Prediction of Oral Drug Absorption in Rats from In Vitro Data.

PURPOSE: In drug discovery, rats are widely used for pharmacological and toxicological studies. We previously reported that a mechanism-based oral absorption model, the gastrointestinal unified theoretical framework (GUT framework), can appropriately predict the fraction of a dose absorbed (Fa) in humans and dogs. However, there are large species differences between humans and rats. The purpose of the present study was to evaluate the predictability of the GUT framework for rat Fa. METHOD: The Fa values of 20 model drugs (a total of 39 Fa data) were predicted in a bottom-up manner. Based on the literature survey, the bile acid concentration (Cbile) and the intestinal fluid volume were set to 15 mM and 4 mL/kg, respectively, five and two times higher than in humans. LogP, pKa, molecular weight, intrinsic solubility, bile micelle partition coefficients, and Caco-2 permeability were used as input data. RESULTS: The Fa values were appropriately predicted for highly soluble drugs (absolute average fold error (AAFE) = 1.65, 18 Fa data) and poorly soluble drugs (AAFE = 1.57, 21 Fa data). When the species difference in Cbile was ignored, Fa was over- and under-predicted for permeability and solubility limited cases, respectively. High Cbile in rats reduces the free fraction of drug molecules available for epithelial membrane permeation while increasing the solubility of poorly soluble drugs. CONCLUSION: The Fa values in rats were appropriately predicted by the GUT framework. This result would be of great help for a better understanding of species differences and model-informed preclinical formulation development.

Empagliflozin as adjunct to insulin in Japanese participants with type 1 diabetes: Results of a 4-week, double-blind, randomized, placebo-controlled phase 2 trial.

AIMS: This phase 2, double-blind, randomized, placebo-controlled trial (ClinicalTrials.gov NCT02702011) with 4 sites in Japan investigated the pharmacodynamics (PD), pharmacokinetics (PK) and safety profile of empagliflozin in Japanese participants with type 1 diabetes mellitus (T1DM) as adjunctive therapy to insulin. MATERIALS AND METHODS: Participants using multiple daily injections of insulin for ≥12 months, with HbA1c of 7.5%-10.0%, entered a 2-week, open-label, placebo run-in period, followed by a 4-week, double-blind period during which participants were randomized 1:1:1:1 to receive empagliflozin 2.5 mg (n = 13), empagliflozin 10 mg (n = 12), empagliflozin 25 mg (n = 12) or placebo (n = 11). The primary objective was to assess the effect of empagliflozin vs placebo on urinary glucose excretion (UGE) after 7 days of treatment. RESULTS: PD: Empagliflozin resulted in a dose-dependent significant increase in 24-hour UGE compared with placebo (UGE placebo-corrected mean [95% confidence interval] change from baseline: 2.5 mg, 65.10 [43.29, 86.90] g/24 h; 10 mg, 81.19 [58.80, 103.58] g/24 h; 25 mg, 98.11 [75.91, 120.31] g/24 h). After 4 weeks of treatment, UGE increase was associated with improved glycaemic control, reduced body weight and decreased insulin needs. Empagliflozin treatment also resulted in dose-dependent increases in serum ketone bodies and free fatty acids. PK: Plasma empagliflozin levels increased in a dose-dependent manner and peaked at 1.5 hours. In this short study, empagliflozin was well tolerated, with no increase in rate of hypoglycaemia and no diabetic ketoacidosis events reported. CONCLUSIONS: Based on this short-duration phase 2 study, the PK/PD profile of empagliflozin in Japanese participants with T1DM is comparable to that of non-Japanese participants.

Population pharmacokinetic/pharmacodynamic analysis of the DPP-4 inhibitor linagliptin in Japanese patients with type 2 diabetes mellitus.

