Three patients in a Beijing trial saw most of their seizures stop

Three adults whose epilepsy had not responded to drugs had far fewer seizures after an experimental gene therapy, Nature reported on November 4, 2026. Yang Dai, a neurosurgeon at Xuanwu Hospital of Capital Medical University in Beijing, and colleagues described the early trial in the New England Journal of Medicine. Each person had scarring on one side of the hippocampus, had lived with epilepsy for 10 to 25 years, had not been helped by at least two medicines, and had been having at least two seizures a month.

Surgeons infused a virus carrying a gene into the small patch of brain where the seizures started. The gene makes those neurons sensitive to clozapine. Two weeks later the patients began a low dose of that drug every eight hours. About two months on, monthly seizures had fallen from 4.5 to 0.5 for two of them and from 4 to 0 for the third, a drop of more than 90 percent. Nature said they did not have serious side effects. The study was built to look at safety. There was no comparison group.

Matthew Walker, a neurologist at University College London who was not part of the trial, told Nature the size of the change is exciting and the side effects look limited, and also that three people cannot show whether the gene therapy, the drug, the surgery, or something else explains it. High doses of clozapine have been tied to heart and other risks. These patients were on a low dose, and the follow-up Nature describes is about two months. The news is that short record in three people. It is not a treatment available beyond the trial.