The FDA today granted GW Pharmaceuticals approval for the first drug that contains a purified drug substance derived from marijuana—the first in a new category of antiepileptic drugs.
Epidiolex® (cannabidiol) is an oral drug indicated to treat seizures associated with Lennox-Gastaut syndrome (LGS) or Dravet syndrome in patients two years of age or older. Epidolex is the first FDA-approved drug specifically indicated for Dravet, but among options for Lennox-Gastaut.
According to GW, Epidiolex is the first prescription pharmaceutical formulation of highly purified, plant-derived cannabidiol (CBD), a chemical component of marijuana that lacks the high associated with pot, specifically its primary psychoactive component THC.
“This approval serves as a reminder that advancing sound development programs that properly evaluate active ingredients contained in marijuana can lead to important medical therapies,” FDA Commissioner Scott Gottlieb, M.D., said in a statement issued by the agency.
GW said it plans to market Epidiolex in the U.S. through its U.S. subsidiary, Greenwich Biosciences. GW is also awaiting a decision on Epidolex by the European Medicines Agency, which is expected to decide whether to recommend approval by the European Commission in the first quarter of 2019.
In a company statement, GW CEO Justin Gover added: “Today’s approval of Epidiolex is a historic milestone, offering patients and their families the first and only FDA-approved CBD medicine to treat two severe, childhood-onset epilepsies.”
“This approval is the culmination of GW’s many years of partnership with patients, their families, and physicians in the epilepsy community to develop a much needed, novel medicine,” Gover added. “These patients deserve and will soon have access to a cannabinoid medicine that has been thoroughly studied in clinical trials, manufactured to assure quality and consistency, and available by prescription under a physician’s care.”
Three Trials, 516 Patients
The FDA said it approved Epidiolex based on positive data from three randomized, double-blind, placebo-controlled clinical trials involving 516 patients with either Lennox-Gastaut syndrome or Dravet syndrome. Epidiolex, taken along with other medications, was shown to be effective in reducing the frequency of seizures when compared with placebo.
The most common side effects that occurred in Epidiolex-treated patients in the clinical trials were: sleepiness, sedation, and lethargy; elevated liver enzymes; decreased appetite; diarrhea; rash; fatigue, malaise and weakness; insomnia, sleep disorder and poor quality sleep; and infections.
GW conducted nonclinical as well as clinical studies to assess the abuse potential of CBD, since CBD is now classified as a Schedule I substance under the Controlled Substances Act. CBD is expected to be rescheduled within 90 days—a requirement before it can be made available to patients. Rescheduling is expected to occur within 90 days
“Because of the adequate and well-controlled clinical studies that supported this approval, prescribers can have confidence in the drug’s uniform strength and consistent delivery that support appropriate dosing needed for treating patients with these complex and serious epilepsy syndromes,” Dr. Gottlieb said.
“We’ll continue to support rigorous scientific research on the potential medical uses of marijuana-derived products and work with product developers who are interested in bringing patients safe and effective, high-quality products,” Dr. Gottlieb also stated, adding that the FDA will act against illegal marketing of CBD-containing products with serious, unproven medical claims.
The FDA directed GW to dispense Epidiolex with a patient medication guide containing information about the drug’s uses and risks. As with other drugs indicated for 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 which, while generally mild, raised the possibility of rare, but more severe injury, the FDA said, including nausea, vomiting, abdominal pain, fatigue, anorexia, jaundice, and/or dark urine.