OBJECTIVES: Linagliptin is a novel, highly selective and long acting DPP-4 inhibitor for the treatment of type 2 diabetes mellitus (T2DM). Linagliptin exhibits non-linear pharmacokinetics (PK) due to saturable binding to plasma and tissue DPP-4. The aim of this study was to characterize the PK and PK/DPP-4 inhibition relationship of linagliptin in Japanese patients with T2DM using a population PK/DPP-4 model and to support the rationale for the therapeutic dose in Japanese patients by simulation. METHODS: Linagliptin plasma concentration and DPP-4 inhibition measurements from a placebo-controlled, parallel group multiple (28 days) dose trial that included 36 T2DM patients (18 patients each in 2.5 mg and 10 mg dose group) were used for analysis. Modeling was performed using FOCE INTERACTION estimation method implemented in NONMEM V. The linagliptin plasma concentration- and DPP-4 inhibition- time profiles were simulated for Japanese patients receiving 5 mg linagliptin once daily by the model established. RESULTS: Nonlinear PK of linagliptin in T2DM patients were well described by a 2-compartment model assuming concentration-dependent binding to DPP-4 in the central and peripheral compartment. Plasma DPP-4 inhibition was integrated in the model by relating the model-predicted DPP-4 occupancy with linagliptin linearly to DPP-4 inhibition. The simulation predicted that for the 5 mg dose group the trough DPP-4 inhibition at steady-state was 84.2%, which is higher than the target inhibition (≥80%) for an effective dose of DPP-4 inhibitor. In 2.5 mg dose group, steady-state DPP-4 inhibition of >80% was not maintained over 24 hours (observed and simulated). CONCLUSIONS: The nonlinear PK of linagliptin and its plasma DPP-4 inhibition in patients were well characterized by a target-mediated drug disposition model relating DPP-4 occupancy with linagliptin to DPP-4 inhibition. Simulations of plasma DPP-4 inhibition suggest that 5 mg linagliptin once daily is an appropriate therapeutic dose for Japanese patients with T2DM.

Phase I study of the VEGF/Ang-2 inhibitor BI 836880 alone or combined with the anti-programmed cell death protein-1 antibody ezabenlimab in Japanese patients with advanced solid tumors.

PURPOSE: This two-part, open-label, non-randomized dose-escalation study aimed to define the maximum tolerated dose (MTD) of BI 836880 (humanized bispecific nanobody® targeting vascular endothelial growth factor and angiopoietin-2) as monotherapy and in combination with ezabenlimab (programmed death protein-1 inhibitor) in Japanese patients with advanced and/or metastatic solid tumors. METHODS: In part 1, patients received an intravenous infusion of BI 836880 at 360 or 720 mg every 3 weeks (Q3W). In part 2, patients received BI 836880 at doses of 120, 360, or 720 mg in combination with ezabenlimab 240 mg Q3W. The primary endpoints were the MTD and the recommended phase II dose (RP2D) of BI 836880 as monotherapy and in combination with ezabenlimab, based on dose-limiting toxicities (DLTs) during the first cycle. RESULTS: Twenty-one patients were treated; nine in part 1 and 12 in part 2. No DLTs were reported in either part and the MTD was not reached. The RP2Ds were BI 836880 720 mg Q3W as monotherapy and BI 836880 720 mg plus ezabenlimab 240 mg Q3W. The most common adverse events were hypertension and proteinuria (33.3%) with BI 836880 monotherapy and diarrhea (41.7%) with the combination. Four patients (44.4%) in part 1 had stable disease as best overall tumor response. In part 2, two patients (16.7%) had confirmed partial responses and five had stable disease (41.7%). CONCLUSION: MTD was not reached. BI 836880 alone and in combination with ezabenlimab had a manageable safety profile with preliminary clinical activity in Japanese patients with advanced solid tumors. TRIAL REGISTRATION AND DATE: NCT03972150, registered on June 3, 2019.

