Scientists have hailed a potentially life-changing drug for children with a hard to treat form of epilepsy, after promising early clinical trial results.
Dravet syndrome is a genetic disorder which causes treatment resistant epilepsy and is often accompanied by speech and developmental delays. About 3,000 people are thought to have the condition in the UK. Current treatments aim to control the number and severity of seizures, but often do not work.
These preliminary trials, led by UCL and Great Ormond Street hospital (GOSH), found that the drug appeared to be safe and well tolerated by the 81 children taking part.
Before the study, the participants – aged between two and 18 – experienced an average of 17 seizures a month. But after taking a 70mg dose of Zorevunersen, they had on average 50% fewer seizures, and about 80% fewer seizures after three doses.
The study, published in The New England Journal of Medicine, also showed improved quality of life, including motor skills, communication and ability to cope.
A phase 3 clinical trial will be conducted to study Zorevunersen over time, to identify possible long-term risks and any rare but potentially serious side effects, and to determine which patients are most likely to benefit.
The lead author Helen Cross, director and professor of childhood epilepsy at the UCL Institute of Child Health and honorary consultant in paediatric neurology at GOSH, said: “I regularly see patients with hard-to-treat genetic epilepsies, who can have multiple seizures a week. Many are unable to do anything independently for themselves; they require around the clock care and are at high risk of sudden expected death in epilepsy.”
If the phase 3 trials are successful, she added, this new treatment “could help children with Dravet syndrome lead much healthier and happier lives”.
Epilepsy experts celebrated the findings. Jowinn Chew, head of research at Young Epilepsy, said the preliminary results were a “clinically significant step forward” towards a future treatment that targets the underlying cause of Dravet syndrome rather than only managing symptoms.
Dr Alfredo Gonzalez-Sulser, at the Institute for Neuroscience and Cardiovascular Research, University of Edinburgh, said the findings were “incredibly exciting” and could suggest new treatment avenues for other hard-to-treat forms of epilepsy. “There are now over 800 genetic epilepsies that need therapeutics similar to Zorevunersen. This sets a clear path to achieve effective interventions for these severe life-altering diseases for both patients and carers.”
Deb Pal, a professor of epilepsy at King’s College London, said the landmark study gives “enormous hope for the families of thousands of children and young people affected by monogenic [caused by a single gene mutation] epilepsies worldwide”.
• The headline of this article was amended on 5 March 2026 to clarify that the drug is potentially life-changing. Also, the main picture was changed because the previous image was computer generated.
