Enzalutamide has been authorised in European Union (EU) for the treatment of adult men with metastatic castration-resistant prostate cancer whose disease has progressed on or after docetaxel therapy[1].

Astellas Pharma Europe has announced that following the regulatory review process by the European Medicines Agency (EMA) and a positive Committee for Medicinal Products for Human Use(CHMP) opinion on 25th April 2013,[2] the European Commission (EC) has granted the marketing authorisation for 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. It inhibits multiple steps in the androgen receptor (AR) signalling pathway, which 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.”

Professor de Bono, who is also Head of the Drug Development Unit, a joint facility between The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, located at The Royal Marsden, added: “Enzalutamide, an oral drug, improves the quality of life and survival time for patients who have an advanced form of this common disease and is generally well tolerated.”

The EU authorisation is 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]. The study also concluded that enzalutamide was generally well tolerated by patients and met all secondary endpoints.

The phase III AFFIRM trial was a randomised, 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.

Advanced prostate cancer is defined as cancer that has spread outside of the prostate to other areas of the body (metastasised).

A high number of men with advanced prostate cancer eventually develop resistance to androgen deprivation treatment, which is called castration-resistant prostate cancer (CRPC).[5] Around 10-20% of patients with prostate cancer present at an advanced stage, and up to 40% of men diagnosed with prostate cancer will eventually develop advanced disease.[6],[7]

Dr Erik Briers, Executive Director, European Cancer Patient Coalition (ECPC) and member of the strategic committee of Europa Uomo comments: “Unfortunately prostate cancer can evolve into a life threatening castration resistant metastatic condition where treatment options are needed because all patients are not identical. A new treatment such as enzalutamide is one more option that will give selected patients a new chance if other options fail. Patients with advanced prostate cancer are very concerned about their quality of life, so they favour treatments with fewer side effects. Enzalutamide has been shown to be generally well tolerated.”

Upon receiving marketing authorisation in Europe, Astellas will provide Medivation with a $15 million milestone payment, as reflected in Astellas’ current fiscal year (from 1st April 2013 to 31st March 2014) financial forecast.

Enzalutamide was licensed by the U.S. Food and Drug Administration on 31st August, 2012 and launched in the U.S. in September 2012 for the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC) who have previously received docetaxel (chemotherapy).[8]

The EC grant of the marketing authorisation applies in all European Union (EU) Member States, as well as in the European Economic Area (EEA) countries Iceland, Liechtenstein and Norway.

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