Sage Therapeutics Announces Third Quarter 2020 Financial Results and Highlights Pipeline and Business Progress Ongoing zuranolone Phase 3 pivotal trials in major depression and postpartum depression progressing well; exp

Sage Therapeutics Announces Third Quarter 2020 Financial Results and Highlights Pipeline and Business

Ongoing zuranolone Phase 3 pivotal trials in major depression and postpartum depression

progressing well; expect to initiate dosing in CORAL Study in 4Q 2020

Continued execution across brain health franchises highlighted during 2nd annual

First patient dosed in PARADIGM Study investigating SAGE-718 in patients

with Parkinson s disease cognitive dysfunction

Conference call today at 8:30 a.m. ET

CAMBRIDGE, Mass. November 5, 2020 Today, Sage Therapeutics, Inc. (NASDAQ: SAGE), a biopharmaceutical company committed

to developing novel therapies with the potential to transform the lives of people with debilitating disorders of the brain, reported business highlights and financial results for the third quarter ended September 30, 2020.

Today I m pleased to report that our clinical programs across three franchises remain on track, with a series of key milestones anticipated over

the next 12 to 18 months, said Mike Cloonan, chief operating officer at Sage Therapeutics. During the third quarter, we continued progress across our deep and robust clinical pipeline, a pipeline that spans multiple disease states with

programs in early, mid and late stage development. The Sage team continues to execute well during the COVID-19 pandemic and remains determined to provide much needed options to patients suffering with

debilitating brain health disorders.

Sage recently reported positive, interim topline results from a July data cut of the ongoing Phase 3 open-label SHORELINE Study of zuranolone in major

depressive disorder (MDD). The data analyzed to date show that zuranolone was generally well-tolerated in the 30 mg dose and among the initial patients treated with the 50 mg dose. Adverse events reported in the trial during the period analyzed were

generally consistent with results seen in previous zuranolone clinical trials.

As the first naturalistic, longitudinal, clinical development trial

conducted in MDD, the SHORELINE Study provides real world insight into the potential use of zuranolone, if successfully developed and approved as an as-needed treatment for MDD, and builds on the data

assembled in the LANDSCAPE clinical program. The Company plans to report comprehensive data from the 30 mg dose of the SHORELINE Study in the first half of 2021 and will include additional analyses of the data set.

Sage is advancing a portfolio

of novel, new chemical entities with the potential to become differentiated products designed to improve brain health by targeting the GABAA and NMDA receptor systems. Dysfunction in these systems is thought to be at the core of numerous

neurological and neuropsychiatric disorders.

Depression Franchise

Sage s depression franchise features zuranolone, Sage s next-generation positive allosteric modulator (PAM) of GABAA receptors being evaluated in

clinical development as a treatment for various affective disorders and ZULRESSO (brexanolone) CIV injection, approved by the U.S. Food and Drug Administration (FDA) as the first treatment

specifically indicated for postpartum depression (PPD). Zuranolone has received breakthrough therapy designation from the FDA for the treatment of MDD.

Sage expects to initiate dosing of the third new zuranolone Phase 3 trial in 2020:

SAGE-324, a next-generation PAM of GABAA receptors and Sage s lead neurology asset, is in development as a potential oral therapy for neurological

conditions, such as essential tremor (ET), epilepsy and Parkinson s disease (PD).

Neuropsychiatry Franchise

SAGE-718, Sage s first-in-class NMDA receptor PAM and lead neuropsychiatric drug candidate, is in development as a potential oral

therapy for cognitive disorders associated with NMDA receptor dysfunction, potentially including Huntington s disease (HD), PD and Alzheimer s disease (AD).

Results from these studies will inform potential advancement of

SAGE-718 into further development.

During the third quarter, the Company strengthened its leadership with two key additions:

The Company also hosted the 2nd annual FutureCast:

An R&D Portfolio Review in the third quarter to review the Company s research and development strategy, and clinical progress in its key depression, neurology, and neuropsychiatry franchise programs.

Anticipated Upcoming Milestones

Financial Results for the Third Quarter 2020

Conference Call Information

Sage will host a conference call and webcast today, Thursday, November 5, at 8:30 a.m. ET to discuss its third quarter 2020 financial results

and recent corporate updates. The live webcast can be accessed on the investor page of Sage s website at investor.sagerx.com. 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 biopharmaceutical company committed to developing novel therapies with the potential to transform the lives of people with

debilitating disorders of the brain. We are pursuing new pathways with the goal of improving brain health, and our depression, neurology and neuropsychiatry franchise programs aim to change how brain disorders are thought about and treated. Our

mission is to make medicines that matter so people can get better, sooner. For more information, please visit www.sagerx.com.

