Spyre Therapeutics, Inc. ("Spyre" or the "Company") (NASDAQ:SYRE), a clinical-stage biotechnology company advancing best-in-class antibody engineering, dose optimization, and rational therapeutic combinations for the treatment of Inflammatory Bowel Disease ("IBD") and other immune-mediated diseases, today announced that it has commenced an underwritten public offering of $300.0 million of shares of its common stock. In addition, the Company is expected to grant the underwriters of the offering an option for a period of 30 days to purchase an additional $45.0 million of shares of common stock at the public offering price, less the underwriting discount. All of the shares of common stock in the offering will be sold by Spyre.