Positive Results at End of Phase 3 Trial of Candidate Tuberous Sclerosis Complex Drug – CBD

According to a press release from the British biotechnology company GW Pharmaceuticals, the company has reported successful results at the conclusion of its phase 3 trial of tuberous sclerosis complex drug candidate Epidiolex.

Did that sound professional enough? Because you might know Epidiolex better as cannabidiol (CBD) – one of the over 100 cannabinoids found in cannabis.

What is Tuberous Sclerosis Complex?

Tuberous sclerosis complex (TSC) is a genetic disorder chiefly characterized by the growth of benign tumors throughout the body. The tumors can form in the skin, brain, kidneys, or other organs, and although they are noncancerous, their presence can still lead to significant health problems.

Skin abnormalities, including raised, discolored, or otherwise irregular patches are virtually universal among affected individuals. The brain is a frequent site of TSC-associated tumor growth, leading to epileptic seizures and, frequently, developmental and behavioral problems. The kidneys, another frequent tumor site, can be seriously damaged by the growths.

Damage to such vital organs can, in some cases, threaten the lives of affected individuals.

Effective treatments for TSC are important to find because as many as 1 in 6,000 are affected.

The Politics of CBD and Medicine

CBD is a bit of a hot topic in medical research lately. Confusions about effectiveness, legality, and regulation have many in the consumer industry scratching their heads.

Epidiolex is currently the only brand of CBD approved for use in any treatment by the U.S. Food and Drug Administration (FDA). That means any form of CBD that isn’t manufactured by GW Pharmaceuticals and prescribed by a doctor is still technically illegal under federal law.

Epidiolex first started turning heads in 2013 when it received Orphan Drug Designation from the FDA. In 2018, Epidiolex was approved for the treatment of Lennox-Gastaut (LGS) and Dravet syndromes – rare and severe forms of epilepsy.

When a designated orphan drug is approved by the FDA, a number of benefits kick in – most notably a seven-year long window of market exclusivity when no other competing product can be marketed for the same target condition.

That last detail is important, because technically CBD could still theoretically be produced by a competitor as long as it treated a different condition. To avoid such competition, Epidiolex manufacturer GW Pharmaceuticals started snatching up whatever Orphan Drug Designations for Epidiolex they could, receiving Orphan Drug Designation for the same drug two more times in the two years following their first approval.

Though the benefits of Orphan Drug Designation are meant to offset the often high cost of research and development of drug development, GW Pharmaceutical’s navigation of the system is clearly more about maximizing profits than simply offsetting their research costs. The end result could be needlessly high prices for Epidiolex, which would not be unprecedented behavior for a pharmaceutical company in the seven-year exclusivity window.

About the Study

The phase 3 study of 224 patients with TSC found that patients receiving a dose of Epidiolex enjoyed an almost 50% (averaging 48.1%) reduction in seizure frequency from baseline numbers. The dose of Epidiolex seemed to have only marginal if any effect on efficacy, with a 50mg/kg/day dose being slightly less effective than a 25mg/kg/day dose.

These numbers seem pretty good compared to the placebo group, who reported a 26.5% reduction in seizure frequency. The study was randomized and double-blind, though because of the popularity of CBD in the public eye, there is perhaps room for discussion that the phenomenal results reported by the placebo group are a hint of the difficulties securing bias-free data in CBD studies.

Epidiolex received Orphan Drug Designation for TSC in 2016. With the conclusion of phase 3 testing, it could possibly gain FDA approval by late this year or early next year.


What do you think of this exciting news for TSC patients? Do you think the orphan drug designation system could improve? Why or why not? Share your thoughts with Patient Worthy!

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