Surgeons carry out ground-breaking stem cell therapy for AMD

A stem cell therapy that could restore vision in patients with age-related macular degeneration (AMD), a leading cause of blindness, has been tested in a UK patient for the first time.

Surgeons at the Moorfields Eye Hospital in London have carried out the procedure – which involves seeding the damaged retina with modified human embryonic stem cells – on the first of 10 patients due to be enrolled in the clinical trial.

AMD is caused when a layer of cells that supports the light-detecting rods and cones of the macula area of the retina starts to degrade, causing progressive loss of central vision. The stem cell therapy is being tested in patients with the 'wet' form of AMD, in which the retinal damage is caused by defective blood vessels.

The procedure uses stem cells that have been encouraged to differentiate into the retinal pigment epithelium (RPE) cells that form the supporting layer in the retina. They are collected into a patch that is implanted behind the macula in an operation lasting a couple of hours.

This first operation – in a 60-year-old woman – is a major milestone in the 10-year-old London Project to Cure Blindness, which was set up as a joint initiative between Moorfields, the UCL Institute of Ophthalmology, and the National Institute for Health Research (NIHR).

In 2009 Pfizer also joined the scheme, offering to fund the trials and help bring the technology through the regulatory process.

It will only be a few weeks before the team behind the procedure will be able to get an inkling of whether it will be effective, according to a Moorfields statement, which said it was hoping for the first visual acuity data in December.

While drugs are available for AMD, such as Novartis/Roche's Lucentis (ranibizumab) and Bayer/Regeneron's Eylea (aflibercept), these drugs are designed to slow down the progression of the disease. To date there is no therapy that can help restore vision that has already been lost.

As the biologic drugs are expensive and must be given chronically to keep patients' vision from deteriorating, the hope is that a surgical procedure could represent both a clinical advance and a more cost-effective therapy for AMD. Sales of Lucentis were almost $4.3 billion last year, with Eylea bringing in another $3 billion.

"There is real potential that people with wet AMD will benefit in the future from transplantation of these cells," said retinal surgeon Professor Lyndon Da Cruz from Moorfields, who is performing the operations and is co-leading the London Project with Professor Pete Coffey from UCL, whose team developed the procedure for converting the stem cells into RPEs.