7519 Withdrawal of DCCR (Diazoxide Choline) Extended-Release Tablets Worsens Hyperphagia and Increases Weight and BMI in a 16-week Double-blind, Placebo-controlled, Randomized Withdrawal Period in Patients with Prader Willi Syndrome

Abstract

Background: Prader-Willi syndrome (PWS) is a rare genetic neurobehavioral-metabolic disease characterized by hyperphagia, endocrinopathies, weight gain, hypotonia, behavioral problems, and an increased risk of mortality and reduced life expectancy. There are currently no approved treatments for hyperphagia in PWS. Diazoxide choline extended-release (DCCR) is a novel, once daily oral therapy being developed for the treatment of PWS. Herein, we present results of the Randomized Withdrawal Period (RWP) of Clinical Study C602, a long-term treatment study of DCCR in people with PWS. Objectives and Methods: This was a 16-week multi-center, double-blind, placebo-controlled RWP that enrolled participants ≥4 years of age who were actively enrolled in the open label period of Clinical Study C602 and had received 2-4 years of DCCR treatment (target dose: ≥3.3 mg/kg; optimal range: 4.2-5.8 mg/kg) at the time of RWP entry. RWP-eligible participants were randomized 1:1 to continue DCCR or withdraw from DCCR and receive Placebo. The primary objective was to evaluate the effect of continued DCCR administration versus Placebo on hyperphagia based on the change in Hyperphagia Questionnaire for Clinical Trials (HQ-CT) Total Score from Baseline to Week 16. Additional endpoints included: the Clinical Global Impression of Severity (CGI-S) and Clinical Global Impression of Improvement (CGI-I) at Week 16; changes in body composition (weight, BMI, and BMI z-scores) at Week 16; and the safety profile of DCCR. Results: DCCR (n=38) and Placebo (n=39) groups were generally balanced for demographic and baseline characteristics. At Week 16, a statistically significant difference in change from baseline in HQ-CT Total Score was observed between DCCR and Placebo groups with HQ-CT Total Scores increasing markedly (indicating worsening hyperphagia) in the Placebo group compared to the DCCR group (LSMean difference [SE] -5.0 [1.57], p=0.002). CGI-S and CGI-I showed trends towards worsening in the Placebo group versus the DCCR group (p=0.079 and 0.092, respectively). The Placebo group also experienced significantly greater increases in weight, BMI, and BMI z-scores (p=0.035, 0.034, and 0.023, respectively) than the DCCR group. DCCR was well-tolerated, with no new or unexpected safety signals, and no serious adverse events or discontinuations due to adverse events in the DCCR group. Conclusions: In this 16-week RWP, the Placebo group experienced significant worsening in hyperphagia and increases in body weight, BMI, and BMI z-scores, along with worsening trends for the CGI-S and CGI-I, compared to the DCCR group. DCCR was well tolerated, with a safety profile that was consistent with prior experience. These data suggest treatment with DCCR may lead to clinical benefits in people with PWS by reducing hyperphagia and improving body composition.