Gene Therapy Offers Hope For Patients With Rare Vision Loss

A groundbreaking gene therapy treatment has shown remarkable success in improving vision for patients with Leber congenital amaurosis (LCA1), a rare inherited condition that causes severe vision loss. The therapy, which targets a specific genetic mutation, has resulted in significant improvements in vision for some patients.

In a recent clinical trial, 15 patients with LCA1 received different doses of the gene therapy, ATSN-101. The treatment involves surgically injecting the therapy under the retina. Results from the trial were published in The Lancet.

The most significant improvement was seen in patients who received the highest dose of the therapy. Some patients experienced a 10,000-fold improvement in their vision, allowing them to see their surroundings in much lower light conditions.

“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 the study’s lead author, Artur Cideciyan, PhD.

The study offers hope for patients with LCA1 and other inherited retinal diseases. While more research is needed, the results of this trial suggest that gene therapy could be a promising treatment option for these conditions.

Improvements were noticed quickly, often within the first month, after the therapy was applied, and lasted for at least 12 months. Observations of participating patients are also ongoing.

Three of six high-dosage patients who were tested to navigate a mobility course in varying levels of light achieved the maximum possible score. Other tests used eye charts or measured the dimmest flashes of light patients perceived in a dark environment.

“Even though we previously predicted a large vision improvement potential in LCA1, we did not know how receptive patients’ photoreceptors would be to treatment after decades of blindness. It is very satisfying to see a successful multi-center trial that shows gene therapy can be dramatically efficacious,” ” said Cideciyan.

The primary goal of the clinical trial was to assess the safety and efficacy of the gene therapy at various dosage levels. While some patients experienced side effects, the majority were related to the surgical procedure itself. The most common side effect was conjunctival hemorrhage, which resolved without complications. Two patients developed eye inflammation that was successfully treated with steroids. Importantly, no serious side effects were attributed to the study drug.