Population pharmacokinetics of tamsulosin hydrochloride in paediatric patients with neuropathic and non-neuropathic bladder.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT: Tamsulosin is available on prescription as a modified release capsule in the US (Flomax), and in most European countries for the treatment of the signs and symptoms of benign prostatic hyperplasia (BPH). The pharmacokinetics of tamsulosin hydrochloride (HCl) have been extensively studied in adults, but no pharmacokinetic data for paediatrics have been published to date. WHAT THIS STUDY ADDS: A population pharmacokinetic model of tamsulosin HCl was developed in paediatric patients. Covariate analysis revealed that body weight and alpha(1)-acid glycoprotein influenced both the apparent clearance and the apparent volume of distribution. This study confirms that there is no major difference in the pharmacokinetics of tamsulosin HCl between paediatrics (age range 2-16 years) and adults when the effect of body weight is taken into consideration. AIMS: The main objective of this study was to characterize the population pharmacokinetics of tamsulosin hydrochloride (HCl) in paediatric patients with neuropathic and non-neuropathic bladder. A secondary objective was to compare the pharmacokinetics in paediatric patients and adults. METHODS: Tamsulosin HCl plasma concentrations in 1082 plasma samples from 189 paediatric patients (age range 2-16 years) were analyzed with NONMEM, applying a one compartment model with first-order absorption. Based on the principles of allometry, body weight was incorporated in the base model, along with fixed allometric exponents. Covariate analysis was performed by means of a stepwise forward inclusion and backward elimination procedure. Simulations based on the final model were used to compare the pharmacokinetics with those in adults. RESULTS: Beside the priori-implemented body weight, only alpha(1)-acid glycoprotein had an effect on both apparent clearance and apparent volume of distribution. No other investigated covariates, including gender, age, race, patient population and concomitant therapy with anti-cholinergics, significantly affected the pharmacokinetics of tamsulosin HCl (P < 0.001). The results of simulations indicated that the exposure in 12.5 kg paediatric patients was 3.5-4.3 fold higher than that in 70.0 kg adults. After a weight-based dose administration, the exposure in paediatric patients was comparable with that in healthy adults. CONCLUSIONS: A population pharmacokinetic model of tamsulosin HCl in paediatric patients was established and it described the data well. There was no major difference in the pharmacokinetics of tamsulosin HCl between paediatric patients (age range 2-16 years) and adults when the effect of body weight was taken into consideration.

Physiologically Based Pharmacokinetic Model of the DPP-4 Inhibitor Linagliptin to Describe its Nonlinear Pharmacokinetics in Humans.

Linagliptin, a dipeptidyl peptidase (DPP)-4 inhibitor, for type 2 diabetes exhibits nonlinear plasma protein binding in the therapeutic concentration range due to its high affinity binding to the pharmacological target DPP-4, and its pharmacokinetics both in plasma and urine is also nonlinear. The purpose of the present study was to explain the nonlinear pharmacokinetic profiles using a physiologically based pharmacokinetic (PBPK) model with saturable binding of linagliptin to soluble and membrane-bound DPP-4 in blood and organs including kidneys. The model was first fitted to previously reported full-scale plasma concentrations and urinary excretion data at 4 intravenous (iv) dose levels. Additional fitting to the data from 4 oral (po) dose levels was then performed to yield the final iv-po based model including gastrointestinal absorption-associated parameters. Data from [14C]linagliptin mass balance study were also used for optimizing parameters related to enterohepatic circulation. The PBPK model was thus constructed and well describes the nonlinear pharmacokinetic profiles of linagliptin in both plasma and urine, demonstrating that the nonlinear pharmacokinetics are fully explained by its specific binding to target protein. The present study thus introduces the involvement of target-mediated disposition for linagliptin in humans.

Prediction Characteristics of Oral Absorption Simulation Software Evaluated Using Structurally Diverse Low-Solubility Drugs.

The purpose of the present study was to characterize current biopharmaceutics modeling and simulation software regarding the prediction of the fraction of a dose absorbed (Fa) in humans. As commercial software products, GastroPlus™ and Simcyp® were used. In addition, the gastrointestinal unified theoretical framework, a simple and publicly accessible model, was used as a benchmark. The Fa prediction characteristics for a total of 96 clinical Fa data of 27 model drugs were systematically evaluated using the default settings of each software product. The molecular weight, dissociation constant, octanol-water partition coefficient, solubility in biorelevant media, dose, and particle size of model drugs were used as input data. Although the same input parameters were used, GastroPlus™, Simcyp®, and the gastrointestinal unified theoretical framework showed different Fa prediction characteristics depending on the rate-limiting steps of oral drug absorption. The results of the present study would be of great help for the overall progression of physiologically based absorption models.

Phase I Study of the Focal Adhesion Kinase Inhibitor BI 853520 in Japanese and Taiwanese Patients with Advanced or Metastatic Solid Tumors.

