Pharmacokinetics and Bioequivalence of Abiraterone Acetate Tablets in Healthy Chinese Volunteers: An Open, Randomized, Single-Dose, Three-Period, Three-Sequence Crossover Study

Abstract

Abstract Background and Objective Abiraterone acetate tablet is an inhibitor of androgen synthesis, primarily for the treatment of metastatic castration-resistant prostate cancer (mCRPC). This study evaluated the bioequivalence and pharmacokinetics of the reference and test formulations of abiraterone acetate tablets in healthy Chinese volunteers. Methods A single-center, open, single-dose, randomized, three-period, three-sequence, semi-repeat (only repeated reference formulations), and reference formulation-corrected fasting reference-scaled average bioequivalence test was conducted in 36 healthy volunteers included in this study. Volunteers were randomly assigned to one of three groups in a 1:1:1 ratio. There was a minimum 7-day washout period between each dose. Blood samples were collected at prescribed time intervals, the plasma concentration of abiraterone acetate tablets was determined by liquid chromatography-tandem mass spectrometry, and adverse events were recorded. Results Under fasting conditions, the maximum plasma concentration (C max) was 27.02 ± 14.21 ng/mL, area under the concentration-time curve from time zero to time t (AUC t ) was 125.30 ± 82.41 h·ng/mL, and AUC from time zero to infinity (AUC ∞ ) was 133.70 ± 83.99 h·ng/mL. The 90% confidence intervals (CIs) of the geometric mean ratio (GMR) of AUC t and AUC ∞ were in the range of 0.8000–1.2500, and the coefficient of variation (CVWR) of C max was more than 30%. The Critbound result was − 0.0522, and the GMR was between 0.8000 and 1.2500. Conclusion Both test and reference formulations of abiraterone acetate tablets were bioequivalent in healthy Chinese subjects under fasting conditions. Trial registration ClinicalTrials.gov identifier NCT04863105, registered 26 April 2021—retrospectively registered ( https://register.clinicaltrials.gov/prs/app/action/SelectProtocol?sid=S000ARAA&selectaction=Edit&uid=U00050YQ&ts=2&cx=-vbtjri