A drug derived from marijuana to treat epilepsy is on the brink of becoming the first of its kind to win US government approval.

The drug, called Epidiolex, contains a compound in cannabis that is not responsible for a high called CBD.

In its third positive clinical trial, the drug appeared to reduce the number of severe seizures in people with a form of epilepsy called Lennox-Gastaut syndrome.



An experimental drug derived from cannabis to treat epilepsy is on the brink of becoming the first of its kind to win US government approval.

The drug is called Epidiolex, and its active ingredient is cannabidiol, or CBD, the compound in marijuana thought to be responsible for many of its therapeutic effects but not linked with a high. No FDA-approved medications currently include a marijuana compound derived from the plant; only one drug that includes lab-produced THC is on the market.

According to new research, CBD appears to help reduce seizures in two of the hardest-to-treat forms of epilepsy, known as Lennox-Gastaut syndrome and Dravet syndrome.

Positive findings published on Wednesday in the New England Journal of Medicine suggest that two different doses of Epidiolex significantly curbed the number of dangerous seizures in patients with Lennox-Gastaut.

The research comes on the heels of a recent unanimous vote for Epidiolex's safety and efficacy by a panel of outside scientists convened by the US Food and Drug Administration. It also follows two other large clinical trials with similarly promising results.

Based on those findings, Shlomo Shinnar, the president of the American Epilepsy Society and a professor of neurology and epidemiology at the Albert Einstein College of Medicine, told Business Insider he strongly believes Epidiolex "can and should be approved" for people with the two syndromes.

Positive findings build

Cannabidiol doesn't contain THC, the main psychoactive ingredient in marijuana, so it doesn't get users high. In the plant, both compounds exist together, but researchers can isolate them — which is how British drugmaker GW Pharmaceuticals produces Epidiolex.

For the latest study of the drug, a team of researchers looked at 225 patients with Lennox-Gastaut. Participants' ages ranged between two and 55 years old, and they were spread across 30 international locations.

The researchers found strong evidence that an even lower dose of Epidiolex than the one previously studied was effective for curbing seizures.

The study participants were split into three groups to see how well two different daily doses worked in comparison to a placebo pill. The group that received the lowest dose (10 milligrams per kilogram) saw a type of severe seizure known as "drop seizures" cut down by more than a third. Among those given a placebo, the rate was only reduced by 17%. Those in the higher-dose group saw their drop seizures decline by nearly 42%.

Orrin Devinsky, one of the study's lead authors and a neurologist at New York University Langone Health, told Business Insider that low dose might be "the sweet spot" where most patients can achieve a relief from symptoms while any unwanted side effects, such as drowsiness.

'I'd personally be very surprised if this drug was not approved'

As in previous studies, the majority of patients in the trial experienced some side effects. Those ranged from mild issues like drowsiness and decreased appetite to more severe problems like upper respiratory infection and vomiting.

But the recent study results are evidence that a lower dose of the drug could still provide significant benefits while producing fewer symptoms.

"The major finding from this is that the 10-milligram-per-kilogram dose is going to be a more ideal dose for most. With the 20 milligram, there will probably be a little bit more of a benefit but the side effects are greater," Devinsky said.

In the two other clinical trials of the drug, one of which Devinsky also co-authored, researchers looked at Epidiolex's effects in another 225 young people with Lennox-Gastaut syndrome and in 120 children with Dravet syndrome. Like the latest study, the researchers split the participants into three groups and gave them either a high dose of the drug, a low dose, or a placebo. In general, those in the high-dose group saw their seizure occurrence drop by around 40% and those in the low-dose group saw a slightly smaller drop. By comparison, those given the placebo saw only a small reduction in seizure occurrence.

Devinsky believes those consistent findings should be enough to get Epidiolex a green light from the FDA. In 2016, the agency awarded the drug with its "Fast Track" designation — a priority label designed to speed treatments that address a critical need through the traditionally protracted drug-approval process.

"There’s a boatload of evidence to show for this drug at this point," Devinsky said. “I’d personally be very surprised if this drug was not approved."