BIOGEN INC. — Director's Dealing 2025

Sep 2, 2025

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: BIOGEN INC. (BIIB)
CIK: 0000875045
Period of Report: 2025-08-29

Reporting Person: Singhal Priya (Head of Development)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2025-08-29	Common Stock	M	1669	—	Acquired	7096.1428	Direct
2025-08-29	Common Stock	F	807	$132.22	Disposed	6289.1428	Direct
2025-09-02	Common Stock	S	517	$133.55	Disposed	5772.1428	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2025-08-29	Restricted Stock Unit	$0	M	1669	Disposed	2025-09-01	Common Stock (1669)	Direct

Footnotes

F1: This award was granted to the reporting person on September 1,
2022 and will vest in three equal installments on each anniversary of the grant date.