Armstrong AJ, et al. - Researchers tested enzalutamide, a potent androgen-receptor inhibitor, with respect to its effectiveness and safety in metastatic hormone-sensitive prostate cancer (mHSPC) patients (n=1,150) enrolled in a multinational, double-blind, phase 3 trial. The patients were randomized 1:1 to enzalutamide (160 mg/day) or placebo, plus androgen deprivation therapy (ADT), and stratified by disease volume and previous docetaxel chemotherapy. Radiographic progression-free survival was evaluated as the primary end point. Significantly attenuated risk of metastatic progression or death over time was reported in relation to treatment with enzalutamide with ADT vs placebo plus ADT in men with mHSPC; these effects were seen even in those with low-volume disease and/or prior docetaxel. The safety profile seen in this study appeared consistent with the safety profile of enzalutamide in earlier clinical trials in castration-resistant prostate cancer.