BIOGEN INC. — Director's Dealing 2025

Oct 6, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2025-10-02

Reporting Person: Godbout Sean (Chief Accounting Officer)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-10-02	Common Stock	M	26	—	Acquired	502.6667	Direct
2025-10-02	Common Stock	F	8	$155.25	Disposed	494.6667	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-10-02	Restricted Stock Unit	$0	M	26	Disposed	2026-10-02	Common Stock (26)	Direct

Footnotes

F1: The restricted stock units vest in three (3) equal annual installments commencing one year after the grant date of 10/02/2023.