The great news for for our brothers in Europe is that Xtandi (Enzalutamide) has been approved for use in the European Union (EU) for the treatment of men with metastatic castration-resistant prostate cancer whose disease has progressed on or after chemotherapy (docetaxel).

Following the regulatory review process by the European Medicines Agency (EMA) and a positive review from the Committee for Medicinal Products for Human Use (CHMP) on 25th April 2013, the European Commission (EC) has granted the marketing authorization for XTANDI (enzalutamide) capsules for the treatment of adult men with metastatic castration-resistant prostate cancer whose disease has progressed on or after docetaxel therapy.

Enzalutamide is a novel, once-daily, oral androgen receptor signalling inhibitor (androgen receptor blockade) that inhibits multiple steps in the androgen receptor (AR) signaling pathway. The interruption of the androgen signaling has been shown to decrease cancer cell growth and induce cancer cell death (apoptosis).
Professor Johann de Bono, Professor of Experimental Cancer Medicine at The Institute of Cancer Research, London, and Consultant Medical Oncologist at The Royal Marsden NHS Foundation Trust, said: “This is a major development in prostate cancer therapeutics that will provide an important new treatment option for patients with advanced prostate cancer following chemotherapy.”

The EU granted its authorization based on results from the phase III AFFIRM study which confirmed that enzalutamide demonstrated a statistically significant improvement (p<0.0001) in overall survival compared to placebo, with a median survival of 18.4 months in the enzalutamide group versus 13.6 months in the placebo group, an advantage of 4.8 months

[hazard ratio (HR) = 0.631]. This was the same study that was used to grant the approval in the United States by the FDA in August of 2012.

The study also found that enzalutamide was generally well tolerated by men and met all of its secondary endpoints.

The phase III AFFIRM trial was a randomized, double-blind, placebo-controlled, multinational trial evaluating enzalutamide (160 mg/day) versus placebo in 1,199 men with progressive metastatic castration-resistant prostate cancer who were previously treated with docetaxel-based chemotherapy.
The EC grant of the marketing authorization applies in all European Union (EU) Member States, as well as in the European Economic Area (EEA) countries Iceland, Liechtenstein and Norway.

Joel T. Nowak, M.A., M.S.W.