GW Pharmaceuticals Announces New Positive Phase III Data

GW Pharmaceuticals plc recently announced additional positive Epidiolex (cannabidiol or CBD) Phase III data in poster presentations at the 70th Annual Meeting of the American Epilepsy Society. These data are from the positive pivotal Phase III study of Epidiolex in Dravet syndrome and the first pivotal Phase III study of Epidiolex in Lennox-Gastaut syndrome (LGS), both reported earlier this year.

“We are pleased to present key findings from two pivotal Phase III studies of Epidiolex and believe these additional positive data reinforce the robust nature of the results achieved in two of the most difficult-to-treat epilepsy patient populations,” said Justin Gover, GW’s Chief Executive Officer. “We are making very good progress toward a NDA submission to the FDA as well as preparations for commercial launch and look forward to the opportunity to make this important new medicine available to patients as quickly as possible.”

Highlights of Findings in Both Phase III Studies

-Each pivotal Phase III study achieved the primary endpoint demonstrating a statistically significant difference between Epidiolex and placebo in seizure frequency reduction during the 14 week treatment period.

-In the 12-week maintenance period (excluding the initial dose escalation), the treatment effect increased for patients receiving Epidiolex and showed a greater level of statistical significance compared with placebo.

-Caregivers of patients receiving Epidiolex were significantly more likely to report an improvement in overall condition.

-A consistent separation between Epidiolex and placebo across all response rates was seen. In the LGS study, the drop seizure responder analysis showed a statistically significant separation between Epidiolex and placebo at the 50% seizure reduction threshold.

-Epidiolex efficacy was established relatively early in treatment.

-Epidiolex was generally well tolerated.

“These placebo-controlled studies demonstrate that Epidiolex provides clinically meaningful reductions in seizure frequency together with an acceptable safety and tolerability profile,” said Orrin Devinsky, MD, of New York University Langone Medical Center’s Comprehensive Epilepsy Center and Principal Investigator of the Dravet syndrome trial. “The epilepsy community has been eagerly anticipating the presentation of this high-quality scientific data from the Epidiolex program at the American Epilepsy Society. My colleagues and I are excited at the future prospect of prescribing an appropriately standardized and tested pharmaceutical formulation of cannabidiol.”

“Dravet syndrome and Lennox-Gastaut syndrome are diagnosed in early childhood and represent some of the most difficult types of epilepsy to treat. Nearly all patients continue to have uncontrolled seizures and other medical needs throughout their lifetime. These trial results show that Epidiolex offers much needed new hope for children and their families,” added Elizabeth Thiele, MD, PhD, Director of Pediatric Epilepsy at the Massachusetts General Hospital, Professor of Neurology at the Harvard Medical School and Principal Investigator of the LGS trial. “I very much look forward to the day when Epidiolex is available as a new prescription option for my patients.”

The studies represented in the posters are the first randomized, double-blind, placebo-controlled studies to investigate the efficacy and safety of CBD added to concomitant antiepileptic drug (AED) therapy in Dravet syndrome and LGS. The following are links to the posters presented:

Phase 3 Trial in Lennox-Gastaut syndrome (click to access)
Phase 3 Trial in Dravet syndrome (Part A) (click to access)
Phase 3 Trial in Dravet syndrome (Part B) (click to access)

The peak onset of LGS typically occurs between ages of 3 to 5 years and can be caused by a number of conditions, including brain malformations, severe head injuries, central nervous system infections, and inherited degenerative or metabolic conditions. In up to 30% of patients, no cause can be found. Patients with LGS commonly have multiple seizure types including non-convulsive, convulsive, and drop seizures, which frequently lead to falls and injuries. Drug resistance is one of the main features of LGS. Most children with LGS experience some degree of impaired intellectual functioning, as well as developmental delays and behavioral disturbances. It is estimated that there are approximately 14,000-18,500 patients with LGS in the United States and 23,000-31,000 patients with LGS in Europe.

Dravet syndrome is a severe infantile-onset and highly treatment-resistant epileptic syndrome frequently associated with a genetic mutation in sodium channels. Onset of Dravet syndrome occurs during the first year of life in previously healthy and developmentally normal infants. Initial seizures are often temperature related, severe, and long-lasting. Over time, people with Dravet syndrome can develop multiple types of seizures, including tonic-clonic, myoclonic, and atypical absences and are prone to bouts of prolonged seizures called status epilepticus, which can be life threatening. Risk of premature death including SUDEP (sudden expected death in epilepsy) is elevated in people with Dravet syndrome. Additionally, the majority will develop moderate-to-severe intellectual and development disabilities and require lifelong supervision and care. There are currently no FDA-approved treatments and nearly all patients continue to have uncontrolled seizures and other medical needs throughout their lifetime.

Epidiolex, GW’s lead cannabinoid product candidate, is a liquid formulation of pure plant-derived CBD, which is in development for the treatment of a number of rare pediatric epilepsy disorders. GW has conducted extensive preclinical research of CBD in epilepsy since 2007. This research has shown that CBD has significant anti-epileptiform and anticonvulsant activity using a variety of in vitro and in vivo models and has the ability to treat seizures in acute animal models of epilepsy with significantly fewer side effects than existing anti-epileptic drugs. To date, GW has received Orphan Drug Designation from the FDA for Epidiolex in the treatment of both Dravet syndrome and Lennox-Gastaut syndrome. Additionally, GW has received Fast Track Designation from the FDA and Orphan Designation from the European Medicines Agency for Epidiolex for the treatment of Dravet syndrome. GW is currently evaluating additional clinical development programs in other orphan seizure disorders.

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 is advancing an orphan drug program in the field of childhood epilepsy with a focus on Epidiolex (cannabidiol), which is in Phase III clinical development for the treatment of Dravet syndrome, Lennox-Gastaut syndrome, Tuberous Sclerosis Complex and Infantile Spasms. GW commercialized the world’s first plant-derived cannabinoid prescription drug, Sativex, which is approved for the treatment of spasticity due to multiple sclerosis in 30 countries outside the United States. The company has a deep pipeline of additional cannabinoid product candidates which includes compounds in Phase I and II trials for glioma, schizophrenia, and epilepsy. In the United States, GW is operating as Greenwich Biosciences Inc. For more information, visit www.gwpharm.com.