In a nutshell
The authors interpreted the results of a phase III trial on the use of enzalutamide (Xtandi) in treating patients with metastatic (cancer that has spread) hormone-resistant (castration-resistant) prostate cancer.
Some background
Hormone therapy is a common treatment used in prostate cancer. It targets the male sex hormones active in prostate cancer, such as testosterone. Some patients may develop a resistance to hormone therapy and will no longer respond to treatment. This is called hormone-resistant or castration-resistant prostate cancer. Enzalutamide is a hormone drug used in advanced prostate cancer. It prevents cancer growth by stopping hormone production and in some cases has been used to treat metastatic prostate cancer.
Further studies will determine the benefit of enzalutamide in treating metastatic hormone-resistant prostate cancer.
Methods & findings
The aim of this study was to determine the benefit of enzalutamide in treating metastatic hormone-resistant prostate cancer.
1,199 patients were used in this study. 800 patients in group 1 received enzalutamide. 399 patients in group 2 received placebo (control harmless drug used instead of the active drug).
The median (midpoint) overall survival (patients who were still alive following treatment) was 18.4 months in group 1 and 13.6 months in group 2. For patients who were below 75 years old, there was a 37% reduced risk of dying from the treatment in group 1 compared to group 2. For patients who were 75 years old or older, there was a 39% reduced risk of dying from the treatment in group 1 compared to group 2.
The radiographic progression free survival (rPFS) was also evaluated for patients in two groups. PFS is the time following the treatment before the disease progresses. The extent of disease progression in rPFS is assessed by some radiographic testing. For patients who were below 75 years old, there was a 55% reduced risk of rPFS in group 1 compared to group 2. For patients who were 75 years old or older, there was a 73% reduced risk rPFS in group 1 compared to group 2.
Side effects were similar between both groups. The most common side effects were fluid build-up in the limbs, fatigue, low blood pressure and diarrhea. These side effects were more common (in both groups) in patients who were 75 years old or older.
The bottom line
The authors concluded that enzalutamide significantly improved outcomes in both younger and elderly metastatic prostate cancer patients.
Published By :
Annals of oncology
Date :
Feb 01, 2014
