Soleno Therapeutics Submits and Validates EMA Application for Diazoxide Choline Tablets for Prader-Willi Hyperphagia

Soleno Therapeutics, Inc., a biopharmaceutical company based in Redwood City, California, announced a significant step forward in its efforts to combat Prader-Willi syndrome (PWS). The company has submitted a Marketing Authorization Application (MAA) for its Diazoxide Choline Prolonged-Release Tablets to the European Medicines Agency (EMA). This application seeks approval for the use of the medication in treating adults and children aged four and older who suffer from PWS-related hyperphagia, a life-limiting condition characterized by an insatiable appetite.

Anish Bhatnagar, M.D., the Chairman and CEO of Soleno Therapeutics, emphasized that the validation of their MAA marks a critical advancement in providing this essential therapy to the PWS community, particularly within the European Union. The company is optimistic about the potential of Diazoxide Choline to address the debilitating symptom of hyperphagia, which significantly affects the quality of life for individuals with PWS and their families. Soleno plans to collaborate closely with European regulatory bodies during the review process to expedite the availability of this treatment to patients in Europe, pending approval.

Soleno's estimations suggest that there are approximately 9,500 PWS patients across the United Kingdom, France, Germany, Italy, and Spain. The company has already secured Orphan Drug Designation for Diazoxide Choline in the EU, which could grant Soleno a decade of market exclusivity if the drug is approved. Such designation also comes with various regulatory and financial benefits that could bolster the company’s efforts in addressing this rare disease.

In the United States, Diazoxide Choline Prolonged-Release Tablets, marketed under the name VYKAT™ XR, received approval from the Food and Drug Administration (FDA) on March 26, 2025. This approval highlights the drug's role in treating hyperphagia among adults and pediatric patients aged four and older who are diagnosed with PWS.

Prader-Willi syndrome is a rare genetic disorder caused by abnormalities in chromosome 15, affecting neurodevelopment. It is estimated to occur in about one in every 15,000 live births. The most prominent symptom of PWS is hyperphagia, which manifests as an uncontrollable hunger, leading to food-related behavioral issues and a lack of normal satiety. This condition not only poses immediate health risks such as stomach rupture and choking but also contributes to long-term health problems like diabetes, obesity, and cardiovascular disease.

In terms of safety, the use of VYKAT XR is contraindicated in patients with known hypersensitivity to its components or to thiazides. Furthermore, hyperglycemia, including instances of diabetic ketoacidosis, has been reported in patients using the medication. Therefore, it is crucial for healthcare providers to monitor blood glucose levels before and during treatment, especially in patients with existing risk factors for hyperglycemia. Additionally, the medication has been associated with cases of edema due to fluid overload, necessitating careful monitoring for such symptoms.

The most common side effects observed with VYKAT XR include hypertrichosis, edema, hyperglycemia, and rash, occurring at a rate of 10% or more among patients, which is at least 2% higher than in those receiving a placebo. It is important for patients and healthcare providers to refer to the full prescribing information for comprehensive safety guidance.

Soleno Therapeutics remains dedicated to the development and commercialization of innovative treatments for rare diseases. With VYKAT XR as their first commercial product, the company continues to focus on meeting the needs of individuals affected by rare and challenging medical conditions like Prader-Willi syndrome.