BACKGROUND: Focal adhesion kinase (FAK) inhibitors have demonstrated anti-tumor activity preclinically and are currently being evaluated in humans. A first-in-human study evaluating the novel FAK inhibitor BI 853520 in a predominantly Caucasian population with advanced or metastatic non-hematologic malignancies demonstrated acceptable tolerability and favorable pharmacokinetics. OBJECTIVE: This study was undertaken to investigate the safety, tolerability, and maximum tolerated dose (MTD) of BI 853520 in Japanese and Taiwanese patients with advanced solid tumors. PATIENTS AND METHODS: In this open-label, phase I, dose-finding study, BI 853520 was administered once daily (QD) in a continuous daily dosing regimen with 28-day cycles and escalating doses to sequential cohorts of patients. Twenty-one patients (62% male; median age 65 years) were treated at two sites in Japan and Taiwan. RESULTS: The median duration of treatment was 1.2 months (range 0.2-7.7). As no dose-limiting toxicities were observed during cycle 1 in the 50, 100, or 200 mg cohorts, the MTD of BI 853520 was determined to be 200 mg QD. Drug-related adverse events were reported in 19 patients (90%), and all except one were of grade 1 or 2. Pharmacokinetic parameters were supportive of a once-daily dosing schedule. A confirmed objective response rate of 5% and disease control rate of 29% were achieved; median duration of disease control was 3.7 months. CONCLUSIONS: This trial demonstrated a manageable and acceptable safety profile, favorable pharmacokinetics, and potential anti-tumor activity of BI 853520 in pretreated Japanese and Taiwanese patients with advanced or metastatic solid tumors. CLINICAL TRIALS REGISTRATION: NCT01905111.

An open-label feasibility study of nintedanib combined with docetaxel in Japanese patients with locally advanced or metastatic lung adenocarcinoma after failure of first-line chemotherapy.

PURPOSE: This open-label feasibility study assessed the tolerability of nintedanib 200 mg in combination with docetaxel 75 mg/m2 as a starting dose in Japanese patients with a body surface area (BSA) < 1.5 m2 and locally advanced or metastatic lung adenocarcinoma. METHODS: Eligible patients received docetaxel 75 mg/m2 every 21 days and nintedanib administered at 200 mg twice daily (bid), starting on day 2 of each cycle. Treatment was continued until disease progression or undue toxicity. The primary endpoint was the number of patients experiencing dose-limiting toxicities (DLTs) in cycle 1 (days 1-21). RESULTS: Of 10 treated patients, 2 patients (20%) experienced DLTs during cycle 1. These DLTs were grade 3 liver enzyme elevations [alanine aminotransferase (2 patients) and aspartate aminotransferase (2 patients)], and grade 2 hyperbilirubinemia (1 patient). Nine patients met the predefined criteria for nintedanib 200 mg bid plus docetaxel 75 mg/m2 to be considered a tolerable starting dose. All patients experienced ≥ 1 adverse event (AE) during the treatment period (all drug-related), but no patients experienced AEs that led to discontinuation of nintedanib. Of the five serious AEs reported during treatment, none were drug-related. There was no apparent effect of nintedanib on the pharmacokinetics of docetaxel. The objective response and disease control rates were 40 and 70%, respectively. CONCLUSION: Nintedanib 200 mg bid plus docetaxel 75 mg/m2 is a tolerable starting dose in Japanese patients with a BSA < 1.5 m2 with locally advanced or metastatic lung adenocarcinoma. CLINICALTRIALS. GOV NUMBER: NCT02300298.

Comparable pharmacodynamics, efficacy, and safety of linagliptin 5 mg among Japanese, Asian and white patients with type 2 diabetes.

AIMS/INTRODUCTION: The efficacy and safety of drugs can vary between different races or ethnic populations because of differences in the relationship of dose to exposure, pharmacodynamic response or clinical efficacy and safety. In the present post-hoc analysis, we assessed the influence of race on the pharmacokinetics, pharmacodynamics, efficacy and safety of monotherapy with the dipeptidyl peptidase-4 inhibitor, linagliptin, in patients with type 2 diabetes enrolled in two comparable, previously reported randomized phase III trials. MATERIALS AND METHODS: Study 1 (with a 12-week placebo-controlled phase) recruited Japanese patients only (linagliptin, n = 159; placebo, n = 80); study 2 (24-week trial) enrolled Asian (non-Japanese; linagliptin, n = 156; placebo, n = 76) and white patients (linagliptin, n = 180; placebo, n = 90). RESULTS: Linagliptin trough concentrations were equivalent across study and race groups, and were higher than half-maximal inhibitory concentration, resulting in dipeptidyl peptidase-4 inhibition >80% at trough. Linagliptin inhibited plasma dipeptidyl peptidase-4 activity to a similar degree in study 1 and study 2. Linagliptin reduced fasting plasma glucose concentrations by a similar magnitude across groups, leading to clinically relevant reductions in glycated hemoglobin in all groups. Glycated hemoglobin levels decreased to a slightly greater extent in study 1 (Japanese) and in Asian (non-Japanese) patients from study 2. Linagliptin had a favorable safety profile in each race group. CONCLUSIONS: Trough exposure, pharmacodynamic response, and efficacy and safety of linagliptin monotherapy were comparable among Japanese, Asian (non-Japanese) and white patients, confirming that the recommended 5-mg once-daily dose of linagliptin is appropriate for use among different race groups.

