---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-218290"
form_type: "8-K/A"
ticker: "MREO"
cik: "0001719714"
company_name: "Mereo BioPharma Group plc"
filed_at: "2026-05-12T12:56:29+00:00"
generated_at: "2026-05-12T13:05:41.296341+00:00"
event_type: "earnings"
sentiment: "negative"
materiality_score: 0.95
calibrated_materiality_score: 0.95
confidence: "high"
source: SEC EDGAR
---

# Mereo BioPharma Q1 net loss $6.7M; setrusumab Phase 3 fails primary endpoint, regulator engagement begun

## Summary
- Net loss of $6.7M in Q1 2026 vs $12.9M in Q1 2025; cash and equivalents $36.2M as of March 31, 2026.
- Setrusumab Phase 3 studies in OI did not meet primary fracture-rate endpoints; high significance on BMD, vertebral fracture reduction, and PROs.
- Mereo and partner Ultragenyx initiated regulatory discussions for pediatric OI path; no approved therapies exist.
- Alvelestat partnership discussions active; single Phase 3 trial of ~220 patients with SGRQ (US) and lung density (EU) endpoints planned.

## SEC filing metadata
- accession: 0001193125-26-218290
- form_type: 8-K/A
- ticker: MREO
- cik: 0001719714
- company_name: Mereo BioPharma Group plc
- filed_at: 2026-05-12T12:56:29+00:00
- event_type: earnings
- sentiment: negative
- materiality_score: 0.95
- calibrated_materiality_score: 0.95
- confidence: high
- sec_items: 2.02, 2.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1719714/000119312526218290/0001193125-26-218290-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1719714/000119312526218290/mreo-20260512.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-218290
- JSON: https://secwatch.observer/filing/0001193125-26-218290.json
- Plain text: https://secwatch.observer/filing/0001193125-26-218290.txt

## Key facts
- Earnings Releases
  Mereo BioPharma Group plc reported first quarter ended March 31, 2026 results: net income $6.7 million. Guidance reaffirmed.
  - Period: first quarter ended March 31, 2026
  - Net income: $6.7 million
  - Guidance: reaffirmed
  - Result: reported results
  source text: Net loss for the first quarter of 2026 was $6.7 million
  evidence_url: https://www.sec.gov/Archives/edgar/data/1719714/000119312526218290/0001193125-26-218290-index.htm

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