Experimental gene therapy cuts seizures by more than 90% in three adults

Three adults with drug-resistant epilepsy experienced reductions of more than 90% in monthly seizures after experimental gene therapy, researchers reported in The New England Journal of Medicine. The early-stage trial targeted the small patch of brain tissue responsible for each participant's seizures; none experienced serious side effects. Viruses delivered a gene that makes targeted neurons produce receptors activated by clozapine. The drug reduces those neurons' activity, allowing researchers to adjust the treatment's potency. Neurologist Matthew Walker, who was not involved in the study, cautioned that the trial was small and raised concerns about long-term clozapine use. High doses have been associated with cardiovascular problems and other adverse effects.