# EDGAR Filing Document

**Accession Number:** 0001636282
**File Stem:** 0001628280-26-012785
**Filing Date:** 2026-2
**Character Count:** 7139
**Document Hash:** 42b8cd92147c7b8e64d6acd7cff05177
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001628280-26-012785.hdr.sgml**: 20260227

**ACCESSION NUMBER**: 0001628280-26-012785

**CONFORMED SUBMISSION TYPE**: POS AM

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260227

**DATE AS OF CHANGE**: 20260227

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Spyre Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001636282
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 464312787
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** POS AM
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-285341
- **FILM NUMBER:** 26699471

**BUSINESS ADDRESS:**
- **STREET 1:** 221 CRESCENT STREET
- **STREET 2:** BUILDING 23, SUITE 105
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02453
- **BUSINESS PHONE:** 6176515940

**MAIL ADDRESS:**
- **STREET 1:** 221 CRESCENT STREET
- **STREET 2:** BUILDING 23, SUITE 105
- **CITY:** WALTHAM
- **STATE:** MA
- **ZIP:** 02453

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Aeglea BioTherapeutics, Inc.
- **DATE OF NAME CHANGE:** 20150311

**As filed with the Securities and Exchange Commission on February 27, 2026.**

**Registration No. 333-285341**

**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**Washington, D.C. 20549**

**FORM S-3**

**(Post-Effective Amendment No. 1)**

**REGISTRATION STATEMENT**

***UNDER***

***THE SECURITIES ACT OF 1933***

**Spyre Therapeutics, Inc.**

(Exact name of registrant as specified in its charter)

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| | |
|:---|:---|
| **Delaware** | **46-4312787** |
| **(State or other jurisdiction of incorporation or organization)** | **(I.R.S. Employer Identification Number)** |

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**221 Crescent Street**

**Building 23, Suite 105**

**Waltham, MA 02453**

**(617) 651-5940**

**(Address, including zip code, and telephone number, including area code, of principal executive offices)**

**Heidy King-Jones** 

**Chief Legal Officer and Corporate Secretary** 

**Spyre Therapeutics, Inc.**

**221 Crescent Street**

**Building 23, Suite 105**

**Waltham, MA 02453** 

**(617) 651-5940** 

**(Name, address, including zip code, and telephone number, including area code, of agent for service)**

***Copies to:***

**Thomas Danielski**

**Ropes & Gray LLP**

**Prudential Tower**

**800 Boylston St.**

**Boston, Massachusetts 02199**

**(617) 951-7000**

Approximate date of commencement of proposed sale to the public: This post-effective amendment No. 1 deregisters those securities that remain unsold hereunder as of the effective date hereof.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, as amended, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box: ☐

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):

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| | | | |
|:---|:---|:---|:---|
| Large accelerated filer | ☒ | Accelerated filer | ☐ |
| Non-accelerated filer | ☐ | Smaller reporting company | ☐ |
| | | Emerging growth company | ☐ |

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If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. ☐

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**EXPLANATORY NOTE** 

**DEREGISTRATION OF SECURITIES**

This Post-Effective Amendment No. 1 (this "Amendment") relates to the following Registration Statement on Form S-3 (the "Registration Statement"), filed by Spyre Therapeutics, Inc., a Delaware corporation (the "Company"), with the Securities and Exchange Commission:

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;• Registration Statement No. 333-285341, initially filed on February 27, 2025 and declared effective on March 7, 2025, utilizing a "shelf" registration process to offer and sell in one or more offerings from time to time up to a maximum aggregate offering price of $500,000,000 in securities and to register for issuance and sale, up to a maximum aggregate offering price of $179,059,869 of common stock that may be issued and sold under a sales agreement, dated September 6, 2024, with TD Securities (USA) LLC, or TD Cowen.

The Company has terminated all offerings of securities pursuant to the Registration Statement. In accordance with the undertakings made by the Company in the Registration Statement to remove from registration, by means of a post-effective amendment, any of the securities that had been registered for issuance that remain unsold at the termination of such offering, the Company hereby removes from registration by means of this Amendment, all of such securities registered but unsold under the Registration Statement.

In reliance upon Rule 478, under the Securities Act no other person is required to sign this Amendment.

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**SIGNATURES**

Pursuant to the requirements of the Securities Act of 1933, as amended, the Company certifies that it has reasonable grounds to believe that it meets all of the requirements for filing on Form S-3 and has duly caused this Amendment to be signed on its behalf by the undersigned, thereunto duly authorized, in the City of Waltham, Commonwealth of Massachusetts, on February 27, 2026.

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| | |
|:---|:---|
| **Spyre Therapeutics, Inc.** | **Spyre Therapeutics, Inc.** |
| By: | /s/ Cameron Turtle, DPhil |
|  | Cameron Turtle, DPhil |
|  | Chief Executive Officer |
|  | (Principal Executive Officer) |

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