Abiraterone

Abiraterone, developmental code name CB-7598, also known as 17-(3-pyridyl)androsta-5,16-dien-3β-ol, is a synthetic, steroidal CYP17A1 inhibitor. It is the active metabolite of abiraterone acetate, an ester and prodrug of abiraterone. Abiraterone, developmental code name CB-7598, also known as 17-(3-pyridyl)androsta-5,16-dien-3β-ol, is a synthetic, steroidal CYP17A1 inhibitor. It is the active metabolite of abiraterone acetate, an ester and prodrug of abiraterone. A metabolite of abiraterone has been found to act as an agonist of the androgen receptor, and may antagonize the clinical effectiveness of abiraterone acetate. Abiraterone acetate (brand names Zytiga, Abiratas, Abretone, Abirapro) is used in the treatment of prostate cancer. Prostate cancer cells are stimulated to grow and spread by circulating androgen hormones. The intended effect of the drug is to block both physiologic and tumor-related androgen (e.g. testosterone) production, in order to slow or stop the spread of cancer cells. Since the drug blocks normal physiologic production of steroids by the adrenal glands, it is commonly prescribed with a low-dose steroid in order to prevent adrenal insufficiency. In addition to acting as an irreversible inhibitor of CYP17A1 (17α-hydroxylase/17,20-lyase), abiraterone inhibits 3β-hydroxysteroid dehydrogenase (3β-HSD), steroid 11β-hydroxylase (CYP11B1), 5α-reductase (via a metabolite) and certain hepatic cytochrome P450 enzymes (e.g., CYP1A2, CYP2C9, and CYP3A4). The drug acts as a partial antagonist of the androgen receptor and as an agonist of the estrogen receptor.