New Prostate Cancer Drug Provides Some Hope

As any regular Dispatch reader knows, recommendations for screening for as well as treating prostate cancer are always shifting. The latest research on treatment comes from a small clinical trial of Zytiga (abiraterone), a powerful anti-androgen: When combined with standard therapy over six months, the drug eliminated or nearly eliminated tumors in about one-third of men whose cancer had a high risk of spreading beyond the prostate gland. The trial was small, involving only 58 men, but researchers are hopeful that larger trials will confirm that Zytiga is widely effective.

For the purposes of their research, investigators led by an oncologist at the Dana-Farber Cancer Institute in Boston put half the group on the drug and half on a placebo control. All of the men had localized cancer, meaning the disease had not yet spread beyond the prostate, but cellular evaluation indicated a tumor with a high risk of spreading. They were given Zytiga for either 12 or 24 weeks, combined with a steroid and the standard hormone therapy. Afterward, their prostate glands were removed and examined.

The success rate for those in the 24-week treatment group was more than double that of those who had taken Zytiga for only 12 weeks. In the 24-week group, 10 percent had no detectable tumor upon surgery, while another 24 percent had only a tiny amount of tumor. In contrast, only 4 percent of the 12-week group saw complete response, and only 11 percent had a near-complete response.

Because the treatment is costly (about $5,000 a month), and since the trial was small and preliminary, researchers are waiting for the results of other studies a few of which are already in progress before coming to any conclusions about the efficacy of Zytiga.

ACSH's Dr. Gilbert Ross also acknowledges the limitations of the study's size, but he s optimistic about its findings. The treatment is aimed at men whose cancers have a high likelihood of spreading, he points out. Should further trials bear out these preliminary results, such high-risk patients will have a much more viable treatment option. We d have liked even more details of this study, but it will be presented at the ASCO meetings in June and has not yet been published."