Exhibit 5.1
February 27, 2019
Sage Therapeutics, Inc.
215 First Street
Cambridge, MA 02142
Re: Securities Registered under Registration Statement on FormS-3
Ladies and Gentlemen:
We have acted as counsel to you in connection with your filing of a Registration Statement on FormS-3ASR (FileNo. 333-228879) (as amended or supplemented, the “Registration Statement”) filed on December 18, 2018 with the Securities and Exchange Commission (the “Commission”) pursuant to the Securities Act of 1933, as amended (the “Securities Act”), relating to the registration of the offer by Sage Therapeutics, Inc., a Delaware corporation (the “Company”) of an indeterminate amount of any combination of securities of the types specified therein. The Registration Statement became effective under the Securities Act upon filing on December 18, 2018. Reference is made to our opinion letter dated December 18, 2018 and included as Exhibit 5.1 to the Registration Statement. We are delivering this supplemental opinion letter in connection with the prospectus supplement (the “Prospectus Supplement”) filed on February 27, 2019 by the Company with the Commission pursuant to Rule 424 under the Securities Act. The Prospectus Supplement relates to the offering by the Company of up to 3,833,334 shares of the Company’s common stock, par value $0.0001 per share (the “Shares”) covered by the Registration Statement. The Shares include an over-allotment option granted to the underwriters of the offering to purchase 500,000 Shares. The Shares are being sold to the several underwriters named in, and pursuant to, an underwriting agreement among the Company and such underwriters (the “Underwriting Agreement”).
We have reviewed such documents and made such examination of law as we have deemed appropriate to give the opinion set forth below. We have relied, without independent verification, on certificates of public officials and, as to matters of fact material to the opinion set forth below, on certificates of officers of the Company.
The opinion set forth below is limited to the Delaware General Corporation Law.
Based on the foregoing, we are of the opinion that the Shares have been duly authorized and, upon issuance and delivery against payment therefor in accordance with the terms of the Underwriting Agreement, the Shares will be validly issued, fully paid andnon-assessable.
