---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-26-000303"
form_type: "8-K"
ticker: "ABUS"
cik: "0001447028"
company_name: "Arbutus Biopharma Corp"
filed_at: "2026-01-16T23:59:59+00:00"
generated_at: "2026-05-16T09:45:49.609541+00:00"
event_type: "litigation"
sentiment: "negative"
materiality_score: 0.75
calibrated_materiality_score: 0.75
confidence: "high"
source: SEC EDGAR
---

# EPO revokes Arbutus' European patent EP 2279254; company plans appeal

## Summary
- EPO Board of Appeal revoked Arbutus' European patent EP 2279254 on Jan 15, 2026; verbal decision without reasons; written decision expected in months.
- Opposition originally filed by Moderna affiliates and Merck in April 2018; two prior EPO decisions had upheld amended patent.
- Company plans to petition EPO Enlarged Board of Appeal upon receipt of written decision; decision affects cases vs Moderna in Switzerland and UPC Case UPC_CFI_191/2025.
- Decision does not impact litigations in US, Japan, Canada, other UPC case (UPC_CFI_192/2025), or cases against Pfizer/BioNTech.
- Company notes added-matter standard used by EPO does not apply in US or other jurisdictions; no impact on other patent cases.

## SEC filing metadata
- accession: 0001171843-26-000303
- form_type: 8-K
- ticker: ABUS
- cik: 0001447028
- company_name: Arbutus Biopharma Corp
- filed_at: 2026-01-16T23:59:59+00:00
- event_type: litigation
- sentiment: negative
- materiality_score: 0.75
- calibrated_materiality_score: 0.75
- confidence: high
- sec_items: 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447028/000117184326000303/0001171843-26-000303-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447028/000117184326000303/f8k_011626.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-26-000303
- JSON: https://secwatch.observer/filing/0001171843-26-000303.json
- Plain text: https://secwatch.observer/filing/0001171843-26-000303.txt

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