Pharmacokinetics of mometasone furoate delivered via two dry powder inhalers.

BACKGROUND: QMF149 is an inhaled fixed-dose combination of indacaterol acetate and mometasone furoate (MF) delivered via Breezhaler®, under development for once-daily treatment of asthma. MF delivered via Twisthaler® is approved as Asmanex® Twisthaler® for the treatment of asthma. Bridging of MF delivered via Twisthaler® to MF delivered via Breezhaler® was undertaken as part of QMF149 development to enable dose comparisons between the devices. Pharmacokinetics (PK) of MF were characterized in two studies; a single dose PK study in healthy volunteers and a pharmacokinetic/pharmacodynamic (PK/PD) study in asthma patients. OBJECTIVES: The PK study in healthy volunteers evaluated the PK of single doses of MF via Breezhaler® (50-400 µg) and compared systemic exposure of MF following administration via Breezhaler® and Twisthaler® 400 µg (2 inhalations of 200 µg). The study in patients with asthma characterized the MF PK profile following once-daily inhalation of MF via Breezhaler® and Twisthaler® devices for 4 weeks. METHODS: In the open-label, single-dose, crossover study, healthy subjects sequentially received MF via Twisthaler® (400 µg, medium-dose inhaled corticosteroid [ICS]) and escalating doses via Breezhaler® (50, 100, 200, 400 µg). PK data were obtained up to 72 h post-dose. In the double-blind, double-dummy, parallel-group study, asthma patients were randomised to receive either MF 80 µg (low-dose ICS) or 320 µg (high-dose ICS) via Breezhaler®, or 200 µg (low-dose ICS) or 800 µg (2 inhalations of 400 µg; high-dose ICS) via Twisthaler® once daily for 4 weeks. PK sampling was performed on Days 1 and 28 at pre-dose and up to 24 h post-dose. RESULTS: In the healthy volunteer PK study, 20 healthy subjects completed all treatments. Dose-normalised AUClast of MF was 1.8-1.9-fold higher when delivered via Breezhaler® versus Twisthaler®. AUC and Cmax of MF increased in a dose-proportional manner over the range of 50-400 µg via Breezhaler®. Results from this study guided dose selection of MF via Breezhaler® for the asthma study. In the asthma study, in a subset of 96 patients, mean systemic exposure (AUClast and Cmax) for MF 80 and 320 µg via Breezhaler® was comparable with MF 200 and 800 µg via Twisthaler®, respectively, on Day 28. CONCLUSION: PK characterization in a healthy volunteer PK study and subsequently an asthma study enabled selection of 80 µg (low), 160 µg (medium), and 320 µg (high) delivered via Breezhaler® as MF doses comparable to the 200 µg, 400 µg and 800 µg doses delivered by Twisthaler®, respectively, as part of QMF149 formulation development.

Dose bridging data for mometasone furoate in once-daily fixed-dose inhaled combinations of mometasone furoate/indacaterol and mometasone furoate/ indacaterol/glycopyrronium in patients with asthma.

Once-daily (o.d.) fixed-dose combinations of mometasone furoate/indacaterol acetate (MF/IND) and mometasone furoate/indacaterol acetate/glycopyrronium bromide (MF/IND/GLY), both delivered via the Breezhaler® device, are approved for the maintenance treatment of asthma. Across these fixed-dose combinations, while the doses of bronchodilators remain the same, the nominal doses of mometasone furoate in micrograms differ. This article presents the steps followed in bridging the mometasone furoate doses at the corresponding dose strengths in the mometasone furoate formulation delivered via the Twisthaler® and mometasone furoate/indacaterol acetate and mometasone furoate/indacaterol acetate/glycopyrronium bromide formulations delivered via the Breezhaler®. These were: (i) bridging the mometasone furoate doses in the Twisthaler® (previously approved) to mometasone furoate doses in the Breezhaler®; (ii) bridging the mometasone furoate doses in the Breezhaler® to mometasone furoate/indacaterol acetate and mometasone furoate/indacaterol acetate/glycopyrronium bromide formulation. Following this stepwise approach, it was determined that mometasone furoate 80 µg o.d. (medium-dose strength) and 160 µg o.d. (high-dose strength) in mometasone furoate/indacaterol acetate/glycopyrronium bromide formulation provided comparable inhaled corticosteroid efficacy to mometasone furoate 160 µg o.d. (medium-dose strength) and 320 µg o.d. (high-dose strength) in the mometasone furoate/indacaterol acetate formulation, respectively. These doses were used in the PLATINUM Phase III clinical program that investigated the efficacy and safety of mometasone furoate/indacaterol acetate and mometasone furoate/indacaterol acetate/glycopyrronium bromide combinations in patients with asthma.

