GW Pharma moves beyond Sativex with epilepsy trial

UK drugmaker GW Pharma will shortly start a Phase 3 trial programme for epilepsy drug Epidiolex, which some believe could transform the fortunes of the company.

GW Pharma already makes revenues from cannabinoid drug Sativex for the treatment of spasticity due to multiple sclerosis (MS), which brought in around £30 million in sales last year, but Epidiolex has the potential to dwarf that product.

By the end of this quarter Epidiolex is due to start three phase III trials in to childhood epilepsies – Dravet syndrome and Lennox Gastaut syndrome – with the first data due before the end of the year. Children with these conditions often do not respond to existing epilepsy drugs.

The active ingredient in Epidiolex is a purified liquid extract from the cannabis plant, known as cannabidiol, which is derived from medical-grade cannabis grown at a secret location in the south of England.

Analysts at Edison say that is ahead of their expectations and puts GW Pharma ahead of competing products from Insys Therapeutics (also cannabidiol) and Zogenix (low-dose fenfluramine) that are not due to start pivotal trials until the second half of this year.

The two childhood epilepsies “represent an unmet medical need and significant commercial opportunity,” according to Edison analysts Christian Glennie and Lala Gregorek.

They put the market opportunity at around $800 million and possibly more if Epidiolex shows activity in other refractory forms of childhood epilepsy such as tuberous sclerosis-related epilepsy and febrile infection-related epilepsy syndrome (FIRES).

GW Pharma also has “highly encouraging results” from a physician-led Phase 2/3 in 58 children, they note, with Epidiolex achieving “substantial reductions in seizure frequency” with high rates of response and a very low drop-out rate.

A fast-track designation already awarded to Epidiolex by the FDA last June, there is a chance of approval by the end of next year or in early 2017.

Meanwhile, GW Pharma has also completed enrolment in a Phase 3 trial of Sativex in cancer pain and is due to report results in the coming weeks, with a second confirmatory trial scheduled to generate results in the second quarter.

If positive, the company could move ahead with a regulatory filing in that indication before the end of the year, although that is a little speculative as the first study missed its primary endpoint.

Meanwhile, GW Pharma also has a number of other cannabinoid-derived drugs coming through the pipeline, including GWP42006 for epilepsy and GWP42003 for schizophrenia and ulcerative colitis, which are in Phase 2a trials.

Image courtesy of Shutterstock / Adrian Niederhaeuser

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