In a new paper published in The New England Journal of Medicine, the researchers found that children with Dravet syndrome had up to 91% fewer seizures while being regularly administered a new medication called zorevunersen.

Dravet syndrome is a devastating genetic condition which causes frequent, hard-to-control seizures and long-term neurodevelopmental impairment. The condition also causes feeding difficulties, movement problems and has a high risk of premature death. Current treatments fail to control seizures in most patients and there are no approved medicines that address the condition's devastating cognitive and behavioural impacts.

Zorevunersen, produced by Stoke Therapeutics in collaboration with Biogen, works by tackling the underlying cause of the disease – a faulty gene.

The results show, for the first time, the potential to reduce the impact of the condition on a child's mental processes and behaviour. The children's quality of life improved over a three-year period, and most of the treatment's side effects were mild.

Lead author Professor Helen Cross, director and professor of childhood epilepsy at the UCL Institute of Child Health and an honorary consultant in paediatric neurology at Great Ormond Street Hospital, said: 'I regularly see patients with hard-to-treat genetic epilepsies with impacts that go beyond seizures and it's heart-breaking when treatment options are limited. This new treatment could help children with Dravet syndrome lead much healthier and happier lives.

'Overall, our findings showed that zorevunersen is safe to use and well tolerated by most patients and supports further evaluation in the ongoing phase three study.'