FDA Committee in Favor of Cannabidiol to Treat Two Rare Seizure Disorders

The FDA’s Peripheral and Central Nervous System Drugs Advisory Committee has unanimously recommended approval of the New Drug Application for GW Pharmaceuticals’ proposed cannabidiol oral solution for the adjunctive treatment of seizures associated with 2 rare disorders, Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS), in patients aged 2 years and older.

LGS typically occurs between ages 3 and 5 years, can cause multiple seizure types, and is often resistant to anti-epileptic drugs. DS, a severe, infantile-onset, highly treatment-resistant epileptic encephalopathy, is associated with an elevated risk of premature death. Currently, there are no FDA-approved treatments for DS.

GW Pharmaceuticals’ product, which it plans to market as Epidiolex if it is eventually approved, would be both the first in a new category of anti-epileptic drugs and the first pharmaceutical formulated from plant-based cannabidiol. The exact mechanism of the anticonvulsant effect of cannabidiol is not known.

The advisory committee based its unanimous vote in favor of the drug’s benefit—risk profile on data from 3 randomized, double-blind, placebo-controlled trials, 2 of which were 14-week trials in patients with LGS. The third study was a 14-week trial in patients with DS. In all 3 studies, more patients who received cannabidiol had a 50% reduction in the number of seizures than did patients who received placebo.

Elizabeth Thiele, MD, PhD, director of pediatric epilepsy at Massachusetts General Hospital, professor of Neurology at Harvard Medical School, and a primary investigator for 1 of the trials in patients with LGS, said in a statement, “As a physician who treats LGS and [DS], I know that patients and their families usually face significant difficulties getting seizures under control using existing therapies. The results from these studies suggest that this pharmaceutical formulation of cannabidiol may provide hope for a new treatment option that may be effective for some patients.”

GW Pharmaceuticals says that it expects the drug to be approved by the FDA, on the strength of the advisory committee’s recommendation, on June 27, 2018, and to become commercially available in the second half of 2018.