Pharmacokinetics of indacaterol, glycopyrronium and mometasone furoate administered as an inhaled fixed-dose combination in Japanese and Caucasian healthy subjects.

BACKGROUND: A once-daily (o.d.) fixed-dose combination of indacaterol acetate (IND), glycopyrronium bromide (GLY), and mometasone furoate (MF) delivered via the Breezhaler® device (IND/GLY/MF) is being developed for treatment of asthma. This study compared steady-state pharmacokinetics of IND, GLY and MF between Japanese and Caucasian male subjects after multiple inhalations of IND/GLY/MF o.d. METHODS: This was a single-center, open-label, 2-treatment crossover study with a 21-day washout period. Japanese and Caucasian subjects received IND/GLY/MF 150/50/80 µg (inhaled corticosteroid [ICS] medium-dose) or 150/50/160 µg o.d. (ICS high-dose) for 14 days in each period. Pharmacokinetics were characterized up to 24 h post-dose on Days 1 and 14. RESULTS: In total, 16 Japanese (median age 31 years [range 20-40 years], mean weight 68.3 kg) and 17 Caucasian subjects (median age 27 years [range 21-43 years], mean weight 75.0 kg) were randomized. Geometric mean ratios (Japanese/Caucasian) [90% confidence interval (CI)] for Cmax for IND, GLY and MF at the high ICS dose on Day 14 were 1.31 [1.13, 1.51] 1.38 [1.13, 1.69] and 1.07 [0.969, 1.18], respectively. Geometric mean ratios (Japanese/Caucasian) [90% CI] for AUC0-24h on Day 14 for IND, GLY and MF at the high ICS dose were 1.17 [1.01, 1.35], 1.05 [0.920, 1.20] and 1.15 [1.05, 1.27] respectively. Similar trends were noted for all components for the medium ICS dose treatment. IND/GLY/MF was safe and well tolerated; no AEs suspected to be study drug-related were observed. CONCLUSION: Pharmacokinetics of IND, GLY and MF (high and medium dose) when delivered as a fixed-dose combination were comparable between Japanese and Caucasian subjects. The IND/GLY/MF combination at the administrated doses was safe and well tolerated in both ethnic groups. TRIAL REGISTRATION: Japan Registry of Clinical Trial: jRCT2031200227, retrospectively registered on 04, December, 2020.

Lung function, pharmacokinetics, and tolerability of inhaled indacaterol maleate and acetate in asthma patients.

BACKGROUND: Indacaterol maleate delivered with the Breezhaler® inhalation device is a long-acting ß2-agonist approved for chronic obstructive pulmonary disease. In the development of a once daily, inhaled fixed dose combination (FDC) of indacaterol, glycopyrronium bromide (a long-acting muscarinic antagonist), and mometasone furoate (an inhaled corticosteroid [ICS]) for the treatment of patients with asthma, the acetate salt of indacaterol is used instead of the maleate salt. Here, we investigated the lung function, pharmacokinetics (PK) and safety of indacaterol maleate 150 µg once daily (o.d.) and indacaterol acetate 150 µg o.d. in comparison with placebo. METHODS: This was a randomised, double-blind, three-period crossover study (ClinicalTrials.gov identifier, NCT03257995) in patients with asthma on background ICS therapy. Patients with percent predicted pre-bronchodilator forced expiratory volume per second (FEV1) ≥50% and ≤ 90% were included in the study. Patients received indacaterol maleate 150 µg o.d., indacaterol acetate 150 µg o.d., or placebo on top of stable background ICS in randomised sequence. Trough FEV1 was assessed after 14 days of treatment. PK of indacaterol salts were assessed at steady state after 14 days of treatment; peak expiratory flow (PEF) rate and rescue medication use were collected with a combined PEF-meter/electronic diary throughout the study. RESULTS: Of the 54 adult patients (median age of 48 years), 51 patients completed the study. Both indacaterol salts demonstrated statistically significant improvements in trough FEV1 of 186 mL (maleate) and 146 mL (acetate) compared with placebo (both P < 0.001). FEV1 AUC0-4h improved by 248 mL (maleate) and 245 mL (acetate), and PEF by 33 L/min (maleate) and 30.8 L/min (acetate) versus placebo. Systemic exposure of indacaterol (AUC0-24h,ss and Cmax,ss on Day 14) was comparable after administration of both salt forms. Both salt forms demonstrated a good safety profile and were well tolerated, with a difference in the reporting frequency of AEs of coughing (maleate, 23.5%; acetate, 0%). CONCLUSIONS: In patients with asthma, indacaterol maleate and acetate elicited comparable and significant improvements in lung function compared with placebo and achieved comparable systemic exposure. Both indacaterol salts were safe and well tolerated. TRIAL REGISTRATION: ClinicalTrials.gov NCT03257995 June 06, 2017.

