Spyre Therapeutics Inc. (NASDAQ: SYRE) announced it has commenced an underwritten public offering of $300 million of common stock shares. The biotechnology company also expects to grant underwriters a 30-day option to purchase an additional $45 million of shares at the public offering price, less underwriting discount.

The Waltham, Massachusetts-based company focuses on developing treatments for inflammatory bowel disease and other immune-mediated diseases through antibody engineering and therapeutic combinations. All shares in the offering will be sold by Spyre.

Jefferies LLC, Goldman Sachs & Co. LLC, Evercore ISI, and Guggenheim Securities LLC serve as joint book-running managers for the offering. LifeSci Capital LLC acts as passive bookrunner.

The offering remains subject to market and other conditions. The company stated there can be no assurance regarding whether or when the offering may be completed, or the actual size or terms of the final offering.

A registration statement on Form S-3 relating to the securities was filed with the Securities and Exchange Commission and became effective on February 27, 2026. The offering will be conducted through a prospectus supplement and accompanying prospectus.

Spyre's pipeline includes investigational extended half-life antibodies targeting α4β7, TL1A, and IL-23 for inflammatory bowel disease and other immune-mediated conditions.