Nature of the Business	6 Months Ended
Jun. 30, 2025
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Nature of the Business	1. Nature of the Business Sage Therapeutics, Inc. (“Sage” or the “Company”) is a biopharmaceutical company with a mission to pioneer solutions to deliver life-changing brain health medicines, so every person can thrive. The Company’s product ZURZUVAE® (zuranolone) was approved by the U.S. Food and Drug Administration (the “FDA”) on August 4, 2023, for the treatment of postpartum depression (“PPD”) in adults. ZURZUVAE is a neuroactive steroid that is a positive allosteric modulator of GABAA receptors, targeting both synaptic and extrasynaptic GABAA receptors, and is the first oral, once-daily, 14-day treatment specifically indicated for adults with PPD. ZURZUVAE became commercially available for women with PPD in December 2023. The Company and Biogen MA Inc. (“BIMA”) and Biogen International GmbH (together with BIMA, “Biogen”) collaborate on the commercialization of ZURZUVAE for the treatment of women with PPD. The Company has a portfolio of product candidates with a current focus on modulating two critical central nervous system (“CNS”) receptor systems, GABA and NMDA. The GABA receptor family, which is recognized as the major inhibitory neurotransmitter in the CNS, mediates downstream neurologic and bodily function via activation of GABAA receptors. The NMDA-type receptors of the glutamate receptor system are a major excitatory receptor system in the CNS. Dysfunction in these systems is implicated in a broad range of CNS disorders. The Company is targeting diseases and disorders of the brain across its pipeline. The Company’s product ZULRESSO® (brexanolone) CIV injection was previously approved in the U.S. for the treatment of PPD in individuals 15 years old and older. The Company discontinued commercial availability of ZULRESSO as of December 31, 2024, and withdrew the NDA for ZULRESSO in April 2025. In October 2024, the Company executed a plan to reorganize its business operations, including a reduction of approximately 33% of the Company’s total workforce and approximately 55% of the Company’s research and development workforce. See Note 11, Restructuring, for further details. The Company was incorporated under the laws of the State of Delaware on April 16, 2010, and commenced operations on January 19, 2011, as Sterogen Biopharma, Inc. On September 13, 2011, the Company changed its name to Sage Therapeutics, Inc. Proposed Acquisition by Supernus Pharmaceuticals, Inc. On June 13, 2025, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”), by and among the Company, Supernus Pharmaceuticals, Inc., a Delaware corporation (“Supernus”), and Saphire, Inc., a Delaware corporation and a wholly owned subsidiary of Supernus (“Purchaser”). Pursuant to the Merger Agreement, on July 2, 2025, Purchaser commenced a tender offer to purchase all of the outstanding shares of the Company’s common stock (the “Shares”) for $8.50 per Share, net to the seller in cash, without interest and subject to any withholding of taxes, plus one nontransferable contractual contingent value right (“CVR”) per Share, which represents the right to receive up to $3.50 per Share upon the satisfaction of specified milestones, net to the seller in cash, without interest and subject to any withholding of taxes, pursuant to the CVR Agreement (as defined in the Merger Agreement), upon the terms and subject to the conditions set forth in the Offer to Purchase, dated July 2, 2025, as amended or supplemented from time to time, and in the related Letter of Transmittal, as amended or supplemented from time to time (together, the “Offer”). The initial expiration date of the Offer is one minute after 11:59 p.m., Eastern Time, on July 30, 2025, unless extended or earlier terminated as permitted by the Merger Agreement. Each CVR represents the right to receive (i) $0.50 upon the first commercial sale in Japan after regulatory approval in Japan to a third-party customer of the pharmaceutical product that, as of the date of the CVR Agreement, is marketed in the U.S. under the name ZURZUVAE and is the subject of the current regulatory filing (including any amended filings based thereon) by Shionogi & Co., Ltd. (“Shionogi”), inclusive of its affiliates, the Company’s collaboration partner in Japan, for the treatment of major depressive disorder on or prior to June 30, 2026; (ii) $1.00 upon achievement of Net Sales (as defined in the CVR Agreement) of ZURZUVAE equal to or exceeding $250,000,000 in the U.S. during a calendar year on or prior to December 31, 2027; (iii) $1.00 upon achievement of Net Sales of ZURZUVAE equal to or exceeding $300,000,000 in the U.S. during a calendar year on or prior to December 31, 2028; and (iv) $1.00 upon achievement of Net Sales of ZURZUVAE equal to or exceeding $375,000,000 in the U.S. during a calendar year on or prior to December 31, 2030. If more than one milestone is achieved during any twelve-month period, all milestone payments corresponding to such achieved milestones shall be payable. The Merger Agreement provides, among other things, that if the Offer is consummated, as soon as practicable (and in no event later than one (1) business day) following the consummation of the Offer and subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, and in accordance with the relevant provisions of the Delaware General Corporation Law (the “DGCL”) and other applicable legal requirements, Purchaser will be merged with and into the Company (the “Merger”), the separate existence of Purchaser will cease and the Company will continue as the surviving corporation in the Merger, becoming a wholly owned subsidiary of Supernus. As a result of the Merger, the Company will cease to be a publicly traded company. The consummation of the Offer is subject to the satisfaction or waiver of various conditions set forth in the Merger Agreement, including (i) there being validly tendered (and not validly withdrawn) Shares that, considered together with all other Shares (if any) beneficially owned by Supernus and its affiliates, represent one more Share than 50% of the total number of Shares outstanding at the time of the expiration of the Offer (the “Minimum Condition”); provided, however, that