Aims: To investigate the pharmacokinetics and effects on the hypothalamic-pituitary-adrenal (HPA) axis of mometasone furoate (MF), fluticasone propionate (FP) and fluticasone furoate (FF). Methods: Study 1: Fourteen healthy participants received inhaled and intravenous MF (inhaled dose via Twist -haler) and FP (inhaled dose via Diskus), both given at 400 mu g, using a randomised, single-dose, four-way crossover design. Study 2: Twenty-seven participants with mild to moderate asthma, who discontinued their corticosteroid medication for 5 days to obtain a baseline 24 h serum cortisol, received inhaled MF Twisthaler and FP Diskus, both given at 400 mu g twice daily (BID), using a randomised, 14-day repeat dose, two-way crossover design. Study 3: Forty-four healthy participants were randomised to a double-blind, placebo-controlled, five -period crossover study where the following treatments were administered via the inhaled route for 7 days: FP Diskus (250, 500, 1000 mu g BID), FF Diskus (100, 200, 400, 800, 1600 mu g once daily [QD]) or placebo Diskus. In each study, 24-h serial blood samples were collected and assayed to assess concentrations of MF, 68-hydroxy mometasone, mometasone, FP, FF and cortisol. Pharmacokinetic and serum cortisol parameters were estimated as geometric means and 95% confidence intervals (CI).Results: Study 1: For intravenous MF and FP, respectively: absolute bioavailability was 11.4% (95% CI: 7.5, 17.6) and 7.8% (6.3, 9.6); plasma clearance was 47 L/h (41, 52) and 60 L/h (52, 69); half-life was 7.4 h (6.9, 8.0) and 7.2 h (6.5, 8.0); and volume of distribution was 499 L (439, 567) and 623 L (557, 698). Inhalation of single dose MF or FP did not significantly affect serum cortisol (<10% reduction from baseline), whereas intravenous administration of MF or FP each changed serum cortisol by approximately-50% from baseline. Study 2: For MF and FP, respectively: area under the curve up to the last measurable concentration on Day 1 was 421 pg h/mL (270, 659) and 248 pg h/mL (154, 400), and on Day 14 was 1092 pg h/mL (939, 1269) and 591 pg h/mL (501, 696); absolute bioavailability was 12.8% (11.2, 14.2) and 8.9% (7.7, 10.2). On Day 14, 24-h serum cortisol change from baseline was-35% (-44%,-26%) and-18% (-28%,-5%) for MF and FP, respectively; the reduction was significantly greater for MF than FP (ratio for geometric adjusted mean serum cortisol concen-tration: 1.28 [1.04, 1.56]). Low plasma concentrations of 68-hydroxy mometasone were detected after intra-venous dosing (Study 1) and after multiple inhaled dosing (Study 2); mometasone was not detected in any samples. Study 3: Inhaled FP and FF had similar systemic bioavailability estimates (12.0% [11.0, 13.2] and 15.0% [12.0, 17.3], respectively), but a differential effect on the HPA axis which was in agreement with the known 1.7-fold higher glucocorticoid receptor-binding affinity of FF versus FP. However, for FP 250 mu g BID and FF 100, 200 and 400 mu g QD, reduction in serum cortisol was not significantly different from placebo. For higher doses, FP 500 and 1000 mu g BID, and FF 800 and 1600 mu g QD, changes in serum cortisol concentration relative to placebo were-30%,-70%,-41% and-90%, respectively. Repeat inhaled dosing of FP 1000 mu g/day (within the therapeutic dose range) resulted in comparable cortisol suppression to MF in the therapeutic range (30% reduction); whereas for FF this occurred at more than 3-fold above the therapeutic dose range (644 mu g/day). Conclusions: Single inhaled and intravenous doses of MF and FP (400 mu g) resulted in similar bioavailability and reductions in serum cortisol. Repeat dosing of inhaled MF and FP in the therapeutic range (800 mu g/day) resulted in greater systemic exposure for MF, and a 35% reduction in serum cortisol that was 2-fold greater than for FP. The higher glucocorticoid receptor-binding affinity and bioavailability, lower clearance and the presence of active metabolites may contribute to the greater systemic exposure and effect on cortisol for MF. Repeat dosing of inhaled FP and FF resulted in similar systemic bioavailability but differed in terms of the dose required for comparable cortisol suppression to MF in the therapeutic range. Unlike FP and FF, MF has active metabolites that may contribute to its systemic effects, while device/formulation performance differences also exist between MF-containing products.

