XORTX Therapeutics Inc美股招股说明书(2025-10-23版)

572,470 Common Shares1,177,530 Pre-Funded Warrants to Purchase 1,177,530 Common Shares1,177,530 Common Shares Underlying such Pre-Funded Warrants Pursuant to this prospectus supplement and the accompanying prospectus, XORTX Therapeutics Inc. (“we”, the “Company” or“XORTX”) is offering to an institutional accredited investor (the “Purchaser”) under a securities purchase agreement entered into onOctober 21, 2025 between the Company and the Purchaser (the “Purchase Agreement”), 572,470 common shares, without par value, ofthe Company (the “Shares”). Each Share is being sold at a price of $0.63. We are also offering 1,177,530 pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to 1,177,530 common shares of theCompany (the “Pre-Funded Warrant Shares”) to the same Purchaser, whose purchase of Shares in this offering would otherwise result inthe Purchaser, together with its respective affiliates and certain related parties, beneficially owning more than 4.99% (or, at the election ofthe Purchaser at closing, 9.99%) of our outstanding common shares immediately following the consummation of this offering, in lieu ofShares that would otherwise result in such Purchaser’s beneficial ownership exceeding 4.99% (or, at the election of the purchaser atclosing, 9.99%) of our outstanding common shares. The offering price of each Pre-Funded Warrant is $0.62999 (equal to the price perShare being sold in this offering, minus $0.00001), and the exercise price of each Pre-Funded Warrant is $0.00001 per Pre-Funded WarrantShare. The Pre-Funded Warrants will be immediately exercisable and may be exercised at any time until all of the Pre-Funded Warrants areexercised in full. We are also offering the Pre-Funded Warrant Shares that are issuable from time to time upon exercise of the Pre-FundedWarrants. Our common shares are listed on the TSX Venture Exchange (“TSXV”) and the Nasdaq Capital Market under the trading symbol “XRTX”.OnOctober21, 2025, the last trading day prior to the date of this prospectus supplement, the closing price of the common shares on theTSXV was US$0.74 (based on the daily exchange rate for the U.S. dollar in terms of Canadian dollars, as quoted by the Bank of Canada,on October 20, 2025 of C$1.00 = US$0.71), and on the Nasdaq Capital Market was US$0.72. The Company has applied to list the Sharesand the Pre-Funded Warrant Shares on the TSXV and has notified The Nasdaq Stock Market LLC (“Nasdaq”) of the offering. Listing ofthe Shares and the Pre-Funded Warrant Shares will be subject to the approval of the TSXV. There is no established public trading market for the Pre-Funded Warrants, and the Company does not expect a market to develop, and thePurchaser may not be able to resell the Pre-Funded Warrants purchased under this prospectus supplement and the accompanyingprospectus. In addition, the Company does not intend to apply for listing of the Pre-Funded Warrants on any securities exchange or othernationally recognized trading system. We have engaged D. Boral Capital LLC (the “Placement Agent”), as our exclusive placement agent in connection with this offering. ThePlacement Agent has no obligation to buy any of the securities from us or to arrange for the purchase or sale of any specific number ordollar amount of securities buthas agreed to use its best efforts to arrange for the sale of the securities in this offering. We have agreed topay the Placement Agent the placement agent fees set forth in the table below. See “Plan of Distribution” beginning on page S-31 of thisprospectus supplement for more information regarding these arrangements. As of October 21, 2025, the aggregate market value of our outstanding common shares held by non-affiliates was approximately$5,403,405, which was calculated based on 4,912,186 outstanding common shares held by non-affiliates, at a price per share of $1.10, theclosing price of our common shares on October 17, 2025, the highest closing price of the Company’s common shares on the NasdaqCapital Market during the preceding sixty (60) day period. Pursuant to General Instruction I.B.5 of Form F-3, in no event will we sell thesecurities described in this prospectus in a public primary offering with a value exceeding more than one-third (1/3) of the aggregatemarket value of our common shares held by non-affiliates in any twelve (12)-month period, so long as the aggregate market value of ouroutstanding common shares held by non-affiliates remains below $75,000,000. During the twelve (12) calendar months prior to andincluding the date of this prospectus supplement, we have sold $114,000 of securities pursuant to General Instruction I.B.5 of Form F-3. (1)In addition, we have agreed to reimburse certain expenses of the Placement Agent in connection with this offering. See “Plan ofDistribution” for additional disclosure regarding Placement Agent compensation. Investing in our securities involves risks. You should review carefully the risks and uncertainties described under