New drug treatment extends lives of men with prostate cancer

The study in the May 26, 2011 issue of the New England Journal of Medicine was co-authored by Thomas W. Flaig, MD, medical oncologist at the University of Colorado Hospital's Tony Grampsas Urologic Oncology Clinic and assistant professor at the University of Colorado School of Medicine.

"Abiraterone acetate is a new, life-extending pill for the treatment of advanced prostate cancer. Unlike the traditional chemotherapy drugs used in these situations, abiraterone is generally very well tolerated," said Flaig.

The multi-center Phase III clinical trial of 1195 participants looked at the effectiveness of treating patients who had received prior chemotherapy with a combination of abiraterone acetate (ZytigaTM ) and prednisone. When this trial was initiated, there were no treatments that clearly prolonged survival in this late phase of prostate cancer. The patients were randomized to receive abiraterone acetate plus prednisone or a placebo plus prednisone each day. Treatment continued until the cancer progressed, there were unfavorable reactions, a new treatment was initiated or the patient withdrew from the trial.

The study shows participants taking abiraterone acetate lived about four months longer than participants taking the placebo. In addition, more patients receiving abiraterone acetate experienced a significant drop in the PSA blood level than those on the placebo.

"The survival benefit observed in this study is especially notable, since this was seen in the most advanced cases of prostate cancer," said Flaig. "Other studies are being done to examine the benefit of using abiraterone acetate earlier in the disease process, where it may be even more effective."

The FDA approved abiraterone acetate at the end of April. The tablet has few side effects but careful medical attention is required to monitor for specific potential side effects including liver blood test changes, low potassium levels, leg swelling and high blood pressure.