for purposes of determining whether the Minimum Condition has been satisfied, the parties shall exclude Shares tendered in the Offer pursuant to guaranteed delivery procedures that have not yet been “received” (as such term is defined in Section 251(h)(6)(f) of the DGCL); (ii) any waiting period (or any extension thereof) applicable to the Offer under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, which waiting period expired on July 25, 2025; (iii) the accuracy of the representations and warranties of the Company contained in the Merger Agreement, subject to customary materiality standards, thresholds and exceptions; (iv) the Company’s compliance with, or performance of, in all material respects its covenants and agreements contained in the Merger Agreement; (v) there having not occurred any Material Adverse Effect (as defined in the Merger Agreement) that is continuing; and (vi) other customary conditions set forth in Annex I to the Merger Agreement. The consummation of the Offer and Merger is not subject to a financing condition. The Merger Agreement includes representations, warranties and covenants of the parties customary for a transaction of this nature, including with respect to the operations of the business of the Company between signing and closing, governmental filings and approvals and other matters. The Merger Agreement also includes customary termination provisions for both the Company and Supernus and provides that, in connection with the termination of the Merger Agreement under specified circumstances, including termination by the Company in order to enter into an acquisition agreement that the Board of Directors of the Company (the “Board”) has determined constitutes a Superior Offer (as defined in the Merger Agreement), the Company will be required to pay Supernus a termination fee of $22,376,056. Risks and Uncertainties The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, but not limited to, the risks associated with developing product candidates at each stage of non-clinical and clinical development; the challenges associated with gaining regulatory approval of such product candidates; the risks associated with the marketing and sale of pharmaceutical products; the potential for development by third parties of new technological innovations that may compete with the Company’s products and product candidates; the dependence on key personnel; the challenges of protecting proprietary technology; the need to comply with government regulations; the high costs of drug development; the uncertainty of being able to secure additional capital when needed to fund operations; and the direct or indirect impacts of the macroeconomic environment and geopolitical events on its development activities, operations and financial condition. The product candidates developed by the Company require approvals from the FDA or foreign regulatory authorities prior to commercial sales. There can be no assurance that the current and future product candidates of the Company will receive, or that ZURZUVAE will maintain, the necessary approvals. If the Company fails to successfully complete clinical development and generate results sufficient to file for regulatory approval or is denied approval or approval is delayed for any of its product candidates, such occurrences may have a material adverse impact on the Company’s business and its financial condition. The Company is also subject to additional risks and uncertainties arising from changes to the macroeconomic environment and geopolitical events. U.S. and global financial markets have experienced volatility and disruption due to macroeconomic and geopolitical events such as the implementation of tariffs, inflation, the risk of a recession and ongoing conflicts in other countries. In addition, if equity and credit markets deteriorate, it may make any future debt or equity financing more difficult to obtain on favorable terms, and potentially more dilutive to existing stockholders. The Company cannot predict at this time to what extent it and its collaborators, employees, suppliers, contract manufacturers and/or vendors could potentially be negatively impacted by these events. Going Concern Under Accounting Standards Update (“ASU”) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40), the Company has the responsibility to evaluate whether conditions and/or events raise substantial doubt about its ability to meet its future financial obligations as they become due within one year after the date that the financial statements are issued. The Company has incurred losses and negative cash flows from operations in each year since its inception, except for net income of $606.1 million for the year ended December 31, 2020, reflecting revenue recognized under a collaboration and license agreement with Biogen (the “Biogen Collaboration Agreement”). As of June 30, 2025, the Company had an accumulated deficit of $3.1 billion. Until such time, if ever, as the Company can generate substantial product revenue and/or collaboration revenue and achieve sustained profitability, the Company expects to finance its cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other sources of funding. If the Company is unable to raise additional funds through equity or debt financings or other sources of funding when needed, the Company may need to delay, limit, reduce or terminate product development or future commercialization efforts or grant rights to develop and market products or product candidates that the Company would otherwise prefer to develop and market itself. The Company expects that, based on its current operating plans, the Company’s existing cash, cash equivalents and marketable securities will be sufficient to fund its currently planned operations for at least the next 12 months from the filing date of these unaudited interim condensed consolidated financial statements (“condensed consolidated financial statements”). The Company anticipates it will require additional financing to fund its future operations. Even if the Company believes it has sufficient funds for its current or future operating plans, the Company may seek to raise additional capital if market conditions are favorable or in light of other strategic considerations.

