Biopharmaceutical company GW Pharmaceuticals has reported a positive Phase 3 trial of its new drug Epidiolex (cannabidiol), in the treatment of a rare and severe form of childhood epilepsy known as Dravet syndrome.The drug achieved its primary endpoint of a statistically significant reduction in convulsive seizures, assessed over 14-week treatment period.According to the trial report, the study involved 120 people with an average age of 10 years (30% under six years), who had a diagnosis of Dravet syndrome. At recruitment the children were taking an average of three AEDs, having previously tried and failed an average of more than four other AEDs, and their average monthly seizure rate (during a 4-week ‘baseline’ observation period) was 13.The cohort was split into two groups. One (containing 61 children) was given a daily regimen of 20 mg/Kg of Epidiolex in addition to their current anti-epileptic drug (AED) treatment, and the other (containing 59 children) received a daily placebo in addition to their existing AED treatment.Over the course of the 14-week trial, the children in the Epidiolex group experienced an average reduction in seizure frequency  of 39%, compared to a 13% reduction in the placebo (or control) group. According to the researchers, this difference in effect between Epidiolex and placebo emerged during the first month of treatment and was sustained during the entire treatment period. They also note that there were other findings that reinforced the effectiveness seen in Epidiolex.Epidiolex is reported to have been generally well tolerated in this study. The most common unwanted side effects (adverse events) observed (occurring in more than 10% of Epidiolex-treated subjects) included: diarrhoea, decreased appetite, fatigue, fever, vomiting and convulsion. Of the children taking Epidiolex who reported an adverse event, 84% said that it was mild or moderate. Ten children in the Epidiolex group experienced a serious adverse event, compared with three in the placebo group. A total of eight subjects on Epidiolex discontinued treatment due to adverse events, compared with one on placebo.Responding to the publication of this Phase 3 trial, Executive Director of the Dravet Syndrome Foundation, Mary Anne Meskis, stated:”Dravet syndrome is one of the most catastrophic types of epilepsy in children and safe and effective treatments are desperately needed.”We are thrilled to learn of these positive results, which bring much needed hope to the children and families who have been living with these debilitating seizures.”Click here for more articles about epilepsy in children.Please note that Epilepsy Research UK does not endorse/promote individual AEDs or pharmaceutical companies.