Eye experts in Southampton are trialling a drug that was previously tested to treat stomach ulcers to help prevent sight loss in young people with Stargardt disease.
Stargardt disease is a rare genetic condition that affects the area of the retina called the macula. It is caused by a genetic fault that means the eye cannot clear away a by-product of vitamin A metabolism – known as lipofuscin – which accumulates at the back of the eye.
Affecting around one in 10,000 children and young adults, Stargardt disease is the most common form of juvenile macular degeneration, causing a gradual decline in vision and, ultimately, blindness.
Whilst a number of interventions are being investigated, there is currently no available treatment for the condition, and patients are advised to avoid exposure to bright light and wear UV-blocking sunglasses to try to slow disease progression.
Now, Professor Andrew Lotery, a consultant ophthalmologist at University Hospital Southampton NHS Foundation Trust, is leading the UK’s participation in a European-wide study looking to develop the first treatment for the debilitating disease.
Removing lipofuscin
The drug, Soraprazan, was originally tested to treat stomach ulcers. The discovery that it can remove lipofuscin from cells convinced the EU to fund this European trial for Stargardt disease.
Professor Lotery and his team will investigate if it can safely clear away lipofuscin, preventing the damaging build-up, and if it leads to any improvements in vision.
Participants in the study will take Soraprazan as a tablet, meaning that, unlike many other treatments for eye diseases, they do not need an injection into their eye or have to undergo surgery.
The researchers are aiming to involve 15 patients with Stargardt disease, who will be split into two groups – one will take Soraprazan for a year, while the other will take a placebo. While conducting the study, neither the patients nor the researchers will be aware of which group the patients are in.
Lipofuscin is naturally fluorescent, so the researchers will use a special camera to see how much is present at the back of the eye, by shining a particular wavelength of light into the eye and measuring the fluorescence given off. This will allow them to see if the treatment clears away lipofuscin.
Hope for young patients
“There is currently no approved treatment available for Stargardt disease, so we are excited about the opportunity to test Soraprazan,” explained Professor Lotery, who is based at Southampton General Hospital’s eye unit and is a professor of ophthalmology at the University of Southampton.
“It could not only prevent a devastating loss of central vision but, by improving conditions in the eye, there is also the possibility that it might help restore some sight.
“If successful, this trial has the potential to greatly improve the lives of young people with the disease.”
This study has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 779317.
Posted on Friday 6 December 2019