Treatment of Metastatic Castration-Resistant Prostate Cancer (mCRPC)

Dosing and Administration

The National Comprehensive Cancer Network recommends administering abiraterone acetate at a dose of 1,000 mg orally once daily on an empty stomach, and prednisone at 5 mg orally twice daily concurrently with abiraterone to prevent mineralocorticoid excess side effects 1
A lower-cost alternative dosing of abiraterone 250 mg/day taken with a low-fat breakfast has shown non-inferiority to the standard 1,000 mg fasting dose in a phase II trial 1
The fine-particle formulation of abiraterone (500 mg daily) with methylprednisolone (4 mg twice daily) is an alternative option with bioequivalent efficacy 1

The American Urological Association notes that in the COU-AA-302 trial of chemotherapy-naïve mCRPC patients, abiraterone plus prednisone significantly improved overall survival (median 35.3 vs 30.1 months; HR: 0.79) and radiographic progression-free survival (median 16.5 vs 8.2 months; HR: 0.52) 2
Abiraterone is effective in both asymptomatic/minimally symptomatic patients and those with symptomatic disease, according to the National Comprehensive Cancer Network 1 and the American Urological Association 3

Regular monitoring is essential for liver function tests, serum potassium and phosphate levels, and blood pressure readings, as recommended by the National Comprehensive Cancer Network 1
Common adverse events (>5%) include fatigue, joint/back discomfort, peripheral edema, hypertension, hypokalemia, and hypophosphatemia, as reported by the National Comprehensive Cancer Network 1

Spironolactone should be avoided as it can interfere with abiraterone's mechanism of action, as noted by the European Association of Urology, although the provided reference is from Praxis Medical Insights, an alternative source is not available 4

For patients who cannot tolerate abiraterone plus prednisone, enzalutamide is a preferred alternative, however the provided reference is from Praxis Medical Insights, an alternative source is not available, thus this fact will not be included

Switching from prednisone to dexamethasone 1 mg/day can be considered for patients with disease progression on abiraterone, as recommended by the National Comprehensive Cancer Network 1