Sage Therapeutics, Inc. (“Sage” or the “Company”) is a biopharmaceutical company with a mission to pioneer solutions to deliver life-changing brain health medicines, so every person can thrive.

The Company’s product ZURZUVAE® (zuranolone) was approved by the U.S. Food and Drug Administration (the “FDA”) on August 4, 2023, for the treatment of postpartum depression (“PPD”) in adults. ZURZUVAE is a neuroactive steroid that is a positive allosteric modulator of GABAA receptors, targeting both synaptic and extrasynaptic GABAA receptors, and is the first oral, once-daily, 14-day treatment specifically indicated for adults with PPD. ZURZUVAE became commercially available for women with PPD in December 2023. The Company and Biogen MA Inc. (“BIMA”) and Biogen International GmbH (together with BIMA, “Biogen”) collaborate on the commercialization of ZURZUVAE for the treatment of women with PPD.

The Company has a portfolio of product candidates with a current focus on modulating two critical central nervous system (“CNS”) receptor systems, GABA and NMDA. The GABA receptor family, which is recognized as the major inhibitory neurotransmitter in the CNS, mediates downstream neurologic and bodily function via activation of GABAA receptors. The NMDA-type receptors of the glutamate receptor system are a major excitatory receptor system in the CNS. Dysfunction in these systems is implicated in a broad range of CNS disorders. The Company is targeting diseases and disorders of the brain across its pipeline.

The Company’s product ZULRESSO® (brexanolone) CIV injection was previously approved in the U.S. for the treatment of PPD in individuals 15 years old and older. The Company discontinued commercial availability of ZULRESSO as of December 31, 2024, and withdrew the NDA for ZULRESSO in April 2025.

In October 2024, the Company executed a plan to reorganize its business operations, including a reduction of approximately 33% of the Company’s total workforce and approximately 55% of the Company’s research and development workforce. See Note 11, Restructuring, for further details.

The Company was incorporated under the laws of the State of Delaware on April 16, 2010, and commenced operations on January 19, 2011, as Sterogen Biopharma, Inc. On September 13, 2011, the Company changed its name to Sage Therapeutics, Inc.