Pharmacokinetics of indacaterol, glycopyrronium and mometasone furoate following once-daily inhalation as a combination in healthy subjects.

Indacaterol (IND), is co-formulated with glycopyrronium (GLY), and mometasone furoate (MF) as a once-daily (o.d.) inhaled fixed-dose combination (IND/GLY/MF) delivered via the Breezhaler® device for maintenance treatment of asthma. We evaluated the steady state plasma pharmacokinetics (PK) of IND, GLY and MF following inhalation of IND/GLY/MF or as monotherapies. This was a randomized, open-label, four-way crossover study. Subjects received IND/GLY/MF 150/50/160 µg (high-dose), IND 150 µg, GLY 50 µg or MF 190 µg (in vitro fine particle mass comparable to 160 µg MF in IND/GLY/MF) via the Breezhaler® device, o.d. for 14 days in each period, with a washout of at least 7 days. PK was characterized on Day 14, up to 24 h post-dose. In total, 36 healthy subjects were randomized. For IND, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 0.922 (0.878, 0.969) and 1.02 (0.967, 1.08), respectively for the IND/GLY/MF versus IND monotherapy comparison. For GLY, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 0.986 (0.944, 1.03) and 1.21 (1.09, 1.34), respectively for the IND/GLY/MF versus GLY comparison. For MF, the geometric mean ratios (90% CI) for AUC0-24h,ss and Cmax,ss were 1.16 (1.09, 1.24) and 1.17 (1.09, 1.25), respectively for IND/GLY/MF versus MF comparison. Similar systemic exposure was noted for IND/GLY/MF versus monotherapy for all three mono-components, indicating a lack of PK interaction. Multiple inhaled doses of IND, GLY and MF were safe and well tolerated, when administered alone or in combination. There was no clinically relevant pharmacokinetic interaction between IND, GLY and MF when administered as IND/GLY/MF.

Pharmacokinetics of indacaterol and mometasone furoate delivered alone or in a free or fixed dose combination in healthy subjects.

PURPOSE: QMF149 is a fixed-dose combination of the long-acting ß2 agonist, indacaterol and the corticosteroid, mometasone furoate that is currently under development for treatment of patients with asthma and chronic obstructive pulmonary disease. We describe here a study designed to assess any pharmacokinetic (PK) and/or biopharmaceutical interaction between indacaterol and mometasone furoate when administered via the Breezhaler(®) device, either alone or in a free or fixed combination (QMF149) in healthy adult subjects. METHODS: In this randomized, open-label, four-way crossover study, subjects were randomized to receive indacaterol acetate 150 µg, mometasone furoate 320 µg, alone and as free combination of the individual components, or QMF149 (indacaterol acetate 150 µg/mometasone furoate 320 µg) once daily for 14 days in each period, followed by a 7-day washout between periods. PK profiles were characterized on Day 14 up to 168 h post-dose. RESULTS: Indacaterol AUC0-24h,ss and Cmax,ss after administration of QMF149 were 13% [ratio: 1.13; 90%CI: 1.09, 1.17] and 18% [ratio: 1.18; 90%CI: 1.12, 1.25] higher, respectively, than indacaterol monotherapy. Mometasone furoate AUC0-24h,ss and Cmax,ss after administration of QMF149 were 14% [ratio: 1.14; 90%CI: 1.09, 1.20] and 19% [ratio: 1.19; 90%CI: 1.13, 1.26], higher, respectively than mometasone furoate monotherapy. The majority (three of four comparisons between QMF149 and monotherapy) of the 90% confidence intervals of the between-treatment ratios for AUC0-24h,ss and Cmax,ss were within the 0.80 to 1.25 interval and therefore fulfilled bioequivalence criteria. The 90% confidence interval for Cmax,ss for MF for the QMF149 vs. monotherapy comparison was [1.13, 1.26]. Although no definitive data can be provided on the basis of the present study results, it is unlikely that the small observed differences in expsoure are clinically meaningful. Multiple inhaled doses of indacaterol and mometasone furoate, when administered alone, in free combination or as QMF149 were well tolerated. CONCLUSIONS: The QMF149 fixed dose combination treatment showed comparable systemic exposure to the free combination and monotherapy treatments in terms of AUC0-24h,ss and Cmax,ss for both indacaterol and mometasone furoate, indicating an absence of clinically relevant PK or biopharmaceutical interactions. These data support further development of QMF149 without dose adjustment.

