Gene Therapy Could Cut Epilepsy Seizures 90%
Adults with drug-resistant epilepsy saw monthly seizures fall sharply in a three-person early trial.
Updated on Nov. 4, 2026 in Stroke
Researchers reported that three participants with drug-resistant epilepsy saw their monthly seizures fall by more than 90% after an experimental gene therapy delivered viruses directly into brain tissue in an early-stage clinical trial. The results were published in The New England Journal of Medicine, and the approach is still at an early stage for people whose seizures do not respond to standard medications.
Why it matters
For people whose epilepsy keeps breaking through two or more anti-seizure drugs, the finding points to a possible new direction focused on the specific brain tissue producing seizures rather than whole-body medication. Because the study involved only three participants, it shows feasibility and early safety signals rather than proof that the approach works broadly.
This early-stage clinical trial enrolled three people with drug-resistant epilepsy who had developed resistance to at least two anti-seizure drugs. Their seizure frequency fell by more than 90% after treatment, and no serious side effects were reported.
The players
Yang Dai
A neurosurgeon at Xuanwu Hospital of Capital Medical University in Beijing who led the study on gene therapy for drug-resistant epilepsy.
Focalis Bio
A company based in Canterbury, UK, whose co-founder is connected to the gene therapy work, focused on developing targeted neurological treatments.
University College London
A London-based university whose neurologist commented on the findings of the early-stage epilepsy gene therapy trial.
The details
The gene therapy uses adeno-associated virus 9 to carry a gene into neurons in a small patch of brain tissue that was the source of seizures. That gene produces a receptor that binds to clozapine, a drug already in use, so that when clozapine is given it activates those receptors and reduces the activity of the targeted neurons. The virus was infused directly into the participants' brains, and the treatment was aimed at the one hippocampus affected by sclerosis.
Timeline
Participants were diagnosed with epilepsy 10 to 25 years before enrollment in the trial.
Before enrollment, participants averaged at least two seizures per month.
Results were reported in The New England Journal of Medicine on November 4, 2026.
Health Landscape
Drug-resistant epilepsy, where seizures continue despite two or more anti-seizure medications, remains a major unmet need in neurology. This early gene therapy approach differs from standard drug treatment by acting on a specific brain region rather than the whole body.
If you have epilepsy that has not responded to several medications, this early research is worth raising with your neurologist as a topic of interest, though it remains experimental. The finding is most relevant to people with focal seizures tied to a specific brain region, and it does not yet change standard care.
The takeaway
Early results show that targeted gene therapy can sharply reduce seizures in a small group with drug-resistant epilepsy. If you have epilepsy that is hard to control, discuss clinical trial options with your physician.
Further reading
For more on brain conditions and treatment research, explore our Stroke coverage.
