Rett syndrome is a rare genetic neurological disorder that interferes with the brain's ability to control important functions. Around 6-18 months, children with Rett syndrome begin to lose earned developmental skills-such as purposeful hand use, speech, balance, and other motor abilities.
A new multi-center clinical trial is bringing hope for girls and women with Rett syndrome and their families. The Embolden
trial, by Neurogene Inc., is investigating the safety and efficacy of a new, potentially life-changing gene therapy for females aged 3 and older.
Yael Shiloh-Malawsky, MD
On June 8, 2026, Neurogene announced that the Embolden trial has successfully completed enrollment and dosing of 25 participants. The UNC site of the Embolden trial is led by Yael Shiloh-Malawsky, MD, a pediatric neurologist and director of the UNC Rett Syndrome Center of Excellence at UNC Hospitals.
"This is a milestone for the trial and for our site," said Dr. Shiloh-Malawsky, a professor of neurology at the UNC School of Medicine. "We are excited to take part and contribute to this landmark trial."
There is no cure for Rett syndrome, and current treatment focuses on managing symptoms and reducing the risk of serious complications through comprehensive care.
The neurological disorder is caused by genetic changes to the MECP2 gene on the X chromosome. When MECP2 is not functioning properly, it can cause a wide range of developmental and neurological challenges; in girls, it typically results in Rett syndrome. While it is more commonly diagnosed in females, males can also be affected.
Illustration by Xian Marie Boles.
NGN-401 (1E15 vg), a gene therapy being developed for females with Rett syndrome by Neurogene, is a one-time dose that provides functional copies of the MECP2 gene to the brain. The dose of NGN-401 is administered to the intracerebroventricular space, an area of the brain that houses cerebrospinal fluid (CSF), by an expert neurosurgeon.
Scott Elton, MD, who is director of pediatric neurosurgery at the UNC School of Medicine, dosed the first patient at UNC Hospitals in January of this year.
Scott Elton, MD, FAANS, FAAP
"Gene therapy is the future for both fields of neurology and neurosurgery," said Dr. Elton. "I think this trial exhibits that UNC Health can, as a team, provide a level of care that can positively impact people in North Carolina and beyond. It feels very special to be a part of something so innovative."
Neurogene has shared updated results of a Phase 1/2 trial, showing encouraging findings. The results of the Embolden trial are expected in the second half of next year.
"While we won't know what the outcome might be for some time, at the end of the day, we're offering great hope for those living with Rett syndrome and their families," said Dr. Elton.