On June 13, 2025, the Company entered into an Agreement and Plan of Merger (the “Merger Agreement”), by and among the Company, Supernus Pharmaceuticals, Inc., a Delaware corporation (“Supernus”), and Saphire, Inc., a Delaware corporation and a wholly owned subsidiary of Supernus (“Purchaser”). Pursuant to the Merger Agreement, on July 2, 2025, Purchaser commenced a tender offer to purchase all of the outstanding shares of the Company’s common stock (the “Shares”) for $8.50 per Share, net to the seller in cash, without interest and subject to any withholding of taxes, plus one nontransferable contractual contingent value right (“CVR”) per Share, which represents the right to receive up to $3.50 per Share upon the satisfaction of specified milestones, net to the seller in cash, without interest and subject to any withholding of taxes, pursuant to the CVR Agreement (as defined in the Merger Agreement), upon the terms and subject to the conditions set forth in the Offer to Purchase, dated July 2, 2025, as amended or supplemented from time to time, and in the related Letter of Transmittal, as amended or supplemented from time to time (together, the “Offer”). The initial expiration date of the Offer is one minute after 11:59 p.m., Eastern Time, on July 30, 2025, unless extended or earlier terminated as permitted by the Merger Agreement.

Each CVR represents the right to receive (i) $0.50 upon the first commercial sale in Japan after regulatory approval in Japan to a third-party customer of the pharmaceutical product that, as of the date of the CVR Agreement, is marketed in the U.S. under the name ZURZUVAE and is the subject of the current regulatory filing (including any amended filings based thereon) by Shionogi & Co., Ltd. (“Shionogi”), inclusive of its affiliates, the Company’s collaboration partner in Japan, for the treatment of major depressive disorder on or prior to June 30, 2026; (ii) $1.00 upon achievement of Net Sales (as defined in the CVR Agreement) of ZURZUVAE equal to or exceeding $250,000,000 in the U.S. during a calendar year on or prior to December 31, 2027; (iii) $1.00 upon achievement of Net Sales of ZURZUVAE equal to or exceeding $300,000,000 in the U.S. during a calendar year on or prior to December 31, 2028; and (iv) $1.00 upon achievement of Net Sales of ZURZUVAE equal to or exceeding $375,000,000 in the U.S. during a calendar year on or prior to December 31, 2030. If more than one milestone is achieved during any twelve-month period, all milestone payments corresponding to such achieved milestones shall be payable.

The Merger Agreement provides, among other things, that if the Offer is consummated, as soon as practicable (and in no event later than one (1) business day) following the consummation of the Offer and subject to the satisfaction or waiver of the conditions set forth in the Merger Agreement, and in accordance with the relevant provisions of the Delaware General Corporation Law (the “DGCL”) and other applicable legal requirements, Purchaser will be merged with and into the Company (the “Merger”), the separate existence of Purchaser will cease and the Company will continue as the surviving corporation in the Merger, becoming a wholly owned subsidiary of Supernus. As a result of the Merger, the Company will cease to be a publicly traded company.

The consummation of the Offer is subject to the satisfaction or waiver of various conditions set forth in the Merger Agreement, including (i) there being validly tendered (and not validly withdrawn) Shares that, considered together with all other Shares (if any) beneficially owned by Supernus and its affiliates, represent one more Share than 50% of the total number of Shares outstanding at the time of the expiration of the Offer (the “Minimum Condition”); provided, however, that for purposes of determining whether the Minimum Condition has been satisfied, the parties shall exclude Shares tendered in the Offer pursuant to guaranteed delivery procedures that have not yet been “received” (as such term is defined in Section 251(h)(6)(f) of the DGCL); (ii) any waiting period (or any extension thereof) applicable to the Offer under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, which waiting period expired on July 25, 2025; (iii) the accuracy of the representations and warranties of the Company contained in the Merger Agreement, subject to customary materiality standards, thresholds and exceptions; (iv) the Company’s compliance with, or performance of, in all material respects its covenants and agreements contained in the Merger Agreement; (v) there having not occurred any Material Adverse Effect (as defined in the Merger Agreement) that is continuing; and (vi) other customary conditions set forth in Annex I to the Merger Agreement. The consummation of the Offer and Merger is not subject to a financing condition.

