The FDA Approves a Once-Daily Medication for Treating Hyperphagia Caused by Prader-Willi Syndrome

The Food and Drug Administration (FDA) has approved Vykat XR (diazoxide choline [DCCR] extended-release tablets; Soleno, Redwood City, CA) for the treatment of hyperphagia in people with Prader-Willi syndrome (PWS) aged 4 years and older. Vykat XR is an extended-release formulation of DCCR, a crystalline salt of diazoxide that activates the ATP-sensitive potassium (KATP) channels in tissues, thereby addressing hyperphagia—the most burdensome symptom associated with the neurodevelopmental disorder PWS. Vykat XR is approved for once-daily oral administration.

The approval was based on data from the phase 3 randomized, double-blind, placebo-controlled DESTINY PWS clinical trial (NCT03440814), in which 127 participants aged 4 years or older with a diagnosis of PWS were randomized 2:1 to receive either Vykat XR or placebo once daily. The primary endpoint was reduction in hyperphagia from baseline to week 13, as measured by caregiver questionnaire.

• The primary endpoint was not met with statistical significance for the overall population.
• Compared with placebo, a subset of participants treated with Vykat XR who had severe hyperphagia at baseline did meet the primary endpoint, showing significant reductions hyperphagia (least-squares mean [LSM], -9.67 vs -4.26; P=.012).
• Participants who received Vykat XR showed significant improvements in clinical global impression of improvement (CG-I; P=.029) and reductions in body fat mass (P=.023) compared with those who received placebo.
• Common adverse events included hypertrichosis, peripheral edema, and hyperglycemia, with a low discontinuation rate (7.2%).

“I am excited to have VYKAT XR available to help treat hyperphagia, which is the most life-limiting aspect of PWS,” said Jennifer Miller, MD, Professor of Pediatric Endocrinology at the University of Florida, Gainesville and Prnicipal Investigator of the Vykat XR clinical development program. “Families of people with PWS 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.”