Termination of Material Agreement Form 8 K

On September 20, 2024, Biogen MA, Inc. and Biogen International GmbH (collectively, "Biogen") notified Sage Therapeutics, Inc. (the "Company") of its termination of the Collaboration and License Agreement, dated November 27, 2020, by and between the Company and Biogen (as amended to date, the "Collaboration Agreement"), solely with respect to products containing the Company's SAGE-324molecule (the "Licensed 324 Products") on a worldwide basis (the "Territory"), effective February 17, 2025 (the "Termination Effective Date"). In accordance with the terms of the Collaboration Agreement, Biogen has the right to terminate the Collaboration Agreement for its convenience (i) in its entirety, (ii) on a Product Class (as defined below)-by-ProductClass basis in specified territories, or (iii) for a Product Class in its entirety. The Company and Biogen recently announced negative results from the Phase 2 KINETIC 2 Study of SAGE-324for the chronic treatment of essential tremor and the parties' decision to discontinue further clinical development of SAGE-324in essential tremor. In accordance with the Collaboration Agreement, the Company and Biogen continue to partner on ZURZUVAE^® (zuranolone), the first and only FDA-approvedoral treatment for women with postpartum depression.

As previously disclosed, under the Collaboration Agreement, the Company and Biogen agreed to jointly develop and commercialize products containing the Company's SAGE-217molecule (the "Licensed 217 Products") and Licensed 324 Products (together with the Licensed 217 Products, "Licensed Products" and each of the Licensed 217 Products and Licensed 324 Products, a "Product Class") in the United States and to permit Biogen to solely develop and commercialize the Licensed Products in all other countries except, with respect to the Licensed 217 Products, Japan, South Korea and Taiwan. Pursuant to the Collaboration Agreement, the Company granted to Biogen a non-transferable,sublicensable (subject to specified exceptions) license to certain intellectual property of the Company as needed to perform the activities under the Collaboration Agreement. Each of the Company and Biogen continues to be responsible for its respective share of costs for ongoing activities related to the Licensed 324 Products in accordance with the terms of the Collaboration Agreement until the Termination Effective Date.

As a result of the termination, as of the Termination Effective Date, all licenses granted by the Company to Biogen or by Biogen to the Company regarding the Licensed 324 Products shall expire with respect to the Licensed 324 Products in the Territory. Biogen shall grant to the Company an irrevocable, perpetual license for any Biogen background technology, Biogen collaboration technology or joint collaboration technology that exists as of the Termination Effective Date with respect to the Licensed 324 Products in the Territory, in each case in accordance with the terms of the Collaboration Agreement.

In connection with the parties' entry into the Collaboration Agreement, Biogen MA, Inc. also entered into a stock purchase agreement with the Company, pursuant to which Biogen has certain continuing rights and obligations with respect to its shares of the Company.

The foregoing description of the terms and conditions of the Collaboration Agreement material to the Company is qualified in its entirety by reference to the Collaboration and License Agreement, dated November 27, 2020, by and between the Company and Biogen, a copy of which was filed with the Securities and Exchange Commission (the "Commission") on the Company's Annual Report on Form 10-Kon February 24, 2021, as modified by that certain Side Letter, a copy of which was filed with the Commission on the Company's Quarterly Report on Form 10-Qon November 2, 2021, each of which is incorporated by reference herein.