Investigational Cannabidiol Medication Shown to Reduce Seizures

GW Pharmaceuticals, a London-based biopharmaceutical company focused on the development and commercialization of therapeutics derived from its cannabinoid product platform, announced on March 14, 2016 that it had successfully completed a Phase III study of its investigational medicine Epidiolex (cannabidiol or CBD) for the treatment of Dravet syndrome. Epidiolex is derived from cannabidiol, a component present in marijuana. According to a report in the New York Times, if approved, the drug will become the first prescription drug in the US extracted from the plant.

Dravet syndrome is a rare form of epilepsy that affects patients from infancy. According to the Dravet Syndrome Foundation, individuals suffering from Dravet syndrome often experience frequent seizures, poor seizure control, and developmental delays. Treatment options for the syndrome are extremely limited, and there are currently no approved drugs for the disease in the United States.

The results of GW’s Phase III clinical trial with Epidiolex showed that the drug achieved a median reduction in monthly convulsive seizures of 39% over the 14-month treatment period compared with placebo, which demonstrated a 13% decrease. The study was completed with 120 patients, who were given Epidiolex or a placebo, in addition to regular anti-epileptic treatment regimens. The 120 patients participating in the study averaged 10 years of age, with 30% of patients under the age of six.

While there have been reports prior to this study of marijuana-based products reducing frequency of seizures, the New York Times says experts have been “cautious about anecdotal reports, saying that such treatments needed to be compared with a placebo to make sure they work.” Orrin Devinsky, MD, of New York University Langone Medical Center Comprehensive Epilepsy Center, said in a statement that this trial represents the first placebo-controlled evidence to support CBD’s “safety and efficacy” in children.

Epidiolex has also received Fast Track designation and Orphan Drug designation from FDA for the treatment of Dravet syndrome. The agency referenced the drug in a June 2015 statement as an example of an investigational drug derived from marijuana being studied for clinical efficacy. In the statement, FDA says, “If there is any future for marijuana as medicine, it lies in its isolated components, the cannabinoids and their synthetic derivatives.” These components, the agency says, will produce more reliable results than crude plant mixtures. More than 300 American children are currently taking Epidiolex under FDA’s expanded access program, according to the New York Times.

Recently, the use of CBD has been a popular topic of discussion in the pharmaceutical industry. In March 2016, US regulators approved the import of pharmaceutical grade cannabidiol by Catalent Pharma Solutions and Kannalife Sciences for feasibility studies. In February 2016, FDA issued eight warning letters to CBD sellers who, the agency said, were marketing dietary supplements as new medications, although they had not been tested by FDA. 

Source: GW Pharmaceuticals