[pegleg]

This came through my Google Alerts about GDNF. There is a place at the link below to make c omments - PLEASE do!

http://www.dailymail.co.uk/pages/liv...#StartComments

Why won't they let Parkinson's sufferers take a life-changing drug?
By NIKKI MURFITT Last updated at 11:01am on 31st October 2006


Determined: Parkinson's sufferer Tom Isaacs

When Tom Isaacs was 27 he was diagnosed with Parkinson's disease. The condition gradually destroys the brain's ability to control the muscles - there is no cure.

Determined to give himself the best possible prognosis, Tom embarked on a very personal journey to meet leading scientists in the hope of finding new treatments that would help him.

Three years ago it seemed he'd found the answer: a new drug GDNF (glial derived neurotrophic growth factor). A group of Parkinson's patients had been treated with GDNF at Bristol's Frenchay Hospital and their transformation had been remarkable: sufferers who'd been trapped in a living hell were suddenly able to walk, talk and smile again.

Parkinson's is caused by a shortage of dopamine, a chemical messenger involved in movement, mood and behaviour. Why this happens is still not known.

GDNF seems to work by stimulating dopamine production and preventing degeneration of the brain cells. The drug is delivered via a catheter permanently implanted in the brain. The catheter is connected to a Jaffa cake-sized pump sewn into the abdomen.
When GDNF was given to the Bristol patients the results were astonishing. 'Men who had been unable to get up out of a chair unaided were walking normally across a room. Their hand co-ordination was unbelievable, in exercises they could move their hand easily from left to right, something that had previously been impossible under the onslaught of Parkinson's,' says Tom.
So impressive were the results that the study was rolled out to North America and by September 2004, 50 patients were receiving the drug. The Parkinson's Disease Society in the UK planned to hand over £1.2 million to fund further trials in Bristol.

But suddenly, at the end of 2004, and without warning, this lifeline was snatched away. Amgen, the American drug company which holds the patent for manufacturing GDNF, claimed the drug was dangerous as it could cause brain damage and refused to continue prescribing it.

Amgen's decision has caused huge divisions within the Parkinson's community, pitting scientists against each other and leaving patients angry and frustrated.

As Tom explains: 'We were left with a situation where half the doctors involved in the studies sided with Amgen and the other half sided with the patients who wanted to keep taking the drug.

'The doctors didn't believe there was anything wrong with the drug and yet it was being taken away. They couldn't offer their patients an explanation because they did not agree there was one to give.'
Tom, now 38, had hoped to be able to have GDNF treatment himself, but is now leading the fight to get the drug back in use, and with his charity Movers and Shakers has raised more than £1 million to fund further research.

One of those desperate to be given the treatment is Stephen Waites. He was also 27 when he was told he had Parkinson's, and as his condition deteriorated, he had to give up his flourishing architecture business and relied instead on benefits.

But 30 years later in 2001, when he was 58, he became part of the Frenchay Hospital trial. He says he was given back his life. 'I was able to restart my business. I had more than 40 projects on the go and I really had taken on a new lease of life. I could drive again and even bought myself a new Jaguar.

'GDNF made me independent, and after so many years living with Parkinson's, I began to get my confidence back. It was a cure because it improved my condition more than 60 per cent - I could not ask for more than that and I was delighted.

'When I was told at the beginning of last year that the drug was being taken away I felt that they'd taken my life away along with it. I had committed myself to a huge workload and without the drug I couldn't fulfil my commitments.

'I've deteriorated since the GDNF was stopped - I can't drive any more so the Jaguar has had to go and we also had to downsize the house because I'd been able to start earning good money again but that went too.

'I was willing to sign anything to absolve Amgen of responsibility if anything went wrong, if only they'd let me keep taking GDNF, but they were having none of it.

'I've been very low mentally for the past 12 months and I just can't seem to rise above it.'

Tom adds: 'I think what hurts most is the total lack of communication by Amgen, who have put up a brick wall and won't discuss the issue. Two patients in America sued the company in an effort to gain 'compassionate access' to the drug but lost.

