Soleno Therapeutics has announced positive top-line results from the randomised withdrawal period of Study C602, a long-term treatment study of Diazoxide Choline (DCCR) Extended-Release tablets for the treatment of Prader-Willi syndrome (PWS).
The multi-centre, randomised, double-blind, placebo-controlled randomized withdrawal period enrolled 77 patients previously enrolled in Study C602 who had been on open-label treatment with DCCR for between two and four years. Participants were randomised 1:1 to receive either DCCR (n=38) or placebo (n=39) for a period of four months. The primary endpoint was the change from baseline in hyperphagia-related behaviours as assessed by the hyperphagia questionnaire for clinical trials (HQ-CT), a caregiver-completed nine item validated questionnaire for assessing hyperphagia in PWS. Secondary endpoints included investigator assessments of participants’ overall severity of illness and change in condition, as measured by Clinical Global Impression of Severity (CGI-S) and Clinical Global Impression of Improvement (CGI-I) ratings, respectively.
The results showed:
Hyperphagia-related behaviours markedly worsened in the placebo group compared to DCCR, represented by a highly statistically significant, clinically meaningful difference in mean change from baseline in the HQ-CT total score of 5.0 at week 16 (p=0.0022).
Secondary endpoints of CGI-S and CGI-I both showed strong trends towards worsening in the placebo group compared to DCCR over the course of the randomized withdrawal period (p=0.08 and 0.09), respectively.
DCCR continued to be generally well-tolerated in the randomized withdrawal period with no new or unexpected safety signals, including no serious adverse events or discontinuations due to adverse events occurring in any participants in the DCCR group.
“These results will support our planned submission of a New Drug Application (NDA) to the US Food and Drug Administration (FDA) mid-year of next year. We would like to thank the patients, families, investigators, study site personnel and the advocacy community involved in this study, as well as the entire Soleno team for their support of the DCCR development programme,” said Dr Anish Bhatnagar, Chief Executive Officer of Soleno. “We remain committed to the goal of delivering DCCR, if approved, as an effective and safe therapy to individuals with PWS as expeditiously as possible.”
The FDA previously acknowledged that data from this study have the potential to support an NDA submission for DCCR, which has Orphan Drug designation for the treatment of PWS in the US and EU and Fast Track designation from the FDA.