Sage Therapeutics Announces Second Quarter 2016 Financial Results and Provides Corporate Update Portfolio Expansion Underway Based on Recent Positive Data from SAGE-547 and SAGE-217 Top-line Data Readout of Phase 3 STATU

Sage Therapeutics Announces Second Quarter 2016 Financial Results and Provides Corporate Update

Portfolio Expansion Underway Based on Recent Positive Data from SAGE-547 and SAGE-217

Top-line Data Readout of Phase 3 STATUS Trial in SRSE Now Expected in 1H 2017

Dosing Commenced in Expanded Phase 2 Program for SAGE-547 in Moderate and Severe Postpartum Depression

Phase 2 Initiations Planned for SAGE-217 in Essential Tremor and Postpartum Depression in 2H 2016

Proof-of-Concept Study Initiations Planned with SAGE-547 in Major Depressive Disorder and SAGE-217 in Parkinson s Disease in 2H 2016

Conference Call Today at 8:00 AM ET

CAMBRIDGE, Mass., August 9, 2016 Sage Therapeutics, Inc. (NASDAQ: SAGE) today reported business highlights and

financial results for the second quarter ended June 30, 2016, and provided an update on corporate strategy and financial guidance.

completion of our recent clinical studies has allowed us to begin a portfolio transformation at Sage. While it is commonly understood that GABA dysfunction is at the core of many CNS conditions, Sage is pursuing development of compounds that

modulate GABA in a more complex and tailored manner, and we re executing a new approach to drug development, said Jeff Jonas, M.D., Chief Executive Officer of Sage. Sage s growing pipeline of drug candidates impacting GABA

provides us with an industry-leading opportunity to develop medicines leveraging this mechanism of action.

We have recently expanded our

Phase 2 development program exploring SAGE-547 for postpartum depression with the initiation of two clinical trials in moderate and severe PPD. This year, we also plan to advance the development of SAGE-217 with a focus on essential tremor and

postpartum depression. In considering new indications, Major Depressive Disorder and Parkinson s disease, we expect to continue to exploit small, efficient proof-of-concept studies to guide portfolio strategy. We are also evaluating several

additional candidates within our GABA pipeline, such as SAGE-105 and SAGE-324, to explore their potential impact in such CNS disorders as orphan epilepsies. Lastly, while the data readout of the STATUS Trial in SRSE is delayed, we remain confident

in our overall assessment of the unmet medical need.

Corporate and Clinical Strategy Update

Recent and Expected Near-Term Clinical Milestones

Second Quarter 2016 Financial Results

Conference Call Information

conference call and webcast today at 8:00 AM ET to discuss its second quarter 2016 financial results and recent business updates. The live webcast can be accessed on the investor page of Sage s website at investor.sagerx.com. The

conference call can be accessed by dialing 1-866-450-8683 (toll-free domestic) or 1-281-542-4847 (international) and using the conference ID 57731355. A replay of the webcast will be available on Sage s website approximately two hours after the

completion of the event and will be archived for up to 30 days.

About Sage Therapeutics

Sage Therapeutics is a clinical-stage biopharmaceutical company committed to developing novel medicines to transform the lives of patients with

life-altering central nervous system (CNS) disorders. Sage has a portfolio of novel product candidates targeting critical CNS receptor systems, GABA and NMDA. Sage s lead program, SAGE-547, is in Phase 3 clinical development for

super-refractory status epilepticus, a rare and severe seizure disorder, and is being developed for severe postpartum depression. Sage is developing its next generation modulators, including SAGE-217, SAGE-689 and SAGE-718, with a focus on acute and

chronic CNS disorders. For more information, please visit www.sagerx.com.

Forward-Looking Statements

Various statements in this release concern Sage s future expectations, plans and prospects, including without limitation, our expectations regarding

development of our product candidates and their potential in the treatment of various CNS disorders; the expected timing of clinical trials and IND-enabling activities; the anticipated availability and announcement of data and results from clinical

trials of our product candidates; our plans for evaluation of new indications and new compounds; our expectations regarding enrollment trends in the STATUS trial; our belief in the unmet need in SRSE, and our estimates as to the potential number of

patients with SRSE; our expectations regarding timing of a potential launch of SAGE-547 in SRSE, if successfully developed and approved; and our expectations with respect to the sufficiency of our cash, cash equivalents and marketable

securities. These forward-looking statements are neither promises nor guarantees of future performance, and are subject to a variety of risks and uncertainties, many of which are beyond our control, which could cause actual results to differ

materially from those contemplated in these forward-looking statements, including the risks that: we may continue to experience slower than expected enrollment and randomization of evaluable patients in the STATUS trial or slower than expected

clinical site initiation and enrollment in our other clinical trials, or the potential need for additional analysis or data or the need to enroll additional patients, leading to possible delays in completion of trials or in the availability of data;

we may not be able to generate supportive non-clinical data or to successfully demonstrate the efficacy and safety of our product candidates at each stage of development; success in our non-clinical studies or in earlier stage clinical trials

may not be repeated or observed in ongoing or future studies involving the same compound or other product candidates, and ongoing and future pre-clinical and clinical results may not support further development of product candidates or be sufficient

to gain regulatory approval to market any product; decisions or actions of regulatory agencies may affect the initiation, timing, progress and cost of clinical trials, and our ability to proceed with further clinical studies of a product candidate

or to obtain marketing approval; the actual size of the patient populations associated with the diseases for which we are developing our product candidates may be significantly lower than our estimates; the internal and external costs required for

our activities, and to build our organization in connection with such activities, and the resulting use of cash, may be higher than expected, or we may conduct additional clinical trials or pre-clinical studies or engage in new activities, requiring

additional expenditures and using cash more quickly than anticipated; and we may encounter technical and other unexpected hurdles in the development and manufacture of our products which may delay our timing or increase our expenses and use of

cash, as well as those risks more fully discussed in the section entitled Risk Factors in our most recent Quarterly Report on Form 10-Q, as well as discussions of potential risks, uncertainties, and other important factors in our

subsequent filings with the Securities and Exchange Commission. In addition, any forward-looking statements represent our views only as of today, and should not be relied upon as representing our views as of any subsequent date. We explicitly

disclaim any obligation to update any forward-looking statements.

Paul Cox, Sage Therapeutics

Maureen L. Suda, Suda Communications LLC

Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Balance Sheets

Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Statements of Operations

(in thousands, except share and per share data)