Key facts
- Mean monthly seizures fell from 4.5 to 0.5, from 4.0 to zero and from 4.5 to 0.5 in the three patients.
- The vector GA002 was delivered into the hippocampus under MRI guidance, followed by low-dose oral ligand dosing.
- Recorded adverse events were grade 1 or grade 2, including one asymptomatic liver enzyme rise that resolved without intervention.
- The first two patients remained seizure-free in follow-up; the third had two seizures after an unplanned drug interruption.
- The hospital said GA002 completed US and Chinese investigational new drug filings on October 31, 2026.
A research team at Xuanwu Hospital in Beijing reported that a two-step chemogenetic technique reduced seizures by an average of 92.6% in three patients with drug-resistant epilepsy, according to a study published in the New England Journal of Medicine on November 5, 2026. The work was led by Zhao Guoguang, the hospital's president, who is the paper's corresponding author.
The approach pairs surgery with a pill. Under MRI guidance, the team delivered a gene therapy vector called GA002 into the hippocampus on the side of the brain where seizures originated, so that excitatory neurons there expressed an engineered inhibitory receptor. After a two-week observation period, patients began taking a low-dose oral ligand drug that activates the receptor, lowering the excitability of those neurons, while continuing their existing antiseizure medication.
During the evaluation window from week 5 to week 12 after surgery, mean monthly seizure counts fell from 4.5 to 0.5 in the first patient, from 4.0 to zero in the second and from 4.5 to 0.5 in the third. Seizure severity scores fell in all three, and video electroencephalogram recordings showed fewer epileptiform spikes between seizures, the release said.
Recorded adverse events were grade 1 or grade 2, including one patient with asymptomatic liver enzyme elevation that resolved without intervention. Cognitive testing found no clinically meaningful decline. In follow-up of 12 months, 8 months and 8 months respectively, the first two patients remained seizure-free; the third had two seizures during an unplanned interruption of the ligand drug and none after resuming it.
The hospital said the team will continue long-term safety follow-up and evaluate the strategy in larger clinical trials. The release said GA002 completed investigational new drug filings in both China and the United States on October 31, 2026, and that a phase 1/2 registration trial led by Xuanwu Hospital is recruiting. Nature News also reported on the study on November 5.