Placental ABC Transporters: Biological Impact and Pharmaceutical Significance.

The human placenta fulfills a variety of essential functions during prenatal life. Several ABC transporters are expressed in the human placenta, where they play a role in the transport of endogenous compounds and may protect the fetus from exogenous compounds such as therapeutic agents, drugs of abuse, and other xenobiotics. To date, considerable progress has been made toward understanding ABC transporters in the placenta. Recent studies on the expression and functional activities are discussed. This review discusses the placental expression and functional roles of several members of ABC transporter subfamilies B, C, and G including MDR1/P-glycoprotein, the MRPs, and BCRP, respectively. Since placental ABC transporters modulate fetal exposure to various compounds, an understanding of their functional and regulatory mechanisms will lead to more optimal medication use when necessary in pregnancy.

Single therapeutic and supratherapeutic doses of sacubitril/valsartan (LCZ696) do not affect cardiac repolarization.

PURPOSE: Sacubitril/valsartan (LCZ696) is a first-in-class angiotensin receptor neprilysin inhibitor (ARNI) indicated to reduce the risk of cardiovascular death and hospitalization for heart failure in patients with chronic heart failure (NYHA class II-IV) and reduced ejection fraction. This study was aimed to evaluate the effect of single oral therapeutic (400 mg) and supratherapeutic (1200 mg) doses of LCZ696 on cardiac repolarization. METHOD: This randomized double-blind crossover study in healthy male subjects compared the effect of therapeutic and supratherapeutic doses of LCZ696 with placebo and moxifloxacin 400 mg (open-label treatment) as positive control. The primary assessment was mean baseline- and placebo-corrected QTcF (∆∆QTcF; Fridericia correction). Additional assessments included the ∆∆QTcB (Bazett's correction), PR interval, QRS duration, heart rate (HR), LCZ696 pharmacokinetics, pharmacokinetic/pharmacodynamic relationships, and safety. RESULTS: Of the 84 subjects enrolled, 81 completed the study. The maximum upper bound of the two-sided 90 % confidence interval for ∆∆QTcF for LCZ696 400 mg and 1200 mg were <10 ms, and assay sensitivity was confirmed with moxifloxacin. No relevant treatment-emergent changes were observed in any of the ECG-derived parameters with LCZ696 or placebo, and the incidence of adverse events was comparable among the treatment groups. CONCLUSION: Single therapeutic and supratherapeutic doses of LCZ696 did not affect cardiac repolarization as defined by the E14 ICH guidelines.

Pharmacokinetics of QMF149 in Japanese versus Caucasian subjects: an open-label, randomized phase I study.

OBJECTIVES: This study aimed to evaluate influence of ethnic factors on the pharmacokinetics of orally inhaled QMF149, a novel combination of an approved longacting ß2-agonist, indacaterol (Onbrez® Breezhaler® for COPD), and an approved inhaled corticosteroid, mometasone furoate (MF), (Asmanex® Twisthaler® for asthma), following multiple dose administration of QMF149 (indacaterol acetate/MF) 150/80 µg and 150/320 µg via the Breezhaler® device in healthy Japanese and Caucasian subjects. METHODS: This was a single-center, openlabel, multiple-dose, two-period, complete crossover study that randomized healthy Japanese and, age and weight matched Caucasian subjects to QMF149 150/80 µg or 150/320 µg once daily (o.d.) for 14 days in each period. Pharmacokinetics (PK) were assessed up to 24 hours on days 1 and 14. RESULTS: 24 Japanese and 24 Caucasian healthy subjects were enrolled. Indacaterol and MF had similar PK profiles across both the doses and both ethnic groups. The maximum geometric mean ratios (90% confidence interval (CI)) for Japanese vs. Caucasian subjects for Cmax were 1.23 (1.11 - 1.38) and 1.24 (1.11 - 1.38) for indacaterol and MF, respectively. For AUC, the maximum ratios were 1.22 (1.09 - 1.36) and 1.30 (1.18 - 1.44) for indacaterol and MF, respectively. The mild trend towards higher exposure in Japanese subjects could be explained by the fact that the mean body weight was 14% higher for Caucasians compared to their Japanese counterparts. No serious adverse events or discontinuations related to study medication were reported. CONCLUSION: The study demonstrated increase of mean exposure parameters in Japanese subjects vs. Caucasian subjects, which ranged between 19 - 23% and 17 - 30%, for indacaterol and MF components, respectively. Multiple doses of both the QMF149 dose levels were safe and well-tolerated in all subjects. Body weight was considered a key contributory factor for the observed difference in exposure. These results suggest no dose adjustment for QMF149 is required in Asian populations.

