---
schema_version: "secwatch.filing_event.v1"
accession: "0001171843-23-006795"
form_type: "8-K"
ticker: "ABUS"
cik: "0001447028"
company_name: "Arbutus Biopharma Corp"
filed_at: "2023-11-07T23:59:59+00:00"
generated_at: "2026-06-08T14:33:57.794381+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Arbutus Biopharma CEO William Collier to retire Dec 31; COO McElhaugh named interim CEO

## Summary
- William H. Collier retires as President, CEO, and director effective Dec 31, 2023.
- Michael J. McElhaugh, Co-founder and COO, appointed interim President and CEO effective Jan 1, 2024.
- McElhaugh will also join the Board on Jan 1, 2024.
- Collier's retirement is not due to any disagreement with the company.

## SEC filing metadata
- accession: 0001171843-23-006795
- form_type: 8-K
- ticker: ABUS
- cik: 0001447028
- company_name: Arbutus Biopharma Corp
- filed_at: 2023-11-07T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1447028/000117184323006795/0001171843-23-006795-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1447028/000117184323006795/f8k_110723.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001171843-23-006795
- JSON: https://secwatch.observer/filing/0001171843-23-006795.json
- Plain text: https://secwatch.observer/filing/0001171843-23-006795.txt

## Key facts
- Executive change
  William H. Collier retired as President and Chief Executive Officer at Arbutus Biopharma Corp.
  - Action: retired
  - Role: President and Chief Executive Officer
  source text: On November 1, 2023, William H. Collier informed Arbutus Biopharma Corporation (the “Company”) of his retirement as the Company’s Chief Executive Officer (“CEO”) and from the Board of Directors (the “Board”) of the Company, effective as of December 31, 2023.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1447028/000117184323006795/0001171843-23-006795-index.htm
- Executive change
  Michael J. McElhaugh was appointed as Interim President and Chief Executive Officer at Arbutus Biopharma Corp.
  - Action: appointed
  - Role: Interim President and Chief Executive Officer
  source text: the Board appointed Michael J. McElhaugh, Co-founder and Chief Operating Officer of the Company, as interim President and CEO, effective January 1, 2024.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1447028/000117184323006795/0001171843-23-006795-index.htm

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