Scientists working on sheep scrapie, a similar brain disorder to bovine spongiform encephalopathy (BSE), demonstrated in the 1980s that the drug pentosan polysulphate can delay or avert the onset of the disease.
Because pentosan polysulphate is already in use in America, it has undergone the extensive toxicity trials that all new drugs have to pass and so would pose few practical problems for licensing in Britain.
Although the scrapie research on pentosan polysulphate was abandoned more than 10 years ago, scientists believe the work should be revitalised to investigate whether the drug might be used to help people at high risk of developing new variant Creutzfeldt Jakob disease (nvCJD), the human form of BSE.
Chris Bostock, the director of the Institute of Animal Health, said he had applied for funds from the government to research the drug, which was first investigated by the institute's Neuropathogenesis Unit in Edinburgh.
Alan Dickinson, the institute's former director who carried out the work with his colleague Christine Farquhar, said pentosan polysulphate "should be taken seriously" as a possible anti-CJD treatment.
In 1984, two independent teams of researchers showed in experiments on mice which had been injected with scrapie that pentosan polysulphate can prevent the onset of disease in some animals, Dr Dickinson said. He cautioned, however, that this does not mean the same effects will occur in humans because of differences in the genetics of mice, and because the doses used on the animals were relatively large.
Stephen Dealler, a scientist from Burnley Hospital who is pressing the Department of Health to adopt the new drug, said there was evidence that pentosan polysulphate will work as an anti-CJD agent at much lower doses to those used in the mouse experiments.
He said the dose of 100 milligrams a day given to American patients to treat interstitial cystitis was 100 times greater than the amount that would have an effect against CJD.
"The problem is that pentosan polysulphate cannot be given to humans as a CJD prophylactic unless it is proven to work and it is impossible to prove it will work unless it is tried," Dr Dealler said.
People at highest risk of nvCJD, such as the children of those who developed the disease or people who received blood transfusions, could be offered the drug with informed consent, he said.