# EDGAR Filing Document

**Accession Number:** 0001733294
**File Stem:** 0001104659-26-017534
**Filing Date:** 2026-2
**Character Count:** 2725
**Document Hash:** 3497e7bdcbecc132fd07116ae5e0b323
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001104659-26-017534.hdr.sgml**: 20260219

**ACCESSION NUMBER**: 0001104659-26-017534

**CONFORMED SUBMISSION TYPE**: 15-12G

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260219

**DATE AS OF CHANGE**: 20260219

**EFFECTIVENESS DATE**: 20260219

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Generation Bio Co.
- **CENTRAL INDEX KEY:** 0001733294
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 814301284
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** 15-12G
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-39319
- **FILM NUMBER:** 26654307

**BUSINESS ADDRESS:**
- **STREET 1:** 301 BINNEY STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
- **BUSINESS PHONE:** 857-529-5908

**MAIL ADDRESS:**
- **STREET 1:** 301 BINNEY STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142

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**UNITED STATES**

**SECURITIES AND EXCHANGE COMMISSION**

**WASHINGTON, D.C. 20549**

**FORM 15**

**CERTIFICATION AND NOTICE OF TERMINATION OF REGISTRATION**

**UNDER SECTION 12(g) OF THE SECURITIES EXCHANGE ACT OF 1934**

**OR SUSPENSION OF DUTY TO FILE REPORTS UNDER SECTIONS 13 AND 15(d) OF THE**

**SECURITIES EXCHANGE ACT OF 1934.**

**Commission File Number: 001-39319**

**Generation Bio Co.**

(Exact name of registrant as specified in its charter)

**2200 Powell Street, Suite 310**

**Emeryville, California 94608**

**(510) 204-7200**

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

**Common Stock, par value $0.0001 per share**

**(Title of each class of securities covered by this Form)**

**None**

**(Titles of all other classes of securities for which a duty to file reports under Section 13(a) or 15(d) remains)**

Please place an X in the box(es) to designate the appropriate rule provision(s) relied upon to terminate or suspend the duty to file reports:

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| | |
|:---|:---|
| Rule 12g-4(a)(l) | ☒ |
| Rule 12g-4(a)(2) | ☐ |
| Rule 12h-3(b)(l)(i) | ☒ |
| Rule 12h-3(b)(l)(ii) | ☐ |
| Rule 15d-6 | ☐ |
| Rule 15d-22(b) | ☐ |

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Approximate number of holders of record as of the certification or notice date: one (1) holder.

Pursuant to the requirements of the Securities Exchange Act of 1934, Generation Bio Co. has caused this certification/notice to be signed on its behalf by the undersigned duly authorized person.

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| | | |
|:---|:---|:---|
|  | **Generation Bio Co.** | **Generation Bio Co.** |
|  | By: | /s/ Owen Hughes |
|  | Name:  | Owen Hughes |
|  | Title:  | President, Treasurer and Secretary |
| Date: February 19, 2026 |  |  |

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