Abiraterone Acetate – Targeted Therapy
Abiraterone Acetate is a selective inhibitor of androgen biosynthesis used in the targeted therapy of prostate cancer. The drug is a prodrug that is converted in the body to abiraterone, an active metabolite that suppresses testosterone production from all its sources, including the testes, adrenal glands, and the tumor tissue itself.
The mechanism of action of abiraterone is based on the specific inhibition of the CYP17 enzyme (17α-hydroxylase/C17,20-lyase). This enzyme is essential for the biosynthesis of androgens in body tissues. Since prostate cancer growth depends directly on the presence of male sex hormones, suppressing CYP17 leads to a critical reduction in testosterone levels to undetectable values. This slows disease progression and contributes to the reduction of tumor lesions.
The drug is highly effective in castration-resistant forms of cancer. A key feature of the therapy is the mandatory co-administration with low-dose corticosteroids (prednisone) to compensate for the resulting adrenal hormone deficiency.
Indications
Abiraterone acetate is used in urologic oncology for the treatment of the following conditions:
- Metastatic Castration-Resistant Prostate Cancer (mCRPC): therapy for patients before or after receiving docetaxel-based chemotherapy.
- Metastatic Hormone-Sensitive Prostate Cancer (mHSPC): in combination with androgen deprivation therapy in patients with newly diagnosed high-risk disease.
- Combination Therapy: the drug is always prescribed in combination with prednisone or methylprednisolone.
Dosage and administration
The abiraterone dosing regimen requires strict adherence to dietary rules to prevent toxicity.
- Standard Dose: 1,000 mg (two 500 mg tablets or four 250 mg tablets) once daily.
- Administration Rules: the drug must be taken on an empty stomach (at least 1 hour before or 2 hours after food). Taking it with food sharply increases the concentration of abiraterone in the blood, which can be dangerous.
- Concomitant Therapy: prednisone is prescribed at a dose of 5 mg or 10 mg daily, depending on the indication.
- Missed Dose: if a dose is missed, take the usual dose the following day. Do not double the dosage.
- Monitoring: during treatment, transaminase levels (ALT, AST), bilirubin, and blood pressure should be checked monthly.
