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

Signature
/s/ Kevin Brennan, Attorney-in-Fact
Issuer symbol
XLO
Transactions as of
21 Nov 2025
Net transactions value
$0
Form type
4
Filing time
25 Nov 2025, 16:10:04 UTC
Previous filing
03 Jan 2025
Next filing
05 Jan 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Luptakova Katarina CHIEF MEDICAL OFFICER 828 WINTER STREET, SUITE 300, WALTHAM /s/ Kevin Brennan, Attorney-in-Fact 25 Nov 2025 0001991149

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 +625,000 $0.000000 625,000 21 Nov 2025 Common Stock 625,000 $0.8410 Direct F1, F2
transaction XLO Stock Option (right to buy) Disposed to Issuer -44,210 -100% 0 21 Nov 2025 Common Stock 44,210 $9.69 Direct F3, F4
transaction XLO Stock Option (right to buy) Award +44,210 44,210 21 Nov 2025 Common Stock 44,210 $1.50 Direct F3, F4
transaction XLO Stock Option (right to buy) Disposed to Issuer -15,000 -100% 0 21 Nov 2025 Common Stock 15,000 $2.37 Direct F4, F5
transaction XLO Stock Option (right to buy) Award +15,000 15,000 21 Nov 2025 Common Stock 15,000 $1.50 Direct F4, F5
transaction XLO Stock Option (right to buy) Disposed to Issuer -35,000 -100% 0 21 Nov 2025 Common Stock 35,000 $2.69 Direct F4, F6
transaction XLO Stock Option (right to buy) Award +35,000 35,000 21 Nov 2025 Common Stock 35,000 $1.50 Direct F4, F6
transaction XLO Stock Option (right to buy) Disposed to Issuer -25,000 -100% 0 21 Nov 2025 Common Stock 25,000 $2.78 Direct F4, F7
transaction XLO Stock Option (right to buy) Award +25,000 25,000 21 Nov 2025 Common Stock 25,000 $1.50 Direct F4, F7
transaction XLO Stock Option (right to buy) Disposed to Issuer -106,000 -100% 0 21 Nov 2025 Common Stock 106,000 $2.79 Direct F4, F8
transaction XLO Stock Option (right to buy) Award +106,000 106,000 21 Nov 2025 Common Stock 106,000 $1.50 Direct F4, F8
* 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 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.
F3 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.
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 $1.50 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.
F5 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.
F6 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.
F7 Immediately exercisable.
F8 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.