'It has been a crushing blow, especially as it has not been seen to be doing any harm to anyone, quite the reverse.' In the human trials in America some of the catheters became dislodged and as a result GDNF was floating around the brain instead of getting to where it was supposed to go.

'There were fears that this would give rise to antibodies in the brain which could then attack a patient's own reserves of GDNF and lead to brain damage,' says Tom.

'One or two patients on the American trial had shown up in scans as having antibodies, but their specialists said they'd had them there for three years and it hadn't done them any harm.'

Amgen also said that several monkeys that had received high does of the drug suffered irreversible brain damage, and subsequently died.
A spokesman for Amgen, David Polk, explained that the company had stopped providing GDNF because of 'serious safety concerns' and the absence of any demonstrated medical benefit.'

'Stopping the GDNF trial was an incredibly difficult decision, but given what we learned about GDNF we could not ethically continue to administer it to patients.

'We are actively pursuing further understanding of the toxicity and safety issues, as well as the possibility for a safe and effective alternate method of delivery.'

The patients understand that in a climate of litigation Amgen had to be cautious. But, says Tom, 'They believe that to take the drug from those on the trial who were willing to sign anything to stay normal and seemingly Parkinson's-free just seems cruel.'

Dr Stephen Gill, a neurosurgoen who headed the Bristol trial, says: 'GDNF is the best possible drug for Parkinson's and as close to a cure as you are going to get and our results in Bristol showed this. Unfortunately it wasn't demonstrated as well in the Amgen trials in America.

'It was when we learned that our patients would be stopped from having GDNF. The department was in tears and it was very stressful for everyone involved.

'I believe that Amgen's tests, which led to them withdrawing the drug, were inappropriate and were not a realistic test of the toxicology of a drug. I do not feel that there is a safety issue at all.'

Although the decision to withdraw GDNF may seem unfair, Dr Piers Benn, a lecturer in Medical Ethics and Law at London's Imperial College, says: 'It comes down to a risk-benefit analysis. If it's believed that the drug may produce side effects then the drug company has to operate cautiously and within the law.

'You can talk about informed consent from patients, but when someone is ill and anxious for a chance to improve their condition, they don't look at the situation objectively and don't always take into account the risk involved.'

Funded by the Movers and Shakers charity, Dr Gill and his team are investigating a safer form of delivery for the drug. Tom has also asked Mary Baker, chair of the World Health Organisation's steering committee on Parkinson's, to preside over a meeting with Amgen.
'If we can prove to Amgen that this new system is safe and effective then they would have to reconsider their decision,' he says.
Meanwhile, Tom, whose condition is managed with a cocktail of 15 tablets a day, has given up his job as a chartered surveyor and now raises funds to find a cure for Parkinson's.

He says: 'I know that neither GDNF or anything else is going to make it go away, but it can improve the quality of my life.
Tom Issacs can be heard in Chasing A Cure, Radio 4, November 8.

[paula_w]

Amgen also said that several monkeys that had received high does of the drug suffered irreversible brain damage, and subsequently died.
A spokesman for Amgen, David Polk, explained that the company had stopped providing GDNF because of 'serious safety concerns' and the absence of any demonstrated medical benefit.'

This a little backwards and severely misleading. The monkeys were first euthanized, and then the brain damage found. The above statement makes it sound like the brain damage killed them.

Paula

[jeanb]

Peggy's comments to the article are posted there
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I am living with Parkinson's, also. Like Tom, I am a young onset - now into my 12th year with this dreadful disease. I am also a participant in an experimental brain surgery trial - 6 years post-op.

All people with Parkinson's (PWP) want is a better quality of life, and hopefully a cure. GDNF has been one of the most promising therapies to hit the research field. The proof was seeing how it visibly improved patients at first; then an autopsy of oen of the trial participants who died of an unrelated problem showoed neural fiber growth - somethign NEVER shown in human trials. Researchers have put their reputations on the line in showing that the study design was flawed. And Amgen turns its back on such information.

We have to get the word out - this may not be the answer, but it's the closest science has come. Yet,if the possible cure (GDNF) or at the very least a chance to improve some PWP's lives remains on the shelf, we'll never know. Tell Amgen you want to find that out.

- Peggy Willocks, Johnson City, TN USA
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