The Company and Basis of Presentation

12 Months Ended

Dec. 31, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

The Company and Basis of Presentation

The Company and Basis of Presentation

Spyre Therapeutics, Inc., formerly Aeglea BioTherapeutics, Inc., (“Spyre” or the “Company”) is a clinical stage biotechnology company focused on developing next generation therapeutics for patients living with inflammatory bowel disease and other immune-mediated diseases. The Company was formed as a Limited Liability Company ("LLC") in Delaware on December 16, 2013 under the name Aeglea BioTherapeutics Holdings, LLC and was converted from a Delaware LLC to a Delaware corporation on March 10, 2015. On November 27, 2023, the Company completed its corporate rebranding, changing the name of the Company to Spyre Therapeutics, Inc. The Company operates in one segment and has its principal offices in Waltham, Massachusetts.

On September 8, 2023, the Company effected a reverse stock split of its common stock at a ratio of 1-for-25 (the “Reverse Split”). Except as indicated otherwise, all share numbers related to the Company's common stock disclosed in these financial statements have been adjusted on a post-Reverse Split basis.

On April 12, 2023, based on the review of the inconclusive interim results from the Company's Phase 1/2 clinical trial of pegtarviliase for the treatment of Classical Homocystinuria and other business considerations, the Company announced that it had initiated a process to explore strategic alternatives to maximize stockholder value and engaged an independent exclusive financial advisor to support this process. As a result, in April 2023, the Company implemented a restructuring plan resulting in an approximate 83% reduction of the Company’s existing headcount.

On June 22, 2023, the Company acquired, in accordance with the terms of the Agreement and Plan of Merger (the "Acquisition Agreement"), the assets of Spyre Therapeutics, Inc. (“Pre-Merger Spyre”) as disclosed in Note 7 and 8, a privately held biotechnology company advancing a pipeline of antibody therapeutics with the potential to transform the treatment of inflammatory bowel disease through a research and development option agreement ("Paragon Agreement") with Paragon Therapeutics ("Paragon"). The asset acquisition was accomplished through a two-step reverse triangular merger whereby Aspen Merger Sub I, Inc., a Delaware corporation and a wholly owned subsidiary of the Company ("First Merger Sub"), merged with and into Pre-Merger Spyre, which existed at the time the Acquisition Agreement was entered into, became a wholly owned subsidiary of the Company in accordance with the terms of the Acquisition Agreement. Immediately following this merger, Pre-Merger Spyre merged with and into Sequoia Merger Sub II, LLC, a Delaware limited liability company and a wholly subsidiary of the Company (“Second Merger Sub”), in accordance with the terms of the Acquisition Agreement and Pre-Merger Spyre ceased to exist. Subsequently, Aeglea BioTherapeutics, Inc. was renamed Spyre Therapeutics, Inc. and is a different entity than Pre-Merger Spyre, which ceased to exist upon merging with Second Merger Sub. The transaction was structured as a stock-for-stock transaction pursuant to which all of Pre-Merger Spyre's outstanding equity interests were exchanged based on a fixed exchange ratio of 0.5494488 to 1 for consideration from the Company of 517,809 shares of common stock and 364,887 shares of Series A non-voting convertible preferred stock, par value of $0.0001 per share ("Series A Preferred Stock") (convertible on a 40 to 1 basis), in addition to the assumption of outstanding and unexercised stock options to purchase 2,734 shares of common stock from the Amended and Restated Spyre 2023 Equity Incentive Plan (the "Asset Acquisition"). The common stock and Series A Preferred Stock related to the Asset Acquisition were issued to the Pre-Merger Spyre stockholders on July 7, 2023. For additional information, see Note 7.

In connection with the Asset Acquisition, on June 26, 2023, the Company completed a private placement of shares of Series A Preferred Stock (the “June 2023 PIPE” and, together with the Asset Acquisition, the "June 2023 Transactions") to a group of investors (the “June 2023 Investors”). The Company sold an aggregate of 721,452 shares of Series A Preferred Stock (the “June 2023 PIPE Securities”) at $291.08 per share for net proceeds of $197.3 million after deducting approximately $12.7 million of placement agent and other offering expenses. For additional information, see Note 12.

