Cannabidiol Reduces Seizures in People With Tuberous Sclerosis Complex-Related Seizures in Clinical Trials

Findings from a clinical trial (NCT02544763) presented at the American Epilepsy Society Annual Meeting December 6-10, 2019 in Baltimore, MD showed that people with tuberous sclerosis complex (TSC), a genetic condition associated with treatment-resistant seizures, may benefit from a highly purified pharmaceutical form of cannabidiol (CBD), one of 500 compounds in cannabis. 

The TSc causes cancerous tumors to form throughout the body, and approximately 90% of people with the disorder have seizures that are difficult to treat. Cannibidiol (with less than .01% THC) (Epidolex; Greenwich Biosciences, Carlsbad, CA) was approved last year by the Food and Drug Administration (FDA) for treating 2 other challenging forms of epilepsy, Dravet syndrome and Lennox-Gastaut syndrome.   

The trial included 224 people, 1 year of age to 65 years of age, with TSC who were randomized to receive either 25 mg of CBD per day, 50 mg of CBD per day, or placebo over 16 weeks of treatment. All patients had tried and discontinued an average of 4 antiepileptic drugs (AEDs) and were taking an average of 3 AEDs during the trial, usually valproate, vigabatrin, levetiracetam, or clobazam.

The findings showed that the therapy reduced TSC-associated seizure frequency by about half: 49% for the 25 mg dose and 48% for the 50 mg dose, making it nearly twice as effective as the placebo (27%). People who took the therapy had a greater overall reduction in seizures (36% for 25 mg; 40% for 50 mg) than placebo (22%). 

“Our findings suggest this formulation of purified CBD offers patients with TSC a new treatment option for their very difficult-to-manage seizures,” said Elizabeth Thiele, MD, PhD, 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. “Studies show that the benefits of CBD treatment can last up to 6 years, with no changes in safety. Physicians are finding that CBD may be helpful for other treatment-resistant epilepsies as well, including Aicardi, Doose, CDKL5, and Dup15q.”