---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-210825"
form_type: "8-K"
ticker: "MBX"
cik: "0001776111"
company_name: "MBX Biosciences, Inc."
filed_at: "2026-05-07T23:59:59+00:00"
generated_at: "2026-05-14T21:56:42.449021+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# MBX Biosciences Q1 net loss $23.5M; Phase 3 canvuparatide start on track for Q3 2026

## Summary
- Cash, equivalents and marketable securities of $440M; expected to fund operations into 2029.
- R&D expenses $18.5M (down from $22.4M YoY); G&A expenses $8.8M (up from $4.1M YoY).
- Phase 3 trial of once-weekly canvuparatide for hypoparathyroidism to initiate in Q3 2026 after successful FDA End-of-Phase 2 meeting.
- Appointed Mark Soued as Chief Commercial Officer; he led Alnylam's US amyloidosis business and AMVUTTRA launch.
- Obesity Day on May 11 to present initial blinded MBX 4291 Phase 1 data; amycretin prodrug nomination expected this quarter.

## SEC filing metadata
- accession: 0001193125-26-210825
- form_type: 8-K
- ticker: MBX
- cik: 0001776111
- company_name: MBX Biosciences, Inc.
- filed_at: 2026-05-07T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1776111/000119312526210825/0001193125-26-210825-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1776111/000119312526210825/mbx-20260507.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-210825
- JSON: https://secwatch.observer/filing/0001193125-26-210825.json
- Plain text: https://secwatch.observer/filing/0001193125-26-210825.txt

## Key facts
- Earnings Releases
  MBX Biosciences, Inc. reported first quarter ended March 31, 2026 results: net income Net loss for the three months ended March 31, 2026, was $23.5 million.
  - Period: first quarter ended March 31, 2026
  - Net income: Net loss for the three months ended March 31, 2026, was $23.5 million
  - Result: reported results
  source text: Net loss for the three months ended March 31, 2026, was $23.5 million compared to a net loss of $23.9 million for the same period in 2025.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1776111/000119312526210825/0001193125-26-210825-index.htm

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