FDA Approves First Treatment for Hyperphagia in Prader-Willi Syndrome

The U.S. Food and Drug Administration (FDA) has approved Soleno Therapeutics' Vykat XR (diazoxide choline extended-release tablet) as the first treatment for hyperphagia associated with Prader-Willi syndrome (PWS). This landmark decision marks a significant breakthrough in addressing one of the most challenging aspects of this rare genetic disorder.

A New Hope for PWS Patients

Prader-Willi syndrome, affecting approximately one in every 15,000 live births, is characterized by low muscle tone, short stature, intellectual disabilities, and most notably, an insatiable hunger known as hyperphagia. Vykat XR is now approved for both adult and pediatric patients aged 4 years and older, offering a novel approach to managing this life-altering symptom.

Dr. Jennifer Miller of the University of Florida, a principal investigator in Vykat XR's clinical development program, emphasized the drug's potential impact: "This will help families of those with PWS who have been prisoners in their own homes because of the need to provide constant, eyes-on supervision 24/7 with access to food being completely restricted."

Clinical Efficacy and Safety Profile

Vykat XR's approval is supported by a comprehensive clinical program, including a Phase III trial consisting of two studies: C601 and C602. The efficacy of the drug was demonstrated in a unique 16-week withdrawal study, where patients who switched to placebo showed a statistically significant worsening of hyperphagia compared to those who remained on Vykat XR.

Long-term data presented in June 2022 revealed significant improvements in metabolic parameters, including better lean body mass, fasting insulin and leptin levels, insulin sensitivity, and adiponectin levels. The drug's safety profile, established over four years of data collection, showed common adverse reactions such as hypertrichosis, edema, hyperglycemia, and rash occurring in approximately 10% of patients.

Market Impact and Pricing

The approval of Vykat XR has had a significant impact on Soleno Therapeutics' market position, with the company's share price surging by 37% following the announcement. Analysts at Stifel have labeled the approval "a significant win" for Soleno, highlighting the drug's favorable label and lack of boxed warnings or exclusions based on hyperphagia severity.

Soleno has set the annual price for Vykat XR at $466,200, based on the average weight of patients in its clinical trials. The company expects to make the drug available in the United States as early as next month.

Anish Bhatnagar, M.D., CEO of Soleno Therapeutics, stated, "This approval represents a significant milestone for our company and for the PWS community who have had no options to treat the most disruptive aspect of this disease."

As the pharmaceutical industry continues to make strides in rare disease treatments, Vykat XR's approval highlights the ongoing commitment to addressing unmet medical needs and improving the lives of patients with challenging genetic disorders.