Old drug offers new MS hope

Last Updated: 4:01pm GMT 13/11/2007

Trials of the drug are to start next year, reports Roger Highfield

Tens of thousands of people who suffer the degenerative disease multiple sclerosis receive new hope of more effective treatments after the discovery that an old fashioned drug could be effective.

Multiple Sclerosis is the most common disabling neurological disease among young adults and affects around 85,000 people in the UK. It is thought to be an auto immune disease, where the body's own protective immune system turns on itself so that inflammation strips the insulation from nerve cells, so they degenerate, causing weakness, fatigue, brain damage and dependency.

A diuretic drug, amiloride, which has been used for four decades to treat high blood pressure and heart failure has now been found to reduce the degeneration of nerve tissue and symptoms of multiple sclerosis in mice and a team in Oxford is preparing to test the drug on patients next year.

The discovery was made by a team led by Professor Lars Fugger of the Medical Research Council Human Immunology Unit and Department of Clinical Neurology at Oxford University and is published in Nature Medicine.

Prof Fugger said that, because the side effects of the drug are already well understood, years of expensive effort have been saved in the effort to turn this fundamental understanding into a new treatment.

"This drug [amiloride] is already licensed for another purpose. Looking for new ways to use established drugs is usually cheaper than starting the discovery process from scratch, we've had a really positive result."

He stressed that clinical trials in people, to test the drug's full potential "are crucial" before it is given as a treatment for the disease. And the drug will not counter the underlying disease process, only help nerve cells to survive for longer.

The drug affects the way that charged atoms - ions - move into nerve cells, through special proteins, called channels, in the membranes of nerves. Prof Fugger's team found that the damage of MS was caused by surges of charged sodium and calcium atoms into the axon, the long stem of the nerve that carries signals.

"We found that this damage was reduced in mice given amiloride. The drug appears to work by blocking the action of the channel that lets sodium and calcium molecules into the cell."

Overall this suggests that drugs targeted at one particular kind of channel (Acid-sensing ion channel 1), such as amiloride, could help reduce the level of nerve damage caused by multiple sclerosis. "We are in the process of setting up the clinical trial and hope to start next year," said Prof Fugger. "It is too early to say how many patients will be enrolled."

The team is also interested to find out whether any MS patients in the past have used amiloride, to see if there is any evidence of an effect. "We are trying to find out by get access to various data bases.

"However, one should be aware that most MS patients are younger than the patients who are treated for hypertension. Accordingly, it might be a challenge to find an overlapping group that is sufficiently large to allow us to draw any conclusion."
Submitted  11/14/2007 10:45:05 AM