Pharmacokinetics of AXA1665, a Novel Composition of Amino Acids, in Comparison With Protein Supplement: A Single-Dose, Open-Label, Randomized Study in Healthy Subjects.

We evaluated the safety and tolerability of AXA1665, a novel investigational fixed-ratio amino acid (AA) composition, the pharmacokinetics (PK) of the constituent AAs within AXA1665, and their relative bioavailability versus standard protein supplement. This study was conducted in 2 phases; in the initial phase, healthy subjects (N = 16) were randomly assigned to 4 treatment sequences (AXA1665 4.9, 9.8, and 19.6 g or 35 g protein supplement) in an open-label, single-dose, 4-way crossover study, while in the extension phase, they received single AXA1665 doses of 29.4 and 39.2 g in a sequential crossover manner. The net area under the plasma concentration-time curve (AUC) and observed time to reach maximum plasma concentration were estimated. A dose-dependent increase in plasma AUC from time 0 to the last measurable concentration (AUClast ) and maximum plasma concentration (Cmax ) was observed for all AXA1665-dosed AAs (4.9-39.2 g) except aspartic acid. AXA1665 19.6 g resulted in 1.5- to 9.5-fold higher systemic exposure to all AXA1665-dosed AAs except for aspartic acid and lysine and lower exposure to all nondosed AAs except for glutamine and alanine versus protein supplement. AXA1665 doses, up to 39.2 g, can deliver AXA1665-dosed AAs in the systemic circulation in the linear AUC range.

Efficacy, Safety, and Systemic Exposure of Once-Daily Indacaterol Acetate in Pediatric Asthma: A Randomized, Double-Blind, Controlled Dose-Finding Study.

BACKGROUND: Indacaterol acetate (IND), a long-acting ß2-agonist in combination with mometasone furoate (MF), an inhaled corticosteroid (ICS), is being explored as a once-daily (od) treatment for asthma in children. This study examined the efficacy, safety, and systemic exposure of IND 75 µg and IND 150 µg in children with persistent asthma. METHODS: In this Phase IIb, multicenter, randomized, double-blind, parallel-group study, pediatric patients (aged ≥ 6 to < 12 years) with persistent asthma were randomized (1:1) to receive either IND 75 µg od or IND 150 µg od via Breezhaler® in combination with ICS background therapy. The primary endpoint was change from baseline in pre-dose trough forced expiratory volume in one second (FEV1) after two weeks of treatment. RESULTS: In total, 80 patients received IND 75 µg (n = 39) or IND 150 µg (n = 41). The study met its primary endpoint; both doses demonstrated improvements in pre-dose trough FEV1 from baseline to Day 14 (mean change [Δ]: 212 mL, IND 75 µg; 171 mL, IND 150 µg). The secondary spirometry parameters (post-dose FEV1 after 1-h, post-dose forced vital capacity; morning and evening peak expiratory flow) also improved. Overall, 36.1% in IND 75 µg group and 25% patients in IND 150 µg group achieved a decrease from baseline in Pediatric Interviewer-administered Asthma Control Questionnaire score of ≥ 0.5 units. A dose-dependent increase in plasma IND concentration was noted between the two groups. Both IND doses demonstrated an acceptable safety profile. CONCLUSIONS: Once-daily IND 75 µg and IND 150 µg via Breezhaler® in combination with background ICS therapy provided substantial bronchodilation in children with asthma and were well tolerated. Taken together, these clinical and systemic exposure findings support IND 75 µg as the most appropriate dose for evaluation in Phase III trials in combination with MF in pediatric asthma. TRIAL REGISTRATION: ClinicalTrials.gov (NCT02892019; 08-Sep-2016).

Population Pharmacokinetic Analysis of Indacaterol/Glycopyrronium/Mometasone Furoate After Administration of Combination Therapies Using the Breezhaler® Device in Patients with Asthma.

