Model-Informed Dose Justifications of Posaconazole in Japanese Patients for Prophylaxis and Treatment Against Fungal Infection.

Posaconazole is a globally approved broad-spectrum triazole antifungal compound. In Japanese patients, posaconazole has identical dosing regimens as those approved globally for both tablet and intravenous formulations. This article aims to describe a model-informed approach for dose justification of posaconazole in the Japanese population as either high-risk patients with fungal infections (prophylaxis patients) or patients with fungal infections (treatment patients). A simultaneous population pharmacokinetic (PK) model for tablet and intravenous formulation was developed on the basis of a data set including Japanese data from healthy participants and treatment patients. The PK profiles and exposure distributions in Japanese patients were predicted and compared against foreign patients, that is, patients outside of Japan. Relationships between the post hoc posaconazole exposures and frequently observed clinical adverse events were evaluated. Although clinical trials for Japanese prophylaxis patients were not conducted, PK profiles in Japanese prophylaxis patients were predicted using the population PK model and demographic covariate information obtained from the published literature. Based upon the globally approved dosing regimen, posaconazole exposure distribution was predicted to be the highest in Japanese treatment patients, and generally similar between Japanese and foreign prophylaxis patients. Exposures in Japanese patients exceeded the efficacy target level (500 ng/mL). Safety profiles in Japanese treatment patients with the highest exposures were clinically acceptable without specific concerns to Japanese patients and appeared to have no relationship with posaconazole exposures. From PK, safety, and efficacy perspectives, the use of the same dosing regimen as in foreign patients was justified in Japanese prophylaxis and treatment patients.

The Bioequivalence and Effect of Food on the Pharmacokinetics of a Fixed-Dose Combination Tablet Containing Rosuvastatin and Ezetimibe in Healthy Japanese Subjects.

Certain patient populations are unable to achieve the recommended low-density lipoprotein cholesterol goals with statin monotherapy alone. Such patients may benefit from concomitant therapy with ezetimibe (EZE) 10 mg added on to a statin. To this end, fixed-dose combination (FDC) tablets containing EZE 10 mg and rosuvastatin (ROS) 2.5 mg (EZE/ROS2.5) and EZE 10 mg and ROS 5 mg (EZE/ROS5) have been developed for treatment of hypercholesterolemia. The purpose of the series of clinical studies reported herein was to evaluate the potential food effect (MK-0653H, protocol 836 (P836)) and the bioequivalence between FDC and co-administration of EZE and ROS in healthy Japanese subjects under fasted and fed conditions (MK-0653H, protocol 835 (P835) and MK-0653H, protocol 846 (P846), respectively). These studies show there is no clinically relevant food effect on EZE exposure following single oral administration of the FDC EZE/ROS5 in healthy Japanese subjects; however, ROS exposure was decreased in the fed state under conditions used to evaluate the maximum food effect. Following single oral administration of individual ROS tablets under the same conditions, the magnitude of decrease in ROS exposure was comparable to that seen with FDC, suggesting that the effect of food on ROS exposure was similar between the FDC tablet and co-administration of individual EZE and ROS tablets. The FDC EZE/ROS5 was generally well tolerated in healthy Japanese subjects under fasted and fed conditions.