Xenova, one of the UK's oldest biotechnology companies, says its vaccine for cocaine addiction stops users getting high and prevents a significant number from going back on the drug.
These are the results of the latest US trials of the product Xenova has codenamed TA-CD, one of the most exciting in a pipeline of new drugs that also includes a vaccine against smoking.
David Oxlade, the chief executive, said that TA-CD was given to 22 addicts and that a significant majority stayed clean during the three months of the study.
"The trial investigators say this is a remarkable performance, because these patients are being treated on an out-patient basis and normally about 50 per cent of cases go back on cocaine within 12 weeks. With TA-CD, 42 per cent were still drug free after six months."
Mr Oxlade characterised the results as "anecdotal and circumstantial" evidence that TA-CD is stopping cocaine getting into the brain. The vaccine stimulates the immune system to produce antibodies that stop the addict getting high - breaking the cycle of addiction.
Analysts cautioned that the real proof of the drug will come in 2006 with the results of a 130-patient trial pitting the vaccine against a placebo. Xenova shares rose 0.25p to 9p.Reuse content