Gene Therapy Restores Vision in Teen with Leber Congenital Amaurosis

Gene Therapy Restores Vision in Teen with Leber Congenital Amaurosis

April 06, 2023

In a groundbreaking clinical trial sponsored by Atsena Therapeutics, 16-year-old Aiden Van De Rostyne-Moore was given the gift of sight after years of blindness caused by Leber congenital amaurosis. Thanks to an experimental gene therapy treatment, Aiden was able to see snowflakes for the first time in her life.

Atsena's experimental gene therapy treatment for Leber congenital amaurosis (LCA) involves sending tiny molecular machinery to the retina at the back of the eye. The aim of the therapy is to provide a working form of a critical gene for vision.

LCA is a rare genetic condition caused by mutations in at least 20 genes. It affects approximately one in 50,000 babies, causing them to be born legally blind or to lose most of their vision as children. Aiden Van De Rostyne-Moore, the subject of the article, was born with LCA caused by a mutation in the GUCY2D gene.

Atsena's ATSN-101 gene therapy is designed to deliver working copies of the GUCY2D gene, which is critical for vision, to the retina. The treatment sends molecular machinery to the back of the eye, where it can provide the necessary gene to replace the mutated one causing the blindness.

Aiden is one of 15 people in the United States who are taking part in the Phase I/II trial of an experimental treatment. This early clinical study aims to assess the safety and efficacy of the treatment. According to initial results released in October 2022, participants who received the highest dose of the gene therapy, including Aiden, have shown "meaningful improvements in vision." Moreover, there have been no significant safety concerns related to the gene therapy observed so far.

“Aiden being able to see a snowflake for the first time offers a wonderful, real-life account of gene therapy’s potential benefits,” said Paul Yang, M.D., Ph.D., an associate professor of ophthalmology in the OHSU School of Medicine who leads the university’s involvement in the trial at the OHSU Casey Eye Institute. “As a physician-scientist who works to develop and bring new treatments to patients, it’s an honor to be among the first who get to witness signs of clinical success like this.”

In late 2017, the FDA granted approval for the very first gene therapy designed to treat an inherited disease, Leber congenital amaurosis (LCA). However, this particular therapy is not suitable for Aiden's case as it is intended for a different type of the condition that is caused by another gene.

Despite this setback, Aiden and her family remained optimistic and were eventually informed of Atsena's clinical trial through their healthcare team at the OHSU Casey Eye Institute in the previous year.

Aiden's Experience with Gene Therapy

Prior to participating in the clinical trial, Aiden's visual impairment was severe. During eye exams, she could only identify the largest letter on the chart. To differentiate between shapes or letters on paper, she had to bring the paper very close to her nose, leaving a small space between it and her eyes. She had some ability to distinguish light and dark but was easily overwhelmed by bright light or sunshine, which made it impossible for her to see anything.

After receiving the experimental gene therapy in one eye, Aiden reported that she was able to see more of her mother's face. Her paraeducator also observed that Aiden was running into fewer obstacles at school. Although Aiden did not provide detailed descriptions of these changes, various tests conducted as part of the clinical trial indicate that her vision has indeed improved. Notably, she can now read more letters on the eye chart.

OHSU, Atsena, and the University of Pennsylvania (the other trial site) will continue to track Aiden and the other trial participants for an additional four years to monitor both their vision and general health.

Additional findings from the clinical trial are expected to be announced later this month at the 2023 meeting of the Association for Research in Vision & Ophthalmology.