Q32 Bio Inc美股招股说明书(2026-07-13版)

The information in this preliminary prospectus supplement is not complete and may be changed. A registration statement relating to these securities has been filed withthe Securities and Exchange Commission and is effective. This preliminary prospectus supplement and the accompanying prospectus are not an offer to sell thesesecurities and they are not soliciting an offer to buy these securities in any jurisdiction where the offer or sale is not permitted. $200,000,000 Pre-Funded Warrants to Purchase up to Shares of Common Stock We are offeringshares of our common stock and, in lieu of common stock to certain investors that so choose, pre-funded warrants to purchase up tocommon stock in this offering. The per share purchase price of the common stock is $. The purchase price of each pre-funded warrant will be equal to the price per share at which shares of our commonstock are being sold to the public in this offering, minus $0.0001, which is the exercise price of each pre-funded warrant. Each pre-funded warrant is exercisable for one share ofour common stock at an exercise price of $0.0001 per share. The pre-funded warrants are exercisable at any time after issuance, subject to ownership limitations, and will expirewhen exercised in full. This offering also relates to the shares of common stock issuable upon exercise of the pre-funded warrants sold in this offering. Our common stock is listed on the Nasdaq Capital Market under the symbol “QTTB.” On July 10, 2026, the last reported sale price of our common stock on the Nasdaq CapitalMarket was $11.21 per share. There is no established public trading market for the pre-funded warrants, and we do not expect a market to develop. We do not intend to list thepre-funded warrants on the Nasdaq Capital Market or any other national securities exchange or nationally recognized trading system. As of the date of this prospectus supplement, we are a “smaller reporting company” as defined under Rule 405 of the Securities Act of 1933, as amended (the “Securities Act”),and, as such, are subject to certain reduced public company reporting requirements. See “Prospectus Summary—Implications of Being a Smaller Reporting Company” on pageS-5 of this prospectus supplement. Public offering price Underwriting discounts and commissions (1)Proceeds, before expenses, to us We have granted the underwriters an option for a period of 30 days from the date of this prospectus supplement to purchase up to an additional $30,000,000 of shares of ourcommon stock at the public offering price, less the underwriting discounts and commissions. Investing in our common stock or pre-funded warrants involves a high degree of risk. You should review carefully the risks and uncertainties described under the header“Risk Factors” contained in this prospectus supplement beginning on page S-8 and under similar headings in the other documents that are incorporated by reference into thisprospectus supplement and the accompanying prospectus. Neither the Securities and Exchange Commission, nor any state securities commission nor any other regulatory body has approved or disapproved of these securities or passedupon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Any representation to the contrary is a criminal offense. The underwriters expect to deliver the shares of common stock and pre-funded warrants against payment therefor on or about, 2026. MorganStanley Lead Manager H.C. Wainwright& Co. Table of Contents TABLE OF CONTENTS Prospectus Supplement ABOUT THIS PROSPECTUS SUPPLEMENTPROSPECTUS SUPPLEMENT SUMMARYTHE OFFERINGRISK FACTORSCAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSUSE OF PROCEEDSDIVIDEND POLICYDILUTIONDESCRIPTION OF PRE-FUNDED WARRANTSMATERIAL U.S. FEDERAL INCOME TAX CONSEQUENCES TO NON-U.S. HOLDERSUNDERWRITERSLEGAL MATTERSEXPERTSWHERE YOU CAN FIND MORE INFORMATIONINCORPORATION BY REFERENCE Prospectus ABOUT THIS PROSPECTUSCAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTSPROSPECTUS SUMMARYSECURITIES WE MAY OFFERRISK FACTORSUSE OF PROCEEDSDESCRIPTION OF CAPITAL STOCKDESCRIPTION OF DEBT SECURITIESDESCRIPTION OF WARRANTSDESCRIPTION OF UNITSTAXATIONPLAN OF DISTRIBUTIONLEGAL MATTERSEXPERTSWHERE YOU CAN FIND MORE INFORMATIONINCORPORATION BY REFERENCE Table of Contents ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the specific terms of this offering of common stockand pre-funded warrants and also adds to and updates information contained in the accompanying prospectus and the documents incorporated byreference into this prospectus supplement and the accompanying prospectus. The second part is the accompanying prospectus dated July13, 2026,included in our registration statement on Form S-3, along with the documents incorporated by reference therein, which provides more generalinformation, some of which may not apply to this offering. Generally, when we refer