BIOGEN INC.

Q: Jun 30 2026

Q: Mar 31 2026

FY: Dec 31 2025

Q: Sep 30 2025

Q: Jun 30 2025

Q: Mar 31 2025

FY: Dec 31 2024

Q: Sep 30 2024

Q: Jun 30 2024

Q: Mar 31 2024

FY: Dec 31 2023

Q: Sep 30 2023

Q: Jun 30 2023

Q: Mar 31 2023

FY: Dec 31 2022

Q: Sep 30 2022

Q: Jun 30 2022

Q: Mar 31 2022

FY: Dec 31 2021

Q: Sep 30 2021

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Submission of Matters to a Vote of Security Holders

Financial Statements and Exhibits

Entry into a Material Definitive Agreement

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Entry into a Material Definitive Agreement

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain Officers

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Submission of Matters to a Vote of Security Holders

Other Events

Results of Operations and Financial Condition

Results of Operations and Financial Condition

Prospectus Supplement for Delayed or Continuous Offering

Free Writing Prospectus

Prospectus Supplement for Delayed or Continuous Offering

Automatic Shelf Registration

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Notice of Effectiveness

Post-effective amendment to a registration statement

Prospectus Supplement for Primary Offering

Notice of Effectiveness

Registration statement under Securities Act of 1933

Free Writing Prospectus

Prospectus Supplement for Delayed or Continuous Offering

Prospectus Supplement for Delayed or Continuous Offering

Automatic Shelf Registration

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Free Writing Prospectus

Prospectus Supplement for Delayed or Continuous Offering

Prospectus Supplement for Delayed or Continuous Offering

Automatic Shelf Registration

Registration statement under Securities Act of 1933 to be offered to employees pursuant to certain plans

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Preliminary Proxy Statement

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Required Information in Proxy Statement

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Additional Information for Proxy Statement/ Votes

Definitive Proxy Statement

Additional Information for Proxy Statement/ Votes

Shareholder Letter

Additional Information for Proxy Statement/ Votes

Godbout Sean

Parini Michael

Parini Michael

FMR LLC

Minor Lloyd

Minor Lloyd

Minor Lloyd

Mantas Jesus B

LANGER SUSAN

Patolawala Monish D

Pangalos Menelas N

Minor Lloyd

Freire Maria C

HAWKINS WILLIAM A

SHERWIN STEPHEN A

Rowinsky Eric K

FMR LLC

BIOGEN INC.

BIOGEN INC.

BIOGEN INC.

Annual Report Scanned (Paper)

Annual Report Scanned (Paper)

Annual Report Scanned (Paper)

Annual Report Scanned (Paper)

Correspondence with the SEC

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Letter from the SEC

Correspondence with the SEC

Letter from the SEC

Correspondence with the SEC