---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-064961"
form_type: "8-K"
ticker: "BIIB"
cik: "0000875045"
company_name: "BIOGEN INC."
filed_at: "2023-03-09T23:59:59+00:00"
generated_at: "2026-06-18T08:05:22.124310+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Biogen Chair Stelios Papadopoulos to step down; Caroline D. Dorsa elected as new Chair

## Summary
- Stelios Papadopoulos will not stand for re-election at the 2023 Annual Meeting; departure unrelated to any disagreement with Board or Company.
- Board elected Caroline D. Dorsa to serve as Chair of the Board, effective after the Annual Meeting.
- Papadopoulos' decision is a planned succession; no operational or policy disputes cited.

## SEC filing metadata
- accession: 0001193125-23-064961
- form_type: 8-K
- ticker: BIIB
- cik: 0000875045
- company_name: BIOGEN INC.
- filed_at: 2023-03-09T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 5.02, 8.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/875045/000119312523064961/0001193125-23-064961-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/875045/000119312523064961/d446055d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-064961
- JSON: https://secwatch.observer/filing/0001193125-23-064961.json
- Plain text: https://secwatch.observer/filing/0001193125-23-064961.txt

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