New gene therapy boosts vision up to 10,000 times in rare eye disease patients

A new gene therapy trial has showcased promise for improving vision in people with a rare genetic disease.

This gene therapy has been developed for patients with Leber congenital amaurosis (LCA1). This genetic condition leads to major ​​ eyesight loss in early childhood and impacts less than 100,000 people globally.

After receiving this therapy, some study participants’ vision improved “100 times.” Remarkably, a couple of them reported a “10,000-fold improvement” in their vision after getting the maximum dose of this new gene therapy.

“That 10,000-fold improvement is the same as a patient being able to see their surroundings on a moonlit night outdoors as opposed to requiring bright indoor lighting before treatment,” said Artur Cideciyan, lead author and a research professor of Ophthalmology.

“One patient reported for the first time being able to navigate at midnight outdoors only with the light of a bonfire,” said Cideciyan, who is also co-director of the Center for Hereditary Retinal Degenerations.

The clinical trials were co-led by researchers from the Perelman School of Medicine at the University of Pennsylvania.

Therapy surgically injected

The gene therapy (ATSN-101) is specifically designed to target and correct the genetic mutation in the GUCY2D gene. This g e ne creates vision-imparting proteins. ATSN-101 is “adapted from the AAV5 microorganism.”

The Phase I/II trial enrolled 15 participants, three of whom were pediatric patients. Patients were surgically injected under the retina with different gene therapy dosages.

All participants suffered from “severe vision loss” — their best vision was 20/80 or worse.

This means that if a person with normal vision could see an object clearly from 80 feet away, these patients would need to move closer to 20 feet to see it clearly.

The gene treatment was shown to be both safe and effective, with eyesight improvements beginning within a month and lasting at least a year.

Three of the six patients who received the highest dosage were able to navigate in various lighting conditions. Other tests used eye charts to determine how well individuals could see faint flashes of light.

Two high-dosage participants experienced a remarkable 10,000-fold improvement in their vision.

“It is very satisfying to see a successful multi-center trial that shows gene therapy can be dramatically efficacious,” said Cideciyan in the press release.

No major side effects reported

In terms of negative impact, some patients showcased side effects, but most were from the surgery.

Some participants suffered from conjunctival hemorrhage, a condition where small blood vessels beneath the clear surface of the eye break. The researchers say that this condition healed on its own. Two patients had eye inflammation, but it was fixed with steroids.

Up next, the team aims to conduct a randomized trial.

This is a major step forward in the treatment of inherited retinal diseases. For this condition, glasses can only help with focusing problems in the eye. They can’t fix the underlying medical causes of vision loss.

The patients of this gene therapy trial are being monitored to evaluate further improvements or any potential challenges.

The findings were reported in the journal The Lancet.