The U.S. Food and Drug Administration has approved Epidiolex (cannabidiol) oral solution for the treatment of seizures associated with tuberous sclerosis complex (TSC), a genetic disorder characterized by growth of numerous noncancerous tumors.
Epidiolex was previously approved for the treatment of seizures associated with two rare and severe forms of epilepsy, Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS). This is the only FDA-approved drug that contains a purified drug substance derived from cannabis. It is also the second FDA approval of a drug for the treatment of seizures associated with TSC.
Cannabidiol (CBD) is a chemical component of the Cannabis sativa plant. However, CBD does not cause intoxication or euphoria that comes from tetrahydrocannabinol (THC).
"The FDA continues to believe the drug approval process represents the best way to make new medicines, including any drugs derived from cannabis, available to patients in need of appropriate medical therapy such as the treatment of seizures associated with these rare conditions,” said Douglas Throckmorton, M.D., deputy center director for regulatory programs in the FDA's Center for Drug Evaluation and Research. “This paradigm ensures new therapies are safe, effective, and manufactured to a high quality that provides uniform and reliable dosing for patients. The agency is committed to supporting rigorous scientific research on the potential medical uses of cannabis-derived products and working with product developers who are interested in bringing patients safe and effective, high quality products."
TSC is a rare genetic disease that causes non-cancerous (benign) tumors to grow in the brain and other parts of the body like the eyes, heart, kidneys, lungs and skin. TSC usually affects the central nervous system and can result in a combination of symptoms including seizures, developmental delay and behavioral problems, although the signs and symptoms of the condition, as well as the severity of symptoms, vary widely. TSC affects about 1 in 6,000 people.
Epidiolex's effectiveness for the treatment of seizures associated with TSC was established in a randomized, double-blind, placebo-controlled trial where 148 patients out of a total of 224 in the study received Epidiolex. The study measured the change from baseline in seizure frequency.
In the study, patients treated with Epidiolex had a significantly greater reduction in the frequency of seizures during the treatment period than patients who received placebo (inactive treatment). This effect was seen within eight weeks and remained consistent throughout the 16-week treatment period.
FDA approval includes a recommended maintenance dose of 25 mg/kg/day for TSC patients, which is supported by data from a Phase 3 safety and efficacy study evaluating 25 mg/kg/day of Epidiolex.
The most common side effects that occurred in Epidiolex-treated patients with TSC in the clinical trial were diarrhea, elevated liver enzymes, decreased appetite, sleepiness, fever and vomiting. Additional side effects for patients with LGS, DS, or TSC include liver injury, decreased weight, anemia and increased creatinine.
Justin Gover, CEO of Epidiolex developer GW Pharmaceuticals plc, called the FDA’s approval “exciting news” for TSC patients.
“This label expansion, including the expansion of the age range in all approved indications, further demonstrates that the FDA process can continue to enable broader patient access to appropriately tested, regulatory approved cannabinoid medicines,” Gover said. “It also provides hope for these patients and their families and is yet another important milestone for Epidiolex as a first-in-class antiepileptic drug.”