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Headshot of Steven Howarth, photo credit BBC News

Steven Howarth, 18
(photo credit BBC News)

Gene Therapy Improves Sight of 18 Year-Old Member

27 April 2008

Scientists at Moorfields Eye Hospital in London today announced initial results of their clinical trial of revolutionary Gene Therapy as a treatment for Leber Congenital Amaurosis (LCA), a form of retinitis pigmentosa that affects the young. LCA is rare and caused by an abnormality in a gene called RPE65.

The trials, which are supported financially by RP Fighting Blindness, are primarily designed to ensure the safety of the viral vector used to introduce the genetic material into the retina, and the surgical procedures involved. However one patient in particular has demonstrated significantly improved night vision.

Steven Howarth, aged 18 and a member of RP Fighting Blindness (The British Retinitis Pigmentosa Society), demonstrated improvement just a few weeks after the operation, most notably in tests of his ability to navigate around obstacles in very low light. A video clip illustrating the tests can be viewed on our Chief Executive's blog which is linked at the foot of this news item. Steven was diagnosed at the age of 8 and his vision had continued to deteriorate rapidly.

The news was released by Moorfields Eye Hospital in London, stating that researchers from the Biomedical Research Centre for Ophthalmology based at Moorfields Eye Hospital and UCL Institute of Ophthalmology have published results today in the New England Journal of Medicine.

The trial, led by Professor Robin Ali, shows that the experimental treatment is safe and can improve sight. The findings are a landmark for gene therapy technology and could have a significant impact on future treatments for RP.

Crucially, the experimental treatment was found to cause no side effects in this trial. Following the treatment, the three patients involved underwent a series of tests designed to establish the effects of the therapy on vision. They all achieved levels of vision at least equivalent to before the operation, but Steven benefited from significantly improved night vision.

Professor Ali believes the operation’s success for Steven could be because his disease had not progressed to the same extent as the others. The other two patients may also still benefit from the new treatment in the future, but it will be some time before this becomes apparent. The team has already begun to trial the technique in younger patients, where they hope to achieve even better results.

The team conducting the trial is led by Professor Robin Ali and includes eye surgeon Mr James Bainbridge and retinal specialist Professor Tony Moore. The technique used in the trial involved inserting healthy copies of the missing RPE65 gene into the cells of the retina to help them to function normally. This involved an operation which delivered the normal genes to the retina, using a harmless virus or ‘vector’ to carry the gene into the cells.

Commenting on the findings, Professor Ali said: “Showing for the first time that gene therapy can work in patients with eye disease is a very significant milestone. This trial establishes proof of principle of gene therapy for inherited retinal disease and paves the way for the development of gene therapy approaches for a broad range of eye disorders.”

Explaining the technique, Mr James Bainbridge, who leads the surgical team, said: "We developed surgical techniques to enable access to the cells beneath the retinas of patients, using a very fine needle to deliver the virus. It is tremendously exciting to see that this technique is safe in an extremely fragile tissue and can improve vision in a condition previously considered wholly untreatable."

Professor Moore, who is also a member of the charity's Medical Advisory Board and one of our trustees, said: “It is very encouraging to see that this treatment can work, even in young adults who have severely advanced disease. We anticipate an even better outcome in the younger patients we are now beginning to involve as the trial proceeds, as we will be treating the disease in the early stages of its development.”

Professor Ali added: “These results give us great confidence that this technique is safe and can bring real benefit to patients with impaired vision. While we’re very excited about the improvement in Steven’s vision, it’s important to emphasise that gene therapy is still an experimental treatment not yet generally available to patients. The technique will be tested in other patients with LCA and we also hope to begin trials for other forms of retinal disease in the future.”

BBC item about the trials including TV report.

The best way to understand the impact on Steven of the treatment is to watch this short ‘before’ and ‘after’ video of Steven navigating a darkened room with obstacles in his way:




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