# EDGAR Filing Document

**Accession Number:** 0001597553
**File Stem:** 0000950157-25-000596
**Filing Date:** 2025-7
**Character Count:** 8663
**Document Hash:** 121ec61f94421e953a7efbc8230428d2
**Contains OCR:** False
**Source Format:** 

## Filing Content

## Filing Summary
**0000950157-25-000596.hdr.sgml**: 20250730

**ACCESSION NUMBER**: 0000950157-25-000596

**CONFORMED SUBMISSION TYPE**: SCHEDULE 13D/A

**PUBLIC DOCUMENT COUNT**: 1

**FILED AS OF DATE**: 20250730

**DATE AS OF CHANGE**: 20250730

**SUBJECT COMPANY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** Sage Therapeutics, Inc.
- **CENTRAL INDEX KEY:** 0001597553
- **STANDARD INDUSTRIAL CLASSIFICATION:** PHARMACEUTICAL PREPARATIONS [2834]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 000000000
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A
- **SEC ACT:** 1934 Act
- **SEC FILE NUMBER:** 005-88275
- **FILM NUMBER:** 251168429

**BUSINESS ADDRESS:**
- **STREET 1:** 55 CAMBRIDGE PARKWAY
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
- **BUSINESS PHONE:** 617-299-8380

**MAIL ADDRESS:**
- **STREET 1:** 55 CAMBRIDGE PARKWAY
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
**FILED BY**: 

**COMPANY DATA:**
- **COMPANY CONFORMED NAME:** BIOGEN INC.
- **CENTRAL INDEX KEY:** 0000875045
- **STANDARD INDUSTRIAL CLASSIFICATION:** BIOLOGICAL PRODUCTS (NO DIAGNOSTIC SUBSTANCES) [2836]
- **ORGANIZATION NAME:** 03 Life Sciences
- **EIN:** 330112644
- **STATE OF INCORPORATION:** DE
- **FISCAL YEAR END:** 1231

**FILING VALUES:**
- **FORM TYPE:** SCHEDULE 13D/A

**BUSINESS ADDRESS:**
- **STREET 1:** 225 BINNEY STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142
- **BUSINESS PHONE:** 7814642000

**MAIL ADDRESS:**
- **STREET 1:** 225 BINNEY STREET
- **CITY:** CAMBRIDGE
- **STATE:** MA
- **ZIP:** 02142

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BIOGEN IDEC INC.
- **DATE OF NAME CHANGE:** 20070427

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** BIOGEN IDEC INC
- **DATE OF NAME CHANGE:** 20031112

**FORMER COMPANY:**
- **FORMER CONFORMED NAME:** IDEC PHARMACEUTICALS CORP / DE
- **DATE OF NAME CHANGE:** 19970530

### UNITED STATES SECURITIES AND EXCHANGE COMMISSION
**Washington, D.C. 20549**

## SCHEDULE 13D

### 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**<br>Biogen Inc.<br>225 Binney Street<br>Cambridge MA 02142<br>(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)*

| **CUSIP No.** | **78667J108** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Biogen Inc.** | Name of reporting person<br>**Biogen Inc.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**DELAWARE** | Citizenship or place of organization<br>**DELAWARE** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0%** | Percent of class represented by amount in Row (11)<br>**0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

| **CUSIP No.** | **78667J108** |

---

| | | | |
|:--|:--|:--|:--|
| 1 | Name of reporting person<br>**Biogen MA Inc.** | Name of reporting person<br>**Biogen MA Inc.** | |
| 2 | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | Check the appropriate box if a member of a Group (See Instructions)<br>[x] (a)<br>[ ] (b) | |
| 3 | SEC use only | SEC use only | |
| 4 | Source of funds (See Instructions)<br>**OO** | Source of funds (See Instructions)<br>**OO** | |
| 5 | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | Check if disclosure of legal proceedings is required pursuant to Items 2(d) or 2(e)<br>[ ] | |
| 6 | Citizenship or place of organization<br>**MASSACHUSETTS** | Citizenship or place of organization<br>**MASSACHUSETTS** | |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 7 | Sole Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 8 | Shared Voting Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 9 | Sole Dispositive Power<br>**0.00** |
| Number of Shares<br>Beneficially Owned by<br>Each Reporting Person With: | 10 | Shared Dispositive Power<br>**0.00** |
| 11 | Aggregate amount beneficially owned by each reporting person<br>**0.00** | Aggregate amount beneficially owned by each reporting person<br>**0.00** | |
| 12 | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | Check if the aggregate amount in Row (11) excludes certain shares (See Instructions)<br>[ ] | |
| 13 | Percent of class represented by amount in Row (11)<br>**0%** | Percent of class represented by amount in Row (11)<br>**0%** | |
| 14 | Type of Reporting Person (See Instructions)<br>**CO** | Type of Reporting Person (See Instructions)<br>**CO** | |

---

**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, MA, 02142

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).

### 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.

**Reporting Person:** Biogen Inc.

**Signature:** /s/ Michael Dambach

**Name/Title:** Michael Dambach / Treasurer

**Date:** 07/30/2025

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.

**Reporting Person:** Biogen MA Inc.

**Signature:** /s/ Michael Dambach

**Name/Title:** Michael Dambach / Treasurer

**Date:** 07/30/2025