# EDGAR Filing Document

**Accession Number:** 0001776111
**File Stem:** 9999999995-25-003084
**Filing Date:** 2025-9
**Character Count:** 1323
**Document Hash:** c0a8203ede80d334f6747df278e95869
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**9999999995-25-003084.hdr.sgml**: 20250925

**ACCESSION NUMBER**: 9999999995-25-003084

**CONFORMED SUBMISSION TYPE**: EFFECT

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250924

**DATE AS OF CHANGE**: 20250925

**EFFECTIVENESS DATE**: 20250924

**FILER**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** MBX Biosciences, Inc.
- **CENTRAL INDEX KEY:** 0001776111
- **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:** EFFECT
- **SEC ACT:** 1933 Act
- **SEC FILE NUMBER:** 333-290447
- **FILM NUMBER:** 251340143

**BUSINESS ADDRESS:**
- **STREET 1:** 11711 N. MERIDIAN STREET
- **STREET 2:** SUITE 300
- **CITY:** CARMEL
- **STATE:** IN
- **ZIP:** 46032
- **BUSINESS PHONE:** 3179893100

**MAIL ADDRESS:**
- **STREET 1:** 11711 N. MERIDIAN STREET
- **STREET 2:** SUITE 300
- **CITY:** CARMEL
- **STATE:** IN
- **ZIP:** 46032

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

## Notice of Effectiveness

**Date:** September 24, 2025

**Time:** 16:00:00

**Form Type:** S-1

---

**CIK:** 0001776111

**Company Name:** MBX Biosciences, Inc.

**File Number:** 333-290447