In connection with the Asset Acquisition, a non-transferable contingent value right ("CVR") was distributed to stockholders of record of the Company as of the close of business on July 3, 2023 (the "Legacy Stockholders"), but was not distributed to the holders of shares of common stock or Series A Preferred Stock issued to the former stockholders of Pre-Merger Spyre or June 2023 Investors in the June 2023 Transactions.

Holders of the CVRs will be entitled to receive certain cash payments from proceeds received by the Company prior to the third anniversary of the CVR Agreement, if any, related to the disposition or monetization of its legacy assets during the one-year period following the closing of the Asset Acquisition. For additional information, see Note 3.

On November 21, 2023, the Company's stockholders approved the conversion of the Company's Series A non-voting convertible preferred stock to common stock. For additional information, see Note 12.

On December 11, 2023, the Company completed a private placement of shares of common stock and Series B non-voting convertible preferred stock, par value of $0.0001 per share ("Series B Preferred Stock") (convertible on a 40 to 1 basis) (collectively, the “December 2023 PIPE”) to a group of investors (the “December 2023 PIPE Investors”). The Company sold an aggregate of 6,000,000 shares of its common stock at an offering price of $15.00 per share and 150,000 shares of Series B Preferred Stock (the “December 2023 PIPE Securities”) at $600.00 per share for net proceeds of approximately $169.1 million after deducting approximately $10.9 million of placement agent and other offering expenses. For additional information, see Note 12.

On March 20, 2024, the Company completed a private placement of Series B Preferred Stock (convertible on a 40 to 1 basis) (the “March 2024 PIPE”) to a group of investors. The Company sold 121,625 shares of Series B Preferred Stock at $1,480 per share. The net proceeds from this offering were approximately $168.9 million after deducting placement and offering costs of $11.2 million.

On April 23, 2024, the Company entered into an exchange agreement with Fairmount Healthcare Fund II L.P. (the “Stockholder”), pursuant to which the Stockholder agreed to exchange an aggregate of 90,992 shares of Series A Preferred Stock, for an aggregate of 3,639,680 shares of the Company's common stock (the “April 2024 Exchange”). The common stock issued in connection with the April 2024 Exchange was issued without registration under the Securities Act of 1933, as amended (the “Securities Act”) in reliance on the exemption from registration contained in Section 3(a)(9) of the Securities Act. The April 2024 Exchange closed on April 25, 2024, with 346,045 shares of Series A Preferred Stock remaining outstanding following the April 2024 Exchange.

On May 14, 2024, the Company's stockholders approved the issuance of its common stock upon conversion of the Company's Series B Preferred Stock to common stock. A total of 254,958 shares of Series B Preferred Stock automatically converted to 10,198,320 shares of common stock; 16,667 shares of Series B Preferred Stock did not automatically convert and remained outstanding as of December 31, 2025.

On September 6, 2024, the Company filed a new shelf registration statement on Form S-3 that was declared effective by the SEC for the potential offering, issuance and sale by the Company of up to $500.0 million of its common stock, preferred stock, debt securities, warrants and/or units consisting of all or some of these securities. Concurrent with the filing of the shelf-registration statement, the Company entered into a sales agreement, dated September 6, 2024, with TD Securities (USA) LLC (“TD Cowen”) ("Sales Agreement"), as its sales agent, pursuant to which the Company may issue and sell shares of its common stock for an aggregate offering price of up to $200.0 million under an at-the-market (“ATM”) offering program included in the shelf registration. During the year ended December 31, 2024, the Company sold an aggregate of 777,432 shares of common stock under the ATM resulting in aggregate net proceeds of approximately $20.5 million after deducting commissions paid to TD Cowen as sales agent and other offering costs.

