The last few days have seen a lot of commotion and celebrating in the prostate cancer world. There have been multiple news stories of an experimental prostate cancer drug, abiraterone, that has been reported to dramatically shrink prostate cancer tumors and extend survival in 70 to 80 percent of men with aggressive prostate cancer. Abiraterone has even been referred to a “magic pill.”
The original story about abiraterone came from a study published in the Journal of Clinical Oncology. This study was under powered having only 21 subjects. There is currently a larger, but still under powered, study going on and happily, the preliminary results look to be consistent with the smaller study.
The key to this potential treatment is its ability to stop the production of testosterone, not only from the testes and adrenal gland (the target of current hormone therapy), but also to stop the tumors themselves from producing testosterone. Recent research show that aggressive tumors are able to produce their own supply of testosterone, (see my post dated June 3, 2008) which allows them to grow despite castrate levels of testosterone in the blood. The result is the tumors continue to grow and circumnavigate the traditional hormone blockade.
Abiraterone seems to be able to eliminate virtually all testosterone production in the body, including in the tumors, leaving the prostate cancer tumors to shrink.
There is also another a clinical trial just starting in a number of sites in the United States and the UK. You can find out more about the trial in my post dated June 4, 2008 or by going to the government’s clinical trial web page and searching under abiraterone and prostate cancer.
Abiraterone, if the trials continue on the same course, might be able to be approved by the FDA by 2011! However, remember that this first trial was not well powered and we still need to wait for the results from the larger and properly powered phase III trial.
The press feeding frenzy has focused on the potential positive effects of abiraterone, but I have yet to come across anything about its side effects. For lack of a better description I can’t help but think of abiraterone as a supper anti-androgen. Does this translate into a drug that will be experienced with super side effects?
Abiraterone clearly does hold out a bright ray of hope for our future. But remember even if Abiraterone does prove out and we get over the hurdles set up by the FDA and the morbidity issues, it does not cure prostate cancer which is our actual goal.
Joel T Nowak MA, MSW