Supernus Pharmaceuticals announced Monday a definitive agreement to acquire Sage Therapeutics through a tender offer valued at up to $795 million, marking a significant expansion of its neuropsychiatry portfolio with the addition of ZURZUVAE, the first FDA-approved oral treatment for postpartum depression.
The deal structure includes an upfront cash payment of $8.50 per share, totaling approximately $561 million, plus one non-tradable contingent value right (CVR) worth up to $3.50 per share in cash upon achieving specific milestones. The transaction is expected to close in the third quarter of 2025, subject to customary closing conditions and regulatory approvals.
Strategic Acquisition Strengthens CNS Portfolio
The acquisition provides Supernus with ZURZUVAE (zuranolone) capsules CIV, a neuroactive steroid GABA-A receptor positive modulator indicated for treating postpartum depression in adults. Through Sage's collaboration agreement with Biogen, Supernus will receive 50% of the total net revenue Biogen records for ZURZUVAE in the U.S.
"This acquisition represents a major step in bolstering our future growth. It augments our growth profile by adding a significant fourth growth product to our portfolio and further diversifies our sources of future growth," said Jack Khattar, President and CEO of Supernus Pharmaceuticals.
ZURZUVAE generated collaboration revenue of $36.1 million for the full year 2024 and $13.8 million for the first quarter of 2025. Combined with Supernus' three other growth products—Qelbree, ONAPGO, and GOCOVRI—the company believes it is positioned for significant future growth.
Financial Impact and Synergies
The acquisition is expected to be significantly accretive in 2026, with potential cost synergies of up to $200 million on an annual basis. The strong fit with existing Supernus infrastructure is anticipated to drive these substantial cost savings while diversifying and increasing the company's revenue base and cash flow.
All cash consideration will be funded through existing balance sheet cash, demonstrating Supernus' strong financial position to execute the transaction without external financing.
Contingent Value Rights Structure
The CVR entitles Sage stockholders to receive additional payments based on achieving specific sales and commercial milestones within defined periods. The milestones include $1.00 per share if annual net sales of ZURZUVAE allocable to Supernus reach $250 million or more in the U.S. by end of 2027, $1.00 per share for reaching $300 million by end of 2028, $1.00 per share for reaching $375 million by end of 2030, and $0.50 per share upon first commercial sale in Japan after regulatory approval for major depressive disorder treatment by June 30, 2026.
Market Response and Strategic Rationale
The announcement sent Sage stock surging more than 35% to $9.07, while Supernus stock rose nearly 2% to $32.62. Analysts viewed the deal favorably given Sage's recent pipeline setbacks and limited commercial success.
"We see the SUPN bid as a best-case scenario for SAGE given the recent pipeline setbacks," said Wedbush analyst Laura Chico. The deal represents approximately a 26% premium over Sage's last closing price and a 17% premium to a previous bid from Biogen earlier in the year.
Barry Greene, CEO of Sage Therapeutics, stated: "This transaction follows a comprehensive strategic review by our Board of Directors, and I am confident this deal maximizes value for shareholders."
Regulatory and Safety Profile
ZURZUVAE carries important safety warnings, including decreased awareness and alertness that can affect driving ability, requiring patients to avoid driving or operating machinery for at least 12 hours after each dose. The drug may cause CNS depressant effects including sleepiness, drowsiness, and confusion. As a Schedule IV controlled substance, ZURZUVAE has potential for abuse and dependence.
The most common side effects include sleepiness, dizziness, common cold symptoms, diarrhea, fatigue, and urinary tract infections. The drug also carries warnings about increased suicide risk in patients under 24 years of age.
Transaction Timeline and Approvals
The transaction has been approved by both companies' boards of directors and is expected to close in the third quarter of 2025. Following the successful tender offer, Supernus will acquire any remaining shares through a second-step merger at the same consideration.
Moelis & Company is serving as exclusive financial advisor to Supernus, while Goldman Sachs is advising Sage. The companies will provide revised financial guidance after the transaction closes.
