Effects of food on the pharmacokinetics of ensartinib in healthy Chinese subjects.

Ensartinib is a promising, aminopyridazine-based small molecule that potently inhibits anaplastic lymphoma kinase. This random, two-period, crossover study evaluated the effects of food on the pharmacokinetics of ensartinib after a single dose (225 mg) in healthy Chinese subjects. The pharmacokinetic parameters of ensartinib were calculated using non-compartmental analysis. Twenty-four healthy Chinese subjects age 20-44 years were included in this study. The area under the concentration-time curve of ensartinib was ~25% lower after the intake of a high-fat, high-calorie meal before dosing, whereas the maximum plasma concentration was decreased by ~37%, illustrating the statistically significant effect of food on ensartinib pharmacokinetics. In addition, food intake prolonged the absorption phase of ensartinib (median time to maximum plasma concentration, from 4.5 to 6 hours). Population pharmacokinetic (PopPK) analysis was conducted using NONMEM, and the influences of food, age, sex, body weight and body mass index were studied via covariate analysis. In this analysis, ensartinib plasma concentrations were best described by a one-compartment model with Weibull absorption. The final model included food and age as covariates on apparent distribution and apparent clearance. Based on the final PopPK model, food was identified as a significant covariate for apparent clearance, apparent volume of distribution and absorption rate constant, consistent with the results of non-compartmental pharmacokinetic analysis.

Interaction potential of the dual orexin receptor antagonist ACT-541468 with CYP3A4 and food: results from two interaction studies.

PURPOSE: ACT-541468 is a novel dual orexin receptor antagonist (DORA) under development for the treatment of insomnia. In vitro studies suggested a significant role of CYP3A4 in ACT-541468 metabolism and an impact on CYP3A4 activity. METHODS: Subsequently, two clinical cross-over studies investigated the victim (n = 14 healthy subjects) and perpetrator (n = 20) potential of 25 mg ACT-541468 with respect to CYP3A4. The effect of food intake on the pharmacokinetics of ACT-541468 was also investigated. RESULTS: Moderate CYP3A4 inhibition by diltiazem (240 mg/day) increased the Cmax and AUC0-∞ of ACT-541468 by 1.4-fold (90% confidence interval (CI): 1.2-1.6) and 2.4-fold (90% CI: 2.0-2.8), respectively, and prolonged t½ by 80% (90% CI: 60-90) without affecting tmax. Single- and multiple-dose administration of 25 mg ACT-541468 had no impact on the pharmacokinetics of the sensitive substrate midazolam and its main metabolite 1-hydroxy midazolam indicated by 90% CI of the geometric mean ratios of Cmax and AUC within bioequivalence criteria and by an unchanged tmax. After a high-fat high-calorie breakfast, the pharmacokinetic profile of 25 mg ACT-541468 showed a decrease of Cmax by 24% (90% CI: 17-31) and a delay of tmax by approximately 2 h (90% CI: 1.4-2.4), whereas t½ and AUC0-24 remained essentially unchanged. ACT-541468 given alone or in combination with diltiazem, midazolam, or food was safe and well tolerated. CONCLUSIONS: Overall, ACT-541468 has been determined as CYP3A4 substrate but without any perpetrator drug-drug interaction potential regarding CYP3A4 in humans. Food affected ACT-541468 absorption without modifying overall exposure.

Nutri-pharmacogenomics of warfarin anticoagulation therapy: VKORC1 genotype-dependent influence of dietary vitamin K intake.

Warfarin is the most widely prescribed oral anticoagulant, but large interindividual variations exist in the dose required to achieve comparable therapeutic effects. Several clinical and genetic variables have been identified that influence warfarin dosing. However, interactions between genotype and nutrition remain uncertain in terms of dietary vitamin K intake. To investigate genotype-nutrient interactions in warfarin anticoagulation therapy, 202 consecutive outpatients (M/F = 142/60, mean age, 69 years) undergoing treatment with warfarin were enrolled. Prevalent single nucleotide polymorphisms in VKORC1 and CYP2C9 were genotyped, and dietary vitamin K intake during the week preceding the blood sampling was quantitatively estimated by a dietitian-assisted questionnaire. Patients were classified according to low, medium, or high vitamin K intake. The mean daily warfarin dose in subjects with a VKORC1-1639 A/A genotype was significantly smaller than that with a -1639A/G genotype (2.74 vs. 3.91 mg/day, respectively, p < 0.0001). Dose requirements did not differ between subjects with a CYP2C9 *1/*3 genotype versus a CYP2C9 *1/*1 genotype. In subjects with a variant VKORC1-1639 G allele, the mean daily warfarin dose was significantly attenuated by low vitamin K intake compared with medium and high intake after adjustment for covariates (3.4 vs. 5.0 vs. 4.0 mg/day, respectively, p = 0.028). No such genotype effects were observed in homozygous patients for the VKORC1-1639 A allele. The results of the present study suggest that the capacity of dietary vitamin K intake to influence warfarin dose requirements during anticoagulation therapy is VKORC1 genotype-dependent, at least in part.

A strategy for analyzing gene-nutrient interactions in type 2 diabetes.

Type 2 diabetes mellitus (T2DM), like all chronic diseases, results from interactions between multiple genes and multiple environmental factors. Nevertheless, many research studies focus on either nutrition or genetic factors independently of each other. The challenges of analyzing gene-nutrient interactions in T2DM are the (i) genetic heterogeneity in humans, (ii) complexity of environmental factors, particularly dietary chemicals, and (iii) diverse physiologies that produce the same apparent disease. Many of these variables are not accounted for in the design or study of T2DM or, indeed, most chronic diseases, although exceptions are noteworthy. Establishing experimental paradigms to analyze the complexity of these interactions and physiologies is challenging, but possible. This article provides a strategy to extend nutrigenomic experimental strategies to include early environmental influences that may promote adult-onset disease.

Intestinal membrane transport of drugs and nutrients: genomics of membrane transporters using expression microarrays.

Carrier-mediated transport across membranes plays an important role in drug and nutrient absorption. However, relevant transporters remain largely unknown for most substrates. Their identification requires global analysis of expressed mRNAs in intestinal tissues. Microarray technologies capable of measuring mRNA profiles have proven useful in detecting the expression of genes encoding transporters and ion channels in intestines and Caco-2 cells. This colon carcinoma cell line with characteristics of absorptive enterocytes serves as a common model for drug absorption studies. Gene expression patterns of membrane transporters and channels define the cell's overall transport capacity. Moreover, transporter mRNA profiles provide a basis for assessing drug-drug and drug-food interactions in intestinal absorption. To determine relevant transporters for any given substrate, chemogenomic methods have emerged correlating mRNA expression in multiple tissues to drug transport or response. The resultant drug-transporter databases permit the search for transporter-drug relationships at a genomic scale.