Patients are enjoying good outcomes for the use of retinal gene therapy to treat choroideremia, a rare inherited cause of severe sight loss, researchers have reported.
The condition is caused by mutations in the CHM gene that limit its normal functions.
Researchers working on the trial published phase I results in 2014. These results showed that two of six patients treated with gene therapy to increase the function of the CHM gene had significant improvements in their vision.
Now the same team, led by Professor Robert MacLaren of Oxford University, UK, report that the benefits have lasted for 3.5 years since treatment. However, this only applies to the treated eye, and in most cases vision has deteriorated in the untreated eye.
This follow-up appeared recently in The New England Journal of Medicine. It was partly funded by the charity Fight for Sight. Director of Research Dolores Conroy says: "We’re delighted to have supported this work through the Tommy Salisbury Choroideremia Fund, which has allowed Professor MacLaren and his team to produce some incredible findings. Maintaining these positive results is very encouraging as similar mechanisms for other conditions have not shown improvement lasting over time."
Professor MacLaren comments: "This clinical trial marked a major step in developing gene therapy treatments for retinal diseases. It would not have been possible without the scientific funding provided by Fight for Sight through the Tommy Salisbury Choroideremia Fund. In my opinion, this is the single most significant factor that has enabled us to lead the world in starting the first clinical trial for this disease. We shouldn’t under-estimate the power that individuals can have in influencing the course of research through their fundraising activities."
Edwards, T. L. et al. Visual Acuity after Retinal Gene Therapy for Choroideremia. The New England Journal of Medicine 27 April 2016; doi: 10.1056/NEJMc1509501 [abstract]
Leave a Reply