BIOGEN INC. — Director's Dealing 2025

May 5, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2025-05-01

Reporting Person: Keeney Adam (Head of Corporate Development)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-05-01	Common Stock	M	938	—	Acquired	2838	Direct
2025-05-01	Common Stock	F	454	$120.93	Disposed	2384	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-05-01	Restricted Stock Unit	$0	M	938	Disposed	2026-05-01	Common Stock (938)	Direct

Footnotes

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