Pharmacokinetics, safety, and tolerability of sodium phenylacetate and sodium benzoate in healthy Japanese volunteers: A phase I, single-center, open-label study.

TAK-123, a combination of sodium phenylacetate (NaPA) and sodium benzoate (NaBZ), is an intravenously administered drug developed for the treatment of acute hyperammonemia in infants, children, and adults with urea cycle enzyme deficiencies. The aim of the current study was to evaluate the pharmacokinetics, safety, and tolerability after intravenous infusion of TAK-123 in Japanese healthy adult volunteers. Ten volunteers received a 3.75 g/m2 loading dose of TAK-123 over a period of 1.5 h followed by a maintenance infusion of the same dose over 24 h. Phenylacetate (PA) and benzoate (BZ) and their respective metabolites, phenylacetylglutamine (PAG) and hippurate (HIP) were measured over a 24-h period using a high-performance liquid chromatography/tandem mass spectrometry method. Non-compartmental analysis was performed using WinNonlin® Professional. During the loading dose, plasma levels of both PA and BZ peaked at 1.5 h. Plasma PA levels plateaued and were maintained up to 6.5 h, whereas plasma BZ levels declined rapidly after switching to maintenance infusion. Urinary excretion ratios of PAG and HIP at 48 h after the administration were 99.3% and 104%, respectively, suggesting that almost all NaPA and NaBZ were metabolized and excreted into urine. Overall, TAK-123 was well-tolerated in healthy Japanese adults.

Pharmacokinetics and Safety After a Single Dose of Imarikiren in Subjects with Renal or Hepatic Impairment.

BACKGROUND AND OBJECTIVE: Imarikiren hydrochloride (TAK-272; SCO-272) is a novel direct renin inhibitor. The objective of this study was to determine the effects of renal impairment (RI) or hepatic impairment (HI) on the pharmacokinetics and safety of imarikiren. METHODS: This phase I, open-label, parallel-group comparative study evaluated the pharmacokinetics and safety of a single 40 mg oral dose of imarikiren in RI [mild, moderate, severe, or end-stage renal disease (ESRD), and on hemodialysis] or HI (mild or moderate) subjects compared with subjects with normal renal or hepatic function. RESULTS: Following administration of a single 40 mg oral imarikiren dose, the geometric mean imarikiren area under the plasma concentration-time curve from time zero to infinity (AUC∞) and maximum observed plasma concentration (Cmax) in subjects with mild, moderate, and severe RI (including non-hemodialysis and ESRD), and hemodialysis subjects compared with normal renal function subjects were approximately 0.5-, 1.2-, 2.7-, and 1.8-fold, respectively, for AUC∞; and approximately 0.6-, 0.8-, 2.1-, and 1.4-fold, respectively, for Cmax. The mean fraction of excretion of imarikiren in dialysate was ~ 3% during the 4 h dialysis period. The geometric mean imarikiren AUC∞ and Cmax in mild and moderate HI subjects compared with normal hepatic function subjects were approximately 1.0- and 1.4-fold, respectively, for AUC∞, and approximately 0.9- and 1.3-fold, respectively, for Cmax. No deaths or serious adverse events were observed; all adverse events were mild or moderate in intensity. CONCLUSIONS: RI and HI are associated with limited changes in imarikiren pharmacokinetics. Imarikiren was safe and well-tolerated, regardless of the severity of RI or HI. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02367872.

Pharmacokinetics of a Single Dose of Azilsartan in Pediatric Patients: A Phase 3, Open-Label, Multicenter Study.