On November 18, 2024, the Company entered into an underwriting agreement (the "November 2024 Underwriting Agreement") with Jefferies LLC, Goldman Sachs & Co. LLC, Evercore Group L.L.C. and Guggenheim Securities, LLC as representatives of the several underwriters (collectively, the "November 2024 Underwriters"), pursuant to which the Company sold an aggregate of 8,366,250 shares of its common stock, inclusive of 1,091,250 shares pursuant to the full exercise of the November 2024 Underwriters' over-allotment option, at a public offering price per share of $27.50, resulting in net proceeds of approximately $215.9 million after deducting approximately $14.2 million of underwriting discounts and other offering costs (the "November 2024 Offering"). The November 2024 Offering closed on November 20, 2024 and the over-allotment option was exercised in full on November 26, 2024 and closed on November 29, 2024.

In February 2025, the Company filed a new shelf registration statement on Form S-3 (the "February 2025 Shelf Registration Statement") that was declared effective by the SEC for the potential offering, issuance

and sale of up to $500.0 million of shares of common stock, preferred stock, debt securities, warrants and/or units consisting of all or some of these securities. Concurrent with the effectiveness of the February 2025 Shelf Registration Statement, the offering of unsold securities under a previous shelf registration statement on Form S-3 (File No. 333-281975), which was initially filed with the SEC on September 6, 2024 and became effective on September 18, 2024, was deemed terminated pursuant to Rule 415(a)(6) under the Securities Act. The February 2025 Shelf Registration Statement contains a sales agreement prospectus supplement covering the offering, issuance and sale by the Company of up to $179.1 million of shares of common stock that may be issued and sold under the Sales Agreement in connection with the ATM offering program. During the three and twelve months ended December 31, 2025, the Company sold an aggregate of 445,668 shares of common stock under the ATM offering program at an average price per share of $33.772 resulting in net proceeds of $14.8 million, after deducting sales agent commissions and other offering costs of $0.3 million. As of December 31, 2025, $164.1 million remained available for sale under the Sales Agreement. Subsequent to December 31, 2025 through February 12, 2026 the Company sold an aggregate of 296,396 shares of common stock under the ATM offering program at an average price per share of $33.566 resulting in net proceeds of $9.7 million after deducting sales agent commissions and other offering costs of $0.2 million.

On October 13, 2025, the Company entered into an underwriting agreement (the "October 2025 Underwriting Agreement") with Jefferies LLC, TD Securities (USA) LLC, Leerink Partners LLC and Stifel, Nicolaus & Company, Incorporated as representatives of the several underwriters (collectively, the "October 2025 Underwriters"), pursuant to which the Company sold an aggregate of 17,094,594 shares of its common stock, inclusive of 2,229,729 shares pursuant to the full exercise of the October 2025 Underwriters' over-allotment option, at a public offering price per share of $18.50, resulting in net proceeds of approximately $296.4 million after deducting approximately $19.9 million of underwriting discounts and other offering costs (the "October 2025 Offering"). The over-allotment option was exercised in full on October 14, 2025 and the transaction closed on October 15, 2025.

Liquidity

The Company is a clinical stage biotechnology company with a limited operating history, and due to its significant research and development expenditures, the Company has generated operating losses since its inception and has not generated any revenue from the commercial sale of any products. There can be no assurance that profitable operations will ever be achieved, and, if achieved, whether profitability can be sustained on a continuing basis.

Since its inception and through December 31, 2025, the Company has funded its operations by raising an aggregate of approximately $1.6 billion of gross proceeds from the sale and issuance of convertible preferred stock and common stock, pre-funded warrants, the collection of grant proceeds, and the licensing of its product rights for commercialization of pegzilarginase in Europe and certain countries in the Middle East. As of December 31, 2025, Spyre had an accumulated deficit of $1.1 billion, and cash, cash equivalents, and marketable securities of $756.5 million.

Based on current operating plans, the Company has sufficient resources to fund operations for at least one year from the issuance date of these financial statements with existing cash, cash equivalents, and marketable securities. The Company will need to secure additional financing in the future to fund additional research and development, and before a commercial drug can be produced, marketed and sold. If the Company is unable to obtain additional financing or generate license or product revenue, the lack of liquidity could have a material adverse effect on the Company.

Basis of Presentation

The consolidated financial statements have been prepared in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) as defined by the Financial Accounting Standards Board (“FASB”) and include the accounts of the Company and its wholly owned subsidiaries. All intercompany balances and transactions have been eliminated in consolidation.