BIOGEN INC. — Director's Dealing 2025

Nov 4, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2025-10-31

Reporting Person: Grogan Jane (Head of Research)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-10-31	Common Stock	M	695	—	Acquired	2128	Direct
2025-10-31	Common Stock	F	337	$154.27	Disposed	1791	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-10-31	Restricted Stock Unit	$0	M	695	Disposed	2026-11-01	Common Stock (695)	Direct

Footnotes

F1: The restricted stock units vest in three equal yearly installments beginning on the first anniversary of the grant date of November 1, 2023.