Pharmacology
Abiraterone acetate is converted to abiraterone, which inhibits CYP17A1. CYP17A1 is involved in steroidogenesis and androgen production.
Pharmacodynamic effect
By suppressing CYP17 activity, abiraterone reduces androgen synthesis in the testes, adrenal glands and prostate tumor tissue. This can reduce androgen stimulation of prostate cancer cells.
Pharmacokinetics
Abiraterone exposure is substantially affected by food. This is the principal reason for the strict empty-stomach administration requirement.
Abiraterone is highly protein bound and undergoes hepatic metabolism. Specific pharmacokinetic parameters depend on the formulation and prescribing source.
CYP interactions
Abiraterone is metabolized through multiple pathways and can influence the exposure of certain medicines, including substrates of CYP2D6 and CYP2C8. Strong CYP3A4 inducers can reduce abiraterone exposure.
Clinical evidence
Clinical studies established the role of abiraterone in advanced prostate cancer. NCI summarizes evidence showing improved clinical outcomes in selected metastatic castration-resistant prostate-cancer populations when abiraterone was combined with prednisone.
The clinical effect is dependent on patient population, prior therapy, disease state and treatment combination.
Clinical limitations
Trial outcomes should not be interpreted as a guarantee of benefit for an individual patient. Treatment selection depends on disease characteristics, previous therapy, performance status, comorbidities, laboratory results and applicable guidelines.