Phase I trial of afatinib plus vinorelbine in Japanese patients with advanced solid tumors, including breast cancer.

PURPOSE: This phase I trial assessed afatinib, an irreversible ErbB family blocker, plus vinorelbine in Japanese patients with advanced solid tumors not amenable to standard treatment. METHODS: Primary objectives were evaluation of safety and the maximum tolerated dose (MTD) of once-daily (QD) afatinib plus weekly intravenous vinorelbine. Secondary objectives included pharmacokinetic assessments and preliminary efficacy. Dose finding utilized a 3 + 3 design, with a starting dose of afatinib 20 mg QD plus vinorelbine 25 mg/m(2) weekly. RESULTS: Seventeen patients were enrolled. Dose level 2 (afatinib 40 mg and vinorelbine 25 mg/m(2)) exceeded the MTD; dose-limiting toxicities (DLTs) were considered vinorelbine-related. Dose finding continued with modified dose levels; dose level 2a: afatinib 40 mg and a reduced dose of vinorelbine 20 mg/m(2) and dose level 3: afatinib 40 mg and vinorelbine 25 mg/m(2) allowing omission of vinorelbine for grade ≥2 neutropenia/thrombocytopenia and afatinib dose modification for adverse events (AEs). At dose level 3, 1/6 patients had a DLT (upper abdominal pain requiring afatinib dose reduction). Overall, the most frequent treatment-related AEs (any/grade 3 and 4) were: neutropenia (100/71 %), leukopenia (100/59 %), diarrhea (94/0 %), anemia (71/12 %) and stomatitis (65/0 %). Two patients with breast cancer achieved a partial response; eight patients (various cancer indications) had stable disease. Pharmacokinetic analyses suggested no relevant drug-drug interactions. CONCLUSIONS: Afatinib 40 mg QD plus vinorelbine 25 mg/m(2) weekly was tolerated in Japanese patients when dose modifications for known AEs for either compound were allowed. Tumor shrinkage was also observed. This dose schedule was recommended for phase II/III trials in Japanese patients.

Phase I study of nintedanib in combination with pemetrexed as second-line treatment of Japanese patients with advanced non-small cell lung cancer.

PURPOSE: This open-label, phase I, dose-escalation part of a phase I/II study evaluated the safety, pharmacokinetics, and preliminary efficacy of nintedanib, a triple angiokinase inhibitor, combined with pemetrexed in Japanese patients with advanced non-small cell lung cancer (NSCLC) after first-line chemotherapy. METHODS: A fixed dose of pemetrexed (500 mg/m(2) iv) was administered on Day 1 of each 21-day cycle followed by oral nintedanib twice daily (bid) on days 2-21, starting at 100 mg bid and escalating to 200 mg bid in 50-mg intervals, using a standard 3 + 3 design. After ≥4 cycles of combination therapy, patients could continue nintedanib monotherapy until disease progression or undue adverse events (AEs). Primary endpoints were maximum tolerated dose (MTD), defined as the highest dose at which the incidence of dose-limiting toxicities (DLTs) was <33.3 % during the first treatment course, and AEs (CTCAE v3.0). DLTs were primarily defined as grade ≥3 non-hematologic or grade 4 hematologic AEs. RESULTS: Eighteen patients were included in the analysis. DLTs were experienced by 2/9 patients receiving 200 mg bid, 1/6 receiving 150 mg bid, and 0/3 receiving the lowest dose. The MTD of nintedanib plus pemetrexed was 200 mg bid. The most common drug-related AEs were elevated liver enzymes and gastrointestinal AEs. Two patients achieved partial response, and 10 had stable disease. CONCLUSIONS: Nintedanib plus pemetrexed had a manageable safety profile and showed promising signs of efficacy in previously treated Japanese patients with advanced NSCLC. As in Caucasian patients, the MTD of nintedanib was 200 mg bid. Clinical trial information NCT00979576.

