FORM LOCK-UP AGREEMENT

Exhibit 99.6

FORM LOCK-UP AGREEMENT

October [•], 2024

Re: Securities Purchase Agreement, dated as of October 17, 2024 (the “Purchase Agreement”), between XORTX Therapeutics Inc. (the “Company”) and the purchasers signatory thereto (each, a “Purchaser” and, collectively, the “Purchasers”)

Ladies and Gentlemen:

Defined terms not otherwise defined in this letter agreement (the “Letter Agreement”) shall have the meanings set forth in the Purchase Agreement. Pursuant to Section 2.2(a) of the Purchase Agreement and in satisfaction of a condition of the Company’s obligations under the Purchase Agreement, the undersigned irrevocably agrees with the Company that, from the date hereof until forty-five (45) days after the Closing Date (such period, the “Restriction Period”) the undersigned will not offer, sell, contract to sell, hypothecate, pledge or otherwise dispose of (or enter into any transaction which is designed to, or might reasonably be expected to, result in the disposition (whether by actual disposition or effective economic disposition due to cash settlement or otherwise) by the undersigned or any Affiliate of the undersigned or any person in privity with the undersigned or any Affiliate of the undersigned), directly or indirectly, or establish or increase a put equivalent position or liquidate or decrease a call equivalent position within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), with respect to, any common shares of the Company or securities convertible, exchangeable or exercisable into, common shares of the Company beneficially owned, held or hereafter acquired by the undersigned (the “Securities”). Beneficial ownership shall be calculated in accordance with Section 13(d) of the Exchange Act.

Notwithstanding the foregoing, and subject to the conditions below, the undersigned may transfer the Securities provided that (1) the Company receives a signed lock-up letter agreement (in the form of this Letter Agreement) for the balance of the Restriction Period from each donee, trustee, distributee, or transferee, as the case may be, prior to such transfer, (2) any such transfer shall not involve a disposition for value, (3) such transfer is not required to be reported with the Securities and Exchange Commission in accordance with the Exchange Act and no report of such transfer shall be made voluntarily, and (4) neither the undersigned nor any donee, trustee, distributee or transferee, as the case may be, otherwise voluntarily effects any public filing or report regarding such transfers, with respect to transfer:

i) as a bona fide gift or gifts, charitable contribution or for bona fide estate planning purposes;

ii) to any immediate family member or to any trust for the direct or indirect benefit of the undersigned or the immediate family of the undersigned (for purposes of this Letter Agreement, “immediate family” shall mean any relationship by blood, marriage or adoption, not more remote than first cousin);

iii) to any corporation, partnership, limited liability company, or other business entity all of the equity holders of which consist of the undersigned and/or the immediate family of the undersigned;

iv) if the undersigned is a corporation, partnership, limited liability company, trust or other business entity (a) to another corporation, partnership, limited liability company, trust or other business entity that is an Affiliate of the undersigned or (b) in the form of a distribution to limited partners, limited liability company members or shareholders of the undersigned;

v) if the undersigned is a trust, to the beneficiary of such trust;

vi) by xxxx, other testamentary document or intestate succession to the legal representative, heir, beneficiary or a member of the immediate family of the undersigned; or

vii)  by operation of law, such as pursuant to a qualified domestic order or in connection with a divorce decree;

viii)  pursuant to a bona fide third-party tender offer, merger, consolidation or other similar transaction that is approved by the Board of Directors of the Company and made to all holders of the Company’s common shares the result of which is that any “person” (as defined in Section 13(d)(3) of the Exchange Act), or group of persons, becomes the beneficial owner (as defined in Rules 13d-3 and 13d-5 of the Exchange Act) of more than 50% of total voting power of the voting shares of the Company or the surviving entity;

ix)  to the Company upon a vesting event of the Securities or upon the exercise of options or warrants to purchase Common Shares on a “cashless” or “net exercise” basis or to cover tax withholding obligations of the undersigned in connection with such vesting or exercise (but for the avoidance of doubt, excluding all manners of exercise that would involve a sale in the open market of any securities relating to such options or warrants, whether to cover the applicable aggregate exercise price, withholding tax obligations or otherwise); provided that any Securities issued upon such exercise shall be subject to the restrictions set forth in this Letter Agreement;

x)  to the Company in connection with the termination of employment whereby the Company has the option to repurchase such shares or securities; or

xi)  of securities purchased in open market transactions after the Closing Date.

