Selective estrogen receptor alpha agonist GTx-758 decreases testosterone with reduced side effects of androgen deprivation therapy in men with advanced prostate cancer.

Background: A need remains for new therapeutic approaches for men with advanced prostate cancer, particularly earlier in the disease course.

Objective: To assess the ability of an oral selective estrogen receptor α agonist (GTx-758) to lower testosterone concentrations compared with leuprolide while minimizing estrogen deficiency-related side effects of androgen-deprivation therapy.

Design, Setting, And Participants: Hormone-naive advanced prostate cancer patients were randomized to oral GTx-758 1000 mg/d, 2000 mg/d, or leuprolide depot.