GW begins phase 3 trial of Epidiolex in third epilepsy use

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GW Pharma is to begin phase 3 trials of its epilepsy drug Epidiolex (cannabidiol) as an adjunctive therapy for the rare disease Tuberous Sclerosis Complex, following its recent late stage success in a rare kind of childhood epilepsy.

The UK-based cannabinoid medicine specialist is facing a transformative year, analysts have said, as it waits for results from four pivotal trials of Epidiolex in two indications – Dravet syndrome and Lennox-Gastaut syndrome, both rare forms of paediatric epilepsy.

Success in all three indications could drive sales above the billion-dollar mark, and GW has already requested a meeting with the FDA over a possible filing after announcing positive top-line results from the first of two pivotal trials in Dravet syndrome.

The company said that epilepsy is the most common symptom of Tuberous Sclerosis Complex (TSC), occurring in around 80-90% of patients, and is a significant cause of morbidity and mortality.

The decision to progress trials in the TSC indication is based on findings from a physician-led expanded access programme, which found TSC patients reported reductions in seizure activity, said GW's CEO, Justin Gover.

Elizabeth Thiele, director of the Pediatric Epilepsy Program at Massachusetts General Hospital, and principal investigator on the trial, said: "The results of our open-label study of Epidiolex in children with TSC have been very encouraging and we are excited to begin this important placebo-controlled clinical trial."

In a research note, Edison predicted Epidiolex will generate peak sales of $195m in Dravet syndrome, $601m in Lennox-Gastaut and $255 million in TSC, based on a 2018 launch year.

These are in line with Thomson Reuters Cortellis consensus forecasts of around $1.1 billion by 2021.

GW already markets Sativex (nabiximols) in multiple sclerosis spasticity, but a failed attempt to get this drug approved in cancer pain have meant sales have fallen short of expectations.

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