Evaluation of Bioequivalence for Avapritinib Tablets in Chinese Participants Under Fasting Conditions Using a Reference-Scaled Average Bioequivalence Method

This study aimed to assess the bioequivalence of 2 avapritinib tablets formulations. A randomized, open-label, single-center trial was conducted on fasting, healthy Chinese participants. The study utilized a partial replicated design with 3 sequences and 3 periods. Participants were assigned to 1 of 3 sequences, with each sequence receiving the reference formulation twice and the test formulation once. Plasma samples were collected and analyzed to determine pharmacokinetic parameters. The bioequivalence of the 2 avapritinib formulations was assessed using reference-scaled average bioequivalence for the maximum plasma concentration (C_max) and the average bioequivalence analysis for the area under the concentration-time curve (AUC). Out of 39 participants, 38 completed the study. For C_max, the 1-sided 95% upper confidence interval (CI) bound from the scaled approach was −0.035 (<0) and the point estimate value was 0.958, falling inside the acceptance range of 0.8-1.25. For both the AUC over all concentrations measured (AUC_0-t) and the AUC from time 0 to infinity (AUC_0-inf), the 90% CIs of geometric mean ratios (0.87-1.01) also met the bioequivalence criteria of 0.8-1.25. Consequently, the study demonstrated that the 2 avapritinib formulations were bioequivalent under fasting conditions.