BACKGROUND AND OBJECTIVE: Clinical evidence suggests no clinically relevant pharmacokinetic interactions between indacaterol (IND), glycopyrronium (GLY) and mometasone furoate (MF). A population pharmacokinetic (popPK) analysis was conducted to identify structural models describing systemic pharmacokinetic profiles of IND, GLY and MF, and estimate the effect of covariates on their pharmacokinetics following inhalation as IND/GLY/MF. METHODS: Pharmacokinetic data from 698 patients with asthma were pooled from two Phase III studies that evaluated IND/MF medium- (150/160 µg) and high-dose (150/320 µg), IND/GLY/MF medium- (150/50/80 µg) and high-dose (150/50/160 µg), and a device bridging Phase II study with MF. One popPK model was developed each for IND, GLY and MF using a nonlinear mixed-effect modelling approach. Maximal and trough plasma concentrations were compared across formulations and studies, including data for IND/GLY from chronic obstructive pulmonary disease (COPD) patients. The effect of predefined covariates on the pharmacokinetics of components was evaluated using a full covariate modelling approach. RESULTS: The final pharmacokinetic models were two-compartment disposition models with first-order elimination and sequential zero-order/first-order absorption (IND), with bolus administration and first-order elimination (GLY), and with mixed zero-order/first-order absorption and first-order elimination (MF). All model parameters were estimated with good precision (% relative standard error: IND and MF ≤25%; GLY <10%). No clinically relevant covariate effect was observed on the pharmacokinetics of IND, GLY and MF. IND and GLY pharmacokinetic profiles were similar across different formulations. CONCLUSION: Two-compartment popPK models adequately described the pharmacokinetics of IND, GLY and MF. The effect of covariates was not clinically relevant. The pharmacokinetic profiles of MF were comparable for combination products at corresponding medium- or high-dose inhaled corticosteroids. On a population level, the pharmacokinetics of IND and GLY were comparable between patients with asthma and COPD.

Drug-Drug Interaction Studies With Oral Contraceptives: Pharmacokinetic/Pharmacodynamic and Study Design Considerations.

Oral contraceptives (OCs) are the most widely used form of birth control among women of childbearing potential. Knowledge of potential drug-drug interactions (DDIs) with OCs becomes imperative to provide information on the medication to women of childbearing potential and enable their inclusion in clinical trials, especially if the new molecular entity is a teratogen. Although a number of DDI guidance documents are available, they do not provide recommendations for the design and conduct of OC DDI studies. The evaluation of DDI potential of a new molecular entity and OCs is particularly challenging because of the availability of a wide variety of combinations of hormonal contraceptives, different doses of the ethinyl estradiol, and different metabolic profiles of the progestin component. The aim of this review is to comprehensively discuss factors to be considered such as pharmacokinetics (PK), pharmacodynamics (PD), choice of OC, and study population for the conduct of in vivo OC DDI studies. In this context, metabolic pathways of OCs, the effect of enzyme inhibitors and inducers, the role of sex hormone-binding globulin in the PK of progestins, current evidence on OC DDIs, and the interpretation of PD end points are reviewed. With the emergence of new tools like physiologically based PK modeling, the decision to conduct an in vivo study can be made with much more confidence. This review provides a comprehensive overview of various factors that need to be considered in designing OC DDI studies and recommends PK-based DDI studies with PK end points as adequate measures to establish clinical drug interaction and measurement of PD end points when there is basis for PD interaction.

Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of the Novel Non-Bile Acid FXR Agonist Tropifexor (LJN452) in Healthy Volunteers.

Tropifexor (LJN452) is a potent, orally available, non-bile acid farnesoid X receptor agonist under clinical development for chronic liver diseases. Here, we present results from a first-in-human study of tropifexor following single- and multiple-ascending doses (SAD/MAD) and food effect substudy in healthy volunteers. The SAD study included 6 fasted cohorts receiving 10- to 3000-µg tropifexor or placebo and 1 cohort receiving 300-µg tropifexor with a high-fat meal. The MAD study included 4 lean cohorts receiving 10 to 100 µg and 1 obese cohort receiving 30-µg once-daily doses or placebo for 14 days. Pharmacodynamic assessment of fibroblast growth factor 19 and fasting plasma lipids was performed after dosing. Overall, 95 volunteers received at least 1 tropifexor or placebo dose. Tropifexor was well tolerated up to 3000 µg and 100 µg in the SAD and MAD studies, respectively; however, 2 subjects discontinued the MAD study due to asymptomatic elevation of liver transaminases. At single doses, tropifexor showed a moderate rate of absorption (median time to maximum concentration, 4 hours), dose-proportional increases in exposure, and elimination half-life of 13.5 to 21.9 hours. When taken with food, tropifexor exposure increased by ∼60%. With multiple dosing, steady state was reached on day 4 with <2-fold accumulation. Single and multiple doses showed dose-dependent increases in fibroblast growth factor 19. No changes in serum lipids were observed in tropifexor- vs placebo-treated obese subjects. In conclusion, tropifexor was well tolerated, had a pharmacokinetic profile suitable for once-daily dosing and showed dose-dependent target engagement without altering plasma lipids in healthy volunteers.

