Evaluation of a New Formulation That Improves the Bioavailability and Food Effect of Abiraterone: An Open‐Label, Crossover, Randomized, Controlled, Phase I Clinical Trial

Abstract This first‐in‐human phase I trial evaluated RL001, a self‐emulsifying soft‐capsule abiraterone developed to overcome the low bioavailability and food sensitivity associated with the 1000‐mg Zytiga tablet that is used with prednisone according to NCCN guidelines. Plasma concentrations were quantified by LC‐MS/MS and modeled in Phoenix WinNonlin 8.1 and SAS; GeoMean confidence intervals compared pharmacokinetics. Against 1000‐mg abiraterone acetate tablet, the 200 mg RL001 achieved abiraterone C max GMR >125% and AUC 0‐t , AUC 0‐∞ 80–125%, indicating higher bioavailability and enabling a lower therapeutic dose. The GMR of prednisone and its metabolite remained within 80%–125%, confirming no interaction. Fed/fasted exposure ratios stayed around 80% for AUC and