Abirakast 250 mg Tablets ABIRAKAST contains Abiraterone Acetate, a prodrug that is converted in vivo to abiraterone, a potent, selective, and irreversible inhibitor of the 17α-hydroxylase/C17,20-lyase enzyme complex (CYP17). CYP17 is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis. By inhibiting CYP17, abiraterone blocks the conversion of pregnenolone and progesterone to testosterone precursors, suppressing androgen production across all three sources. ABIRAKAST is indicated in combination with prednisone or prednisolone for the treatment of metastatic castration-resistant prostate cancer (mCRPC) and metastatic high-risk castration-sensitive prostate cancer (mCSPC).