The Merger Agreement includes representations, warranties and covenants of the parties customary for a transaction of this nature, including with respect to the operations of the business of the Company between signing and closing, governmental filings and approvals and other matters. The Merger Agreement also includes customary termination provisions for both the Company and Supernus and provides that, in connection with the termination of the Merger Agreement under specified circumstances, including termination by the Company in order to enter into an acquisition agreement that the Board of Directors of the Company (the “Board”) has determined constitutes a Superior Offer (as defined in the Merger Agreement), the Company will be required to pay Supernus a termination fee of $22,376,056.

Risks and Uncertainties

The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, but not limited to, the risks associated with developing product candidates at each stage of non-clinical and clinical development; the challenges associated with gaining regulatory approval of such product candidates; the risks associated with the marketing and sale of pharmaceutical products; the potential for development by third parties of new technological innovations that may compete with the Company’s products and product candidates; the dependence on key personnel; the challenges of protecting proprietary technology; the need to comply with government regulations; the high costs of drug development; the uncertainty of being able to secure additional capital

when needed to fund operations; and the direct or indirect impacts of the macroeconomic environment and geopolitical events on its development activities, operations and financial condition.

The product candidates developed by the Company require approvals from the FDA or foreign regulatory authorities prior to commercial sales. There can be no assurance that the current and future product candidates of the Company will receive, or that ZURZUVAE will maintain, the necessary approvals. If the Company fails to successfully complete clinical development and generate results sufficient to file for regulatory approval or is denied approval or approval is delayed for any of its product candidates, such occurrences may have a material adverse impact on the Company’s business and its financial condition.

The Company is also subject to additional risks and uncertainties arising from changes to the macroeconomic environment and geopolitical events. U.S. and global financial markets have experienced volatility and disruption due to macroeconomic and geopolitical events such as the implementation of tariffs, inflation, the risk of a recession and ongoing conflicts in other countries. In addition, if equity and credit markets deteriorate, it may make any future debt or equity financing more difficult to obtain on favorable terms, and potentially more dilutive to existing stockholders. The Company cannot predict at this time to what extent it and its collaborators, employees, suppliers, contract manufacturers and/or vendors could potentially be negatively impacted by these events.

Going Concern

Under Accounting Standards Update (“ASU”) No. 2014-15, Presentation of Financial Statements—Going Concern (Subtopic 205-40), the Company has the responsibility to evaluate whether conditions and/or events raise substantial doubt about its ability to meet its future financial obligations as they become due within one year after the date that the financial statements are issued. The Company has incurred losses and negative cash flows from operations in each year since its inception, except for net income of $606.1 million for the year ended December 31, 2020, reflecting revenue recognized under a collaboration and license agreement with Biogen (the “Biogen Collaboration Agreement”). As of June 30, 2025, the Company had an accumulated deficit of $3.1 billion. Until such time, if ever, as the Company can generate substantial product revenue and/or collaboration revenue and achieve sustained profitability, the Company expects to finance its cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances, licensing arrangements and other sources of funding. If the Company is unable to raise additional funds through equity or debt financings or other sources of funding when needed, the Company may need to delay, limit, reduce or terminate product development or future commercialization efforts or grant rights to develop and market products or product candidates that the Company would otherwise prefer to develop and market itself.

The Company expects that, based on its current operating plans, the Company’s existing cash, cash equivalents and marketable securities will be sufficient to fund its currently planned operations for at least the next 12 months from the filing date of these unaudited interim condensed consolidated financial statements (“condensed consolidated financial statements”). The Company anticipates it will require additional financing to fund its future operations. Even if the Company believes it has sufficient funds for its current or future operating plans, the Company may seek to raise additional capital if market conditions are favorable or in light of other strategic considerations.