Update: A phase III trial of abiraterone has successfully been shown to increase average survival rate for men with advanced prostate cancer. The trial, funded by Janssen Pharmaceutical Companies, included 1195 patients from 13 countries. The average overall survival among the group who received abiraterone plus the steroid prednisone was 14.8 months, compared with 10.9 months for those who received the steroid and a placebo. People on abiraterone were more likely to experience a significant drop in their prostate-specific antigen (PSA) levels, the standard measure of prostate cancer activity, and saw an extended time in which tumour growth was halted. The trial鈥檚 independent data monitoring committee has now recommended unblinding the trial and allowing anyone on the placebo arm to be offered the drug. The article below was first posted on 23 July 2008.
AN AGGRESSIVE form of prostate cancer has been stymied by a drug that stops production of all male sex hormones. The hope is that it could keep the disease in check for years 鈥� today, many men die within 18 months of starting treatment.
Johann de Bono and colleagues at the in London, together with the UK and , a company in Los Angeles, this week announced results of a trial of the drug in 21 prostate cancer patients for whom all other treatments had failed.
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In eight men with measurable tumours, five shrank, while blood concentrations of prostate-specific antigen, which is produced by growing cancers, fell by at least 30 per cent in most men. 鈥淎ll the patients have cancer that had spread, and we saw the tumours shrink everywhere,鈥� says de Bono (Journal of Clinical Oncology, ). He adds that these findings were replicated in further trials in 250 people though the results are not yet published.
鈥淭hese studies have confirmed in American men that this drug is spectacularly effective,鈥� says de Bono.
Today, the only reliable therapy for prostate cancer is to 鈥渃hemically castrate鈥� men using drugs that stop the testes making testosterone. Yet in many cases, the tumours simply start making testosterone themselves.
Abiraterone dodges this problem by penetrating all cell types and disabling an enzyme vital for producing testosterone and other hormones that drive tumour growth. 鈥淭he drug blocks the ability of cancers to make the 鈥榝ertiliser鈥� for the cancer seeds to grow,鈥� says de Bono.
Abiraterone could be available in two years if a trial in 1200 people is successful.
Cancer 鈥� Learn more about one of the world鈥檚 biggest killers in our comprehensive special report.
