Diazoxide choline extended‐release tablet in people with Prader‐Willi syndrome: results from long‐term open‐label study

Abstract Objective This study assessed the effect of 1‐year administration of diazoxide choline extended‐release tablet (DCCR) on hyperphagia and other complications of Prader‐Willi syndrome (PWS). Methods The authors studied 125 participants with PWS, age ≥ 4 years, who were enrolled in the DESTINY PWS Phase 3 study and who received DCCR for up to 52 weeks in DESTINY PWS and/or its open‐label extension. The primary efficacy endpoint was Hyperphagia Questionnaire for Clinical Trials (HQ‐CT) score. Other endpoints included behavioral assessments, body composition, hormonal measures, and safety. Results DCCR administration resulted in significant improvements in HQ‐CT (mean [SE] −9.9 [0.77], p < 0.0001) and greater improvements in those with more severe baseline hyperphagia (HQ‐CT > 22). Improvements were seen in aggression, anxiety, and compulsivity (all p < 0.0001). There were reductions in leptin, insulin, and insulin resistance, as well as a significant increase in adiponectin (all p < 0.004). Lean body mass was increased ( p < 0.0001). Disease severity was reduced as assessed by clinician and caregiver (both p < 0.0001). Common treatment‐emergent adverse events included hypertrichosis, peripheral edema, and hyperglycemia. Adverse events infrequently resulted in discontinuation (7.2%). Conclusions DCCR administration to people with PWS was well tolerated and associated with broad‐ranging improvements in the syndrome. Sustained administration of DCCR has the potential to reduce disease severity and the burden of care for families.