GW Pharmaceuticals, a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from its proprietary cannabinoid product platform, along with its US subsidiary Greenwich Biosciences, announced that The New England Journal of Medicine has published results from a Phase 3 study of Epidiolex (cannabidiol) in children with Dravet syndrome.

Epidiolex, GW’s lead product candidate and the potential first in a new category of anti-epileptic drugs, is a liquid formulation of purified, plant-derived cannabidiol (CBD), a non-psychoactive cannabinoid, which is being studied for the treatment of a number of rare, severe pediatric-onset epilepsy disorders. In the study, Epidiolex significantly reduced monthly convulsive seizure frequency compared to placebo in highly treatment-resistant children when added to existing treatment. Treatment with Epidiolex was generally well tolerated, with a safety profile consistent with prior open label experience.

There are currently no treatments approved by the US Food and Drug Administration (FDA) for Dravet syndrome, a rare form of epilepsy associated with a high mortality rate and significant developmental delays. Results from this study represent the only well-controlled clinical evaluation of a cannabinoid medication for this devastating and drug-resistant condition. The New Drug Application for Epidiolex remains on track for submission to the FDA in the middle of 2017.

"Dravet syndrome is one of the most difficult types of epilepsy to treat and many of the children in this study were experiencing dozens, even hundreds, of seizures per month despite taking multiple concurrent anti-epileptic medications," said Orrin Devinsky, M.D., of NYU Langone Medical Center's Comprehensive Epilepsy Center and lead author of the study. “These results suggest that Epidiolex can provide clinically meaningful benefits and I look forward to the prospect of an appropriately standardized and tested pharmaceutical formulation of cannabidiol available as a treatment option for these patients.”

"The publication of these highly-anticipated positive results represents an important milestone for the Dravet syndrome community in that it provides hope that a new treatment option is within sight for this rare and devastating disease," said Nicole Villas, Scientific Director of the Dravet Syndrome Foundation. "As a foundation dedicated to research and patient assistance, we hope the burden of Dravet syndrome on patients and families is recognized and welcome new, well-researched treatments such as this that might help ease the burden."

The study randomized 120 children ages two to 18 years (mean age 9.8), with Dravet syndrome whose seizures were not controlled by their current anti-epileptic regimen, to receive either Epidiolex (20mg/kg/day) or placebo in addition to standard treatment. Conducted in 23 study centers in the United States and Europe, patients in the study had tried a median of four prior anti-epileptic drugs (range 0-26) and were taking a median of three (range 1-5) during the study. At baseline, patients had a median frequency of 13 convulsive seizures per month, with a wide range of 3.7 to 1,717 seizures per month.

Over the 14-week treatment period, patients taking Epidiolex had a significantly greater median reduction in convulsive seizures (39 percent) compared to placebo (13 percent). The estimated median treatment difference between groups was 23 percent (p=0.01). The proportion of patients who had a 50 percent or better reduction in convulsive seizure frequency was 43 percent with Epidiolex versus 27 percent with placebo (p=0.08). The study also measured improvement on the Caregiver Global Impression of Change (CGIC) scale. Sixty-two percent of patients treated with Epidiolex were rated as improved in overall condition on the CGIC compared to 34 percent of the placebo group (p=0.02). Additionally, more patients became seizure-free on Epidiolex than placebo (5 percent vs 0 percent: p=0.08) and total monthly seizure count was significantly reduced with Epidiolex (p=0.03).