The FDA has given early approval to enzalutimide, a new prostate-cancer drug developed jointly by Medivation (MDVN +1.4%) and Astellas Pharma (OTCPK:ALPMY). The drug - which was approved to treat men with prostate cancer that has spread or returned after prior treatment with another drug, docetaxel - will be sold under the brand name Xtandi. Dendreon (DNDN -0.6%), whose already struggling with lagging sales of its own prostrate drug, Provenge, trades down on the news.