SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549


SCHEDULE 13D/A

Under the Securities Exchange Act of 1934

(Amendment No. 2)*


Sage Therapeutics, Inc.
(Name of Issuer)


Common Stock, par value $0.0001 per share
(Title of Class of Securities)


78667J108
(CUSIP Number)


Wendell Taylor, Secretary
Biogen Inc., 225 Binney Street
Cambridge, MA, 02142
(617) 679-2000
(Name, Address and Telephone Number of Person Authorized to Receive Notices and Communications)
07/30/2025
(Date of Event Which Requires Filing of This Statement)


If the filing person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. ☒

The information required on the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).




SCHEDULE 13D/A
CUSIP No.
78667J108


1 Name of reporting person

Biogen Inc.
2 Check the appropriate box if a member of a Group (See Instructions)

☐  (a)
☐  (b)
3SEC use only
4 Source of funds (See Instructions)

OO
5 Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

☐
6 Citizenship or place of organization

DELAWARE
Number of Shares Beneficially Owned by Each Reporting Person With:
7 Sole Voting Power: 0.00
8 Shared Voting Power: 0.00
9 Sole Dispositive Power: 0.00
10 Shared Dispositive Power: 0.00
11 Aggregate amount beneficially owned by each reporting person

0.00
12 Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

☐
13 Percent of class represented by amount in Row (11)

0 %
14 Type of Reporting Person (See Instructions)

CO



SCHEDULE 13D/A
CUSIP No.
78667J108


1 Name of reporting person

Biogen MA Inc.
2 Check the appropriate box if a member of a Group (See Instructions)

☐  (a)
☐  (b)
3SEC use only
4 Source of funds (See Instructions)

OO
5 Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)

☐
6 Citizenship or place of organization

MASSACHUSETTS
Number of Shares Beneficially Owned by Each Reporting Person With:
7 Sole Voting Power: 0.00
8 Shared Voting Power: 0.00
9 Sole Dispositive Power: 0.00
10 Shared Dispositive Power: 0.00
11 Aggregate amount beneficially owned by each reporting person

0.00
12 Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)

☐
13 Percent of class represented by amount in Row (11)

0 %
14 Type of Reporting Person (See Instructions)

CO




SCHEDULE 13D/A

Item 1.Security and Issuer
(a) Title of Class of Securities:

Common Stock, par value $0.0001 per share
(b) Name of Issuer:

Sage Therapeutics, Inc.
(c) Address of Issuer's Principal Executive Offices:

55 Cambridge Parkway, Cambridge, MASSACHUSETTS , 02142.
Item 1 Comment: The following constitutes Amendment No. 2 to the Schedule 13D filed by the undersigned ("Amendment No. 2") on January 10, 2024, as amended by Amendment No. 1 on July 21, 2025. This Amendment No. 2 amends the Schedule 13D as specifically set forth herein.
Item 5.Interest in Securities of the Issuer
(a)
Item 5 is hereby amended and restated in its entirety as follows: As of July 28, 2025, the aggregate number of shares of Common Stock beneficially owned by the Reporting Persons was 6,241,473.00 shares, representing 9.941% of the 62,784,397 issued and outstanding shares of Common Stock of the Issuer as of July 23, 2025 (as disclosed in the Issuer's most recent quarterly report on Form 10-Q filed on July 30, 2025). On July 29, 2025, the Reporting Persons sold all of their shares of Common Stock at a price per share of $8.53 in a block trade. As of the date of this filing, the Reporting Persons beneficially own no shares of Common Stock, representing 0.00% of the issued and outstanding shares of Common Stock. As of the date of this filing, the Reporting Persons have no powers to vote, or to direct the vote of, or to dispose, or to direct the disposition of, shares of Common Stock.
(b)
Item 5(a) of this Schedule 13D is incorporated by reference into this Item 5(b).
(c)
Item 5(a) of this Schedule 13D is incorporated by reference into this Item 5(c).
(d)
Not applicable.
(e)
On July 29, 2025, the Reporting Persons ceased to be the beneficial owners of more than five percent of Common Stock.

    SIGNATURE 
 
After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

 
Biogen Inc.
 Signature:/s/ Michael Dambach
 Name/Title:Michael Dambach / Treasurer
 Date:07/30/2025
 
Biogen MA Inc.
 Signature:/s/ Michael Dambach
 Name/Title:Michael Dambach / Treasurer
 Date:07/30/2025