An oral androgen receptor inhibitor whose clinical testing in metastatic hormone-sensitive prostate cancer (mHSPC) was co-led by Christopher Sweeney, MBBS of Dana-Farber Cancer Institute, has become a standard first-line therapy for men starting hormonal therapy for metastatic prostate cancer.
The drug, enzalutamide (XTANDI), was approved today by the U.S. Food and Drug Administration (FDA) for men with mHSPC – also referred to as metastatic, castration-sensitive prostate cancer (mCSPC). Enzalutamide is a current standard of care in castration-resistant prostate cancer and this approval helps make the drug available to men earlier in their cancer journey.
The benefits of enzalutamide were borne out in the ANZUP-led international randomized, phase III ENZAMET trial, published in the New England Journal of Medicine. Sweeney, study co-chair, presented interim analysis earlier this year during the plenary session at the American Society of Clinical Oncology (ASCO) Annual Meeting. The ENZAMET trial is not listed on the FDA-label but did provide valuable clinical information in the mHSPC setting.
“Through the ENZAMET trial we discovered that adding enzalutamide to testosterone suppression in men with mHSPC can give much better cancer control and longer survival,” said Sweeney. “This is true both for patients with high burden of disease, with multiple bone metastases or liver metastases, as well as men with a lower burden of disease. The new treatment option is especially relevant for men who cannot tolerate chemotherapy and have a lower burden of disease.”
The ENZAMET study is the only study with long enough follow-up and high quality data to show the clear overall survival benefit. It is also the only study to date with any data looking at whether enzalutamide improved the survival of patients when added to testosterone suppression and docetaxel. At this early analysis, there is no survival benefit and it is not recommended to combine with docetaxel at this time.