Exhibit 99.1 SPY001, an anti-α4β7 antibody engineered for infrequent, subcutaneous dosing successfully completed a 28- day GLP toxicity study and remains on track to begin first-in-human studies in the second quarter of 2024, with interim proof-of-concept data expected year-end 2024 SPY002, an anti-TL1A antibody designed for enhanced potency to both TL1A monomers and trimers, and extended half-life compared to existing molecules, remains on track to begin first-in-human studies in the second half of 2024 Ra ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ____________________________ FORM 10-Q ____________________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR For the transition period from to Commission File Number: 001-37722 SPYRE THERAPEUTICS, INC. (Exact Name of Registrant as Specified in its Charter) ____________________________ Delaware 46-4312787 (State or other jurisdictio ...

Exhibit 99.1 Spyre Therapeutics Reports Fourth Quarter and Full Year 2023 Financial Results and Provides Corporate Update Announced corporate name change to Spyre Therapeutics; appointment of Cameron Turtle, DPhil, as Chief Executive Officer; and began trading on Nasdaq under the symbol "SYRE" SPY001, an anti-α4β7 antibody engineered for infrequent, subcutaneous dosing, demonstrated an updated half-life of 22 days, a greater than three-fold increase relative to vedolizumab in non-human primate pharmacokinet ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 _________________________________________________________ FORM 10-K x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from______ to Commission file number 001-37722 _________________________________________________________ SPY ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 ____________________________ FORM 10-Q ____________________________ (Mark One) x QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Exact Name of Registrant as Specified in its Charter) ____________________________ Delaware 46-4312787 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 221 Crescent Street Building 23, Suite 105 Waltham, MA 02453 For the ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-37722 AEGLEA BIOTHERAPEUTICS, INC. WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 OR (Exact Name of Registrant as Specified in its Charter) (State or other jurisdiction of incorpor ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 AEGLEA BIOTHERAPEUTICS, INC. (Exact Name of Registrant as Specified in its Charter) Delaware 46-4312787 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 805 Las Cimas Parkway Suite 100 Austin, TX 78746 For the quarterly period ended March 31, 2023 OR ☐ TRANSITION REPORT PURSUANT ...

aeglea Redefining the Possible. Human Enzyme Therapies for People with Rare Diseases Corporate Overview – March 2023 Nasdaq: AGLE Forward Looking Statements This presentation and the accompanying oral presentation contain "forward-looking" statements that are based on our management's beliefs and assumptions and on information currently available to management. Forward-looking statements include all statements other than statements of historical fact contained in this presentation, including information con ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file number 001-37722 AEGLEA BIOTHERAPEUTICS, INC. (Exact name of Registrant as specified in its charter) (State or Other Jurisdiction of Incorporation or Organizati ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, DC 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 001-37722 AEGLEA BIOTHERAPEUTICS, INC. (Exact Name of Registrant as Specified in its Charter) Delaware 46-4312787 (State or other juri ...