Soleno Receives FDA Approval for Prader-Willi Syndrome Hyperphagia

The U.S. Food and Drug Administration (FDA) has recently approved Soleno Therapeutics' new medication, Vykat XR, as a notable advancement in treating Prader-Willi syndrome (PWS). This approval marks a significant development in addressing hyperphagia, a predominant symptom of this rare genetic disorder. Vykat XR, formulated as diazoxide choline extended-release tablets, is the first pharmaceutical intervention that directly targets the intense hunger associated with PWS, offering hope to both adult and pediatric patients aged four and older.

Soleno Therapeutics plans to introduce Vykat XR in the United States by next month following this approval. Stifel analysts have highlighted the approval as a "significant win" for Soleno, praising the drug’s label as very favorable due to its clean profile without boxed warnings or restrictions based on hyperphagia severity. They emphasized the potential for Vykat XR to make a strong market entry given the unmet needs within this sector, which they see as a potential blockbuster opportunity.

Prader-Willi syndrome is a rare neurodevelopmental disorder with genetic roots, impacting approximately one in every 15,000 live births. Hyperphagia, characterized by an overwhelming desire to eat, defines PWS, posing risks that extend beyond compromised quality of life to life-threatening complications if left untreated. Vykat XR’s formulation employs diazoxide, a molecule with a history of treating rare conditions in infants, although it was not previously used for PWS.

To explore the efficacy of Vykat XR in treating hyperphagia in PWS patients, Soleno conducted a Phase III clinical program with two trials: C601, a randomized and placebo-controlled study, and C602, an open-label extension study. Results from these trials, presented in June 2022, demonstrated notable improvements in various metabolic parameters. Patients showed enhancements in lean body mass, fasting insulin and leptin levels, as well as insulin sensitivity and adiponectin levels, which is known for its cardioprotective properties.

The approval of Vykat XR is a continuation of advancements within the biopharmaceutical sphere, focusing on rare diseases. For example, Novartis recently received FDA approval for Fabhalta, a factor B inhibitor, targeted at C3 glomerulopathy—a condition characterized by elevated proteinuria. This approval was groundbreaking as no other treatments had been developed for this indication before. Similarly, Mirum Pharmaceuticals achieved approval for Ctelix, used in treating cerebrotendinous xanthomatosis, marking another first in the industry. Additionally, in February, the FDA approved SpringWorks Therapeutics' Gomekli drug for use in both adults and children with neurofibromatosis type 1, specifically targeting symptomatic plexiform neurofibromas.

Overall, the approval of Vykat XR by the FDA represents a significant advancement for Soleno Therapeutics and provides a promising treatment option for individuals living with Prader-Willi syndrome. This development is a part of a broader trend in pharmaceutical innovation targeting rare diseases, indicating ongoing dedication to addressing unmet medical needs.