What Happened to Soleno Therapeutics, Inc.?
Soleno Therapeutics, Inc. is a biopharmaceutical company that successfully developed and commercialized VYKAT™ XR (diazoxide choline extended-release tablets), the first FDA-approved treatment for hyperphagia in Prader-Willi Syndrome. Following its strong commercial launch and significant revenue generation in 2025, the company announced on April 6, 2026, that it would be acquired by Neurocrine Biosciences for approximately $2.9 billion.
Quick Answer
Soleno Therapeutics, Inc. has been a clinical-stage biopharmaceutical company focused on rare diseases, most notably for its drug VYKAT™ XR, approved by the FDA in March 2025 for hyperphagia in Prader-Willi Syndrome. After a successful commercial launch and strong financial performance in 2025, the company announced on April 6, 2026, that it entered into a definitive agreement to be acquired by Neurocrine Biosciences for $53.00 per share in cash, totaling approximately $2.9 billion.
📊Key Facts
📅Complete Timeline15 events
Company Incorporated as Capnia, Inc.
The company was originally incorporated as Capnia, Inc., laying the groundwork for its future in biopharmaceuticals.
Rebranded to Soleno Therapeutics
Capnia, Inc. rebranded to Soleno Therapeutics, Inc., shifting its focus towards developing novel therapeutics for rare diseases.
DCCR Granted FDA Breakthrough Therapy Designation
Soleno's lead product candidate, DCCR (diazoxide choline extended-release tablets), received Breakthrough Therapy Designation from the FDA for the treatment of hyperphagia in Prader-Willi Syndrome.
NDA Submission for DCCR to FDA
Soleno Therapeutics submitted a New Drug Application (NDA) to the U.S. FDA for DCCR for the treatment of Prader-Willi Syndrome.
FDA Accepts NDA for DCCR with Priority Review
The FDA accepted Soleno's NDA for DCCR for filing and granted it Priority Review, setting a PDUFA target action date of December 27, 2024.
FDA Extends DCCR NDA Review Period
The FDA extended the review period for the DCCR NDA to March 27, 2025, citing a major amendment from responses to information requests, without safety concerns.
FDA Approves VYKAT™ XR for Prader-Willi Syndrome
The U.S. FDA approved VYKAT™ XR (formerly DCCR) for the treatment of hyperphagia in adults and children 4 years and older with Prader-Willi Syndrome, making it the first approved therapy for this indication.
Commercial Launch of VYKAT™ XR in U.S.
Soleno Therapeutics commenced the commercial launch of VYKAT™ XR in the United States, making the drug available to patients.
EMA Validates Marketing Authorization Application
The European Medicines Agency (EMA) validated Soleno's Marketing Authorization Application for Diazoxide Choline Prolonged-Release Tablets for PWS, initiating the review process for European approval.
Short Seller Report Published
Scorpion Capital published a report describing DCCR as overpriced and potentially unsafe for children, leading to a stock price decline.
Patient Death Disclosure
Soleno filed an 8-K report disclosing a patient death after taking DCCR, which further impacted its stock price.
Discontinuation Rate Reported
During its Q3 2025 earnings call, Soleno revealed an approximately 8% discontinuation rate for DCCR due to adverse effects.
Reports Strong Full-Year 2025 Financial Results
Soleno reported its Q4 and full-year 2025 financial results, announcing $190.4 million in revenue from VYKAT™ XR since its approval and achieving net income of approximately $20.9 million for the year.
Board Adopts Amended Bylaws
Soleno Therapeutics' Board of Directors approved and adopted amended and restated bylaws, updating governance and legal provisions.
Acquired by Neurocrine Biosciences
Neurocrine Biosciences announced a definitive agreement to acquire Soleno Therapeutics for $53.00 per share in cash, totaling approximately $2.9 billion, to expand its rare disease portfolio.
🔍Deep Dive Analysis
Soleno Therapeutics, Inc., originally incorporated as Capnia, Inc. in 1999, rebranded in May 2017 to focus on the development and commercialization of novel therapeutics for rare diseases. Its flagship product, diazoxide choline extended-release tablets, initially known as DCCR and later branded as VYKAT™ XR, became the cornerstone of its efforts to address Prader-Willi Syndrome (PWS), a rare genetic disorder characterized by chronic, life-threatening hyperphagia (insatiable hunger).
The journey for VYKAT™ XR gained significant momentum with the U.S. Food and Drug Administration (FDA) granting it Breakthrough Therapy, Fast Track, and Orphan Drug designations, underscoring its potential to meet a critical unmet medical need. Soleno submitted its New Drug Application (NDA) for DCCR in June 2024, which the FDA accepted for Priority Review in August 2024, setting an initial Prescription Drug User Fee Act (PDUFA) target action date for December 27, 2024. However, the review period was extended to March 27, 2025, after the FDA determined that responses to recent information requests constituted a major amendment to the NDA, though no safety, efficacy, or manufacturing concerns were cited.
A pivotal turning point occurred on March 26, 2025, when the FDA approved VYKAT™ XR for the treatment of hyperphagia in adults and pediatric patients aged four years and older with PWS, marking it as the first approved therapy for this indication. The commercial launch in the U.S. commenced in April 2025, and the drug quickly demonstrated strong early adoption, generating substantial revenue. By the third quarter of 2025, Soleno reported $66.0 million in revenue with 764 active patients on therapy, and full-year 2025 revenue reached $190.4 million, leading to profitability. In May 2025, Soleno also saw its Marketing Authorization Application for the drug validated by the European Medicines Agency (EMA), signaling potential expansion into European markets.
Despite the commercial success, Soleno faced challenges in late 2025 and early 2026. A short seller report in August 2025 questioned the drug's pricing and safety, followed by the disclosure of a patient death in September 2025 and reports of an 8% discontinuation rate due to adverse effects by November 2025. These events led to multiple securities class action lawsuits alleging that the company had downplayed or concealed safety concerns and data integrity issues related to the Phase 3 program. The company's stock price experienced volatility amidst these developments.
As of April 6, 2026, the most significant development is the announcement that Neurocrine Biosciences has entered into a definitive agreement to acquire Soleno Therapeutics. The all-cash transaction is valued at approximately $2.9 billion, with Neurocrine offering $53.00 per share, representing a premium of about 34% over Soleno's closing share price on April 2, 2026. This acquisition is expected to close within 90 days, subject to customary closing conditions and regulatory approvals, and will integrate VYKAT™ XR into Neurocrine's portfolio, strengthening its position in endocrinology and rare diseases.
What If...?
Explore alternate histories. What if Soleno Therapeutics, Inc. made different choices?