EX-10.13

Exhibit 10.13

Form for Tranche 1 Options

XILIO THERAPEUTICS, INC.
STOCK OPTION AGREEMENT

Xilio Therapeutics, Inc., (the “Company”) hereby grants the following stock option pursuant to its 2025 Stock Incentive Plan. The terms and conditions attached hereto are also a part hereof.

Notice of Grant


Name of optionee (the “Participant”):
Grant Date:
Incentive Stock Option or Nonstatutory Stock Option:
Number of shares of the Company’s Common Stock subject to this option (“Shares”):
Option exercise price per Share:1
Vesting Start Date2:
Final Exercise Date: 3

Vesting Schedule: Options vest in equal monthly installments beginning on the one-month anniversary of the Vesting Start Date and ending on the third anniversary of the Vesting Start Date, subject in each case to the Participant remaining an Eligible Participant on such date, as provided herein.

This option satisfies in full all commitments that the Company has to the Participant with respect to the issuance of stock, stock options or other equity securities. Electronic acceptance of this option pursuant to the Company’s instructions to the Participant (including through an online acceptance process) is acceptable.


	Xilio Therapeutics, Inc.
Signature of Participant
Street Address	By: Name of Officer Title:
City/State/Zip Code	By: Name of Officer Title:

1 Exercise price to be not less than the greater of (i) $0.75 per share (subject to adjustment) and (ii) 100% of the Grant Date Fair Market Value (as defined in the Plan) of the Common Stock on the date of grant (110% in the case of a Participant that owns more than 10% of the total combined voting power of all classes of stock of the Company or its parent or subsidiary (a “10% Shareholder”) for the option to qualify as an incentive stock option (an “ISO”) under Section 422 of the Internal Revenue Code).

2 For purposes of awards granted prior to the date the Company’s shareholders approve the 2025 Stock Incentive Plan (estimated to be November 21, 2025), the Vesting Start Date shall be the date the Company’s shareholders approve the 2025 Stock Incentive Plan.

3 The Final Exercise Date must be no more than 10 years (5 years in the case of a 10% Shareholder) from the date of grant for the option to qualify as an ISO. The correct approach to calculate the final exercise date is to use the day immediately prior to the date ten years out from the date of the stock option award grant (5 years in the case of a 10% stockholder).

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Xilio Therapeutics, Inc.

Stock Option Agreement

Incorporated Terms and Conditions

Grant of Option.

This agreement evidences the grant by the Company, on the grant date (the “Grant Date”) set forth in the Notice of Grant that forms part of this agreement (the “Notice of Grant”), to the Participant of an option to purchase, in whole or in part, on the terms provided herein and in the Company’s 2025 Stock Incentive Plan (the “Plan”), the number of Shares set forth in the Notice of Grant of common stock, $0.0001 par value per share, of the Company (“Common Stock”), at the exercise price per Share set forth in the Notice of Grant. Unless earlier terminated, this option shall expire at 5:00 p.m., Eastern time, on the Final Exercise Date set forth in the Notice of Grant (the “Final Exercise Date”).

The option evidenced by this agreement is intended to be an incentive stock option as defined in Section 422 of the Internal Revenue Code of 1986, as amended, and any regulations promulgated thereunder (the “Code”) to the maximum extent permitted by law, solely to the extent designated as an incentive stock option in the Notice of Grant. Except as otherwise indicated by the context, the term “Participant”, as used in this option, shall be deemed to include any person who acquires the right to exercise this option validly under its terms.

Vesting Schedule.

This option will become exercisable (“vest”) in accordance with the vesting schedule set forth in the Notice of Grant and Section 3 below.

The right of exercise shall be cumulative so that to the extent the option is not exercised in any period to the maximum extent permissible it shall continue to be exercisable, in whole or in part, with respect to all Shares for which it is vested until the earlier of the Final Exercise Date or the termination of this option under Section 3 hereof or the Plan.

Exercise of Option.

(a)

Form of Exercise. Each election to exercise this option shall be in writing, in the form, which may be electronic, as is approved by the Company, together with payment in full in the manner provided in the Plan. The Participant may purchase less than the number of shares covered hereby, provided that no partial exercise of this option may be for any fractional share.

(b)

Continuous Relationship with the Company Required. Except as otherwise provided in this Section 3 or in the Plan, this option may not be exercised unless the Participant, at the time he or she exercises this option, is, and has been at all times since the Grant Date, an employee, director or officer of, or consultant or advisor to, the Company or any other entity the employees, officers, directors, consultants, or advisors of which are eligible to receive option grants under the Plan (an “Eligible Participant”). Notwithstanding anything to the contrary in this agreement, neither the Company nor any subsidiary is obligated, by or as a result of the Plan or this agreement, to continue the Participant in a service relationship with the Company or any

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subsidiary, and neither the Plan nor this agreement shall interfere in any way with the right of the Company or any subsidiary to terminate the service relationship of the Participant with the Company or any subsidiary at any time.

