---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-24-002452"
form_type: "8-K"
ticker: "ABUS"
cik: "0001447028"
company_name: "Arbutus Biopharma Corp"
filed_at: "2024-05-02T23:59:59+00:00"
generated_at: "2026-06-03T00:17:17.125044+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Arbutus CSO Michael Sofia to retire Dec 31, 2024; no successor named yet.

## Summary
- Dr. Michael Sofia, co-founder and Chief Scientific Officer, notified retirement effective December 31, 2024.
- Sofia is a Lasker award-winning antiviral drug discovery scientist with 38-year career.
- Interim CEO Michael McElhaugh thanked Sofia for contributions to HBV functional cure development.
- No replacement for CSO role announced; company continues clinical development.

## SEC filing metadata
- accession: 0001171843-24-002452
- form_type: 8-K
- ticker: ABUS
- cik: 0001447028
- company_name: Arbutus Biopharma Corp
- filed_at: 2024-05-02T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447028/000117184324002452/0001171843-24-002452-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447028/000117184324002452/f8k_050124.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-24-002452
- JSON: https://secwatch.observer/filing/0001171843-24-002452.json
- Plain text: https://secwatch.observer/filing/0001171843-24-002452.txt

## Key facts
- Executive change
  Michael Sofia departed as Chief Scientific Officer at Arbutus Biopharma Corp.
  - Action: notified retirement
  - Role: Chief Scientific Officer
  source text: On May 1, 2024, Dr. Michael Sofia notified Arbutus Biopharma Corporation (the “Company”) of his retirement as Chief Scientific Officer of the Company, effective December 31, 2024.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1447028/000117184324002452/0001171843-24-002452-index.htm

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