# EDGAR Filing Document

**Accession Number:** 0001733294
**File Stem:** 9999999995-26-000506
**Filing Date:** 2026-2
**Character Count:** 1251
**Document Hash:** d9d91d958d5be6297c22739ac671c1f4
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**9999999995-26-000506.hdr.sgml**: 20260211

**ACCESSION NUMBER**: 9999999995-26-000506

**CONFORMED SUBMISSION TYPE**: EFFECT

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20260210

**DATE AS OF CHANGE**: 20260211

**EFFECTIVENESS DATE**: 20260210

**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:** EFFECT
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-281335
- **FILM NUMBER:** 26618196

**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

### UNITED STATES
### SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## Notice of Effectiveness

**Date:** February 10, 2026

**Accession Number:** 0001104659-26-012151

**Form Type:** POS AM

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**CIK:** 0001733294

**Company Name:** Generation Bio Co.

**File Number:** 333-281335