Abiraterone Isopropyl Ether-d7 is the labeled analog of Abiraterone Isoproply Ether (A108532), an impurity of Abiraterone (A108490), a steroidal cytochrome P 450 17α-hydroxylase-17,20-lyase inhibitor (CYP17), is currently undergoing phase II clinical trials as a potential drug for the treatment of androgen-dependent prostate cancer.