Staff of the U.S. Food and Drug Administration (FDA) have given a positive review to Epidiolex, an experimental cannabis-based drug that is intended to treat 2 rare forms of childhood epilepsy. The drug is made by GW Pharmaceuticals.
The briefing document, released on April 17, 2018, was prepared prior to an advisory committee meeting on April 19, with FDA commissioners scheduled to officially approve or disapprove the drug by June 27.
Epidiolex was studied to test its potential benefit in Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS), rare forms of epilepsy that affect children 2 years old and older. The syndromes are resistant to traditional treatments. 
As many as 20% of children with DS die before they reach adulthood, according to the National Institutes of Health (NIH). 
The strawberry-flavored drug comes in syrup form and is made with cannabidiol (CBD), a non-psychoactive constituent of cannabis. It also contains an extremely small amount of the psychoactive ingredient, tetrahydrocannabinol (THC). 
The FDA staff wrote:
“Although CBD is a cannabinoid, it shares almost none of the pharmacologic features of the prototypical cannabinoid.” 
Furthermore, the staff noted, Epidiolex “has significantly less abuse potential” than 2 other forms of cannabis: THC given as 2 doses of dronabinol or a single dose of alprazolam. 
The staff said that three clinical studies indicate that the drug “reduces seizure frequency in patients with drug-resistant LGS or DS while maintaining a predictable and manageable safety profile.” 
The acceptable safety risks of Epidiolex include liver injury, which the staff said can be managed and monitored.
The FDA staff wrote:
“The risk-benefit profile established by the data in the application appears to support approval of cannabidiol.” 
GW Pharmaceuticals is currently studying the drug to determine whether it can treat other diseases, including infantile spasms.
Update: The FDA officially approved Epidiolex on June 25, 2018. 
 Bloomberg News
 FDA News Release