Diazoxide Chloride Designated Breakthrough Therapy for Prader-Willi Syndrome

The Food and Drug Administration (FDA) has granted Breakthrough Therapy designation to diazoxide choline for the treatment of adults and children ages 4 years and older with genetically confirmed Prader-Willi syndrome (PWS) who have hyperphagia.

The investigational product is an extended-release tablet formulation of diazoxide chloride (DCCR), the crystalline salt of diazoxide. In patients with Prader-Willi syndrome, DCCR is expected to reduce hyperphagia through activation of the adenosine triphosphate–sensitive potassium channels in the hypothalamus.

The designation was supported by data from a phase 3 clinical development program that included patients 4 years of age and older with genetically confirmed PWS. In the double-blind, placebo-controlled DESTINY PWS trial (ClinicalTrials.gov Identifier: NCT03440814), study participants were randomly assigned to receive DCCR (n=82) or placebo (n=42). Findings showed DCCR significantly improved hyperphagia in patients with severe hyperphagia at baseline. Significant improvements in body composition were also observed.

In the open-label extension study (ClinicalTrials.gov Identifier: NCT03714373), patients enrolled in the DESTINY PWS trial were assessed following 1 year of DCCR administration. Results showed DCCR was associated with significant improvements in hyperphagia and PWS-related behaviors (eg, anxiety, compulsivity, disordered thinking, aggressive/disruptive behaviors). 

“The granting of Breakthrough Therapy designation, the first for a drug being developed for the treatment of PWS, marks another important milestone for our DCCR clinical development program,” said Anish Bhatnagar, MD, CEO  of Soleno Therapeutics. “This important designation is confirmation that the FDA views PWS as a serious condition and is an indication of DCCR’s potential to be a safe and effective treatment for PWS. We remain focused on preparing our NDA submission for DCCR in PWS, which we continue to expect will occur in mid-2024.”

Diazoxide choline previously received the FDA’s Orphan Drug and Fast Track designations for PWS.