Greenwich Biosciences, a GW Pharmaceuticals Company, Presents New Data for EPIDIOLEX® (cannabidiol) in Patients with Tuberous Sclerosis Complex (TSC) at the American Epilepsy Society Annual Meeting

December 7, 2019

Study results showed EPIDIOLEX significantly reduced difficult-to-treat seizures associated with TSC and improved overall patient condition as reported by caregivers

CARLSBAD, Calif., Dec. 07, 2019 (GLOBE NEWSWIRE) -- GW Pharmaceuticals plc (Nasdaq: GWPH), the world leader in the science, development, and commercialization of cannabinoid prescription medicines, along with U.S. subsidiary Greenwich Biosciences, today presented new data from a Phase 3 clinical trial of EPIDIOLEX® (cannabidiol or CBD) oral solution, CV in tuberous sclerosis complex (TSC) at the American Epilepsy Society (AES) Annual Meeting. The study found that patients treated with EPIDIOLEX 25 mg/kg/day or 50 mg/kg/day experienced a significantly greater reduction in TSC-associated seizures (49% for 25 mg/kg/day and 48% for 50 mg/kg/day) compared to placebo (27%; p=0.0009 and p=0.0018, respectively).

“Epilepsy is the most common neurological feature of TSC,1,2,3 a rare and severe childhood-onset disease, and as many as two-thirds of patients experience treatment-resistant seizures,”4 said Elizabeth Thiele, M.D, Ph.D., director of pediatric epilepsy and director of The Carol and James Herscot Center for Tuberous Sclerosis Complex at Massachusetts General Hospital, professor of neurology at Harvard Medical School, Boston and lead investigator of the trial. “There is a significant need for new treatments to address TSC-related seizures and these positive results suggest patients may benefit from this pharmaceutical formulation of highly-purified CBD.”

New secondary endpoint data, presented for the first time at AES, showed that more patients on EPIDIOLEX experienced a 50% or greater reduction in seizures (36% for 25 mg/kg/day and 40% for 50 mg/kg/day) compared to placebo (22%; p=0.0692 and p=0.0245, respectively). Additionally, 48% of patients taking either dose of EPIDIOLEX in the study experienced a greater reduction in total seizure frequency compared to placebo (27%; p=0.0013 and p=0.0018, respectively). Caregivers and patients also reported overall improvement with EPIDIOLEX in 69% of patients on 25 mg/kg/day and 62% of patients on 50 mg/kg/day compared to 39% on placebo (p=0.0074 and p=0.0580, respectively). Additional analysis showed that patients taking EPIDIOLEX in the study experienced a greater reduction in composite focal seizures (52% for 25 mg/kg/day and 50% for 50 mg/kg/day) compared to placebo (32%; p=0.0076 and p=0.0116, respectively).

“We are pleased to present these results which demonstrate the potential of EPIDIOLEX to reduce both focal and generalized seizures associated with TSC,” said Justin Gover, CEO, GW Pharmaceuticals. “This is promising news for patients and clinicians, and we remain committed to helping those suffering from seizures associated with this difficult-to-treat disease. We look forward to submitting an sNDA to the FDA soon, with the goal of expanding the EPIDIOLEX product label in 2020.”

The safety profile observed in the study was generally consistent with findings from previous studies. Adverse events (AEs) occurred in 93% of the 25 mg/kg/day group, 100% of the 50 mg/kg/day group and 95% of the placebo group. Both doses had an acceptable safety profile, with fewer AEs reported with 25 mg/kg/day than 50 mg/kg/day. The most common AEs were diarrhea, decreased appetite and somnolence. Eight patients on EPIDIOLEX 25 mg/kg/day, 10 on 50 mg/kg/day and 2 on placebo discontinued treatment due to an AE. Additionally, 13% of 25 mg/kg/day patients and 25% of 50 mg/kg/day patients experienced elevated liver enzymes; 79% of these patients were also taking the antiepileptic drug (AED) valproate. Elevations in ALT/AST resolved in all patients. There were no cases of Hy’s law observed and there were no deaths in the trial.

