Exhibit 99.1

Sage Therapeutics Announces Second Quarter 2021 Financial Results and

Highlights Pipeline and Business Progress

Announced positive topline data from pivotal WATERFALL Study of zuranolone in patients with MDD showing statistically significant and clinically meaningful reduction in depressive symptoms at Day 15, primary endpoint

Continued pipeline expansion and acceleration advancing all three brain health franchises, including first patient dosed in SAGE-718 PARADIGM Parkinson’s disease Study Part B and initiation of Phase 1 program for SAGE-689

Updated enrollment guidance for Phase 3 SKYLARK Study of zuranolone in women with PPD with topline data now expected mid-2022

Company announces REDWOOD and RAINFOREST Studies not expected to be required for a potential zuranolone NDA submission

Conference call today at 8:00 a.m. ET

CAMBRIDGE, Mass. – August 3, 2021 – 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 second quarter ended June 30, 2021.

“Sage has made incredible progress on our mission to become the leader in brain health in the first half of 2021, setting us up for multiple near-mid and long-term catalysts.” said Barry Greene, chief executive officer, Sage Therapeutics. “Our goal of making medicines that matter for people with brain health disorders is more important than ever, and we are committed to delivering innovative therapies. The LANDSCAPE and NEST programs for zuranolone are examples of Sage’s unique approach to designing integrated clinical development strategies that we believe will enable us to bring paradigm shifting treatments to market and address the greatest unmet needs for patients. I look forward to providing further updates on zuranolone and the rest of Sage’s robust pipeline in the second half of the year.”

Second Quarter 2021 and Recent Portfolio Updates

Sage is advancing a portfolio of clinical programs featuring internally discovered novel chemical entities with the potential to become differentiated products designed to improve brain health by targeting the GABA_A 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 GABA_A 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 major depressive disorder (MDD).

Zuranolone is being evaluating as a potential rapid-acting, durable, two-week treatment for PPD and MDD in the NEST and LANDSCAPE clinical trial programs.

Sage and Biogen, its collaborator on zuranolone and SAGE-324, recently announced that the WATERFALL Study, a pivotal, Phase 3, double-blind, randomized, placebo-controlled study evaluating the efficacy and safety of zuranolone 50 mg in adults 18 to 64 years with MDD, met its primary endpoint demonstrating statistically significant and clinically meaningful improvement in depressive symptoms compared with placebo at Day 15 as assessed by the 17-item Hamilton Rating Scale for Depression (HAMD-17) total score.

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Zuranolone has been granted Breakthrough Therapy Designation by the FDA, and Sage and Biogen plan to discuss next steps with the Agency. Additional analysis and full data from the WATERFALL Study will be shared at future scientific forums.

Additionally, the Company is formally terminating the REDWOOD and RAINFOREST Studies, which were suspended in the first quarter of 2020. After discussions with the FDA, Sage does not believe that these studies will be required for a potential NDA submission.

The Company expects the following zuranolone data readouts in 2021 and 2022:

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Sage today announced topline data from the Phase 3 CHICKADEE Study evaluating the safety of ZULRESSO treatment in adolescent females aged 15 to 17 with postpartum depression. This study was conducted as a post-marketing requirement to investigate ZULRESSO in an adolescent population diagnosed with PPD. In the study, the safety and pharmacokinetic profile of ZULRESSO in this population was consistent with prior studies in adults and the FDA-approved product label. While not the primary endpoint, efficacy results were positive and consistent with previous studies.

Neurology Franchise

SAGE-324, a next-generation PAM of GABA_A receptors and Sage’s lead neurology program, is in development as a potential oral therapy for neurological conditions, such as essential tremor (ET), epilepsy and Parkinson’s disease (PD).

In the second quarter, Sage and Biogen announced that the KINETIC Study, a Phase 2 multicenter, randomized, double-blind, placebo-controlled study of SAGE-324 in ET, met its primary endpoint.

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).

This quarter, Sage dosed the first patient in the 4-week dosing cohort, or part B, of the PARADIGM Study to gather additional data on SAGE-718 in the PD patient population. The PARADIGM study is a Phase 2a open-label study in patients aged 50 to 75 years old with mild cognitive impairment due to PD. Additionally, the LUMINARY Study, a Phase 2a open-label trial evaluating SAGE-718 in patients with AD mild cognitive impairment and mild dementia is ongoing.

The following milestones are expected for the neuropsychiatry franchise in 2021:

Early Development

Sage expects to complete certain ongoing Phase 1 clinical studies for two programs in its early development pipeline in late 2021, SAGE-689 (single ascending dose) and SAGE-904 (single ascending dose and multiple ascending dose). Results from the Phase 1 studies will inform further development of these programs.

Additionally, IND-enabling work is underway for SAGE-319.

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The Company plans to advance SAGE-421 to preclinical studies.

Other Development Opportunities

Sage’s Phase 3 trial with brexanolone in ventilated intensive care unit patients with advanced COVID-19 related acute respiratory distress syndrome (ARDS) did not meet enrollment expectations and was closed to enrollment this quarter. Sage has terminated the study.

ANTICIPATED 2021 MILESTONES

Late 2021:

FINANCIAL RESULTS FOR THE SECOND QUARTER 2021

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FINANCIAL GUIDANCE

Conference Call Information

Sage will host a conference call and webcast today, Tuesday, August 3, at 8:00 am ET to discuss its second quarter 2021 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.

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Forward-Looking Statements

Various statements in this release concern Sage’s future expectations, plans and prospects, including without limitation: our views and expectations regarding our planned research and development activities and related timelines, including anticipated timelines for reporting clinical trial results, commencement of trials, and initiation of new activities; our plans for advancement of our pipeline; our belief in the potential profile and benefit of our product candidates, the potential for our programs, and the opportunity to help patients in various indications; our belief and expectations as to the potential regulatory pathways and requirements for filing a potential new drug application for zuranolone and for possible approval; potential indications for our product candidates; the mission and goals for our business and potential value creation opportunities; and our expectations with respect to 2021 year-end cash. 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: success in non-clinical studies or in earlier clinical trials or at interim time periods may not be repeated or observed in ongoing or future studies, and ongoing and future non-clinical and clinical results 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; unexpected concerns may arise from additional data, analysis or results from any of our completed studies; 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 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 timelines and increase our costs; the impact of the COVID-19 pandemic on our clinical development efforts may be more significant than we expect if new surges continue; the FDA may ultimately decide that the design or results of our completed, ongoing and planned clinical trials for zuranolone or any of our other product candidates, even if positive, are not sufficient to file for or obtain regulatory approval in the indications that are the focus of our development plans even if we have had prior discussions with the agency supporting our approach; 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; the anticipated benefits of our ongoing collaborations may never be achieved and the need to align with our collaborators may hamper or delay our development and commercialization efforts or increase our costs; our business may be adversely affected and our costs may increase if any of our key collaborators fails to perform its obligations or terminates our collaboration; 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; we may never be able to generate meaningful revenues from sales of ZULRESSO or to generate revenues at levels we expect or at levels necessary to justify our investment; 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; our expectations as to year-end cash 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; additional funding may not be available on acceptable terms when we need it; the number of patients with the diseases or disorders for which our products are developed, the unmet need for additional treatment options and the potential market for our current or future products may be significantly smaller than we expect; and we may encounter technical and other unexpected hurdles in the development and manufacture of our product candidates or the commercialization of our marketed product which may delay our timing or change our plans, increase our costs or otherwise negatively impact our business; 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)

(unaudited)

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Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Balance Sheets

(in thousands)

(unaudited)

ZULRESSO can 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 1-800-FDA-1088.

Before 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.

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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.

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