Sage Therapeutics Announces Fourth Quarter and Full Year 2024 Financial Results and Highlights Pipeline and Business Updates Strong first full year of launch with sustained growth in shipments to women with postpartum de

Sage Therapeutics Announces Fourth Quarter and Full Year 2024 Financial Results and Highlights Pipeline

and Business Updates

Strong first full year of launch with sustained growth in shipments to women with postpartum depression;

Nearly 2,500 shipments in fourth quarter of 2024 (21% increase from third quarter)

$11.4 million in ZURZUVAE (zuranolone) collaboration revenue in the fourth quarter of 2024 and $36.1 million for the year ended December 31, 2024 (50% of the net revenues recorded by Biogen)

Cash, cash equivalents, and marketable securities of $504 million as of December 31, 2024; Cash runway expected to support

operations to mid-2027

CAMBRIDGE, Mass. February 11, 2025 Sage

Therapeutics, Inc. (Nasdaq: SAGE), today reported business highlights and financial results for the fourth quarter and full year ended December 31, 2024.

We are proud to have helped thousands of women with postpartum depression in 2024. ZURZUVAE is being recognized as an important treatment option for

women with postpartum depression and we believe it will continue to be instrumental in accelerating progress in maternal mental health, said Barry Greene, Chief Executive Officer, Sage Therapeutics. In 2025, our focus will remain on

helping more women with postpartum depression receive treatment with ZURZUVAE, advancing our focused R&D efforts, and creating near and long-term value for Sage and its shareholders.

Fourth Quarter 2024 Portfolio Updates

Sage is focused on the goal of

establishing ZURZUVAE as the standard of care for women with postpartum depression (PPD). The current commercialization investment plan includes joint sales force expansions and planned digital marketing campaigns to help expand market growth in

PPD, along with increased disease state awareness efforts to support improved PPD screening and diagnosis. The Company anticipates these investments will help support the goal of significant topline revenue growth in 2025. As of the fourth quarter

and full year ended December 31, 2024, the following results had been achieved:

Related to payor coverage:

In terms of prescriber trends:

SAGE-319 is an extrasynaptic-preferring GABAA receptor positive

allosteric modulator (PAM) designed to have a novel pharmacology and a differentiated clinical profile from other GABAA 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, if any, 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.

FINANCIAL RESULTS FOR THE FOURTH QUARTER AND FULL YEAR 2024

Conference Call Information

Sage will host a conference call and webcast today, February 11, 2025, at 4:30 p.m. ET to review its fourth quarter and full year 2024 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,

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 help 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 investment plans for ZURZUVAE and

our expectations regarding the impact of increased investment, including joint sales force expansions and planned digital marketing campaigns, in support of our goal to achieve significant topline revenue growth; our plans and other goals related to

other aspects of commercialization; anticipated timelines for completion of enrollment in clinical trials and reporting of results with respect to certain of our programs, 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, cost savings (including our anticipated decrease in operating expenses in 2025 as compared to 2024), and our goal to create near and long-term value for Sage and its stockholders; 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, 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 read-outs 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 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 and ZULRESSO; we may not achieve revenues from our

products that may be successfully developed in the future at levels we expect; 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.