Phase 3 Trial of DCCR Therapy Candidate for PWS Hits Target Enrollment, Soleno Says

Target enrollment of approximately 100 participants has been reached in a Phase 3 clinical trial evaluating the investigational oral therapy diazoxide choline controlled-release (DCCR) for reducing excessive appetite in people with Prader-Willi syndrome (PWS), Soleno Therapeutics has announced.

Additional patients who are already scheduled to be screened will still be enrolled over the next few weeks. According to Soleno, which is developing DCCR and sponsoring the DESTINY PWS trial (NCT03440814), the study is on track to have top-line data in the first half of this year.

“The achievement of target enrollment represents an important milestone for our DESTINY PWS clinical program,” Anish Bhatnagar, MD, Soleno’s CEO, said in a press release.

DCCR is an extended-release formulation of diazoxide. It works by blocking the release of two proteins in the brain — called neuropeptide Y and agouti-related protein — which are believed to help drive the abnormally high appetite, or hyperphagia, seen in people with PWS.

It was granted fast-track status by the U.S. Food and Drug Administration in 2018 and was designated an orphan drug in both the U.S. and the European Union.

A prior Phase 1/2 trial (NCT02034071) supported the potential of DCCR, leading to early and sustained reductions in hyperphagia, as well as decreases in body fat and fewer instances of aggressive and violent behaviors.

In the DESTINY PWS trial, taking place at 27 sites in the U.S. and U.K., participants are being randomly assigned to once-daily DCCR at doses of 75–450 mg or a placebo. The primary outcome is change in hyperphagia — as measured by a questionnaire — after 13 weeks of treatment. Secondary assessments include changes in body fat, as well as caregiver and clinician evaluations of clinical progress.

According to Soleno, more than 95% of the participants in DESTINY PWS are either continuing to be treated or have completed the trial.

After treatment, participants have the option of enrolling in an extension study called C602 (NCT03714373), in which all receive DCCR for up to three years. More than 95% of people who have enrolled in C602 are also continuing to be treated, the company said.

“We continue to be encouraged by the significant interest shown by families and investigators in keeping patients on DCCR,” Bhatnagar said.

So far, no serious adverse events related to DCCR have been reported in the DESTINY PWS trial. Recently, a data safety monitoring board — an independent panel of experts responsible for ensuring the safety of participants in clinical trials — recommended for a second time the continuation of the trial.

“I would like to extend my gratitude to all of the patients, families and investigators involved in this study, as well as the Foundation for Prader-Willi Research (FPWR) and Prader-Willi Syndrome Association (PWSA) USA and UK for their support of DESTINY PWS,” Bhatnagar said