A powerful medicine derived from marijuana is drastically changing our perception of pot

By now, you've probably heard of medicinal marijuana. What you may not have heard of is a drug derived from marijuana that could be approved to treat epilepsy.

The drug, Epidiolex, may be on its way to becoming the first of its kind to win FDA approval for the treatment of rare forms of childhood epilepsy. Epidiolex contains cannabidiol, one of the active chemical compounds found in marijuana. Unlike marijuana's main psychoactive ingredient, THC, cannabidiol (or CBD) does not cause feelings of euphoria or intoxication, the characteristic "high" associated with pot. Cannabidiol has been linked for years with different kinds of pain relief and even studied in several clinical studies.

In March, the company came out with phase 3 trial data that showed positive results of the drug in children with Dravet syndrome, a rare, lifelong form of epilepsy that begins in infancy. And about a week ago, the company launched into another phase 3 trial exploring how the drug works in treating a rare genetic condition called tuberos sclerosis complex (or TSC) in which benign tumors grow on organs including the brain, causing serious complications including seizures.

Here's what the research on this drug and its possible approval could mean for the US.

Treating epilepsy

Epilepsy affects roughly 4.3 million people, but the types of epilepsy and kinds of seizures that people with the illness may experience completely vary. That means not every person with epilepsy will respond to certain treatments, including those with cannabidiol. GW is specifically exploring cannabidiol for its potential use in people with Dravet syndrome and Lennox-Gastaut syndrome, a rare form of childhood-onset epilepsy that's associated with multiple types of seizures, and now TSC.

The hope is that eventually, someone taking the drug would be able to either reduce the number of seizures they have or even stop them entirely.

But, with marijuana, and even just the cannabidiol component of the drug, available on a consumer market in states like Colorado, what's the point of having a prescription version?

Schultz said that the difference will be in the uniformity of the product. "The products that people are using, and purchasing, they're artisanal products." That means they can vary batch by batch, and can be influenced by different fertilizers or pesticides. GW's version wouldn't.

"It will have the hallmarks of a true pharmaceutical medicine," he said.

The challenge of getting approval in the US

Today, medical marijuana is legalized on a state-by-state basis. Getting it approved by the FDA as a prescription drug would require the DEA to reschedule it, since marijuana is currently considered a Schedule 1 drug with "no currently accepted medical use and a high potential for abuse." The DEA is expected to make a decision regarding rescheduling by mid-2016.

Epidiolex is not the first cannabis-derived drug the company has brought to market outside the US. Sativex, a treatment for multiple sclerosis and pain related to some cancers, has been approved in at least 27 countries outside the US, but attempts to bring it to the US have fallen flat - the data wasn't good enough to convince the FDA to give it approval. Schultz said the drug's future in the US is still up in the air.

But, when it comes to Epidiolex's positive data results, Schultz has more faith.

GW expects its data on the Lennox-Gastaut syndrome to come out in the second quarter, with plans to file for approval with the FDA by the end of the year.