Tolerability of nintedanib (BIBF 1120) in combination with docetaxel: a phase 1 study in Japanese patients with previously treated non-small-cell lung cancer.

BACKGROUND: This phase I, open-label study evaluated the safety/tolerability and maximum tolerated dose of second-line nintedanib combined with docetaxel in Japanese patients with advanced non-small-cell lung cancer. METHODS: Eligible patients received docetaxel 60 or 75 mg/m(2) (day 1) plus nintedanib 100, 150, or 200 mg twice daily (bid; days 2-21) in 21-day cycles. Standard 3 + 3 dose escalations were performed separately in patient cohorts with a body surface area (BSA) of less than 1.5 m(2) (BSA <1.5) and BSA greater than or equal to 1.5, respectively. RESULTS: Forty-two patients (17 BSA <1.5, 25 BSA ≥ 1.5) were treated. The maximum tolerated dose of nintedanib was 150 and 200 mg bid in patients with BSA less than 1.5 and BSA greater than or equal to 1.5 (BSA ≥ 1.5), respectively, in combination with 75 mg/m(2) of docetaxel. Dose-limiting toxicities (all grade 3 hepatic enzyme elevations) occurred in 12 patients (six per cohort). Drug-related adverse events included neutropenia (95%), leukopenia (83%), fatigue (76%), alopecia (71%), decreased appetite (67%), and elevations in alanine aminotransferase (64%) and aspartate aminotransferase (64%). All hepatic enzyme elevations were reversible and manageable with dose reduction or discontinuation. Among 38 evaluable patients, 10 (26%) had a partial response and 18 (47%) had stable disease. CONCLUSION: Continuous treatment with second-line nintedanib combined with docetaxel was manageable and showed promising signs of efficacy in Japanese patients with advanced non-small-cell lung cancer.

Relationship between pharmacokinetic parameters and occurrence of adverse events in clinical trials performed in Europe and United States for an angiotensin II receptor antagonist, telmisartan.

The objective of this study was to clarify the relationship between the pharmacokinetic parameters of telmisartan and the occurrence of adverse events. In order to perform this study, a total of 1500 adverse events was collected from the eight clinical trials performed in Europe and the United States and the pharmacokinetic parameters (C(max) and AUC) were calculated with the parameters obtained from the population pharmacokinetic model which we have built. Using these data, the pharmacokinetic parameters (C(max) and AUC) were compared between subjects with or without the occurrence of adverse events. The Mann-Whitney test was performed to analyze ten adverse events selected based on the order of frequency. For eight of these ten adverse events, no significant between-group difference was observed in any pharmacokinetic parameter. For two adverse events, pain and sinusitis, the pharmacokinetic parameters, C(max) and AUC, were greater in subjects with adverse events as compared with those without adverse events, but the intersubject variability of pharmacokinetic parameters was large and there were many subjects in whom C(max) and AUC were high without any adverse event. These results suggest that there is no clear relationship between pharmacokinetic parameters of telmisartan and the occurrence of adverse events.

Population pharmacokinetics of an angiotensin II receptor antagonist, telmisartan, in healthy volunteers and hypertensive patients.

OBJECTIVE: To describe the factors affecting pharmacokinetics of telmisartan, an angiotensin II receptor antagonist, a population pharmacokinetic (PPK) model has been developed based upon the data collected from healthy volunteers and hypertensive patients. METHODS: A total of 1566 plasma samples were collected from 20 healthy volunteers and 129 hypertensive patients, together with the demographic background. The data were analyzed by the NONMEM program using two-compartment model with first-order absorption. The robustness of the obtained PPK model was validated by the bootstrapping resampling method. RESULTS: The oral clearance (CL/F) was found to be associated with age, dose and alcohol consumption, but neither related to serum creatinine nor smoking history. The volume of distribution for the central compartment was related to age and dose, and the volume of distribution for the peripheral compartment was related to body weight and gender. The absorption rate constant (Ka) and the absorption lag time were described as function of dose. The CL/F decreased with advanced age. The CL/F decreased and Ka increased with higher dose, reflecting the super-proportional increase in the plasma levels of telmisartan. The AUC and C(max) values predicted by the present PPK model were well consistent with the observed values. The means of parameter estimates obtained with 200 bootstrap replicates were within 95-111% of the final parameter estimates from the original data set. CONCLUSION: A PPK model for telmisartan developed here well described the individual variability and exposure, and robustness of the model has been validated by the bootstrapping method.

