Spyre Therapeutics, Inc.

Trading Plans

During the three months ended September 30, 2026, no director or Section 16 officer adopted orterminated any Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement (in each case, as defined in Item 408(a) of Regulation S-K).

Amendment to Certificate of Incorporation

The information set forth below is included herewith for the purpose of providing the disclosures required under “Item 5.03 - Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year” of Form 8-K.

On October 29, 2026, the Company filed with the Secretary of State of the State of Delaware (i) a Corrected Second Amended and Restated Certificate of Incorporation (the “Corrected COI”) to correct the inadvertent omission from its Second Amended and Restated Certificate of Incorporation of the Series A Certificate of Designation and the Series B Certificate of Designation and (ii) and Certificate of Elimination of Series B Non-Voting Convertible Preferred Stock (the “Series B Preferred Stock”) (the “Series B Certificate of Elimination” and, together with the Corrected COI, the “COI Amendment”) to effect the retirement of its Series B Preferred Stock, which resulted in the previously authorized shares of the retired Series B Preferred Stock being returned to authorized, unissued and undesignated preferred stock.

The foregoing description of the COI Amendment does not purport to be complete and is subject to and qualified in its entirety by reference to the full text of the Corrected COI and Series B Certificate of Elimination, copies of which are attached hereto as Exhibits 3.1 and 3.3 and incorporated herein by reference.

Amendments to Executive Offer Letters

The information set forth below is included herewith for the purpose of providing the disclosures required under “Item 5.02 - Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers” of Form 8-K.

On November 2, 2026, the Company and each of Dr. Cameron Turtle, Mr. Scott Burrows, Ms. Heidy King-Jones and Dr. Sheldon Sloan amended and restated their respective employment letter agreement (the “Amendments”). The Amendments provide for, among other ministerial changes, (i) an increase to Dr. Turtle’s CIC Severance Amount (as defined therein) from 18 months of base salary plus 1.5x his target bonus to 24 months of base salary plus 2.0x his target bonus and an increase to his benefits continuation on a qualifying termination during the Change in Control Period (as defined therein) from 18 months to 24 months, (ii) an increase to each of Mr. Burrows’ and Ms. King-Jones’ CIC Severance Amount (as defined therein) by 0.5x of their respective target bonuses; and (iii) an increase to Dr. Sloan’s Severance Amount (as defined therein) from 9 months to 12 months of base salary, an increase to his benefits continuation on a qualifying termination outside of the Change in Control Period (as defined therein) from 9 months to 12 months, an increase in his CIC Severance Amount (as defined therein) from 12 months of base salary plus 1.0x his target bonus to 18 months of base salary plus 1.5x his target bonus, and an increase to his benefits continuation on a qualifying termination during the Change in Control Period from 12 months to 18 months.

The foregoing description of the Amendments does not purport to be complete and is subject to and qualified in its entirety by reference to the full text of the Amendments, copies of which are attached hereto as Exhibits 10.1, 10.2, 10.3 and 10.4 and incorporated herein by reference.