In First, Drug Made from Cannabis Moves Closer to U.S. Approval

(Bloomberg) -- U.S. drug regulators are edging closer to approving the first-ever medicine derived from a marijuana plant, an experimental epilepsy treatment developed by GW Pharmaceuticals Plc.

On Thursday, a panel of outside advisers to the Food and Drug Administration unanimously voted that the drug’s benefits outweigh its risk in treating two rare forms of childhood epilepsy. The 13-0 vote is a crucial sign-off before the agency makes an official ruling by a June 27 deadline.

“It’s an enormous milestone,” Orrin Devinsky, who specializes in epilepsy at the New York University Langone Medical Center, said in an interview before the advisory panel meeting. “America clearly is moving, more so, and embracing cannabis as something that can be used medicinally.”

GW Pharma’s drug, which the company is calling Epidiolex, is made from a compound in the marijuana plant called cannabidiol, a different chemical from tetrahydrocannabinol, or THC, which gives marijuana its euphoric effect. GW Pharma uses a plant bred to have high cannabidiol, or CBD, content to make the drug, Chief Executive Officer Justin Gover said in an interview earlier this month.

The advisory panel’s backing is a key step. The FDA often brings together outside experts to discuss drugs under review, particularly in cases where there might be questions about a drug’s safety, effectiveness, or other key issues where the agency wants outsiders to weigh in. While the FDA doesn’t always follow the advice of the panels, it often does.

Drug Restrictions

The larger implications for cannabis-based drugs are less clear, and researchers were measured about this opening the floodgates because of U.S. restrictions on researching the compounds, as well as other illegal drugs that might have medical uses. The Drug Enforcement Administration places restrictions on marijuana research that require months of approvals and costly security measures.

Shaun Hussain, director of the infantile spasms program at the University of California, Los Angeles, said if the drug is approved he hopes it “will further change attitudes that we need to facilitate this type of research.”

Since marijuana is restricted as a Schedule 1 drug by the DEA, FDA staff said during the advisory meeting that cannabidiol will need to be rescheduled to be made available for sale if approved. Schedule 1 is the most restrictive of the DEA’s classifications for drugs that could be misused.

Severe Seizures

Epidiolex has been shown to be a significant advance for children with Lennox-Gastaut and Dravet syndromes, in patients aged 2 or older. Both are considered severe forms of epilepsy that begin in childhood. They’re resistant to many existing treatments and as many as 20 percent of children with Dravet syndrome die before reaching adulthood, according to the National Institutes of Health.

“It’s pretty typical these children are having seizures every day,” said Hussain, the University of California doctor. “Some of them are having tens of seizures or hundreds of seizures each day.”

In clinical trials of the drug, patients that added the CBD to existing treatment experienced a 40 percent to 50 percent average reduction in the most common and burdensome seizures they have, GW Pharma CEO Gover said.

Devinsky, the epilepsy specialist, called the therapy a potential “life-changer” for some. FDA staff were also positive on the treatment, saying in a report ahead of the meeting that the U.K.-based drugmaker provided “substantial evidence” of Epidiolex’s effectiveness. FDA staff also said a liver injury risk associated with the drug could be managed.

Charuta Joshi, a pediatric neurologist at Children’s Hospital Colorado who was a principal investigator on three Epidiolex trials, said it will be helpful to have a consistent cannabis product for her patients to try. Doctors at Children’s Colorado don’t prescribe medical marijuana though they will care for children who use it.

“That had been one of the major concerns,” Joshi said. “We weren’t sure what the patients were getting.”

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