Abiraterone

Abiraterone is currently a drug under investigation for use in prostate cancer. It blocks the formation of testosterone by inhibiting CYP17A1 (CYP450c17), an enzyme also known as 17α-hydroxylase/17,20 lyase. This enzyme is involved in the formation of DHEA and androstenedione, which may ultimately be metabolized into testosterone.

The results of two Phase II trials indicate that abiraterone may reduce prostate specific antigen (PSA) levels, as well as shrink tumors. A Phase III trial is planned for 2008.