Lack of a Pharmacokinetic Interaction Between Saxagliptin and Dapagliflozin in Healthy Subjects: A Randomized Crossover Study.

PURPOSE: This single-dose, open-label, randomized, 3-period, 3-treatment crossover drug-drug interaction study was conducted to evaluate differences in the pharmacokinetic properties of saxagliptin and dapagliflozin when coadministered. METHODS: Healthy subjects (N = 42) were randomized to receive saxagliptin 5 mg alone, dapagliflozin 10 mg alone, or saxagliptin 5 mg plus dapagliflozin 10 mg coadministered; there was a washout period of ≥6 days between treatments. Serial blood samples for determining saxagliptin, 5-hydroxy saxagliptin (5-OH saxagliptin; major active metabolite) and dapagliflozin plasma concentrations and pharmacokinetic parameters were collected before and up to 60 hours after the dose. No interaction was to be concluded if the 90% CIs for the geometric mean ratios of the combination compared with each drug given alone for Cmax and AUCinf were within 0.80 to 1.25. FINDINGS: The results indicated that dapagliflozin had no effect on the pharmacokinetic properties of saxagliptin, 5-OH saxagliptin, or saxagliptin total active moiety and vice versa. The 90% CIs for Cmax and AUCinf for all comparisons were contained entirely within the 0.80 to 1.25 equivalence intervals. Other pharmacokinetic parameters (apparent oral clearance or half-life) of saxagliptin or dapagliflozin were similar when each medicine was administered alone or when coadministered. No safety profile or tolerability findings of concern were observed during the study. All adverse events were mild, and no serious adverse events were reported. IMPLICATIONS: These data indicate that coadministration of saxagliptin and dapagliflozin exhibits no pharmacokinetic interaction and is well tolerated. ClinicalTrials.gov identifier: NCT01662999.

An open-label investigation into drug-drug interactions between multiple doses of daclatasvir and single-dose cyclosporine or tacrolimus in healthy subjects.

BACKGROUND AND OBJECTIVE: Chronic hepatitis C virus (HCV) infection is a major cause of liver transplantation. Drug-drug interactions (DDIs) with cyclosporine and tacrolimus hindered the use of first-generation protease inhibitors in transplant recipients. The current study investigated DDIs between daclatasvir-a pan-genotypic HCV NS5A inhibitor with clinical efficacy in multiple regimens (including all-oral)-and cyclosporine or tacrolimus in healthy subjects. METHODS: Healthy fasted subjects (aged 18-49 years; body mass index 18-32 kg/m(2)) received single oral doses of cyclosporine 400 mg on days 1 and 9, and daclatasvir 60 mg once daily on days 4-11 (group 1, n = 14), or a single oral dose of tacrolimus 5 mg on days 1 and 13, and daclatasvir 60 mg once daily on days 8-19 (group 2, n = 14). Blood samples for pharmacokinetic analysis [by liquid chromatography with tandem mass spectrometry (LC-MS/MS)] were collected on days 1 and 9 for cyclosporine (72 h), on days 1 and 13 for tacrolimus (168 h) and on days 8 and 9 (group 1) or on days 12 and 13 (group 2) for daclatasvir (24 h). Plasma concentrations were determined by validated LC-MS/MS methods. RESULTS: Daclatasvir did not affect the pharmacokinetic parameters of cyclosporine or tacrolimus, and tacrolimus did not affect the pharmacokinetic parameters of daclatasvir. Co-administration of cyclosporine resulted in a 40 % increase in the area under the concentration-time curve of daclatasvir but did not affect its maximum observed concentration. CONCLUSION: On the basis of these observations in healthy subjects, no clinically relevant DDIs between daclatasvir and cyclosporine or tacrolimus are anticipated in liver transplant recipients infected with HCV; dose adjustments during co-administration are unlikely to be required.

First clinical experience with TRV130: pharmacokinetics and pharmacodynamics in healthy volunteers.