Study Design
The randomized, double-blind, placebo-controlled trial was conducted at 46 sites in six countries. A total of 224 people (aged 1 to 65) with a confirmed diagnosis of treatment-resistant TSC were randomized to receive either EPIDIOLEX 25 mg/kg/day (n=75), EPIDIOLEX 50 mg/kg/day (n=73), or placebo (n=76) for 16 weeks (4-week titration and 12-week maintenance phase), added to current AED treatment. The primary endpoint was percent change from baseline in TSC-associated focal and generalized seizure frequency for EPIDIOLEX vs placebo over the treatment period. Key secondary endpoints were ≥50% responder rate, percent reduction in total seizure frequency (including focal sensory and epileptic spasms), and subject/caregiver global impression of change (S/CGIC) in overall condition. On average, patients were taking three AEDs, having previously tried and discontinued four other AEDs. The most common concomitant AEDs in this trial were valproate (45%), vigabatrin (33%), levetiracetam (29%), and clobazam (27%). 

About Tuberous Sclerosis Complex (TSC)
Tuberous sclerosis complex (TSC) is a rare genetic condition that affects approximately 50,000 individuals in the U.S. and nearly one million people worldwide.5 At least two children born each day will develop TSC, with an estimated prevalence of one in 6,000 newborns.5 The condition causes mostly benign tumors to grow in vital organs of the body including the brain, skin, heart, eyes, kidneys and lungs 6 and is a leading cause of genetic epilepsy.7 TSC often occurs in the first year of life as either focal seizures or infantile spasms1 and is associated with an increased risk of autism and intellectual disability.8 The severity of the condition can vary widely. In some children the disease is very mild, while others may experience life-threatening complications.6

Epilepsy is present in about 85% of patients with TSC and may progress to become intractable to medication.1,2,3 More than 60% of individuals with TSC do not achieve seizure control4 with standard treatments such as antiepileptic drugs, epilepsy surgery, ketogenic diet, or vagus nerve stimulation2 compared to 30-40% of individuals with epilepsy who do not have TSC who are drug resistant.9,10

About GW Pharmaceuticals plc and Greenwich Biosciences, Inc.
Founded in 1998, GW is a biopharmaceutical company focused on discovering, developing and commercializing novel therapeutics from its proprietary cannabinoid product platform in a broad range of disease areas. GW’s lead product, EPIDIOLEX® (cannabidiol) oral solution is commercialized in the US by its U.S. subsidiary Greenwich Biosciences for the treatment of seizures associated with Lennox-Gastaut syndrome (LGS) or Dravet syndrome in patients two years of age or older. This product has received approval in Europe under the tradename EPIDYOLEX®. The Company continues to evaluate EPIDIOLEX in additional rare conditions including tuberous sclerosis complex (TSC) and Rett syndrome. GW commercialized the world’s first plant-derived cannabinoid prescription drug, Sativex® (nabiximols), which is approved for the treatment of spasticity due to multiple sclerosis in numerous countries outside the United States and for which the Company is now advancing a late stage program in order to seek FDA approval. The Company has a deep pipeline of additional cannabinoid product candidates which includes compounds in Phase 1 and 2 trials for epilepsy, autism, glioblastoma, and schizophrenia. For further information, please visit

Important Safety Information
Important safety information for EPIDIOLEX is available at

Forward-looking statements
This news release contains forward-looking statements that reflect GW's current expectations regarding future events, including statements regarding financial performance, the timing of clinical trials, the timing and outcomes of regulatory or intellectual property decisions, the relevance of GW products commercially available and in development, the clinical benefits of EPIDIOLEX®/EPIDYOLEX® (cannabidiol) oral solution and Sativex® (nabiximols), and the safety profile and commercial potential of both medicines. Forward-looking statements involve risks and uncertainties. Actual events could differ materially from those projected herein and depend on a number of factors, including (inter alia), the success of GW’s research strategies, the applicability of the discoveries made therein, the successful and timely completion and uncertainties related to the regulatory process, and the acceptance of EPIDIOLEX®/EPIDYOLEX®, Sativex® and other products by consumer and medical professionals. A further list and description of risks and uncertainties associated with an investment in GW can be found in GW’s filings with the U.S. Securities and Exchange Commission. Existing and prospective investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. GW undertakes no obligation to update or revise the information contained in this press release, whether as a result of new information, future events or circumstances or otherwise.


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7 TS Alliance Website. Accessed November 19, 2019.
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