Abiraterone made headlines in July 2008 when the first UK Phase I clinical trial reported significant shrinkage of patients’ tumours and reduction in pain. This second publication of a Phase I/II study, reporting on 54 patients, has confirmed the Phase I results. In addition, ICR scientists have worked out how to delay drug resistance and developed a test to identify the men most likely to benefit from abiraterone.

Lead researcher Dr Gert Attard said: “Phase I/II results showed that up to 70 per cent of men responded to the drug, abiraterone. About two-thirds of men experienced significant benefits for an average of eight months, with scans showing their tumours decreased in size and their PSA [prostate-specific antigen] levels dropped substantially.

’Our latest study also shows that by combining abiraterone with a steroid treatment when abiraterone stops working, we can reverse resistance and extend the response to this treatment by another 12 months.

’We have also noticed that the majority of patients who had very significant shrinkage of their tumours had an abnormality of a gene called ERG that was probably driving their cancer. We have developed a test for this ERG gene so we can identify the men most likely to benefit from abiraterone.’

Mike Torr, 70, from Sheffield, was involved in the Phase II abiraterone clinical trial. He stated: ’Two years ago, I was in severe pain as my prostate cancer had spread to my bones. I was involved in the earlier trials and received the additional steroid treatment to combat resistance. This drug has given me over two years of life, symptom-free. I have been able to go back to fully enjoying my retirement and travelling with my wife to places such as India.’

It is hoped that should the trials continue to show a benefit, abiraterone might be available for general use as a prostate cancer treatment by 2011.

One man dies of prostate cancer in the UK every hour. For the majority of men, prostate cancer is not a life-threatening disease; however, approximately 10,000 men die of the aggressive form of the disease each year.