---
schema_version: "secwatch.filing_event.v1"
accession: "0001326190-25-000053"
form_type: "8-K"
ticker: "ALT"
cik: "0001326190"
company_name: "Altimmune, Inc."
filed_at: "2025-10-03T23:59:59+00:00"
generated_at: "2026-05-17T04:42:53.441319+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.55
calibrated_materiality_score: 0.55
confidence: "high"
source: SEC EDGAR
---

# Altimmune appoints Christophe Arbet-Engels as CMO; Dr. Scott Harris to retire as Senior Strategic Advisor by Feb 2026

## Summary
- Dr. Scott Harris stepped down as CMO effective Oct 1, 2025; will serve as Senior Strategic Advisor until retirement on Feb 28, 2026.
- Christophe Arbet-Engels, MD, PhD joined as CMO effective Oct 1, 2025.
- Transition Agreement provides Harris continued salary, benefits, equity vesting, and FY2025 bonus eligibility subject to release and compliance.
- Harris's stock option exercise period extended to 12 months after separation date.

## SEC filing metadata
- accession: 0001326190-25-000053
- form_type: 8-K
- ticker: ALT
- cik: 0001326190
- company_name: Altimmune, Inc.
- filed_at: 2025-10-03T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.55
- calibrated_materiality_score: 0.55
- confidence: high
- sec_items: 5.02
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1326190/000132619025000053/0001326190-25-000053-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1326190/000132619025000053/alt-20251001x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001326190-25-000053
- JSON: https://secwatch.observer/filing/0001326190-25-000053.json
- Plain text: https://secwatch.observer/filing/0001326190-25-000053.txt

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