When given as an add-on therapy, Epidiolex (cannabidiol, CBD) can lower the frequency of seizures in young patients with Dravet and Lennox‐Gastaut syndromes — regardless of whether the children also are taking clobazam — a review has found.
These findings suggest that Epidiolex may have its own anti-epileptic properties, and contradict current theories that its benefits are due only to its ability to increase clobazam’s availability in the body, according to the researchers. Those current theories have restricted the therapy from being prescribed in Europe, they noted.
The review study, “Cannabidiol efficacy and clobazam status: A systematic review and meta-analysis,” was published in the journal Epilepsia.
Epidiolex, marketed by Greenwich Biosciences, a subsidiary of GW Pharmaceuticals, is an oral cannabidiol solution derived from the cannabis plant. It has strong anti-seizure, anti-psychotic, and anti-anxiety (anxiolytic) properties.
Previous clinical trials demonstrated that Epidiolex was able to safely and effectively lower the frequency of seizures in children with Lennox-Gastaut and Dravet syndromes, two drug-resistant forms of epilepsy.
These findings have supported Epidiolex’s approval in the U.S. and Europe as an anti-seizure therapy to treat patients with Dravet and LGS, ages 2 and older. More recently, the U.S. Food and Drug Administration announced it had approved an expansion of the therapy’s original label indication that allows infants, ages 1 and older, to have access to the medication.
The results showed that a significantly greater proportion of patients treated with Epidiolex achieved at least a 50% drop in seizure frequency, compared with those on a placebo. This was true both for patients not on clobazam (29.1% vs. 15.7% in the placebo group) and for those being co-treated with clobazam (52.9% vs. 27.8%).
Patients who were not being co-treated with clobazam showed lower response rates, both on Epidiolex and on the placebo. The researchers hypothesize that these individuals may be particularly difficult to treat, as they had failed more anti-seizure medications, including clobazam, and had higher seizure frequency at enrollment.
Nevertheless, they noted these findings should be interpreted with caution, due to the limited number of patients participating in these trials, and to the fact that treatment with clobazam was not given randomly in any of the studies included in the final meta-analyses.