Medivation, Inc. MDVN and Astellas Pharma, Inc. ALPMY announced that the European Medicines Agency’s (EMA) Committee for Medicinal Products for Human Use (CHMP) has issued a positive opinion recommending the inclusion of data from a head-to-head study (TERRAIN) in Xtandi’s label.The TERRAIN study evaluated Xtandi (enzalutamide) in comparison to AstraZeneca plc’s AZN Casodex (bicalutamide) in patients with metastatic prostate cancer whose disease progressed despite treatment with a luteinizing hormone-releasing hormone (LHRH) analogue therapy or following surgical castration. Results from the study demonstrated a statistically significant improvement in progression-free survival in patients treated with Xtandi than those in bicalutamide arm.We note that Xtandi is currently approved in the EU for the treatment of adult men with metastatic castration-resistant prostate cancer, who are asymptomatic or mildly symptomatic after the failure of androgen deprivation therapy in whom chemotherapy is not yet clinically indicated. The drug is also approved for the treatment of adult men with metastatic castration-resistant prostate cancer whose disease has progressed on or after Taxotere (docetaxel) therapy.In the U.S., Xtandi is approved for the treatment of patients with metastatic castration-resistant prostate cancer. We remind investors that a supplemental New Drug Application for Xtandi capsules, which includes findings from the phase II studies (TERRAIN and STRIVE), is currently under review in the U.S. The companies are looking to update the relevant clinical sections within the current indication. A response from the FDA is expected on Oct 22, 2016.In 2015, worldwide net sales of Xtandi surged 80% to $1.9 billion, with U.S. sales contributing $1.2 billion. For 2016, the U.S. Xtandi sales are expected in the range of $1.425–$1.525 billion.Meanwhile, Xtandi is being evaluated for additional indications. Late last month, Medivation and Astellas Pharma announced the initiation of a phase III study (ARCHES) on the drug for the treatment of patients with metastatic hormone sensitive prostate cancer. The study will evaluate the safety and efficacy of Xtandi with androgen deprivation therapy (ADT) in comparison to placebo with ADT.According to the American Cancer Society, approximately 181,000 new cases of prostate cancer are expected to be diagnosed in 2016, while 26,000 men are anticipated to die of the disease in the country.Medivation currently carries a Zacks Rank #5 (Strong Sell), while Astellas has a Zacks Rank #3 (Hold). AMAG Pharmaceuticals, Inc. AMAG is a better-ranked stock in the health care sector with a Zacks Rank #1 (Strong Buy).Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report ASTRAZENECA PLC (AZN): Free Stock Analysis Report AMAG PHARMA INC (AMAG): Free Stock Analysis Report MEDIVATION INC (MDVN): Free Stock Analysis Report ASTELLAS PHARMA (ALPMY): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research