Biogen files 8-K; Q3 2025 results furnished as Exhibit 99.1

Rhea-AI Filing Summary

Biogen Inc. (BIIB) furnished third-quarter results. The company submitted a press release announcing results of operations and financial condition for the quarter ended September 30, 2025, furnished as Exhibit 99.1.

The press release was provided under Item 2.02 and is not deemed “filed” under Section 18 of the Exchange Act. Biogen’s common stock trades on the Nasdaq Global Select Market under the symbol BIIB.

8-K Event Classification

2 items: 2.02, 9.01

2 items

Item 2.02 Results of Operations and Financial Condition Financial

Disclosure of earnings results, typically an earnings press release or preliminary financials.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Understanding 8-K Material Events →

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): October 30, 2025

BIOGEN INC.

(Exact name of registrant as specified in its charter)

Delaware			0-19311			33-0112644
(State or other jurisdiction of incorporation)			(Commission File Number)			(IRS Employer Identification No.)

225 Binney Street, Cambridge, Massachusetts 02142

(Address of principal executive offices; Zip Code)

Registrant’s telephone number, including area code: (617) 679-2000

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Title of each class

Trading Symbol(s)

Name of each exchange on which registered

Common Stock, $0.0005 par value

BIIB

The Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

☐ Emerging growth company

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 2.02    Results of Operations and Financial Condition.

On October 30, 2025, Biogen Inc. issued a press release announcing its results of operations and financial condition for the third quarter ended September 30, 2025. A copy of the press release is furnished as Exhibit 99.1 and is incorporated herein by reference.

The press release is being furnished pursuant to Item 2.02 of this Current Report on Form 8-K and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934 (the “Exchange Act”) or otherwise subject to the liabilities of that Section, nor shall such document be deemed incorporated by reference in any filing under the Securities Act of 1933 or the Exchange Act.

Item 9.01    Financial Statements and Exhibits.

(d)    Exhibits

The exhibits listed below are furnished as part of this Current Report on Form 8-K.

Exhibit No.			Description
99.1			Biogen's press release dated October 30, 2025
104			Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

BIOGEN INC.
By:			/s/ Wendell Taylor
			Wendell Taylor
			Secretary

Date: October 30, 2025

FAQ

What did Biogen (BIIB) disclose in its 8-K?

Biogen furnished a press release announcing results of operations and financial condition for the quarter ended September 30, 2025, as Exhibit 99.1.

Under which item was Biogen’s press release provided?

It was furnished pursuant to Item 2.02 (Results of Operations and Financial Condition).

Is the Biogen press release considered “filed” under the Exchange Act?

No. It is furnished and not deemed “filed” for purposes of Section 18 of the Exchange Act.

What period does the press release cover?

The third quarter ended September 30, 2025.

What exhibit contains the press release?

Exhibit 99.1 contains Biogen’s press release dated October 30, 2025.

What is Biogen’s trading symbol and exchange?

BIIB on The Nasdaq Global Select Market.