Marijuana plant Epidiolex is a purified form of cannabidiol, one of the hundreds of molecules found in the marijuana plant. Photograph: Martin Schroeder/Getty Images/EyeEm A treatment for childhood epilepsy developed by a UK firm has been approved by US regulators and will become the first cannabis-based medicine on the American market.
Epidiolex, made by GW Pharmaceuticals, is set to be launched in the autumn after being approved by the US Food and Drug Administration (FDA) for the treatment of two rare and severe forms of epilepsy, Lennox-Gastaut syndrome (LGS) and Dravet syndrome, for patients from the age of two.
The syndromes have a higher early mortality rate than other types of epilepsy and do not respond to many of the other drugs available. Epidiolex, an oral solution with a strawberry flavour that is taken twice a day, is the first medicine approved in the US for Dravet syndrome.
It should be available to prescribe by doctors in Britain and the rest of Europe by mid-2019 if the European Medicines Agency approves it early next year.
The FDA commissioner, Scott Gottlieb, said: “This approval serves as a reminder that advancing sound development programmes that properly evaluate active ingredients contained in marijuana can lead to important medical therapies. And the FDA is committed to this kind of careful scientific research and drug development.”
Philip Gattone, president and chief executive of the US-based Epilepsy Foundation, said: “For those living with intractable seizures caused by LGS and Dravet syndrome, Epidiolex represents a true medical advancement.”
The most common side effects in the clinical trials were sleepiness, elevated liver enzymes that can cause liver injury (generally mild), diarrhoea, insomnia and infections. Among other epilepsy drugs, the most serious risks include suicidal thoughts and attempts.
The UK home secretary has just launched a review into medicinal uses of cannabis following public pressure from the families of two sick children: 12-year-old Billy Caldwell and six-year-old Alfie Dingley, who have forms of intractable epilepsy that appear to be eased by the use of cannabis oil.
GW’s chief executive, Justin Gover, stressed that Epidiolex was a prescription drug that had been shown to be effective in reducing seizures in clinical trials. “Cannabis oils are a very different thing. There’s no regulation, no quality control and no information on dose and side effects.” Gover said if GW was approached by the two boys’ physicians to request Epidiolex, the firm would be able to assist.
Epidiolex is a purified form of cannabidiol (CBD), one of the hundreds of molecules found in the marijuana plant. It contains less than 0.1% of tetrahydrocannabinol (THC), which makes people high.
Epidiolex was developed by GW, which is based in London and Cambridge and employs 500 people in the UK, but is listed on the US stock exchange Nasdaq. It was founded in 1998 by the scientist Geoffrey Guy, who is now chairman, and a fellow biotech entrepreneur, Brian Whittle.
The firm has had a Home Office licence to grow cannabis for the past two decades, initially at secret farms in southern England and since 2016 at British Sugar’s 18-hectare glasshouse in Norfolk, and two other glasshouses. The cannabis is moved to a secret location in the UK where CBD is extracted and purified, and made into a medicine.
More than 50 children in the UK have already been treated with Epidiolex free of charge out of 1,500 worldwide, mostly in the US, on a compassionate access programme.
Gover would not reveal the likely price tag. Analysts expect the drug to become GW’s first “blockbuster” medicine with annual sales of more than $1bn (£756m).
Around 30,000 people in the US suffer from LGS and 6,000 from Dravet syndrome, with similar numbers across Europe. Gover said GW had enough capacity to provide treatment for all of them.
GW initially developed Sativex, a mouth spray for multiple sclerosis-related spasticity, which became the first cannabis-based medicine to be licensed in Britain.
The company then started scientific work on CBD as a treatment to reduce seizures. In December 2012, GW was approached by the family of Sam Vogelstein, then 11, who was suffering from severe epilepsy. The boy was given purified CBD, which later became Epidiolex, and he has been seizure-free for more than two years. He testified to the FDA advisory panel.