Withdrawn experimental drug found to reverse Parkinson's brain damage

Jul 5 2005

Neuroscientists at Frenchay hospital in Bristol have discovered that an experimental drug for Parkinson's disease has been shown to trigger new nerve growth in the brain, the first time any treatment has been found to reverse the brain damage caused by the condition.

The discovery was made when they examined the brain of a patient who had taken part in a trial of the drug GDNF four years ago, when all five patients showed a dramatic improvement in their condition.

Consultant neuropathologist Seth Love, examined the brain of a 62- year-old patient who had taken part in the trial but recently died of a heart attack.

On examination he found that nerve fibres in a region of the brain called the putamen had regrown, it is the loss of these fibres, and the chemical dopamine they produce, that leads to Parkinson's disease.

In the initial trial, tests showed that the drug improved patients' control of their movements by between 50% and 80%, and since the treatment stopped six months ago they have experienced no further deterioration.

Professor Love says that this is the first time ever that any treatment has been shown to reverse the disease process. All the other drugs, he says, have just treated the symptoms.

But unfortunately this does not mean a new treatment for Parkinson's disease is on the horizon, because Amgen, the US company that owns GDNF, withdrew the drug last year over concerns about it's safety and efficacy.

Helen Garner of the Parkinson's Disease Society says though the trial was encouraging it is only based on one person and there are 120,000 people with Parkinson's disease in Britain.

The study is published in the journal Nature Medicine.