FDA Grants Fast Track Designation to Prader-Willi Syndrome Treatment, DCCR

The US Food and Drug Administration (FDA) has granted a fast track designation to Soleno Therapeutics, Inc.’s diazoxide choline controlled-release (DCCR) for the treatment of Prader-Willi syndrome (PWS), a rare genetic disorder that occurs in approximately 1 out of every 15,000 births.

“The receipt of Fast Track designation represents a significant milestone for Soleno and our DCCR clinical development program,” said Anish Bhatnagar, MD, chief executive officer of Soleno Therapeutics, Inc., in a recent statement. “PWS is a devastating condition with high unmet medical need and, based on the data generated to date, we believe DCCR has the potential to address this critical treatment gap.”

DCCR is a novel, crystalline patent-protected salt of diazoxide formulated as a controlled release once-a-day tablet; it is currently being investigated as a treatment for PWS in an ongoing phase 3 trial, initiated this past May (2018), in multiple sites throughout the United States.

The purpose of the phase 3 trial is to evaluate the effects of the treatment in children and adults with PWS. A primary outcome measure of the trial is a change in hyperphagia-related behavior as measured by total score of a Hyperphagia Questionnaire in the timeframe of 13 weeks. Secondary outcome measures for the trial include a change in body fat mass, clinical global impression of improvement, and caregiver global impression of change as measured in the timeframe of 13 weeks. Study arms include a placebo and experimental group, with both being administered 75 to 450 mg of either the placebo or DCCR.

The estimated primary completion date is December 2018.

“Enrollment in our phase 3 clinical trial for DCCR in PWS is ongoing at multiple sites in the United States with [a] fast track designation,” added Dr Bhatnagar, “We look forward to continued collaboration with the FDA, with the goal of delivering DCCR to patients in need as expeditiously as possible.”

PWS is a genetic, inherited disease caused by the deletion of a part of chromosome 15, which is inherited from the father. It is hallmarked by hyperphagia—insatiable hunger—which can lead to significant morbidities, such as stomach rupture, obesity, diabetes, cardiovascular disease, and mortality. There are currently no treatments available to treat hyperphagia, which is known to severely diminish the quality of life for patients and their families.

In an exclusive quote to Rare Disease Report®, Theresa V. Strong, PhD, director of research programs at the Foundation for Prader-Willi Research, emphasized the fast track designation. "The granting of Fast Track designation to the DCCR development program reinforces that Prader-Willi syndrome (PWS) is a serious disease associated with morbidity that has a significant impact on day-to-day functioning of the patients and their families. This designation also recognizes DCCR’s potential to address this significant unmet medical need. We hope that the expedited development and review of DCCR, currently in a Phase III clinical trial, will allow this product to commercially-available to PWS patients as soon as possible.”

Previously, DCCR received an orphan drug designation from the FDA and the European Union for the treatment of Prader-Willi syndrome. A 7-year grant of market exclusivity from the FDA in this indication is anticipated.