Sage Therapeutics Announces First Quarter 2025 Financial Results and Highlights Pipeline and Business Updates Achieved $13.8 million in ZURZUVAE (zuranolone) collaboration revenue in the first quarter of 2025 (50% of the

Sage Therapeutics Announces First Quarter 2025 Financial Results and Highlights Pipeline and Business

Achieved $13.8 million in ZURZUVAE (zuranolone) collaboration

revenue in the first quarter of 2025

(50% of the net revenues recorded by Biogen), representing a 21% increase from the fourth

Sustained growth in shipments to women with postpartum depression; Greater than 3,000 shipments in

first quarter of 2025 (22% increase from fourth quarter)

Cash, cash equivalents, and marketable securities of $424 million as of March 31, 2025; Cash runway

expected to support operations to mid-2027

Strategic alternatives review process remains ongoing

CAMBRIDGE, Mass. April 29, 2025 Sage Therapeutics, Inc. (Nasdaq: SAGE), today reported business highlights and financial results

for the first quarter ended March 31, 2025.

We delivered strong growth in revenue and shipments of ZURZUVAE during the first quarter of

2025 through the team s disciplined execution and unwavering commitment to bringing ZURZUVAE to more women with postpartum depression, said Barry Greene, Chief Executive Officer at Sage Therapeutics. We remain focused on

establishing ZURZUVAE as the standard of care for women with postpartum depression and driving our business strategy forward with the goal of creating value for shareholders.

First Quarter 2025 Portfolio Updates

ZURZUVAE was approved by the FDA in

August 2023 as the first-and-only oral treatment indicated for adults with postpartum depression (PPD). ZURZUVAE was made commercially available in the U.S. in December

2023. The current commercialization investment plan includes recent joint sales force expansions and marketing tactics intended to further accelerate ZURZUVAE growth in PPD, along with expanded disease state awareness efforts to support increased

PPD screening and diagnosis. The Company anticipates these investments will help support the goal of significant topline revenue growth in 2025. As of the first quarter ended March 31, 2025, the following results had been achieved:

terms of prescriber and patient trends:

SAGE-319 is an extrasynaptic-preferring GABAA receptor positive

allosteric modulator (PAM) designed to have novel pharmacology and a differentiated clinical profile from other GABAA receptor PAMs in our portfolio. It is currently being investigated as a

potential treatment for behavioral symptoms associated with certain neurodevelopmental disorders. The Company expects data from a Phase 1 multiple ascending dose (MAD) study by late 2025 and will evaluate next steps based on these data.

The Company is continuing to explore targeted work within its NMDA receptor negative allosteric modulator (NAM) platform, focusing on potential treatments for

neurodevelopmental disorders, with SAGE-817 and SAGE-039.

SAGE-324: The Company is evaluating potential indications, including seizures in developmental and epileptic

encephalopathies (DEEs), and expects to provide an update on next steps, if any, in mid-2025.

Strategic Alternatives Review Process

As previously announced, Sage s Board of Directors is evaluating a broad range of strategic alternatives to maximize value for shareholders. The

Board s review process remains ongoing. The Company has not set a timetable for the review process and does not intend to disclose further developments until it determines that disclosure is appropriate or necessary.

FINANCIAL RESULTS FOR THE FIRST QUARTER 2025

Conference Call Information

Sage will host a conference call and webcast today, April 29, 2025, at 4:30 p.m. ET to review its first quarter 2025 financial results and discuss 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 following the completion of the event and will be

archived for up to 30 days.

About Sage Therapeutics

Sage Therapeutics (Nasdaq: SAGE) is a biopharmaceutical company committed to our mission of pioneering solutions to deliver life-changing brain health

medicines, so every person can thrive. Sage developed the only two FDA-approved treatments indicated for postpartum depression and is advancing a pipeline to target unmet needs in brain health. Sage was

founded in 2010 and is headquartered in Cambridge, Mass. Find out more at www.sagerx.com or engage with us on Facebook, LinkedIn, Instagram, and X.

Forward-Looking Statements

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

plans, expectations and goals for commercialization of ZURZUVAE for the treatment of women with PPD, including our goals to establish ZURZUVAE as the standard of care for women with PPD and to bring ZURZUVAE to more women with PPD; our beliefs in

the potential for ZURZUVAE, including that ZURZUVAE will be successful and gain market acceptance as a transformative treatment helping women with PPD and be instrumental in accelerating progress in maternal mental health; our belief that OBGYNs are

increasing the number of PPD patients they treat on average after trying ZURZUVAE, and that drivers of this trend include high unmet need and the potential value demonstrated by ZURZUVAE; our investment plans for ZURZUVAE and our expectations

regarding the impact of increased investment, including recent joint sales force expansions and planned marketing tactics, in support of our goals to accelerate market growth in PPD; our plans for expanded disease state awareness efforts to support

increased PPD screening and diagnosis; our plans and other goals related to other aspects of commercialization; anticipated timelines for our clinical development efforts, including the expected timing of readout of the multiple ascending dose study

for SAGE-319; our belief in the potential profile and benefit of our product candidates, including potential indications for our product candidates; our plans to evaluate

