Tuesday 29 September 2015

First UK patient receives stem cell treatment to cure loss of vision

Experimental transplant uses eye cells grown in a lab and if successful could be used to treat hundreds of thousands of macular degeneration sufferers in UK

A patient has become the first in the UK to receive an experimental stem cell treatment that has the potential to save the sight of hundreds of thousands of Britons.

By December, doctors will know whether the woman, who has age-related macular degeneration, has regained her sight after a successful operation at Moorfields Eye Hospital in London last month. Over 18 months, 10 patients will undergo the treatment.

The transplant involves eye cells, called retinal pigment epithelium, derived from stem cells and grown in the lab to form a patch that can be placed behind the retina during surgery.The potential is huge. Although the first patients have the ‘wet’ form of macular degeneration, the doctors believe it might also eventually work for those who have the ‘dry’ form, who are the vast majority of the UK’s 700,000 sufferers.

The surgery is an exciting moment for the 10-year-old London Project to Cure Blindness, a collaboration between the hospital, the UCL Institute of Ophthalmology and the National Institute for Health Research, which was formed to find a cure for wet age-related macular degeneration, the more serious but less common form of the disease.

Prof Pete Coffey of UCL, one of the founders of the London Project, said he would not be working on the new treatment if he did not believe it would work. He hopes it could become a routine procedure for people afflicted by vision loss, which is as common a problem among older people as dementia. 

“It does involve an operation, but we’re trying to make it as straightforward as a cataract operation,” he said. “It will probably take 45 minutes to an hour. We could treat a substantial number of those patients.”

First they have to get approval. The trial is not just about safety, but also efficacy. There will be a regulatory review after the first few transplants to ensure all is going well.The group of patients chosen have the wet form of the disease and experienced sudden loss of vision within about six weeks. The support cells in the eye, which get rid of daily debris and allow the seeing part to function have died. 

“There is a possibility of restoring their vision,” said Coffey. The aim of the transplant is to restore the support cells so the seeing part of the eye is not affected by what would become an increasingly toxic environment, causing deterioration and serious vision loss. The surgery is being performed by retinal surgeon Prof Lyndon Da Cruz from Moorfields, who is also a co-founder of the London Project.

The team chose people with this dramatic vision loss to see whether the experimental stem cell therapy would reverse the loss of vision. But in those with dry macular degeneration, said Coffey, the process is far slower, which would mean doctors could choose the time to intervene – if the treatment works.

Helping people to regain their sight has long been one of the most hopeful prospects for stem cell transplantation. Other research groups have been trialling the use of stem cells in people with Stargardt’s disease, which destroys the vision at a much earlier age.Stem cells have moved from the drawing board into human trials with incredible speed, scientists say. The first embryonic stem cell was derived in 1989. Using them in eyes was always going to have a big advantage over other prospects, because it is possible to transplant them without an all-out attack by the immune system, as would happen in other parts of the body. Most people who have any sort of transplant have to take drugs that suppress the immune system for the rest of their lives.

Just like conventional medicines, stem cell therapies will very likely have to be developed and marketed by large commercial concerns. The London Project has the US drug company Pfizer on board.

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