Formation and efflux of ATP-binding cassette transporter substrate 2,4-dinitrophenyl-S-glutathione from cultured human term placental villous tissue fragments.

Upon exposure to 1-chloro-2,4-dinitrobenzene (CDNB), the human placental tissue forms its glutathione conjugate 2,4-dinitrophenyl-S-glutathione (DNP-SG). The purpose of this study was to investigate the involvement of human placental ATP-binding cassette (ABC) transporters in the efflux of DNP-SG. Placental tissue samples were obtained from pregnant patients undergoing C-section deliveries following normal pregnancies; villous tissue was cultured in suspension, and DNP-SG formation and efflux upon exposure to 100 microM CDNB were measured by HPLC. DNP-SG efflux decreased by 69.1 (+/-11.3)%, 51.1 (+/-5.4)%, 56.7 (+/-8.3)% and 53.6 (+/-10.8)% (p < 0.05) in the presence of 5 mM sodium orthovanadate (ATPase inhibitor), 100 microM MK571 (MRP-inhibitor), 1 mM dipyridamole (BCRP/P-gp/MRP1-inhibitor) and 100 microM verapamil (P-gp/MRP1 inhibitor) respectively, without any change in DNP-SG formation, total tissue glutathione, GSH/GSSG ratio, tissue integrity or tissue viability. These data clearly established the role of ABC transporters in the human placental efflux of DNP-SG. To investigate the contribution of various ABC transporters toward DNP-SG transport, ATP-dependent transport of 3H-DNP-SG was determined in Sf9 membrane vesicles overexpressing P-gp, BCRP and the MRP proteins. MRP1-mediated DNP-SG transport was inhibited in the presence of sodium orthovanadate, MK571, dipyridamole and verapamil in the presence of glutathione. Furthermore, MRP1-mediated transport [K(t) = 11.3 +/- 1.3 microM and v(max) = 86.7 +/- 1.9 pmol/mg/min] was a high-affinity process compared to MRP2-mediated transport [K(t) = 168 +/- 7 microM and v(max) = 1367 +/- 18 pmol/mg/min]. The inhibition pattern and the kinetics of DNP-SG efflux in the placental villous tissue were consistent with MRP1-mediated DNP-SG efflux, suggesting a functional role and an apical localization for an MRP1-like transporter in the human placental syncytiotrophoblast.

The ABCG2 C421A polymorphism does not affect oral nitrofurantoin pharmacokinetics in healthy Chinese male subjects.

AIMS: A number of drugs are substrates or inhibitors of the efflux transporter breast cancer resistance protein (BCRP; ABCG2), which can limit systemic exposure by reducing absorption and/or increasing biliary elimination. The identification of a BCRP-selective clinical probe drug would provide a useful tool to understand the effect of genetic polymorphisms and transporter-based drug interactions on drug pharmacokinetics. The aim of this study was to assess the utility of nitrofurantoin as a clinical probe substrate for BCRP activity by evaluating the impact of genetic variation on nitrofurantoin pharmacokinetics. METHODS: Nitrofurantoin pharmacokinetics were studied in an open-label, single-oral dose (100 mg) study in 36 male Chinese subjects who were pre-screened for ABCG2 421 CC, CA and AA genotypes (n = 12 each). Plasma and urine concentrations of nitrofurantoin were determined by LC/MS/MS and LC/UV respectively. anova was used to compare pharmacokinetic parameters among genotypes. RESULTS: There were no significant differences in nitrofurantoin pharmacokinetics among the genotypic cohorts. The geometric mean nitrofurantoin plasma AUC((0-infinity)) (95% confidence interval) values were 2.21 (2.00, 2.45), 2.42 (2.11, 2.78) and 2.32 (1.99, 2.70) microg h ml(-1) and half-life values were 0.79 (0.59, 1.0), 0.76 (0.64, 0.89) and 0.72 (0.62, 0.84) h for ABCG2 421 genotypes CC, CA and AA, respectively. The percentage of dose excreted unchanged in the urine was 43, 44 and 39%, respectively. CONCLUSIONS: The ABCG2 C421A polymorphism had no effect on nitrofurantoin plasma and urine pharmacokinetic parameters in healthy Chinese subjects. These results indicate that nitrofurantoin is not a suitable clinical probe substrate for assessing BCRP activity.

