---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-332520"
form_type: "8-K"
ticker: "MREO"
cik: "0001719714"
company_name: "Mereo BioPharma Group plc"
filed_at: "2025-12-29T23:59:59+00:00"
generated_at: "2026-05-16T12:06:56.092470+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Mereo setrusumab Phase 3 trials miss primary fracture endpoints; BMD improvements seen

## Summary
- Neither ORBIT (placebo) nor COSMIC (bisphosphonate) achieved statistical significance on annualized clinical fracture rate.
- Both studies met secondary endpoint of bone mineral density (BMD) improvements with strong statistical significance.
- Cash balance $48.7M at Q3 2025; company reducing pre-commercial and manufacturing costs.
- Additional analyses underway; management cites low placebo fracture rate in ORBIT.
- Continued partnering discussions for alvelestat; pipeline programs with partners remain.

## SEC filing metadata
- accession: 0001193125-25-332520
- form_type: 8-K
- ticker: MREO
- cik: 0001719714
- company_name: Mereo BioPharma Group plc
- filed_at: 2025-12-29T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1719714/000119312525332520/0001193125-25-332520-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1719714/000119312525332520/mreo-20251229.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-332520
- JSON: https://secwatch.observer/filing/0001193125-25-332520.json
- Plain text: https://secwatch.observer/filing/0001193125-25-332520.txt

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