Popis: |
BACKGROUND: It is hypothesised that cotargeting the androgen receptor (AR) and paracrine androgen biosynthesis with enzalutamide and abiraterone acetate in metastatic castration-resistant prostate cancer (mCRPC) will dissipate adaptive feedback loops observed with either agent alone. OBJECTIVE: To assess the safety, efficacy, androgen signalling/metabolome, and drug-drug interactions (DDIs) of enzalutamide with abiraterone acetate in progressive bone mCRPC (bmCRPC). DESIGN, SETTING, AND PARTICIPANTS: This open-label, single-centre interventional study was conducted in bmCRPC patients. INTERVENTION: Enzalutamide 160mg and abiraterone acetate 1000mg once daily; prednisone 5mg twice daily. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Adverse events (AEs), prostate-specific antigen (PSA) response, progression-free survival (PFS), tumour biomarker/metabolite expression, and Cmin plasma concentrations were evaluated. RESULTS AND LIMITATIONS: Sixty patients were enrolled. Common AEs independent of grade/causality included fatigue (72%), hyperglycaemia (67%), alkaline phosphatase (ALP) elevation (53%), and hot flush (43%). Grade 3 AEs included hypertension (17%), alanine aminotransferase elevation (12%), ALP elevation (5%), and arthralgia (5%). No treatment-related grade 4 AEs or deaths were reported. Median treatment-discontinuation time was 312d (95% confidence interval [CI] 196.0-483.0). Maximal PSA decline ≥50% and ≥90% occurred in 46 (77%) and 29 (48%) patients, respectively. Median PFS was 251d (95% CI 147-337). At week 9, median tumour microenvironment androgens, precursors, and nuclear AR expression decreased (p |