A pioneering gene therapy from Nationwide Children’s Hospital is bringing rare optimism to a field that has long struggled to develop such treatments for certain neurodevelopment disorders.
In September, 8-year-old Maxwell Freed became the first person to receive a gene therapy for SLC6A1, a rare condition that causes seizures, developmental delays and autism-like symptoms, Nationwide Children’s in Columbus, Ohio announced Thursday.
The medicine has improved Maxwell’s mood, muscle tone and coordination, enabling a series of firsts, including riding a bike.
“He’s seeing the world for the first time through a brain that is waking up,” his mother, Amber Freed, told
Endpoints News
. “He’s much more interested in the world around him.”
The promising but early results stand in contrast to a setback in 2022, when
Taysha Gene Therapies paused a
separate SLC6A1 gene therapy in the preclinical stage. That decision, one of many pipeline cuts intended to preserve money, left families fearing that the condition would go untreated.
Freed’s foundation, SLC6A1 Connect, had jump-started the work at Taysha but had also quietly launched a collaboration with Nationwide Children’s. Now she’s working to expand Maxwell’s therapy to additional patients with SLC6A1, based on the preliminary results.
The medicine could show a way forward in efforts to develop gene therapies for related conditions.
The SLC6A1 gene helps regulate GABA, a neurotransmitter in the brain that keeps nerve activity in balance. When GABA levels aren’t properly controlled, it can lead to epilepsy and autism-related symptoms. Fixing that imbalance may offer new ways to treat these brain disorders.
“It’s only been three months, and time will tell with this therapy, but it appears to be a good thing for the field,” said Olivia Kim-McManus, a neurologist at Rady Children’s Hospital – San Diego
who specializes in epilepsy
and was not involved in the case.
Translating scientific promise into real treatments remains challenging. A 2024
analysis published in the
World Journal of Pediatrics
found that gene therapies in epilepsy largely remain stuck in preclinical stages.
Delivering medicine to precise brain regions without affecting others is difficult, and viral vectors used to carry genes can trigger immune reactions. The researchers behind Maxwell’s therapy tried to mitigate risk by using a common vector called AAV9. But the therapy was delivered through spinal fluid rather than intravenous infusion, allowing for a lower dose of the therapy.
“Giving too little of gene therapy may not have a therapeutic benefit, but giving too much may overstimulate the central nervous system,” said Allison Bradbury, a principal investigator in a gene therapy center at Nationwide Children’s, who developed the therapy. “So it really takes a Goldilocks approach.”
The inherent risk of gene therapies was underscored by news that emerged the same day that Maxwell was dosed.
A
patient died
in a clinical trial testing Capsida Biotherapeutics’ gene therapy for pediatric STXBP1 epileptic encephalopathy, a brain disorder that’s responsible for seizures and developmental delay. It’s unclear what caused the death. The company’s first-of-its-kind capsid technology was designed to reach the brain while avoiding other organs.
For Freed, the saga began when it became clear that Maxwell was unable to control his body or emotions. Freed said he was trapped in a mind on fire: loving, empathetic and aware of his behavior, but often powerless to stop it. She feared behavioral crises would only worsen with age.
As a source of hope, Taysha Gene Therapies had pledged to develop a medicine that Freed’s nonprofit had funded at UT Southwestern. But in 2022,
Taysha paused its work on its large pipeline
, except that the company has continued to develop a promising treatment for a neurological disease called Rett syndrome.
Even before the pause, Freed had a sense that the company was taking on too many drug programs and wouldn’t make good on its promises.
So in 2019, she began a parallel collaboration with Nationwide Children’s to design an AAV-based therapy from scratch that could restore Maxwell’s missing gene function.
They kept the program under wraps, in part to protect the intellectual property, Freed said.
Bradbury at Nationwide developed the therapy with Kathryn Meyer, a former principal investigator at the children’s hospital. Maxwell’s treatment is energizing the company Galibra Neuroscience, which is developing an SLC6A1-targeted program, a representative from the company said.
Bradbury and Meyer said they’re hopeful that
FDA plans to speed reviews for individualized medicines
will make such treatments less of an immense lift, though key details have yet to be released. While Maxwell’s treatment was delivered as part of a clinical trial just for him, or what’s called an n-of-1 case, the Nationwide team manufactured enough drug for an early-stage study with up to 10 patients.
Freed’s foundation is now trying to raise about $5 million to continue development. It’s also trying to negotiate with Nationwide Children’s for licensing rights, so that future efforts aren’t stalled in case of corporate restructuring.