Sec Form 4 Filing - Burrows Scott L @ Spyre Therapeutics, Inc. - 2026-03-03

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person Burrows Scott L 2. Issuer Name and Ticker or Trading Symbol Spyre Therapeutics, Inc. [ SYRE] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner X __ Officer (give title below) _____ Other (specify below) Chief Financial Officer (Last) (First) (Middle) 221 CRESCENT STREET, BUILDING 23,, SUITE 105 3. Date of Earliest Transaction (MM/DD/YY) 03/03/2026 (Street) WALTHAM, MA02453 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) __ X __ Form filed by One Reporting Person _____ Form filed by More than One Reporting Person (City) (State) (Zip)

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned 1.Title of Security (Instr. 3) 2. Transaction Date (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/03/2026 M( 1 ) 2,500 A $ 14.5 100,494 D Common Stock 03/03/2026 S( 1 ) 2,300 D $ 40.56 ( 2 ) 98,194 D Common Stock 03/03/2026 S( 1 ) 200 D $ 41.66 ( 3 ) 97,994 ( 4 ) D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned ( e.g. , puts, calls, warrants, options, convertible securities) 1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5) 6. Date Exercisable and Expiration Date (MM/DD/YY) 7. Title and Amount of Underlying Securities (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4) Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares Stock Option (Right to Buy) $ 14.5 03/03/2026 M( 1 ) 2,500 ( 5 ) 09/01/2033 Common Stock 2,500 $ 0 402,357 D

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other Burrows Scott L 221 CRESCENT STREET, BUILDING 23, SUITE 105 WALTHAM, MA02453 Chief Financial Officer Signatures /s/ Heidy King-Jones, as Attorney-in-Fact 03/03/2026 Signature of Reporting Person Date

Explanation of Responses:

( 1 )This transaction was executed pursuant to a Rule 10b5-1 trading plan adopted on November 10, 2025. ( 2 )The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $40.17 to $41.11, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission (the "SEC"), upon request, full information regarding the number of shares sold at each separate price within the range. ( 3 )The price reported above is a weighted average price. The shares were sold in multiple transactions at prices ranging from $41.55 to $41.76, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the SEC, upon request, full information regarding the number of shares sold at each separate price within the range. ( 4 )Includes 67,476 restricted stock units ("RSUs"). Each RSU represents a contingent right to receive, upon vesting, one share of Common Stock. The RSUs vest in two equal installments on each of September 1, 2026 and 2027, subject to the Reporting Person's continued employment with the Issuer. ( 5 )This option represents a right to purchase 404,857 shares of the Issuer's common stock (which have been adjusted to reflect the Issuer's 1-for-25 reverse stock split on September 8, 2023), one quarter of which vested and became exercisable on September 1, 2024, with the remaining three quarters vesting in monthly installments over the following three years, subject to the Reporting Person's continued employment with the Issuer.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).

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