TRV130 is a G protein-biased ligand at the µ-opioid receptor. In preclinical studies it was potently analgesic while causing less respiratory depression and gastrointestinal dysfunction than morphine, suggesting unique benefits in acute pain management. A first-in-human study was conducted with ascending doses of TRV130 to explore its tolerability, pharmacokinetics, and pharmacodynamics in healthy volunteers. TRV130 was well-tolerated over the dose range 0.15 to 7 mg administered intravenously over 1 hour. TRV130 geometric mean exposure and Cmax were dose-linear, with AUC0-inf of 2.52 to 205.97 ng h/mL and Cmax of 1.04 to 102.36 ng/mL across the dose range tested, with half-life of 1.6-2.7 hours. A 1.5 mg dose of TRV130 was also well-tolerated when administered as 30, 15, 5, and 1 minute infusions. TRV130 pharmacokinetics were modestly affected by CYP2D6 phenotype: clearance was reduced by 53% in CYP2D6 poor metabolizers.TRV130 caused dose- and exposure-related pupil constriction, confirming central compartment µ-opioid receptor engagement. Marked pupil constriction was noted at 2.2, 4, and 7 mg doses. Nausea and vomiting observed at the 7 mg dose limited further dose escalation. These findings suggest that TRV130 may have a broad margin between doses causing µ-opioid receptor-mediated pharmacology and doses causing µ-opioid receptor-mediated intolerance.

Role of cytochrome p450 isoenzymes 3A and 2D6 in the in vivo metabolism of mirabegron, a ß3-adrenoceptor agonist.

BACKGROUND: Mirabegron is a ß3-adrenoceptor agonist for the treatment of overactive bladder. There has been little information published or presented about the involvement of cytochrome P450 (CYP) isoenzymes 3A and 2D6 in the metabolism of mirabegron in humans; in vitro data indicate that oxidative metabolism is primarily mediated by CYP3A with a minor role for CYP2D6. OBJECTIVE: To determine to what extent CYP3A and CYP2D6 isoenzymes are involved in mirabegron metabolism. METHODS: Two open-label, randomized, one-sequence crossover drug-drug interaction studies in healthy subjects were conducted to assess the effect of ketoconazole and rifampicin on the pharmacokinetics of mirabegron and two parallel-group studies in healthy subjects with either known confirmed or predicted CYP2D6 phenotype. RESULTS: Co-administration of multiple dosages of 400 mg/day ketoconazole with a single 100 mg mirabegron oral controlled absorption system (OCAS) dose increased mirabegron maximum concentration (C(max)) and area under the curve extrapolated to infinity (AUC∞) to 145 % (90 % confidence interval [CI] 123-172 %] and 181 % (90 % CI 163-201 %), respectively. Co-administration of multiple dosages of 600 mg/day rifampicin with a single 100 mg mirabegron OCAS dose decreased mirabegron C max and AUC∞ to 65 % (90 % CI 50-86 %) and 56 % (90 % CI 49-65 %), respectively, without an effect on terminal elimination half-life (t(½)). The urinary excretion of mirabegron was increased by ketoconazole and decreased by rifampicin, reflecting the AUC changes, whereas renal clearance was not affected. Ketoconazole decreased mirabegron t ½ from 50.9 to 37.6 h suggesting that volume of distribution as well as first-pass effect decreased. Rifampicin did not affect mirabegron t ½, suggesting that it affects first pass through the intestinal wall or liver. Rifampicin greatly increased the ratio to parent drug of the presumed CYP-mediated mirabegron metabolites M8 and M15 by 777 and 646 %. Steady-state mirabegron pharmacokinetic parameters (50 and 100 mg mirabegron OCAS) were similar in 13 CYP2D6 poor, 40 intermediate, and 99 extensive metabolizers, whereas C max and AUC under the dosing interval τ of 24 h (AUCτ) were 30-47 % lower in 10 ultrarapid metabolizers. After administration of 160 mg mirabegron immediate release, C(max) was 14 % and AUC∞ 19 % higher in eight poor metabolizers than in eight extensive metabolizers (phenotyped) with similar t ½. All treatments were well tolerated. CONCLUSIONS: Mirabegron is metabolized by CYP3A and to a minor extent by CYP2D6 in humans. Mirabegron is not considered a sensitive substrate of CYP3A in vivo, as ketoconazole increased mirabegron exposure by less than 2-fold. The effect of CYP2D6 phenotype on mirabegron exposure is small and likely of limited clinical importance.

