EMBARGOED FOR RELEASE:
Saturday, Dec. 7, 2019
12:00 PM EST
BALTIMORE – People with tuberous sclerosis complex (TSC) – a genetic condition associated with treatment-resistant seizures – may benefit from a highly purified form of cannabidiol (CBD), according to results of a randomized controlled
trial assessing its safety and effectiveness, which is being presented at the American Epilepsy Society Annual Meeting.
Epidiolex® was approved last year by the Food and Drug Administration (FDA) for the treatment of Dravet syndrome and Lennox-Gastaut syndrome, two other challenging forms of epilepsy. CBD is one of 500 compounds in cannabis, also known as the marijuana
plant. Epidiolex is a purified oral solution form of CBD that contains only trace amounts of tetrahydrocannabinol (THC), which is the component in cannabis that produces a high.
TSC causes non-cancerous tumors to form throughout the body and about 90% of the people with the disorder have seizures, which are difficult to treat. The trial assessed whether the pharmaceutical-grade CBD would benefit people with TSC.
“Our findings suggest purified CBD offers patients with TSC a new treatment option for their very difficult-to-manage seizures,” said Elizabeth Thiele, M.D, Ph.D., senior author of the study, director of pediatric epilepsy and director of
the Herscot Center for Tuberous Sclerosis Complex at Massachusetts General Hospital, and professor of neurology at Harvard Medical School, Boston. “We also assessed two different daily doses and found the lower dose of 25 mg/kg (of weight) provides
the same benefit with fewer side effects compared to a dose of 50 mg/kg and will likely be the recommended dose.”
The trial included 224 people (aged 1 to 65) with TSC at 46 sites in six countries who were randomized to receive either: CBD of 25 mg/kg per day, CBD of 50 mg/kg per day or placebo (containing no CBD) for 16 weeks. All patients had tried and discontinued
a median of four antiepileptic drugs (AEDs) and were taking a median of three AEDs during the trial, most commonly valproate, vigabatrin, levetiracetam or clobazam.
CBD reduced TSC-associated seizure frequency by about half: 49% for 25 mg dose and 48% for 50 mg dose, making it nearly twice as effective as the placebo (27%). People who took CBD had a greater reduction in seizures (36% for 25 mg, 40% for 50 mg) than
placebo (22%). Caregivers reported overall improvement in 69% of those taking 25 mg of CBD, 62% of those taking 50 mg and 40% of those who had the placebo.
Side effects were common, occurring in 93% of the 25 mg group, 100% of the 50 mg group and 95% of placebo group, but most were mild or moderate, such as diarrhea, decreased appetite and sleepiness. The treatment was discontinued due to side effects in
11% of the 25 mg group, 14% of the 50 mg group and 3% of placebo patients. Additionally, 12% of 25 mg patients, 25% of 50 mg patients and no placebo patients had elevated liver enzymes: 81% who had that problem were also taking the AED valproate.
“Studies show that the benefits of CBD treatment can last up to six years, with no changes in safety,” said Dr. Thiele. “Physicians are finding that CBD may be helpful for other treatment-resistant epilepsies as well, including
Aicardi, Doose, CDKL5 and Dup15q.”