SAGE-324 in additional indications, including seizures in DEEs, and the timing of our announcement of next steps regarding the SAGE-324 program; our plans to explore

targeted work within our NMDA receptor NAM platform with SAGE-817 and SAGE-039; our expectations related to the October 2024 reorganization and our pipeline

prioritization efforts, including timing and anticipated cost savings; our expectations regarding our plans to explore strategic alternatives; our belief as to the key business drivers for our business and potential value creation opportunities; and

the mission and goals 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: our commercialization efforts in the U.S. with respect to ZURZUVAE for the treatment of women with PPD may not be successful, and we may be unable to generate revenues from sales of ZURZUVAE at the levels or on the timing we expect or at

levels or on the timing necessary to support our goals; the number of women with PPD, the unmet need for additional treatment options, and the potential market for ZURZUVAE for the treatment of women with PPD may be significantly smaller than we

expect; early positive signs, including ZURZUVAE results in 2024 and the first quarter of 2025, may not be a signal of future success; ZURZUVAE may not achieve, or even if achieved, maintain, the clinical benefit, clinical use or market acceptance

for the treatment of PPD that we expect, including among OBGYNs, or we may encounter reimbursement, market access, process-related, or other issues, including competition in the market, or issues with our distribution network that impact the success

of our commercialization efforts; ZURZUVAE may never become the standard of care for women with PPD; we may encounter delays in initiation, conduct, completion of enrollment or completion and reporting of data with respect to any of our ongoing

studies or clinical trials, such as the completion of the multiple ascending dose study for SAGE-319, including as a result of slower than expected site initiation, slower than expected enrollment, the need or

decision to expand the trials or other changes, that may impact our ability to meet our expected timelines and may increase our costs; success in earlier non-clinical or clinical trials of any of our product

candidates may not be repeated or observed in ongoing or future studies, and ongoing and future clinical trials may not meet their primary or key secondary endpoints, which may substantially impair development; unexpected concerns may arise from

additional data, analysis or results from any of our completed studies; decisions or actions of the FDA or the timing of meetings with the FDA may affect the timing, design, size, progress, and cost of clinical trials or the timing of data readouts

or our ability to proceed with further development or may impair the potential for successful development or the timing or success of filing for and gaining regulatory approval; we may encounter adverse events at any stage that negatively impact

further development and the potential for approval of our product candidates or the potential for successful commercialization of any of our products or that require additional non-clinical and clinical work,

which may not yield positive results; the need to align with our collaborators may hamper or delay our development and commercialization efforts for the products or product candidates that are part of the collaboration or increase our costs; the

anticipated benefits of our ongoing collaborations, including the receipt of payments or the successful development or commercialization of products and generation

of revenue, may never be achieved at the levels or timing we expect or at all; 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, planned, and other future activities, and the resulting impact on expenses and use of cash, may be higher than expected, which may cause us to

use cash quicker than expected or change or curtail some of our plans or both; our expectations as to expenses, cash usage, potential revenue, funding from collaborations, including milestones, cash runway, 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 not achieve anticipated cost savings from our October 2024 reorganization and pipeline prioritization efforts at the levels we expect; we may

be opportunistic in our future financing plans even if available cash is sufficient; we may not be successful in our efforts to gain regulatory approval of products beyond ZURZUVAE; we may not achieve revenues from our products that may be

successfully developed in the future at levels we expect; our exploration of strategic alternatives could result in substantial costs and be a distraction to management and other employees, which could have an adverse effect on our business; the

strategic alternatives review process may not result in any transaction or strategic outcome; if we determine to engage in a transaction as a result of our exploration and evaluation of strategic alternatives, our future business, prospects,

financial position and operating results could be significantly different than those in historical periods or projected by our management; additional funding may not be available on acceptable terms when we need it, or at all, which could hamper our

development and commercialization activities; any of the foregoing events could impair the drivers and value creation opportunities for our business; and we may encounter technical and other unexpected hurdles in the development and manufacture of

our product candidates or the commercialization of any current or future 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 annual or quarterly report filed with the Securities and Exchange Commission, 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 Balance Sheets

Sage Therapeutics, Inc. and Subsidiaries

Condensed Consolidated Statements of Operations

(in thousands, except share and per share data)

SELECT IMPORTANT SAFETY INFORMATION FOR ZURZUVAE

ZURZUVAE (zuranolone) CIV, is a neuroactive steroid gamma-aminobutyric acid (GABA) A receptor positive modulator indicated for the treatment of postpartum

depression in adults.

This does not include all the information needed to use ZURZUVAE safely and effectively. See full prescribing information for

ZURZUVAE may cause serious side effects, including decreased awareness and alertness, which can affect your ability to drive safely or safely

do other dangerous activities. Do not drive, operate machinery, or do other dangerous activities until at least 12 hours after taking each dose. You may not be able to tell on your own if you can drive safely or tell how much ZURZUVAE is affecting

you. ZURZUVAE may cause central nervous system (CNS) depressant effects including sleepiness, drowsiness, slow thinking, dizziness, confusion, and trouble walking. Taking alcohol, other medicines that cause CNS depressant effects such as

benzodiazepines, or opioids while taking ZURZUVAE can make these symptoms worse and may also cause trouble breathing. ZURZUVAE is a federally controlled substance schedule IV because it contains zuranolone, which can be abused or lead to dependence.

Tell your healthcare provider right away if you become pregnant or plan to become pregnant during treatment with ZURZUVAE. You should use effective birth control (contraception) during treatment with ZURZUVAE and for 1 week after the final dose.

ZURZUVAE and other antidepressant medicines may increase the risk of suicidal thoughts and actions in people 24 years of age and younger. ZURZUVAE is not for use in children. The most common side effects of ZURZUVAE include sleepiness or drowsiness,

dizziness, common cold, diarrhea, feeling tired, weak, or having no energy, and urinary tract infection.