Business Description

1. Nature of the Business Q32 Bio Inc. (“Q32” or the “Company”) is a clinical stage biotechnology company focused on developing novel biologics to effectively and safely restore healthy immune balance in patients with autoimmune and inflammatory diseases driven by pathological immune dysfunction. Q32 has multiple product candidates across a variety of autoimmune and inflammatory diseases. The Company was formed in 2017 as Admirx, Inc. under the laws of the state of Delaware and is headquartered in Waltham, Massachusetts. On March 20, 2020, the Company changed its name to Q32 Bio Inc. Sale of ADX-097 On November 28, 2025, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Q32 Bio Operations Inc., a wholly-owned subsidiary of the Company (“Q32 Bio Operations” and, together with the Company, the “Seller”), and Akebia Therapeutics, Inc. (“Akebia”) pursuant to which the Seller sold to Akebia substantially all of the Seller’s assets related to the research, development, manufacture and commercialization of ADX-097 (the “ADX-097 Asset Sale”). Following the ADX-097 Asset Sale, Akebia will be responsible for any future development and commercialization of ADX-097 (see Note 4 for more details surrounding the accounting for the ADX-097 Asset Sale). Merger with Homology On March 25, 2024, Kenobi Merger Sub, Inc. (“Merger Sub”), a wholly-owned subsidiary of Homology Medicines, Inc. (“Homology”), completed its merger with and into Q32 Bio Operations Inc. (previously named Q32 Bio Inc. and also referred to herein as “Legacy Q32”), with Legacy Q32 continuing as the surviving entity as a wholly-owned subsidiary of Homology. This transaction is referred to as the “Merger.” Homology changed its name to Q32 Bio Inc., and Legacy Q32, which remains as a wholly-owned subsidiary of the Company, changed its name to Q32 Bio Operations, Inc. The Merger was effected pursuant to an Agreement and Plan of Merger (the “Merger Agreement”), dated as of November 16, 2023, by and among Homology, Legacy Q32, and Merger Sub. In connection with the Merger Agreement, certain parties entered into a subscription agreement with the Company to purchase shares of Legacy Q32’ s common stock for an aggregate purchase price of $ 42.0 million (the “Pre-Closing Financing”). On March 25, 2024 (the “Closing Date”), the Pre-Closing Financing closed immediately prior to the consummation of the Merger. Shares of Legacy Q32’s common stock issued pursuant to the Pre-Closing Financing were converted into the right to receive 1,682,045 shares of Homology common stock after taking into account the Reverse Stock Split. On March 25, 2024, Homology effected a one-for-eighteen reverse stock split of its then outstanding common stock (the “Reverse Stock Split”) where all issued and outstanding shares of Legacy Q32’s common stock (including common stock issued upon the conversion of all Legacy Q32’s Series A, Series A-1 and Series B preferred stock, conversion of Legacy Q32 convertible notes, but excluding the common stock issued in Pre-Closing Financing) converted into the right to receive an aggregate of 7,017,842 shares of Homology’s common stock based on the final exchange ratio of 0.0480 (the “Exchange Ratio”). Lastly, each option to purchase the Legacy Q32’s shares that was outstanding and unexercised immediately prior to the Merger was converted into an option to purchase shares of Homology based on the Exchange Ratio. Immediately following the Merger, Legacy Q32 stockholders owned approximately 74.4 % of the outstanding common stock of the combined company. The Merger was accounted for as a reverse recapitalization in accordance with accounting principles generally accepted in the United States of America (“GAAP”). For accounting purposes, Legacy Q32 is considered the accounting acquirer and Homology is the acquired company based on the terms of the Merger Agreement and other factors, such as relative voting rights and the composition of the combined company’s board of directors and senior management. Accordingly, the Merger was treated as the equivalent of Legacy Q32’s issuing stock to acquire the net assets of Homology. As a result of the Merger, the net assets of Homology were recorded at their acquisition-date fair value in the financial statements of the combined company and the reported operating results prior to the Merger are those of Legacy Q32.…