In addition, notwithstanding the foregoing, this Letter Agreement shall not restrict the delivery of common shares of the Company to the undersigned upon (i) exercise any options granted under any employee benefit plan of the Company; provided that any common shares or Securities acquired in connection with any such exercise will be subject to the restrictions set forth in this Letter Agreement, or (ii) the exercise of warrants; provided that such common shares delivered to the undersigned in connection with such exercise are subject to the restrictions set forth in this Letter Agreement.

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Furthermore, the undersigned may enter into any new plan established in compliance with Rule 10b5-1 of the Exchange Act; provided that (i) such plan may only be established if no public announcement or filing with the Securities and Exchange Commission, or other applicable regulatory authority, is made in connection with the establishment of such plan during the Restriction Period and (ii) no sale of common shares is made pursuant to such plan during the Restriction Period.

The undersigned acknowledges that the execution, delivery and performance of this Letter Agreement is a material inducement to each Purchaser to complete the transactions contemplated by the Purchase Agreement and the Company shall be entitled to specific performance of the undersigned’s obligations hereunder. The undersigned hereby represents that the undersigned has the power and authority to execute, deliver and perform this Letter Agreement, that the undersigned has received adequate consideration therefor and that the undersigned will indirectly benefit from the closing of the transactions contemplated by the Purchase Agreement.

This Letter Agreement may not be amended or otherwise modified in any respect without the written consent of each of the Company and the undersigned. This Letter Agreement shall be construed and enforced in accordance with the laws of the State of New York without regard to the principles of conflict of laws. The undersigned hereby irrevocably submits to the exclusive jurisdiction of the United States District Court sitting in the Southern District of New York and the courts of the State of New York located in Manhattan, for the purposes of any suit, action or proceeding arising out of or relating to this Letter Agreement, and hereby waives, and agrees not to assert in any such suit, action or proceeding, any claim that (i) it is not personally subject to the jurisdiction of such court, (ii) the suit, action or proceeding is brought in an inconvenient forum, or (iii) the venue of the suit, action or proceeding is improper. The undersigned hereby irrevocably waives personal service of process and consents to process being served in any such suit, action or proceeding by receiving a copy thereof sent to the Company at the address in effect for notices to it under the Purchase Agreement and agrees that such service shall constitute good and sufficient service of process and notice thereof. The undersigned hereby waives any right to a trial by jury. Nothing contained herein shall be deemed to limit in any way any right to serve process in any manner permitted by law. The undersigned agrees and understands that this Letter Agreement does not intend to create any relationship between the undersigned and any Purchaser and that no Purchaser is entitled to cast any votes on the matters herein contemplated and that no issuance or sale of the Securities is created or intended by virtue of this Letter Agreement.

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This Letter Agreement shall be binding on successors and assigns of the undersigned with respect to the Securities and any such successor or assign shall enter into a similar agreement for the benefit of the Company. This Letter Agreement is intended for the benefit of the parties hereto and their respective successors and permitted assigns and is not for the benefit of, nor may any provision hereof be enforced by, any other Person. This Lock-Up Agreement may be delivered via facsimile, electronic mail (including pdf or any electronic signature complying with the U.S. federal ESIGN Act of 2000, e.g., xxx.xxxxxxxx.xxx or xxx.xxxxxxxx.xxx) or other transmission method and any counterpart so delivered shall be deemed to have been duly and validly delivered and be valid and effective for all purposes.

This Letter Agreement (and for the avoidance of doubt, the Restriction Period described herein) and related restrictions shall automatically terminate upon the earliest to occur, if any, of (i) the termination of the Purchase Agreement before the sale of any Securities to the Purchasers or (ii) October 31, 2024, in the event the Closing of the sale of any Securities contemplated by the Purchase Agreement shall not have occurred on or before such date.

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This Letter Agreement may be executed in two or more counterparts, all of which when taken together may be considered one and the same agreement.

Signature

Print Name

Position in Company, if any

Address for Notice:

By signing below, the Company agrees to use commercially reasonable efforts to enforce the restrictions on transfer set forth in this Letter Agreement.

XORTX THERAPEUTICS INC.

By:

Name:

Title:

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