Yes, thank you very much for contributing such informed reporting on the development of such hopeful therapies.

*laughs ruefully*

I think it must have been the Ceregene people I heard this past December here in NYC raising this issue (random virus mutations) as a major concern. I wonder how many years we would need to have to know this is not a possiblity.....

How long does it take to know if there are adverse events?
 

Fiona's point is well taken. In general, many drugs can have consequences and impacts that are never shown during the clinical trials. If drugs were observed for years after their initiation before approval, no drug would ever be approved.

Because this is the case, the FDA has what is called post-marketing surveillance. That is, post-approval observation of the drug and its adverse events. Since gene therapies for PD at this point appear to have multi year continuing impact, we will have to see what happens over long periods of time to people who have these procedures. The good news is that at least over the first three years none of the problems that occurred in earlier gene therapies in the early 1990s appear to be taking place.

My own guess (informed only by some recent results from stem cell studies) is that the gene therapies will have an active "lifespan" of a decade or so and then the processes that lead to Parkinson's will again take over.

Even were this the case, there are probably few people who would complain about having this kind of procedure every ten years or so.

Again, let's all keep our fingers crossed that the Ceregene report later this year is as good as the data in the past has looked.

A gene therapy success story ...
 

http://news.bbc.co.uk/1/hi/health/7369740.stm

A 17-year-old whose sight was failing has had his vision improved in a pioneering operation carried out by doctors at Moorfields Eye Hospital.

The London researchers used gene therapy to regenerate the dying cells in Stephen Howarth's right eye.

As a result he can now confidently walk alone in darkened rooms and streets for the first time.

Stephen is the third person to have the operation, and the researchers expect even better results in future cases.

Before the procedure, he could hardly see at all at night and in time he would have lost his sight completely.

His condition was due to a faulty gene that meant that the light-detecting cells at the back of his eye were damaged and slowly degenerating further.

The operation involves injecting fluid with missing gene within a modified virus into the eye.

A fine needle (cannula) is passed through the front of the eye and across the vitreous gel.

The cannula is pushed through the retina, light sensitive tissue that lines the back of the eye.

The fluid is injected beneath the retina, causing it to detach from the underlying pigment layer.

Cells in the pigment layer absorb the fluid and the retina returns to its normal position.

The virus infects cells of pigment layer, supplying the gene required for normal sight.

But, in a delicate operation, surgeons at Moorfields injected working copies of the gene into the back of Stephen's eye.

After a few months, doctors detected some improvements.

But Stephen did not notice these changes until he confidently strode through a dimly-lit maze designed to test his vision.

Until then he had kept walking into walls - and it would take him nearly a minute to walk a few feet.

His doctors were shocked at the improvement.

Professor Robin Ali, of the Institute for Ophthalmology, who led the trial, said: "To get this indication after only three patients is hugely exciting.

"I find it difficult to remember being as excited as I am today about our science and what it might achieve."

The operation gave Stephen the confidence to try out his improved night-time vision on the streets near his home in Bolton.

Before he had only been able to see the bright lights of passing cars, street lamps and brightly-lit buildings but, to his amazement, he found he could see beyond the bright lights. For the first time he could see the cracks on the pavement, the edge of the curb and markings on the street.

He recently began walking home late at night from the railway station.

James Bainbridge, the consultant surgeon who carried out the operation, said: "It's hugely rewarding and exciting to see that this new treatment can have this impact on a person's quality of life."

'To not have to worry about losing my sight is great'

Stephen also says that it has really helped his confidence.

He is now able to socialise more late at night with his friends. And, as an aspiring musician, he says he can see the frets on his guitar better - and can move around more on a darkened stage.

There may well be further improvements. But without the operation it was likely that Stephen would have lost his sight altogether.

The prospect made him depressed. Now he says he can get on with his life.

"When I used to think about it, it would get me really down and depressed. But now I don't have to think about it. It's a big burden lifted."

The gene therapy has not improved the vision of the other two patients who have received it so far - but it may well stop their vision from declining further.

Robert Johnson was the first person to undergo the operation, as reported by BBC News in May 2007.

He welcomed the results so far: "For the team, I am thrilled that their hard work has come off.

"For me - I am simply pleased that I left what I entered with - a level of sight that gives me my freedom. What more could I ask for?"

Professor Ali said that the team now hoped to treat children: "The next stage is to increase the dose of the gene which we anticipate will improve the outcome - and it's also to treat younger patients, who have better residual vision and in whom we expect to see a much greater benefit."

Although the genetic condition that is being treated is rare, the researchers believe that their technique could be used to treat a wide variety of sight disorders, possibly even age-related sight loss.

Mr Bainbridge added: "This is only the beginning.

"What we've demonstrated so far is proof of principle that gene therapy can be used to treat a particular gene disorder."

The research, which has been funded by the Department of Health, has been published online in the New England Journal of Medicine.

Health Minister Dawn Primarolo said: "This is absolutely brilliant.

"It's been done here in the UK with the expertise of the NHS and the science and research of the Department of Health all coming together to offer such hope for gene therapy for the correction of sight - but also for gene therapy generally.

Neil.

Neil
 

That story made the front page of our leading newspaper (The NZ Herald) today together with photo of the individual who had the surgery done on his eye. This will be an eye opener (DUH):D for the Gene Therapy crowd and should give some kudos to the Ceregens and Neurologix of this world. Fantastic too see Gene Therapy reaping some good news.