Vildagliptin, a novel dipeptidyl peptidase IV inhibitor, has no pharmacokinetic interactions with the antihypertensive agents amlodipine, valsartan, and ramipril in healthy subjects.

We conducted 3 open-label, multiple-dose, 3-period, randomized, crossover studies in healthy subjects to assess the potential pharmacokinetic interaction between vildagliptin, a novel dipeptidyl peptidase IV inhibitor for the treatment of type 2 diabetes, and representatives of 3 commonly prescribed antihypertensive drug classes: (1) the calcium channel blocker, amlodipine; (2) the angiotensin receptor blocker, valsartan; and (3) the angiotensin-converting enzyme inhibitor, ramipril. Coadministration of vildagliptin 100 mg with amlodipine 5 mg, valsartan 320 mg, or ramipril 5 mg had no clinically significant effect on the pharmacokinetics of these drugs. The 90% confidence intervals of the geometric mean ratios for area under the plasma concentration-time curve from time zero to 24 hours (AUC0-24h) and maximum plasma concentration (Cmax) for vildagliptin, amlodipine, and ramipril (and its active metabolite, ramiprilat) were contained within the acceptance range for bioequivalence (0.80-1.25). Valsartan AUC0-24h and Cmax increased by 24% and 14%, respectively, following coadministration of vildagliptin, but this was not considered clinically significant. Vildagliptin was generally well tolerated when given alone or in combination with amlodipine, valsartan, or ramipril in healthy subjects at steady state. No adjustment in dosage based on pharmacokinetic considerations is required should vildagliptin be coadministered with amlodipine, valsartan, or ramipril in patients with type 2 diabetes and hypertension.

Clinical development of an everolimus pediatric formulation: relative bioavailability, food effect, and steady-state pharmacokinetics.

The immunosuppressant everolimus used in organ transplantation is formulated as a conventional tablet for adults and a dispersible tablet that can be administered in water for pediatric use. As part of the pediatric clinical development program, the relative bioavailability and food effect for the dispersible tablet were evaluated in healthy adult subjects as a prelude to characterizing the steady-state pharmacokinetics in pediatric kidney allograft recipients. In a randomized, open-label, three-way crossover study, 24 healthy adults received single 1.5-mg oral doses of everolimus as (1) six 0.25-mg dispersible tablets in water, (2) two 0.75-mg conventional tablets, and (3) six 0.25-mg dispersible tablets in water after a high-fat breakfast. Cmax and AUC were evaluated by standard bioequivalence testing to determine relative bioavailability and to quantify the effect of food. In a multicenter open-label efficacy/safety trial, pediatric renal allograft recipients received 0.8 mg/m2 (maximum 1.5 mg) bid everolimus as dispersible tablets in water. Serial trough concentrations over the first week and a steady-state pharmacokinetic profile on day 7 posttransplant were collected in 19 patients ranging from ages 2 to 16 years old. The bioavailability of everolimus from the dispersible tablet was 10% lower relative to the conventional tablet, with a ratio (90% confidence interval) of 0.90 (0.76-1.07). After a high-fat meal, tmax was delayed by a median 2.5 hours, and Cmax was reduced by 50%. Overall absorption, however, was not affected by food inasmuch as the fed/fasting AUC ratio was 0.99 (0.83-1.17). In pediatric patients, steady state was reached between days 3 and 5. The corresponding steady-state parameters were as follows: Cmin, 4.4 +/- 1.7 ng/ml; Cmax, 13.6 +/- 4.2 ng/ml; and AUC, 87 +/- 27 ng.h/ml. Steady-state concentration-time profiles in pediatric transplant patients receiving the dispersible tablet were comparable to those of adult patients receiving the conventional tablet when both were dosed to yield similar trough concentrations. If a pediatric patient is converted from the everolimus dispersible tablet to the conventional tablet, this should be based on a 1:1 milligram switch with subsequent therapeutic drug monitoring to further individualize the dose as needed. The dispersible tablet formulation should be taken consistently either with or without food to minimize fluctuations in exposure over time.