| Name | Relationship | Address | Signature | Signature date | CIK |
|---|---|---|---|---|---|
| Mantas Jesus B | Director | BIOGEN INC., 225 BINNEY ST., CAMBRIDGE | /s/ Wendell Taylor, Attorney in Fact for Jesus B. Mantas | 2025-06-18 | 0001777331 |
| Type | Sym | Class | Transaction | Value $ | Shares | Change % | * Price $ | Shares After | Date | Ownership | Footnotes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| transaction | BIIB | Common Stock | Award | $0 | +2.37K | +32.08% | $0.00 | 9.76K | Jun 17, 2025 | Direct |