BIOGEN INC. - Director's Dealing 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2025-02-07

Reporting Person: Izzar Rachid (Head of Global Product Strat.)

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-02-07	Common Stock	M	2043	—	Acquired	7224	Direct
2025-02-07	Common Stock	F	600	$141.35	Disposed	6624	Direct
2025-02-07	Common Stock	F	565	$141.35	Disposed	6059	Direct
2025-02-07	Common Stock	M	1801	—	Acquired	7860	Direct

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-02-07	Restricted Stock Unit	$0	M	2043	Disposed	2026-02-08	Common Stock (2043)	Direct
2025-02-07	Restricted Stock Unit	$0	M	1801	Disposed	2027-02-07	Common Stock (1801)	Direct

F1: Total adjusted to reflect transfer of shares to the reporting person's former spouse pursuant to a Domestic Relations Order.

F2: The restricted stock units vest in three (3) equal annual installments commencing one year after the grant date of 02/08/2023.

F3: The restricted stock units vest in three (3) equal annual installments, commencing one year after the grant date of 02/07/2024.