High Quality Content by WIKIPEDIA articles! Abiraterone is a drug used in castration-resistant prostate cancer (formerly hormone-resistant or hormone-refractory prostate cancer) -- ie, prostate cancer not responding to androgen deprivation or treatment with antiandrogens. It is formulated as the prodrug abiraterone acetate and marketed under the trade name Zytiga. The medication works because it decreases "production of the male hormone testosterone, which promotes tumor growth."