---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-219621"
form_type: "8-K"
ticker: "MBX"
cik: "0001776111"
company_name: "MBX Biosciences, Inc."
filed_at: "2024-09-16T23:59:59+00:00"
generated_at: "2026-05-31T04:39:01.203111+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.2
calibrated_materiality_score: 0.2
confidence: "high"
source: SEC EDGAR
---

# MBX Biosciences adopts amended charter and bylaws in connection with IPO

## Summary
- Fourth amended and restated certificate of incorporation filed; authorizes 500M shares of common stock.
- Authorizes 10M shares of undesignated preferred stock with board authority to issue in series.
- Eliminates all references to prior series of preferred stock from earlier charter.
- Amended and restated bylaws establish advance notice procedures for stockholder proposals and director nominations.
- Changes effective immediately prior to IPO consummation as previously disclosed in S-1.

## SEC filing metadata
- accession: 0001193125-24-219621
- form_type: 8-K
- ticker: MBX
- cik: 0001776111
- company_name: MBX Biosciences, Inc.
- filed_at: 2024-09-16T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.2
- calibrated_materiality_score: 0.2
- confidence: high
- sec_items: 5.03, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1776111/000119312524219621/0001193125-24-219621-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1776111/000119312524219621/d888081d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-219621
- JSON: https://secwatch.observer/filing/0001193125-24-219621.json
- Plain text: https://secwatch.observer/filing/0001193125-24-219621.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.