(c)

Termination of Relationship with the Company. If the Participant ceases to be an Eligible Participant for any reason, then, except as provided in paragraphs (d) and (e) below, the right to exercise this option shall terminate three months after such cessation (but in no event after the Final Exercise Date), provided that this option shall be exercisable only to the extent that the Participant was entitled to exercise this option on the date of such cessation. Notwithstanding the foregoing, if the Participant, prior to the Final Exercise Date, violates the restrictive covenants (including, without limitation, the non-competition, non-solicitation, or confidentiality provisions) of any employment contract, any non-competition, non-solicitation, confidentiality or assignment agreement to which the Participant is a party, or any other agreement between the Participant and the Company, the right to exercise this option shall terminate immediately upon such violation.

(d)

Vesting and Exercise Period Upon Death or Disability. If the Participant dies or becomes Disabled (as defined in the Plan) prior to the Final Exercise Date while he or she is an Eligible Participant and the Company has not terminated such relationship for Cause (as defined in the Plan), this option shall (i) become fully vested and exercisable as of the date of such death or Disability and (ii) be exercisable, within the period of one year following the date of death or Disability of the Participant, by the Participant (or in the case of death by an authorized transferee), provided that this option shall not be exercisable after the Final Exercise Date.

(e)

Termination for Cause. If, prior to the Final Exercise Date, the Participant’s service is terminated by the Company for Cause (as defined in the Plan), the right to exercise this option shall terminate immediately upon the effective date of such termination of service. If, prior to the Final Exercise Date, the Participant is given notice by the Company of the termination of his or her service by the Company for Cause, and the effective date of such termination is subsequent to the date of delivery of such notice, the right to exercise this option shall be suspended from the time of the delivery of such notice until the earlier of (i) such time as it is determined or otherwise agreed that the Participant’s service shall not be terminated for Cause as provided in such notice or (ii) the effective date of such termination of service (in which case the right to exercise this option shall, pursuant to the preceding sentence, terminate upon the effective date of such termination of service). The Participant’s service shall be considered to have been terminated for Cause if the Company determines, within 30 days after the Participant’s resignation, that termination for Cause was warranted.

Tax Matters.

(a)

Withholding. No Shares will be issued pursuant to the exercise of this option unless and until the Participant pays to the Company, or makes provision satisfactory to the Company for payment of, any federal, state or local withholding taxes required by law to be withheld in respect of this option.

(b)

Disqualifying Disposition. If this option is an incentive stock option and the Participant disposes of Shares acquired upon exercise of this option within two years from the

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Grant Date or one year after such Shares were acquired pursuant to exercise of this option, the Participant shall notify the Company in writing of such disposition.

Transfer Restrictions; Clawback.

(a)

This option may not be sold, assigned, transferred, pledged, encumbered or otherwise disposed of by the Participant, either voluntarily or by operation of law, except by will or the laws of descent and distribution, and, during the lifetime of the Participant, this option shall be exercisable only by the Participant.

(b)

In accepting this option, the Participant agrees to be bound by any clawback policy that the Company has in place or may adopt in the future.

Data Privacy Consent.

In order to administer the Plan and this agreement and to implement or structure future equity grants, the Company, its subsidiaries and affiliates and certain agents thereof (together, the “Relevant Companies”) may process any and all personal or professional data, including but not limited to social security or other identification number, home address and telephone number, date of birth and other information that is necessary or desirable for the administration of the Plan and/or this agreement (the “Relevant Information”). By entering into this agreement, the Participant (i) authorizes the Company (including Relevant Companies on its behalf) to collect, process, register and transfer to the Relevant Companies all Relevant Information; (ii) waives any privacy rights the Participant may have with respect to the Relevant Information; (iii) authorizes the Relevant Companies to store and transmit such information in electronic form; and (iv) authorizes the transfer of the Relevant Information to any jurisdiction in which the Relevant Companies consider appropriate. The Participant shall have access to, and the right to change, the Relevant Information. Relevant Information will only be used in accordance with applicable law.

Provisions of the Plan.

This option is subject to the provisions of the Plan (including the provisions relating to amendments to the Plan), a copy of which is furnished to the Participant with this option.

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Xilio Therapeutics Inc — 10-K exhibit