Enzalutamide, a Type of Hormone Therapy, Lengthens the Lives of Men with Metastatic Castration-Resistant Prostate Cancer

Genitourinary Cancers Symposium
January 28, 2014

Results from a new study show that the medication enzalutamide (Xtandi) lengthens the lives of men with metastatic castration-resistant prostate cancer by almost a third. Metastatic castration-resistant prostate cancer (mCRPC) is cancer that has spread to parts of the body other than the prostate and continues to grow and spread without needing the male sex hormone testosterone. Enzalutamide is a type of hormone therapy called an androgen-receptor blocker or an anti-androgen. For men with prostate cancer, hormone therapy is used to block or lower the levels of hormones called androgens that can be involved in prostate cancer growth.

As part of this study, 1,717 men with mCRPC who had not yet had chemotherapy received either enzalutamide or a placebo (an inactive treatment) plus standard hormone therapy. The men participating in this study had previously received treatment, such as surgery or radiation therapy, for the original tumor, as well as other types of hormone therapy.

Researchers found that in 59% of the men taking enzalutamide, cancer growth slowed or stopped, compared with 5% of men taking the placebo. In addition, men taking enzalutamide needed chemotherapy 17 months later than those taking the placebo. Based on the results, patients on the trial receiving the placebo were offered enzalutamide.

What this means for patients

“Enzalutamide is likely to become an important new treatment option that has a significant impact on the progression of prostate cancer,” said lead author Tomasz Beer, MD, FACP, Professor of Medicine and Deputy Director of the Knight Cancer Institute at Oregon Health and Science University. “If approved for this use, it will become an important standard option for use before chemotherapy in patients with advanced prostate cancer who have few or no symptoms.” The most common side effects of enzalutamide included fatigue, constipation, and back and joint pain, in addition to side effects associated with hormone therapy, such as weight gain and hot flashes.  

Questions to Ask Your Doctor

  • What type of prostate cancer do I have? What does this mean?
  • Am I receiving hormone therapy? What type?
  • What are the next steps if the treatments I’m currently receiving stop working?

For More Information

Guide to Prostate Cancer

Hormone Therapy for Advanced Prostate Cancer

Hormone Deprivation Symptoms: Men

When the First Treatment Doesn't Work