Cannabis Drug Halved Convulsions in Company-Funded Epilepsy Test

  • GW Pharmaceuticals’ Epidiolex shown to help in Dravet Syndrome
  • Company plans new drug application filing with FDA in mid 2017

A cannabis-based drug halved the frequency of convulsive seizures in sufferers of a rare, catastrophic form of epilepsy in a late-stage study funded by GW Pharmaceuticals Plc.

The median monthly frequency of convulsive seizures fell to 5.9 from 12.4 among children with a drug-resistant form of Dravet syndrome who took the company’s Epidiolex cannabidiol oral solution. That compared with only a slight decline among patients taking a placebo. Results of the randomized controlled trial -- by researchers in New York, London, Chicago, Philadelphia, Miami, Paris, Melbourne and Boston -- were published Thursday in the New England Journal of Medicine.

While patients on Epidiolex were three times more likely to experience side effects, including sleepiness and diarrhea, than controls, 5 percent of those taking the medicine were seizure-free during the study period, compared with none in the placebo group. The results may help Cambridge, England-based GW Pharmaceuticals win U.S. Food and Drug Administration approval for Epidiolex after it submits a new-drug application in mid 2017.

Ingrid Scheffer

Source: The Florey Institute of Neuroscience & Mental Health

“I want it approved and I want it out there,” Ingrid Scheffer, chair of pediatric neurology at the University of Melbourne and a co-author who helped review patients for the trial, said in a phone interview. “It’s wonderful that we’ll have another drug we can use for these very sick children.”

Stock Rally

GW Pharmaceuticals, founded by Chairman Geoffrey Guy in 1998, has gained more than 1,000 percent since its American depository receipts began trading on Nasdaq in May 2013. The stock closed 1.4 percent lower at $106.31 on Wednesday, valuing the company at $2.7 billion.

Cannabis growers and pharmaceutical companies have been making bets on medicinal marijuana providing the next growth source for pain treatment as countries spanning the U.S., Canada to Australia relax rules around pot use. Australia in February relaxed cannabis importation rules as it attempts to create a structured, integrated system where cannabinoid drugs are treated like any other medicine, causing a surge in local pot stocks.

Cannabidiol is a purified compound derived from cannabis seeds, stalks and flowers. Studies have shown that while it works on the cannabinoid receptors in the brain, it doesn’t have the psychoactive properties of tetrahydrocannabinol. Besides its application in pain relief, scientists are studying its potential to treat a range of conditions from autism and opiate addiction to Parkinson’s disease and schizophrenia.

The latest study validates the use of medicinal cannabis and may spur more academic research, said Chris Kallos, a Sydney-based health-care analyst at Morningstar Australasia Pty. “It paves the way for further research into other indications,” he said.

Dravet syndrome is a lifelong, genetic form of epilepsy that results in a potentially lethal brain disorder. Mostly caused by mutations in the SCN1A gene, it occurs in about 1 per 15,700 individuals in the U.S.

The study of 120 patients from 23 centers in the U.S. and Europe didn’t find a significant reduction in the frequency of non-convulsive seizures from Epidiolex, suggesting the benefit of cannabidiol in Dravet syndrome patients may be specific to convulsions.

“This is just for one specific syndrome and there are many forms of epilepsy,” said Scheffer, who is also director of pediatrics at the Austin Hospital in Melbourne. “I think it will be relevant to many other epilepsies, and we need trials to look at that.”

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