Pharmacokinetic comparison of an angiotensin II receptor antagonist, telmisartan, in Japanese and western hypertensive patients using population pharmacokinetic method.

The objectives of this study were to develop a population pharmacokinetic (PPK) model for telmisartan based on the pooled data obtained from the different racial populations and then to identify the factors that affect the pharmacokinetics of telmisartan for the comparison between the regions. A PPK model was established based on the data of 1343 subjects in 12 clinical trials. The PK profiles of telmisartan were described with a 2-compartment model with first-order absorption. The obtained model could predict the observed plasma concentrations well. This PPK model suggested that CL/F was a function of age, dose, gender, race, alcohol consumption and liver function. A marked difference was observed in the plasma concentration profiles between Japanese and other countries' subjects. However, the effect of the factor "race" on CL/F was not large. In the present PPK model, "trial condition" affected all PK parameters except for V(2)/F. The condition differences were in food condition and formulation (Japanese: fed, capsule, US and EU: fasted, tablet). The extent of difference in the plasma concentration profiles simulated for Japanese and Caucasian using the PPK model under the same demographic condition was comparable with the results of the food effect study performed previously in Japan. The findings suggest that the difference in the plasma concentration profiles between Japanese and other countries' subjects was mainly due to the difference of food intake conditions under which the clinical trials were performed.

Effect of renal impairment on the pharmacokinetics, pharmacodynamics, and safety of empagliflozin, a sodium glucose cotransporter 2 inhibitor, in Japanese patients with type 2 diabetes mellitus.

PURPOSE: The purpose of this study was to assess the effect of renal impairment on the pharmacokinetic, pharmacodynamic, and safety profiles of empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, in Japanese patients with type 2 diabetes mellitus (T2DM). METHODS: In an open-label, parallel-group study, 32 Japanese patients with T2DM and different degrees of renal function (n = 8 per renal function category: normal renal function, estimated glomerular filtration rate [eGFR; Japanese equation] ≥90 mL/min/1.73 m(2); mild renal impairment, eGFR of 60-<90 mL/min/1.73 m(2); moderate renal impairment, eGFR of 30-<60 mL/min/1.73 m(2); and severe renal impairment, eGFR of 15-<30 mL/min/1.73 m(2)) received a single 25 mg dose of empagliflozin. FINDINGS: Empagliflozin exposure increased with increasing renal impairment. Maximum empagliflozin plasma concentrations were similar among all renal function groups. Adjusted geometric mean ratios for extent of exposure (AUC0-∞) to empagliflozin versus normal renal function were 128.8% (95% CI, 106.0-156.6%), 143.8% (95% CI, 118.3-174.8%), and 152.3% (95% CI, 125.3-185.2%) for patients with mild, moderate, and severe renal impairment, respectively. Decreases in renal clearance of empagliflozin correlated with eGFR. Urinary glucose excretion decreased with increasing renal impairment and correlated with eGFR (adjusted mean [SE] change from baseline: 75.0 [4.84] g, 62.6 [5.75] g, 57.9 [4.86] g, and 23.7 [5.24] g for patients with normal renal function and mild, moderate, and severe renal impairment, respectively). Only 2 patients (6%) had adverse events; both were mild. IMPLICATIONS: Pharmacokinetic data suggest that no dose adjustment of empagliflozin is necessary in Japanese patients with T2DM and renal impairment because increases in exposure were <2-fold. Urinary glucose excretion decreased with increasing renal impairment. ClinicalTrials.gov identifier: NCT01581658.

Pharmacokinetics, pharmacodynamics, safety and tolerability of 4 weeks' treatment with empagliflozin in Japanese patients with type 2 diabetes mellitus.

