Gene therapy effective in rare blindness, wet AMD next target

Lab work

Patients with a rare eye disease called choroideremia that causes blindness saw their sight improve in the long term with the use of a new gene therapy.

A team at Oxford University published results this week in the New England Journal of Medicine that could be the start of a whole new way of treating some of the causes of blindness.

The disorder affects young men whose light-detecting cells in the backs of their eyes are dying because they have inherited a faulty gene. Until now, there has been no treatment and they gradually become blind. The researchers found that not only does the treatment halt the disease, it revives some of the dying cells and improves the patient's vision, in some cases markedly.

The therapy works by injecting a working copy of the gene into the back of the eyes to help cells regenerate. This is the first strong hint that the treatment is viable and could be widely used on patients, according to the eye surgeon leading the trial, professor Robert MacLaren of Oxford University.

“The concept of gene therapy is that it corrects gene defects,” he told BBC News. "Ideally, we should only have to do that once, because once the DNA is corrected and inserted into the correct cell, that cell should be able to continue its function as normal. We seem to have achieved this concept of one single treatment that does not need to be repeated which is unlike traditional medicines.”

The research is funded by the Health Innovation Challenge Fund, a partnership between the Wellcome Trust and the Department of Health.

MacLaren said that if the next phase of larger trials goes as he hopes, a gene therapy for choroideremia could be licensed in three years.

The researchers will also look to apply for approval to start studies next year to treat more common forms of blindness--which include wet AMD, the most common cause of blindness in people over 55.

Roche ($RHHBY) and Novartis’ ($NVS) Lucentis and Bayer and Regeneron’s ($REGN) Eylea treat wet AMD. Both of these drugs are injected monthly or every other month and work as an anti-VEGF treatment, bringing in blockbuster sales for the drugmakers.

But no gene therapy is currently approved for the eye condition, and in fact only one gene therapy is approved in the western world in the form of UniQure’s ($QURE) Glybera, which is licensed in Europe for a rare inherited condition.

- check out Science Daily’s take
- and the BBC News story
- get the NEJM article