Pill could extend lives of those with genetic diseases

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The Herald

Pill could extend lives of those with genetic diseases

http://www.theherald.co.uk/misc/print.php?artid=1347035

A pill which can reverse the symptoms of muscular dystrophy, cystic

fibrosis and other fatal genetic diseases has been hailed as

a " potential lifesaver " by ish experts.

The new drug " could add decades " to the lives of many young men with

Duchenne muscular dystrophy (DMD), a progressive muscle wasting

disease. The same compound could also be used to treat sufferers of

one form of the lung disease cystic fibrosis (CF).

There is no known cure for either CF or DMD, and sufferers rarely

live beyond their 30s, but now US scientists have announced that mice

suffering from a form of DMD began growing new muscles - after being

treated with a drug known as PTC124.

Writing in the journal Nature, PTC Therapeutics reports how its drug

enabled the mouse muscle cells to override the fault in the

dystrophin gene and build muscle fibres as normal. They also report

that mice with a form of cystic fibrosis also recovered after taking

PTC124, although the results of this study have yet to be published.

The company says its drug has the potential to alleviate symptoms of

a whole range of genetic conditions, including Hurler's syndrome,

spinomuscular atrophy and certain forms of haemophilia.

Phase 2 clinical trials are now under way in patients with both DMD

and CF, with results expected by the end of the year. If the trial is

a success, the drug could be used to treat around 13% of DMD patients

and up to 10% of CF sufferers.

The breakthrough was hailed last night by one of Scotland's leading

experts on muscular dystrophy. Dr Wilcox, senior lecturer and

honorary consultant in medical genetics at Glasgow University,

said: " This is an incredibly exciting new drug, which has the

potential to add decades to patients' lives.

" In Scotland, we have already increased life expectancy of patients

from late teens to late 20s. This drug is one of many new treatments

which could help us improve that even further. "

Dr Marita Pohlschmidt, director of research for the Muscular

Dystrophy Campaign, added: " The findings described are very

encouraging, particularly in the light of the clinical studies which

are being carried out. "

PTC124 is designed to overcome the effect of a specific class of

genetic mutations, called nonsense mutations. The drug " tricks " the

cellular machinery responsible for reading off genetic code to bypass

mutations and thus " make sense out of nonsense. "

PTC124 is one of a new generation of treatments which are bringing

hope to sufferers of cystic fibrosis, such as gene therapy, being

pioneered by Professor Porteous at the Edinburgh University. He

described the announcement of PTC124 as " very exciting " .

" It will be very important to see if this exciting new drug can be

used safely and effectively in the clinic, " he said.

" But PTC124 or similar products could only ever be a small part of

the solution as the vast majority of CF patients have a different

type of mutation from the rare nonsense mutation which is

specifically targeted by this class of compounds. Gene therapy is the

obvious best hope. "

Gene therapy involves manufacturing a fully working version of the

cystic fibrosis gene and introducing it into the cells lining the

lung where it is needed. Prof Porteous is one of a large consortium

of UK doctors and scientists preparing to begin a series of trials on

patients, funded by the Cystic Fibrosis Trust.

Alan Larsen, director of research with Cystic Fibrosis Trust,

said: " We are optimistic that the gene therapy trials later this year

will show that this promising research will provide a significant

improvement to the health and quality of life of the many children

and young adults with this life-threatening condition. "

Among the 600 ish sufferers of cystic fibrosis who are hoping

for a cure is Cara Doran, 28, from Dumbarton, who works as a patient

adviser for the CF Trust.

She said: " This sounds like exciting news for many patients with CF.

" Like many patients, I have been holding out a lot of hope for gene

therapy, although I know it will be many years before it will be

available. I don't suffer much physically, in fact I often say that I

am fighting fit because I can do anything my friends do, but

emotionally I suffer a great deal.

" While my friends are setting down to have families, I am going

through a lot of internal struggles. Is it a good idea to have a

child or commit to a partner when my future is so bleak? All I can do

is wait patiently and try to keep my lungs healthy. "

Links

www.muscular-dystrophy.org

www.cftrust.org.uk

Diseases where search for a cure goes on

CYSTIC FIBROSIS

CF is the UK's most common life-threatening, inherited disease.

There are around 7500 sufferers in the UK, including 600 in Scotland,

and at least 60,000 sufferers worldwide. They include the son of

Chancellor Gordon Brown, Fraser, who was diagnosed in November.

There is no cure for CF, and most individuals with cystic fibrosis

die young - many in their 20s and 30s from lung failure. Patients

have difficulty breathing, as their lungs become choked with fluid. A

low immune system results in frequent lung infections, requiring them

to take frequent antibiotics. CF is caused by a mutation in a gene

called the cystic fibrosis transmembrane conductance regulator, which

helps create digestive juices and mucus.

DUCHENNE MUSCULAR DYSTROPHY (DMD)

DMD is a progressive genetic muscle wasting disease.

It is the best known of more than 20 types of muscular dystrophy,

each with different symptoms and prognosis. DMD affects about 100

children born in the UK each year, the majority male. As it

progresses, it eventually weakens the respiratory system and heart,

and people die in their late twenties. There is no cure. Current

treatments are aimed at control of symptoms. They include steroid

treatment, spinal fusion surgery and physiotherapy. DMD is caused by

mutations in the dystrophin gene, which plays a key role in muscle

generation. The best hope for a cure is stem cell transplants,

injected into muscles to deliver gene copies.

12:01am Monday 23rd April 2007