insider Report for Xilio Therapeutics, Inc. (XLO)

Signature
/s/ Kevin Brennan
Issuer symbol
XLO
Transactions as of
21 Nov 2025
Transactions value $
$0
Form type
4
Filing time
25 Nov 2025, 16:10:06
Previous filing
03 Jan 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Brennan Kevin M. SVP, FINANCE AND ACCOUNTING 828 WINTER STREET, SUITE 300, WALTHAM /s/ Kevin Brennan 25 Nov 2025 0001971303

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction XLO Stock Option (right to buy) Award $0 +132K $0.00 132K 21 Nov 2025 Common Stock 132K $0.84 Direct F1, F2
transaction XLO Stock Option (right to buy) Disposed to Issuer -55K -100% 0 21 Nov 2025 Common Stock 55K $3.17 Direct F3, F4
transaction XLO Stock Option (right to buy) Award +55K 55K 21 Nov 2025 Common Stock 55K $1.00 Direct F3, F4
transaction XLO Stock Option (right to buy) Disposed to Issuer -25K -100% 0 21 Nov 2025 Common Stock 25K $2.79 Direct F4, F5
transaction XLO Stock Option (right to buy) Award +25K 25K 21 Nov 2025 Common Stock 25K $1.00 Direct F4, F5
transaction XLO Stock Option (right to buy) Disposed to Issuer -20K -100% 0 21 Nov 2025 Common Stock 20K $1.08 Direct F4, F6
transaction XLO Stock Option (right to buy) Award +20K 20K 21 Nov 2025 Common Stock 20K $1.00 Direct F4, F6
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 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.
F2 This option vests 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.
F3 This option was granted on April 1, 2023 and vested on March 30, 2024 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 March 30, 2027.
F4 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 $1.00 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.
F5 Immediately exercisable.
F6 This option was granted on May 1, 2024. The shares underlying the option began vesting on June 1, 2024 and continue to vest in equal monthly installments thereafter through May 1, 2028.