INTRODUCTION: To evaluate the pharmacodynamics, pharmacokinetics, safety and tolerability of empagliflozin in Japanese patients with type 2 diabetes mellitus. MATERIALS AND METHODS: In this 4-week, multiple dose, randomized, parallel-group, double-blind, placebo-controlled trial, patients (n = 100) were randomized to receive 1, 5, 10 or 25 mg of empagliflozin, or placebo once daily. Key end-points were urinary glucose excretion (UGE), fasting plasma glucose (FPG) and eight-point glucose profile. RESULTS: Data are presented for 1, 5, 10, 25 mg of empagliflozin and placebo groups, respectively. Adjusted mean changes from baseline to day 27 in UGE were 40.8, 77.1, 80.9, 93.0 and -2.1 g (P < 0.0001 for all empagliflozin groups vs placebo). Adjusted mean changes from baseline to day 28 in FPG were -1.56, -1.96, -2.31, -2.37 and -0.86 mmol/L (P < 0.01 for all empagliflozin groups vs placebo). Adjusted mean changes from baseline to day 27 in eight-point glucose profile were -1.96, -2.21, -2.42, -2.54 and -0.97 mmol/L (P < 0.01 for all empagliflozin groups vs placebo). Empagliflozin reached peak plasma concentration 1.5-2 h after dosing. Mean steady state terminal elimination half-lives ranged from 13.2 to 18.0 h. Of 100 patients, 25 experienced an adverse event, occurring more frequently for empagliflozin (29.1%) than placebo (9.5%); frequency was not dose related. CONCLUSIONS: In Japanese patients with type 2 diabetes mellitus, empagliflozin at doses up to 25 mg once daily for 4 weeks was well tolerated and resulted in significant improvements in glycemic control compared with placebo. This trial was registered with ClinicalTrials.gov (no. NCT00885118).

Safety, tolerability, pharmacokinetics and pharmacodynamics of single doses of empagliflozin, a sodium glucose cotransporter 2 (SGLT2) inhibitor, in healthy Japanese subjects.

This randomized, placebo-controlled within dose groups, double-blind, single rising dose study investigated the safety, tolerability, pharmacokinetics and pharmacodynamics of 1 mg to 100 mg doses of empagliflozin in 48 healthy Japanese male subjects. Empagliflozin was rapidly absorbed, reaching peak levels in 1.25 to 2.50 h; thereafter, plasma concentrations declined in a biphasic fashion, with mean terminal elimination half-life ranging from 7.76 to 11.7 h. Increase in empagliflozin exposure was proportional to dose. Oral clearance was dose independent and ranged from 140 to 172 mL/min. In the 24 h following 100 mg empagliflozin administration, the mean (%CV) amount of glucose excreted in urine was 74.3 (17.1) g. The amount and the maximum rate of glucose excreted via urine increased with dose of empagliflozin. Nine adverse events, all of mild intensity, were reported by 8 subjects (7 with empagliflozin and 1 with the placebo). No hypoglycemia was reported. In conclusion, 1 mg to 100 mg doses of empagliflozin had a good safety and tolerability profile in healthy Japanese male subjects. Exposure to empagliflozin was dose proportional. The amount and rate of urinary glucose excretion were higher with empagliflozin than with the placebo, and increased with empagliflozin dose.

Efficacy and safety of extended- versus immediate-release pramipexole in Japanese patients with advanced and L-dopa-undertreated Parkinson disease: a double-blind, randomized trial.

OBJECTIVES: To compare the efficacy, safety, tolerability, and trough plasma levels of pramipexole extended-release (ER) and pramipexole immediate-release (IR), and to assess the effects of overnight switching from an IR to an ER formulation, in L-dopa-treated patients with Parkinson disease (PD). METHODS: After a 1- to 4-week screening/enrollment, 112 patients who had exhibited L-dopa-related problems or were receiving suboptimal L-dopa dosage were randomized in double-blind, double-dummy, 1:1 fashion to pramipexole ER once daily or pramipexole IR 2 to 3 times daily for 12 weeks, both titrated to a maximum daily dose of 4.5 mg. Successful completers of double-blind treatment were switched to open-label pramipexole ER, beginning with a 4-week dose-adjustment phase. RESULTS: Among the double-blind treatment patients (n = 56 in each group), Unified Parkinson's Disease Rating Scale Parts II+III total scores decreased significantly from baseline and to a similar degree with pramipexole ER and IR formulations. In each group, 47 double-blind patients (83.9%) reported adverse events (AEs), requiring withdrawal of 3 ER patients (5.4%) and 2 IR patients (3.6%). Trough plasma levels at steady state (at the same doses and dose-normalized concentrations) were also similar with both formulations. Among open-label treatment patients (n = 53 from IR to ER), 83% were successfully switched (no worsening of PD symptoms) to pramipexole ER. CONCLUSIONS: In L-dopa-treated patients, pramipexole ER and pramipexole IR demonstrated similar efficacy, safety, tolerability, and trough plasma levels. Patients can be safely switched overnight from pramipexole IR to pramipexole ER with no impact on efficacy.