Simultaneous determination of 1-chloro-2,4-dinitrobenzene, 2,4-dinitrophenyl-S-glutathione and its metabolites for human placental disposition studies by high-performance liquid chromatography.

We developed and validated an HPLC method for determination of 1-chloro-2,4-dinitrobenzene (CDNB) and its glutathione conjugate 2,4-dinitrophenyl-S-glutathione (DNP-SG) to study the kinetics and mechanisms involved in DNP-SG formation and efflux, as a probe for human placental metabolism and transport. This method combines use of 3 microm solid phase, rapid mobile phase gradient with dual wavelength ultraviolet detection to permit determination of a lipophilic parent compound and its hydrophilic metabolites in a single short run. The selectivity, linearity, accuracy, precision, relative recovery and stability of the assay are sufficient for determining CDNB, DNP-SG and its metabolites from buffer and tissue samples to support placental drug metabolism and transport studies.

Lung Delivery of Indacaterol and Mometasone Furoate Following Inhalation of QMF149 in Healthy Volunteers.

This single-dose, 4-period crossover study evaluated the pharmacokinetics (PK) of the ß2 -agonist indacaterol maleate and the corticosteroid mometasone furoate (MF) after inhalation of a fixed-dose combination (QMF149, indacaterol maleate/MF, 500/400 µg) via the Twisthaler (TH) device with and without activated charcoal and postdose mouth rinsing in healthy volunteers. The PK of indacaterol maleate 300 µg inhaled via the Breezhaler (BRZ) device was also characterized. Relative bioavailability of indacaterol and MF for inhalation with versus without charcoal, based on AUClast, was 0.25 (90% confidence interval [CI], 0.18-0.35) and 0.70 (90%CI, 0.52-0.93), respectively. Thus, 25% and 70% of systemic exposure of indacaterol and MF, respectively was due to pulmonary absorption and 75% and 30%, respectively, was due to gastrointestinal absorption. Mouth rinsing reduced the systemic exposure of indacaterol by approximately 35% but had no relevant effect on the exposure of MF. Dose-normalized AUClast for indacaterol inhaled via the BRZ device was 2.3-fold higher than QMF149 via the TH device. All treatments had a good safety profile and were well tolerated. Data from this study and comparison with inhalation of indacaterol via the BRZ device suggest that the latter was more efficient than the TH device regarding lung delivery of indacaterol.

Application of human placental villous tissue explants to study ABC transporter mediated efflux of 2,4-dinitrophenyl-S-glutathione.

OBJECTIVE: The purpose of this study was to characterize the human term placental villous tissue explant culture model as a tool to study the formation and efflux of 1-chloro-2,4-dinitrobenzene (CDNB) conjugate 2,4-dinitrophenyl-S-glutathione (DNP-SG) as a model system for phase II metabolism and ATP-binding cassette (ABC) transporter-mediated cellular efflux. METHODS: Placental tissue samples were obtained after cesarean section following normal pregnancies (n=9). Cultured villous tissue was monitored up to 48 h to study the effect of time in culture on biochemical parameters, formation and efflux of DNP-SG in the absence or presence of ATPase inhibitor sodium orthovanadate and the protein expression of ABC transporters - multidrug resistance associated protein 2 (MRP2), P-glycoprotein (P-gp), breast cancer resistance protein (BCRP), and enzyme glutathione-S-transferase isoform P1-1 (GSTP1-1). RESULTS: Villous tissue structure, tissue viability and expression of BCRP, GSTP1-1 remained unchanged, while expression of MRP2, P-gp and total tissue glutathione decreased with time in culture. Tissue integrity was unchanged up to 24 h but declined at 48 h. However, DNP-SG formation, DNP-SG efflux, and the extent of inhibition of DNP-SG efflux by sodium orthovanadate showed only minor changes through 48 h. Sodium orthovanadate decreased DNP-SG efflux, consistent with inhibition of apical ABC transporters. CONCLUSION: The results support the use of the cultured human term placental villous tissue explants model to study coordinated function of GSTP1-1 and apical ABC transporters in the formation and efflux of the model substrate DNP-SG.