---
schema_version: "secwatch.filing_event.v1"
accession: "0000950170-25-069811"
form_type: "8-K"
ticker: "MREO"
cik: "0001719714"
company_name: "Mereo BioPharma Group plc"
filed_at: "2025-05-13T23:59:59+00:00"
generated_at: "2026-05-21T16:39:05.279965+00:00"
event_type: "earnings"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Mereo BioPharma Q1 net loss $12.9M; setrusumab Phase 3 Orbit on track for mid-year readout

## Summary
- Net loss widened to $12.9M (Q1 2024: $9.0M) on operating loss of $11.2M.
- Cash and equivalents $62.5M at March 31, 2025, down from $69.8M at year-end; runway into 2027.
- R&D expenses $3.9M, flat YoY; setrusumab costs increased $1.3M offset by alvelestat decrease.
- Phase 3 Orbit study of setrusumab in OI on track for second interim mid-2025 or final Q4 2025.
- Alvelestat granted EU orphan designation for alpha-1 antitrypsin deficiency lung disease.

## SEC filing metadata
- accession: 0000950170-25-069811
- form_type: 8-K
- ticker: MREO
- cik: 0001719714
- company_name: Mereo BioPharma Group plc
- filed_at: 2025-05-13T23:59:59+00:00
- event_type: earnings
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 2.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1719714/000095017025069811/0000950170-25-069811-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1719714/000095017025069811/mreo-20250513.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000950170-25-069811
- JSON: https://secwatch.observer/filing/0000950170-25-069811.json
- Plain text: https://secwatch.observer/filing/0000950170-25-069811.txt

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