# EDGAR Filing Document

**Accession Number:** 0001701108
**File Stem:** 0001193125-26-182287
**Filing Date:** 2026-4
**Character Count:** 1297
**Document Hash:** acbab5d88dcf9c1b057a1dbd7de75206
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0001193125-26-182287.hdr.sgml**: 20260427

**ACCESSION NUMBER**: 0001193125-26-182287

**CONFORMED SUBMISSION TYPE**: ARS

**PUBLIC DOCUMENT COUNT**: 1

**CONFORMED PERIOD OF REPORT**: 20251231

**FILED AS OF DATE**: 20260427

**DATE AS OF CHANGE**: 20260427

**EFFECTIVENESS DATE**: 20260427

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Spero Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001701108
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** ARS
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 001-38266
- **FILM NUMBER:** 26901683

**BUSINESS ADDRESS:**
- **STREET 1:** 675 MASSACHUSETTS AVENUE
- **STREET 2:** 14TH FLOOR
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139
- **BUSINESS PHONE:** 857-242-1600

**MAIL ADDRESS:**
- **STREET 1:** 675 MASSACHUSETTS AVENUE
- **STREET 2:** 14TH FLOOR
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02139

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** Spero Therapeutics, LLC
- **DATE OF NAME CHANGE:** 20170316

### Attached PDF Documents

**Attachment 1:** `d22424dars.pdf`

_No text found in this document._