Abiraterone

Abiraterone is a potent, irreversible, and selective inhibitor of 17 αhydroxylase/C17,20-lyase (CYP17), an enzyme expressed in testicular, adrenal, and prostatic tumour tissues, to regulate androgen biosynthesis. Abiraterone was first approved by the FDA and EMA on April, July, and September 2011, respectively. It is used to treat metastatic castration-resistant prostate cancer and hormone-sensitive high-risk metastatic prostate cancer.

As abiraterone has poor oral bioavailability and is susceptible to hydrolysis by esterases, abiraterone acetate was developed as an orally bioavailable prodrug with enhanced stability and absorption.

Abiraterone is indicated for the treatment of metastatic castration-resistant prostate cancer (mCRPC) in combination with methylprednisolone or prednisone.

In Europe and Canada, it is also used in patients with mCRPC who are asymptomatic or mildly symptomatic after the failure of androgen deprivation therapy for whom chemotherapy is not yet clinically indicated. In Europe, it is used in patients whose disease has progressed on or after a docetaxel-based chemotherapy regimen. In Canada, it is used in patients who have received prior chemotherapy containing docetaxel after the failure of androgen deprivation therapy.

Abiraterone is indicated in combination with prednisone for the treatment of metastatic high-risk castration-sensitive prostate cancer (CSPC). In Europe and Canada, it may also be used in combination with prednisolone and androgen deprivation therapy in newly diagnosed patients.

In Canada and the US, abiraterone is also available in a combination product with niraparib, which is indicated with prednisone for the treatment of adults with deleterious or suspected deleterious BRCA-mutated (BRCAm) mCRPC. In Canada, this combination product is also used with prednisolone and is reserved for patients who are asymptomatic or mildly symptomatic, and in whom chemotherapy is not clinically indicated.