New drug benefits advanced prostate cancer patients

The prostate cancer drug abiraterone shows encouraging results in men who have exhausted standard treatment options, according to recent clinical trial results.

A phase II study, led by the Institute of Cancer Research (ICR) and the Royal Marsden NHS Foundation Trust, Sutton, United Kingdom, found that about half of the prostate cancer patients given the drug experienced a substantial reduction in PSA levels.

The 47 men enrolled in the trial all had late-stage, castration-resistant prostate cancer. Almost all of the men exhibited evidence of metastatic cancer and had already received hormone therapy and docetaxel (Taxotere).

"Docetaxel is an important drug, but it extends life for an average of just 2 to 3 months, so there is a desperate need to improve treatment options for late-stage prostate cancer patients," said senior author Johann de Bono, MD of ICR and the Royal Marsden NHS Foundation Trust. "In this trial, abiraterone shrank or stabilized men’s cancers for an average of almost 6 months, which is a very impressive result."

About three-quarters of the men experienced a drop in PSA levels, with half of the patients experiencing a 50% decrease. Three-quarters of the men had a drop in the number of circulating tumor cells. Five of the 47 patients are still taking the drug and benefiting from treatment 3 years after the trial began.

The trial was funded by Cougar Biotechnology, which is now owned by Johnson & Johnson. Phase III trials of abiraterone, which is not FDA approved, are currently under way.

Results from the study were published online in the Journal of Clinical Oncology (Feb. 16, 2010).