Soleno receives FDA approval for Prader-Willi hyperphagia therapy

Soleno Therapeutics has achieved a significant milestone with the U.S. Food and Drug Administration (FDA) granting approval for their drug, diazoxide choline, marketed under the name Vykat XR, aimed at treating excessive hunger in individuals with Prader-Willi syndrome. This decision comes after a brief three-month delay as the FDA required additional time to review the drug application, labeling the responses from Soleno as a "major amendment" in November 2024. Importantly, the FDA did not express any reservations regarding the safety, efficacy, or manufacturing of the drug.

Prader-Willi syndrome is a rare genetic condition resulting from anomalies in chromosome 15, characterized by symptoms such as low muscle tone, developmental delays, and behavioral issues. One of the most severe and distinctive features of this disorder is hyperphagia, or an extreme hunger that, if not properly managed, can lead to severe obesity and related health problems. Vykat XR emerges as the first FDA-approved treatment specifically targeting hyperphagia in individuals with Prader-Willi syndrome.

The FDA's approval relied on findings from the Phase III Study C602-RWP clinical trial, which demonstrated the drug's efficacy during a 16-week randomized withdrawal study. Participants who switched to a placebo experienced a statistically significant deterioration in hyperphagia compared to those who continued treatment with Vykat XR. Additionally, the drug was investigated in the Phase III DESTINY-PWS trial, involving 127 participants with confirmed Prader-Willi syndrome. While the trial did not show a statistically significant reduction in hyperphagia overall, it did reveal "nominally significant" reductions in fat mass and general improvements in the condition of patients, according to investigators.

Vykat XR, an extended-release tablet containing a crystalline salt formulation of diazoxide, operates by activating the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel, a mechanism involved in hunger regulation. Soleno Therapeutics has announced plans to launch Vykat XR in the United States in April 2025.

The approval of Vykat XR has been met with enthusiasm from the Prader-Willi Syndrome Association. Stacy Ward, the CEO of the association, remarked on the historic significance of this development, emphasizing that the FDA's decision represents a monumental step forward in addressing the long-standing unmet needs of those affected by Prader-Willi syndrome and their families.

Looking beyond the United States, Soleno has set its sights on Europe, with intentions to seek approval for Vykat XR in the European Union in the first half of 2025. According to GlobalData's Pharma Intelligence Center, Vykat XR is projected to generate $876 million in sales by 2030.

In summary, the approval of Vykat XR by the FDA marks a pivotal advancement in the treatment of Prader-Willi syndrome, addressing one of its most challenging symptoms. This development offers new hope to patients and their families, promising to improve the quality of life for those affected by this rare genetic disorder. With plans to expand to the European market, Vykat XR is poised to make a substantial impact on the global stage in the coming years.