INTRODUCTION: Azilsartan is an angiotensin II receptor blocker indicated for the treatment of patients with hypertension. The efficacy and safety of azilsartan are established in adults, but have not been evaluated in pediatric patients, nor has its pharmacokinetic profile been determined in pediatric patients. METHODS: In this phase 3, open-label, multicenter study, we investigated the pharmacokinetics and safety of single doses of azilsartan in six Japanese patients with hypertension, aged 9-14 years. The dose of azilsartan was 5 mg for three patients weighing less than 50 kg, with mean body weight at baseline of 27.5 kg, and 10 mg for three patients weighing at least 50 kg, with mean body weight at baseline of 65.9 kg. RESULTS: Mean maximum plasma concentration (Cmax) of azilsartan was 888.3 and 831.3 ng/mL and median time to maximum concentration (Tmax) of unchanged azilsartan was 3.0 and 4.0 h, in the 5-mg and 10-mg groups, respectively. Mean areas under the plasma concentration-time curve (AUC) from 0-24 h post-dose (AUC0-24) and 0 h to infinity (AUC0-inf) were 6350.3 and 6635.7 ng h/mL, respectively, in the 5-mg group, and 6871.7 and 7433.3 ng h/mL, respectively, in the 10-mg group. Both doses were well tolerated; no treatment-emergent adverse events considered to be related to azilsartan occurred during the study. CONCLUSION: Our data suggest that pediatric patients weighing less than 50 kg may have approximately 2-fold greater exposure to azilsartan than those weighing at least 50 kg at the same dose. Exposure to azilsartan in children weighing at least 50 kg is comparable to that in healthy adults at the same dose. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02451150. FUNDING: Takeda Pharmaceutical Co. Ltd.

Pharmacokinetics, Pharmacodynamics and Safety of a Single Dose of Imarikiren, a Novel Renin Inhibitor, in Healthy Male Subjects.

Imarikiren hydrochloride (TAK-272/SCO-272) is a novel direct renin inhibitor with potential indications for cardiovascular and renal diseases. This phase I study evaluated the pharmacokinetics, pharmacodynamics and safety of a single oral administration of imarikiren in healthy Japanese male subjects. The Dose-Ascending part (double-blind, placebo-controlled, parallel-group design; n = 60) comprised six steps from 5 to 200 mg (n = 8 for imarikiren and n = 2 for placebo per step). The Food Effect part (n = 12) was an open-label, 2 × 2 crossover design with a dose of 50 mg to evaluate the effect of food on the pharmacokinetics and safety of imarikiren. There was a generally linear relationship between dose and area under the plasma concentration-time curve (0 to infinity) or maximum plasma concentration of imarikiren. Food had no clinically significant effect on the exposure of imarikiren. Inhibition of plasma renin activity was rapid and lasted up to 24 hr at all doses. Plasma active renin concentration increased, reaching a maximum at approximately 6 hr, in a nearly dose-dependent manner. Across both study parts, the number of subjects with treatment-emergent adverse events ranged from 0 to 3 per group with no dependency on dose. All treatment-emergent adverse events except two were mild in intensity; there were no serious adverse events or deaths. Single oral administration of imarikiren from 5 to 200 mg was safe and well tolerated. These findings suggest that further clinical development of a once-daily imarikiren regimen is warranted.

A Randomized, Single-Center, Double-Blind, Placebo-Controlled Multiple-Dose Phase 1 Study to Evaluate the Safety, Pharmacokinetics, and Pharmacodynamics of Imarikiren in Healthy Adult Nonelderly and Elderly Male Subjects.

Imarikiren hydrochloride (TAK-272/ SCO-272) is a novel direct renin inhibitor. This randomized, double-blind, phase I study evaluated the safety and pharmacokinetics/pharmacodynamics of multiple oral administrations of imarikiren in healthy nonelderly (aged 20-45 years) and elderly (aged 65-85 years) Japanese male subjects. Subjects were randomized within 1 of 3 cohorts to receive imarikiren or placebo: Cohort 1 (imarikiren 80 mg; nonelderly), Cohort 2 (imarikiren 160 mg; nonelderly), or Cohort 3 (imarikiren 80 mg; elderly). Imarikiren or placebo was administered orally, once daily, for 7 days. Accumulation of imarikiren did not occur during the 7-day treatment period. Area under the plasma-concentration time curve and maximum plasma concentration of imarikiren were higher in elderly than in nonelderly subjects (52% and 39% higher, respectively). Inhibition of plasma renin activity was observed for 7 days and was maintained for at least 71 hours after the last imarikiren administration at the 80-mg (nonelderly and elderly) and 160-mg (nonelderly) doses. Plasma active renin concentration increased in nonelderly and elderly subjects; peak concentrations were higher on day 7 than on day 1. Increase from baseline in plasma active renin concentration was smaller in elderly than in nonelderly subjects during the 7-day treatment period and until 71 hours after last imarikiren administration. Treatment-emergent adverse events were reported in 33.3% (elderly) and 22.2% (nonelderly) of imarikiren subjects. Multiple oral administrations of imarikiren for 7 days were safe and well tolerated with no drug accumulation and strong and sustained suppression of plasma renin activity.

