---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-002555"
form_type: "8-K"
ticker: "MBX"
cik: "0001776111"
company_name: "MBX Biosciences, Inc."
filed_at: "2025-01-07T23:59:59+00:00"
generated_at: "2026-05-28T08:50:30.849019+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# MBX Biosciences announces positive Phase 1 topline results for MBX 1416 for PBH; cash $262.1M

## Summary
- MBX 1416 generally well-tolerated; no dose-related serious adverse events; mild/moderate ISRs in 88% resolved ~7 days.
- Median half-life ~90 hours supports once-weekly dosing; Tmax 36-48h at steady state; dose-proportional PK.
- GLP-1 increase within 60 mins of mixed meal test; slight acceleration of gastric emptying observed.
- No meaningful effect on rosuvastatin exposure in drug-drug interaction portion.
- Phase 2 in PBH patients expected to start 2H 2025; cash $262.1M as of Dec 31, 2024.

## SEC filing metadata
- accession: 0000950170-25-002555
- form_type: 8-K
- ticker: MBX
- cik: 0001776111
- company_name: MBX Biosciences, Inc.
- filed_at: 2025-01-07T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1776111/000095017025002555/0000950170-25-002555-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1776111/000095017025002555/mbx-20250107.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-002555
- JSON: https://secwatch.observer/filing/0000950170-25-002555.json
- Plain text: https://secwatch.observer/filing/0000950170-25-002555.txt

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