Forward-Looking Statements

in this release concern Sage s future expectations, plans and prospects, including without limitation: our views and expectations regarding revenues from sales of ZULRESSO; our clinical development plans and expected timelines; our expectations

with respect to 2020 operating expenses and year-end cash; our belief that existing cash will support operations into 2022; our belief in the potential of our product candidates in various indications; the

potential profile and benefit of our product candidates; and the goals, opportunity and potential for our business. These statements constitute forward-looking statements as that term is defined in the Private Securities Litigation Reform Act of

1995. 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 never be able to generate meaningful revenues from sales of ZULRESSO or to generate revenues at levels necessary to justify our investment; the impact of

the COVID-19 pandemic on sales of ZULRESSO may last longer than we expect or may reoccur in waves; our post-restructuring focus on geographies where there are existing, active

ZULRESSO treating sites may not be sufficient for us to achieve success from the sale of ZULRESSO or to generate revenues at meaningful levels or at levels necessary to justify our investment

even after the impact of the COVID-19 pandemic lessens; we may not be able to overcome the barriers to treatment with ZULRESSO or we may continue to encounter other issues or challenges in commercializing

ZULRESSO which could further limit the potential of ZULRESSO and the timing and amount of future revenues; results achieved with use of ZULRESSO in the treatment of PPD in commercial use may be different than observed in clinical trials, and may

vary among patients; the number of patients with the diseases or disorders for which our products are developed or the unmet need for additional treatment options may be significantly smaller than we expect; we may encounter delays in initiation,

conduct or completion of our ongoing and planned clinical trials, including as a result of slower than expected site initiation or enrollment, the need or decision to expand the trials or other changes, that may impact our ability to meet our

expected time-lines and increase our costs; we may not be able to mitigate the impact of COVID-19 on our clinical development timelines and the impact may be more significant than we expect and may negatively

impact expected site initiation, enrollment or conduct in our clinical trials, or cause us to pause trials or not be able to use data, in each case which may significantly impact our ability to meet our expected time-lines or may significantly

impact the integrity or sufficiency of the data from our trials or increase our costs or cause us to have to change our plans; the internal and external costs required for our ongoing and planned activities, and the resulting impact on expense and

use of cash, may be higher than expected which may cause us to use cash more quickly than we expect or change or curtail some of our plans or both; our expectations as to expenses, year-end cash and cash needs

may prove not to be correct for other reasons such as changes in plans or actual events being different than our assumptions; we may be opportunistic in our future financing plans even if available cash is sufficient; we may not be successful in our

development of any of our product candidates in any indication we are currently pursuing or may in the future pursue; success in our non-clinical studies or in earlier clinical trials may not be repeated or

observed in ongoing or future studies, and ongoing and future non-clinical and clinical results or at interim time periods may not meet their primary or key secondary endpoints or be sufficient to file for or

gain regulatory approval to market the product without further development work or may not support further development at all; we may encounter adverse events at any stage of development that negatively impact further development or that require

additional nonclinical and clinical work which may not yield positive results; we may encounter different or more severe adverse events at the higher doses we are studying in new trials; we may encounter issues with the efficacy or durability of

short-term treatment, or co-initiated treatment with zuranolone or safety and efficacy concerns with respect to retreatment that require additional studies be conducted; the FDA may ultimately decide that the

design or results of our completed and planned clinical trials for any of our product candidates, even if positive, are not sufficient for regulatory approval in the indications that are the focus of our development plan; other decisions or actions

of the FDA or other regulatory agencies may affect the initiation, timing, design, size, progress and cost of clinical trials and our ability to proceed with further development; we may encounter technical and other unexpected hurdles in the

development and manufacture of our product candidates which may delay our timing or change our plans or increase our costs; 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.

Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Statements of Operations

(in thousands, except share and per share data)

Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Balance Sheets

About ZULRESSO (brexanolone) CIV injection

ZULRESSO, the first medicine specifically approved by the U.S. Food and Drug Administration (FDA) for the treatment of postpartum depression (PPD) in adults,

is a positive allosteric modulator of both synaptic and extrasynaptic GABAA receptors. Allosteric modulation of neurotransmitter receptor activity results in varying degrees of desired activity rather than complete activation or inhibition of the

SELECT IMPORTANT SAFETY INFORMATION

These are not all the side effects of ZULRESSO.

cause serious side effects, including:

ZULRESSO can cause other serious side effects, including:

The most common side effects of ZULRESSO include:

Call your doctor for medical advice about side effects. You may report side effects to FDA at

receiving ZULRESSO, tell your healthcare provider about all your medical conditions including if you drink alcohol, have kidney problems, are pregnant or think you may be pregnant, or are breastfeeding or plan to breastfeed. It is not known if

ZULRESSO will harm your unborn baby. If you become pregnant during treatment, talk with your healthcare provider about enrolling with the National Pregnancy Registry for Antidepressants at 1-844-405-6185.

While receiving ZULRESSO, avoid the following:

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. ZULRESSO and some medicines may interact with each other and cause serious side effects.

Especially tell your healthcare provider if you take other antidepressants, opioids, or Central

Nervous System (CNS) depressants (such as benzodiazepines).

Please see the patient Medication Guide, including information about serious side effects,

for Zulresso in the full Prescribing Information.