Combination effects of alogliptin and pioglitazone on steatosis and hepatic fibrosis formation in a mouse model of non-alcoholic steatohepatitis.

This study aimed to evaluate the effects of combination therapy with a dipeptidyl peptidase-4 inhibitor, alogliptin, and a peroxisome proliferator-activated receptor-γ agonist, pioglitazone, in a preclinical model of nonalcoholic steatohepatitis using low-density lipoprotein receptor-knockout mice fed a modified choline-deficient l-amino acid-defined diet. Monotherapy with either alogliptin (10-200 mg/kg) or pioglitazone (6-20 mg/kg) significantly decreased hepatic triglyceride content and fibrosis. The concomitant treatment of alogliptin (30 mg/kg), pioglitazone (20 mg/kg) also decreased hepatic triglyceride and hepatic collagen-I mRNA at greater extent compared to monotherapy. Hepatic expression of CD11b mRNA and monocyte chemoattractant protein-1 were also reduced by the concomitant treatment. These results suggest that via an anti-inflammatory potential in addition to anti-metabolic effects, the combination therapy of alogliptin and pioglitazone may provide therapeutic benefits to type 2 diabetes patients with nonalcoholic steatohepatitis, which will be proven in controlled clinical trials.

Trelagliptin (SYR-472, Zafatek), Novel Once-Weekly Treatment for Type 2 Diabetes, Inhibits Dipeptidyl Peptidase-4 (DPP-4) via a Non-Covalent Mechanism.

Trelagliptin (SYR-472), a novel dipeptidyl peptidase-4 inhibitor, shows sustained efficacy by once-weekly dosing in type 2 diabetes patients. In this study, we characterized in vitro properties of trelagliptin, which exhibited approximately 4- and 12-fold more potent inhibition against human dipeptidyl peptidase-4 than alogliptin and sitagliptin, respectively, and >10,000-fold selectivity over related proteases including dipeptidyl peptidase-8 and dipeptidyl peptidase-9. Kinetic analysis revealed reversible, competitive and slow-binding inhibition of dipeptidyl peptidase-4 by trelagliptin (t1/2 for dissociation ≈ 30 minutes). X-ray diffraction data indicated a non-covalent interaction between dipeptidyl peptidase and trelagliptin. Taken together, potent dipeptidyl peptidase inhibition may partially contribute to sustained efficacy of trelagliptin.

Evaluation of the long-term durability and glycemic control of fasting plasma glucose and glycosylated hemoglobin for pioglitazone in Japanese patients with type 2 diabetes.

BACKGROUND: This study applied a pharmacodynamic model-based approach to evaluate the long-term durability and glycemic control of pioglitazone in comparison with other oral glucose-lowering drugs in Japanese type 2 diabetes mellitus (T2DM) patients. SUBJECTS AND METHODS: Japanese T2DM patients were enrolled in a prospective, randomized, open-label, blinded-end point study and received pioglitazone with or without other oral glucose-lowering drugs (excluding another thiazolidinedione [TZD]) (n=293) or oral glucose-lowering drugs excluding TZD (n=294). Treatment was adjusted to achieve glycosylated hemoglobin (HbA1c) <6.9%, and samples for fasting plasma glucose (FPG) and HbA1c were collected over 2.5-4 years. A simultaneous cascading indirect response model structure was applied to describe the time course of FPG and HbA1c. HbA1c levels were described using both an FPG-dependent and an FPG-independent function. To account for titration, drug effects for both treatment groups were implemented using a time-dependent Emax model. RESULTS: Pioglitazone was superior in both time to maximum effect and the magnitude of reduction achieved in FPG and HbA1c. A greater reduction in median FPG (-21 mg/dL vs. -9 mg/dL) was observed with pioglitazone (P<0.05). Maximum drug effect for FPG was predicted to occur earlier (11 months) for pioglitazone than for the control group (14 months). The simulated additional reduction in FPG and HbA1c achieved with pioglitazone was predicted to be maintained beyond the currently observed study duration. CONCLUSIONS: Pioglitazone was found to result in improved glycemic control and durability compared with control treatment. This model-based approach enabled the quantification of differences in FPG and HbA1c for both treatment groups and simulation to evaluate longer-term durability on FPG and HbA1c.