青柠疗法公司美股招股说明书(2025-10-17版)

Up to $75,000,000 Common Stock This prospectus supplement amends and supplements the information in the prospectus, dated December26, 2024, filed with the Securities andExchange Commission as a part of our registration statement onFormS-3(FileNo.333-283897),as supplemented by the prospectus supplement datedMarch24, 2025 (as supplemented, the Prior Prospectus), relating to the offer and sale of up to $75,000,000 of shares of our common stock, $0.001 parvalue per share, pursuant to the Controlled Equity OfferingSMSales Agreement dated as of December18, 2024, or the Sales Agreement, we previouslyentered into with Cantor Fitzgerald& Co. and H.C. Wainwright& Co., LLC, or the Agents. This prospectus supplement should be read in conjunctionwith the Prior Prospectus, and is qualified by reference thereto, except to the extent that the information herein amends or supersedes the informationcontained in the Prior Prospectus. This prospectus supplement is not complete without, and may only be delivered or utilized in connection with, thePrior Prospectus and any future amendments or supplements thereto. The prospectus supplement dated March24, 2025, indicated that we were, at that time, subject to General Instruction I.B.6. of FormS-3,whichlimited the amount that we were able to sell under the registration statement of which the prospectus forms a part. We are currently no longer subject tothe offering limits imposed by General Instruction I.B.6. of FormS-3.If we become subject to the offering limits in General InstructionI.B.6. ofFormS-3in the future, we will file another prospectus supplement. As of the date of this prospectus supplement, we have sold an aggregate of 4,823,859 shares for gross proceeds of $6,496,274 pursuant to theSales Agreement. As a result of such prior sales, as of the date of this prospectus supplement, shares having an aggregate offering price of up to$68,503,726 remain available for offer and sale under the Sales Agreement through the Prospectus. Our common stock is listed on the Nasdaq Global Select Market under the symbol “QNCX.” On October16, 2025, the closing sale price of ourcommon stock on the Nasdaq Global Select Market was $1.93 per share. Investing in our common stock involves a high degree of risk. Please read the information contained in andincorporated by reference under the heading “RiskFactors” beginning on page3 of the Prior Prospectus, and undersimilar headings in the other documents that are filed after the date hereof and incorporated by reference into thisprospectus supplement and the Prior Prospectus. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities orpassed upon the adequacy or accuracy of this prospectus supplement and the Prior Prospectus. Any representation to the contrary is a criminaloffense. H.C. Wainwright& Co. Cantor The date of this prospectus supplement is October17, 2025