Abiraterone acetate, given in combination with prednisone, is indicated for the treatment of prostate cancer. No reports describing its use in human pregnancy have been located, but such reports are unlikely because of the indication. Reproduction studies in pregnant animals have not been conducted. Because of the risk of embryo and fetal harm, the drug is classified as contraindicated in pregnancy.
No reports describing the use of abiraterone acetate during human lactation have been located. Because of the indication, it is unlikely that such reports will occur. The molecular weight of abiraterone acetate (about 392) and the active metabolite abiraterone (about 333), and the long terminal half-life of abiraterone (12 hours) suggest that both agents will be excreted into breast milk. However, the high plasma protein binding (>99%) of abiraterone might limit the exposure. The effects of exposure to the drug on a nursing infant are unknown but, because of the potential for severe toxicity, breastfeeding is classified as contraindicated.
Abiraterone Acetate (Zytiga)
Pregnancy Recommendation:Contraindicated
Breastfeeding Recommendation:Contraindicated
Abiraterone acetate is converted in vivo to abiraterone, an inhibitor of the enzyme (CYP17) that is expressed in testicular, adrenal, and prostatic tumor tissues and is required for androgen biosynthesis. It is indicated for use in combination with prednisone for the treatment of patients with metastatic castration-resistant prostate cancer who have received prior chemotherapy containing docetaxel. The active metabolite abiraterone is further metabolized to inactive metabolites. Abiraterone is highly bound (>99%) to human plasma proteins, albumin, and α1-acid glycoprotein, and the mean terminal half-life is 12 hours (1).
Animal Data: Reproduction and carcinogenesis studies with abiraterone acetate in animals have not been conducted. Neither abiraterone acetate nor abiraterone was mutagenic or clastogenic in multiple assays. In rats and monkeys, abiraterone caused atrophy, aspermia/hypospermia, and hyperplasia in the reproductive system at doses that were 1.14 and 0.6 times, respectively, the human clinical exposure based on AUC. These effects were consistent with the antiandrogenic pharmacologic action of the agent (1).
Placental Transfer: It is not known if abiraterone acetate or its active metabolite abiraterone cross the human placenta. The molecular weight of abiraterone acetate (about 392) and abiraterone (about 333) and the long terminal half-life of abiraterone suggest that both agents will cross to the embryo-fetus, but the high plasma protein binding of abiraterone might limit the exposure.