On Monday, June 25th, FDA approved GW Pharmaceuticals’ Epidiolex (cannabidiol) for the treatment of two rare and severe forms of epilepsy. Epidiolex is the first FDA-approved drug that contains a marijuana derived substance.
What is Epidiolex?
According to a GW Pharmaceuticals press release, “Epidiolex [is] the first prescription, plant-derived cannabinoid medicine in the United States and the first in a new class of anti-epileptic medications.” The drug is a pharmaceutical formulation of pure cannabidiol (CBD). Although CBD is found in cannabis sativa plants, it does not produce the same high because it does not contain tetrahydrocannabinol (THC). CBD is currently a Schedule I substance under the Controlled Substances Act (CSA) because of its relation to the cannabis plant. As such, prior to approval, clinical and nonclinical studies regarding abuse potential had to be conducted. In addition, the Drug Enforcement Administration (DEA) is required to make a scheduling determination.
Epidiolex to Treat Dravet & Lennox-Gastaut Syndromes
Epidiolex has been approved to treat Dravet syndrome and Lennox-Gastaut syndrome in patients two years of age and older. The two conditions are serious forms of epilepsy that develop in childhood. Dravet syndrome is a rare genetic condition that begins during the first year of life and is characterized by frequent and/or prolonged seizures, often related to fever (febrile seizures). Epidiolex is the first FDA approved treatment specifically for Dravet syndrome.
Lennox-Gastaut syndrome (LGS) usually begins in early childhood, between the ages of three and five years old. Children with this type of epilepsy often develop learning issues and experience delayed development of motor skills. Both Dravet syndrome and LGS have been known to be very difficult to treat, with most patients requiring multiple types of seizure medication.
The effectiveness of Epidiolex was studied in three randomized, double-blind, placebo-controlled clinical trials. The study included 516 subjects and the drug was found to be effective in reducing the frequency of seizures when compared to a placebo. Common side-effects included:
- Sedation and lethargy
- Elevated liver enzymes
- Decreased appetite
- Fatigue, malaise and weakness
According to a recent news release from the FDA, “as is true for all drugs that treat epilepsy, the most serious risks include thoughts about suicide, attempts to commit suicide, feelings of agitation, new or worsening depression, aggression and panic attacks. Epidiolex also caused liver injury, generally mild, but raising the possibility of rare, but more severe injury.”