Yoon DY, et al. Transl Clin Pharmacol. 2020 Dec;28(4):189-198. https://doi.org/10.12793/tcp.2020.28.e18

This study aimed to develop a physiologically based pharmacokinetic (PBPK) model of tegoprazan and to predict the drug–drug interaction (DDI) potential between tegoprazan and cytochrome P450 (CYP) 3A4 perpetrators. The PBPK model of tegoprazan was developed using SimCYP Simulator^® and verified by comparing the model-predicted pharmacokinetics (PKs) of tegoprazan with the observed data from phase 1 clinical studies, including DDI studies. DDIs between tegoprazan and three CYP3A4 perpetrators were predicted by simulating the difference in tegoprazan exposure with and without perpetrators, after multiple dosing for a clinically used dose range. The final PBPK model adequately predicted the biphasic distribution profiles of tegoprazan and DDI between tegoprazan and clarithromycin. All ratios of the predicted-to-observed PK parameters were between 0.5 and 2.0. In DDI simulation, systemic exposure to tegoprazan was expected to increase about threefold when co-administered with the maximum recommended dose of clarithromycin or ketoconazole. Meanwhile, tegoprazan exposure was expected to decrease to ~30% when rifampicin was co-administered. Based on the simulation by the PBPK model, it is suggested that the DDI potential be considered when tegoprazan is used with CYP3A4 perpetrator, as the acid suppression effect of tegoprazan is known to be associated with systemic exposure.

This study aimed to evaluate the safety, tolerability, pharmacokinetics, and pharmacodynamics of vutiglabridin, a potential anti‐obesity treatment under development, for the first time in humans. A randomized, placebo‐controlled, single‐ and multiple‐ascending dose study (SAD and MAD, respectively) was performed in healthy Koreans and Whites. Subjects randomly received a single oral dose of 30–720 mg vutiglabridin or placebo at a ratio of 8:2 in the SAD study or 240–480 mg vutiglabridin or placebo once daily for 14 days in the MAD study. Food effect was also evaluated in 240 mg single dose group. Pharmacokinetics were evaluated through plasma concentrations, and pharmacodynamic biomarkers related to obesity or inflammation were analyzed. Safety and tolerability were assessed throughout the study. Single and multiple doses of vutiglabridin were generally well‐tolerated. The pharmacokinetic parameters show less than dose‐proportionality increase, and plasma concentrations increased more than two‐fold after multiple administrations. The mean half‐life of Koreans and Whites in the MAD study was 110 and 73 h, respectively. The systemic exposure of vutiglabridin was significantly increased when taken with a high‐fat meal, and the systemic exposure was lower in Whites than in Koreans. Vutiglabridin was well‐tolerated in healthy Koreans and Whites. The plasma concentration increased less than the dose‐proportionality manner. These results justify further investigation of vutiglabridin in patients with obesity.

Various studies have highlighted the importance of ethnic differences. The consideration of ethnic differences in the field of individualized pharmacotherapy is imperative. Therefore, various organizations and networks across countries should aim to conduct multicountry and multiregional clinical trials (MRCTs). If there is solid evidence available to evaluate the existence of ethnic differences between the same regional areas, it will lead to an increase in the efficiency of drug development. The purpose of this paper was to compare the approval dosing regimen among four Asian countries (Korea, Japan, China, and Taiwan) and elucidate the readiness and current status of the implementation of the International Conference on Harmonization (ICH) E17 guidelines on MRCTs. Reducing unnecessary clinical trials via multinational clinical trials in East Asian countries is also suggested. The approved dosing regimens for some drugs in the four Asian countries were similar; however, some differences might be caused by differences in legislation, even though there were no ethnic differences. This indicates that there are several roles to be expected of the Asia Clinical Pharmacology study network for exploratory MRCTs, which would lead to the accumulation of evidence for MRCTs, ultimately accelerating the efficiency of drug development in East Asian countries. The exposure of the new treatment to the necessary patients through collaborative research coordination and simultaneous multinational subject recruitment would serve its role in providing East Asia with specific personalized medicine with a high treatment success rate.

Kim B, et al. Transl Clin Pharmacol. 2021 Sep;29(3):135-149. https://doi.org/10.12793/tcp.2021.29.e14