Marijuana Plant Extract Reduces Epileptic Seizures by Half

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GW Pharmaceuticals Plc’s cannabidiol, made from the non-psychoactive portion of a marijuana plant, cut by half the seizures suffered by epilepsy patients in an expanded access program that didn’t use a placebo.

The experience of 213 hard-to-treat patients age 2 to 42, including some who were already taking a dozen drugs to fend off seizures, is a promising start for the strawberry-flavored liquid extract, which may be a potent new therapy for the condition, said lead researcher Orrin Devinsky, director of the New York University Langone Comprehensive Epilepsy Center. The findings released Monday are scheduled to be presented at the American Academy of Neurology’s annual meeting on April 22 in Washington.

GW Pharma is seeking regulatory approval for the therapy to treat patients with severe forms of epilepsy and expects to present results from mandated studies by early 2016, said Chief Executive Officer Justin Gover. Epidiolex, as the oil is known, is being compared with a placebo to affirm its safety and effectiveness.

“For this group that has failed multiple medications, the response is quite positive,” Devinsky said. “Over time it’s certainly the hope that this would replace other therapies,” if studies that use comparison groups are successful.

The results were consistent across different types of epilepsy, including Dravet syndrome, a rare and intractable form with few treatment options, and Lennox-Gastaut syndrome, marked by a brief loss of muscle tone that triggers “drop” seizures. Overall, the number of seizures fell by an average of 54 percent for the 137 patients who were on the medication for three months.

GW Pharma’s American depository receipts gained 1.9 percent to $98 in late trading.

Side Effects

GW Pharma has two final-stage trials for each disease already under way.

Side effects included drowsiness, diarrhea and decreased appetite. Six percent of the patients stopped taking the medicine because of side effects or complications.

More than 5 million Americans have been diagnosed with epilepsy, a disorder marked by abnormal electrical activity in the brain. Symptoms can include convulsions, muscle spasms, loss of consciousness and different types of seizures. While there are numerous drugs approved to treat seizures, up to one -third of patients struggle to control the condition with those medications.

The program was the result of good timing, Devinsky said. GW Pharma was working on marijuana-based products to treat conditions including diabetes and ulcerative colitis when reports began to surface on social media about success families were having by treating their epileptic children with marijuana. Unproven products were starting to emerge to meet the demand, he said.

‘Community Effort’

Academic researchers were also seeing benefits in early tests involving animals. Devinsky and other investigators approached the company to see if it was interested in studying their compounds for hard-to-treat epileptics. The company agreed, and some patients have already been using the oil for more than a year with good results, he said.

“It was really a community effort by parents, physicians and industry coming together,” Devinsky said.

If approved, Epidiolex would be the first cannabis plant-derived therapeutic accepted by the U.S. Food and Drug Administration and covered by health insurance. It differs from marijuana-based herbal products because it is pure cannabidiol, with no psychoactive molecules, and is made under strict manufacturing methods, Gover said.

GW Pharma already has a cannabis-based medicine approved outside the U.S. called Sativex for spasticity due to multiple sclerosis. It is also being tested for pain due to advanced cancer, Gover said.

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