Nemiralisib (GSK2269557), a potent inhaled inhibitor of phosphoinositide 3-kinase delta (PI3K delta), is being developed for the treatment of respiratory disorders including chronic obstructive pulmonary disease. Determining the pharmacokinetic (PK) and pharmacodynamic (PD) responses of inhaled drugs early during drug development is key to informing the appropriate dose and preferred dose regimen in patients. We set out to measure PD changes in induced sputum in combination with drug concentrations in plasma and bronchoalveolar lavage (BAL) taken from healthy smokers (n = 56) treated for up to 14 days with increasing doses of inhaled nemiralisib (0.1-6.4 mg). Induced sputum analysis demonstrated a dose-dependent reduction in phosphatidylinositol-(4,5)trisphosphate (PIP3, the product of PI3K activation), with a maximum placebo-corrected reduction of 23% (90% confidence interval [CI], 11%-34%) and 36%(90% CI, 11%-64%) after a single dose or after 14 days of treatment with nemiralisib, respectively (2 mg, once daily). Plasma analysis suggested a linear PK relationship with an observed accumulation of similar to 3-to 4.5-fold (peak vs. trough) in plasma exposure after 14 days of nemiralisib treatment. The BAL analysis at trough confirmed higher levels of the drug in the lungs versus plasma (32-fold in the BAL fluid component, and 214-fold in the BAL cellular fraction). A comparison of the drug levels in plasma and the reductions in sputum PIP3 showed a direct relationship between exposure and PIP3 reduction. These results demonstrated target engagement upon treatment with inhaled nemiralisib and provide confidence for a once-daily dosing regimen.

Introduction: GSK2269557 was investigated as a dry powder formulation in a double blind, placebo controlled study in healthy cigarette smokers. Safety, tolerability, PK and PD data were collected following SD (100, 500, 2000 and 3000 µg) and RD (2000 µg for 14 days). Plasma and lung PK (from bronchoalveolar lavage) and PD (PIP3 proportion [using PIP2] from induced sputum) were measured. Lung PK was the drug concentration in the cellular fraction (CF) and epithelial lining fluid (ELF). PD was measured to demonstrate target engagement. Results: Adverse Events (AE's) were few, of mild to moderate intensity and not different from placebo. SD plasma Cmax (Tmax approx 5 min) dropped rapidly (< 6 hours) followed by a slower elimination (T1/2 was approx 20h). Cmax and AUC(0-t) were 0.04 to 2.6 ng/mL and 0.14 to 33 ng.h/mL for 100 to 3000 µg respectively. RD showed accumulation in plasma with increased peak (3-fold) and trough (4.5-fold) levels. Lung ELF and CF concentrations at 24h post day 14 dose were 55 ng/mL (ELF:plasma ratio 32:1) and 366 ng/mL (CF:plasma ratio 214:1) respectively. PIP3 proportion levels in sputum were reduced by 6.7%, 8.4% and 18.7% at 3hrs post dose, day 1 for 100, 500 and 2000µg respectively, and by 35.7% at 3 hours post dose, day 12 for 2000µg. Conclusions: GSK2269557 was well tolerated with a low incidence of AE's which was not different from placebo. Plasma PK was well defined with lung data confirming higher levels of drug compared to plasma. Target engagement was confirmed by sputum PIP3 data.

Phosphatidylinositol (4,5)-bisphosphate (PIP2) is converted by PI3Kδ into Phosphatidylinositol (3,4,5)-trisphosphate (PIP3). This activates cellular functions including proliferation and differentiation. PI3Kδ, which is inhibited by GSK2269557, is a promising therapeutic target for respiratory disease. Aim: To identify markers of PI3Kδ target engagement. Methods: In one part of a single centre, randomized, double blind, placebo controlled phase I study, 2 cohorts of healthy male smokers were given active dose and placebo in a cross over design (ERS 851005). Sputum or bronchioaveolar lavage (BAL) was taken 3 hours post dosing. In the sputum cohort, PIP3 levels were measured and normalised by PIP2. In the BAL cohort, cell surface L- selectin (CD62L) and phosphorylated forkhead box 01 (p-FOXO1) were measured. Results: PIP3 levels in sputum were reduced by 20% & 23% at 400µg, 6400µg of GSK2269557 respectively [p<0.05]. P-FOXO1: BAL cell expression showed a decrease in the active group in both macrophage and neutrophil cytoplasm [p<0.05] which is maintained in macrophages when pFOXO1 is normalised to total FOXO-1 [p<0.05]. L-selectin : The proportion of cells with cell membrane associated L- selectin showed an increase of 48% for macrophages and 21% for neutrophils in the active groups compared with placebo [p<0.05]. Conclusions : PIP3 is a suitable biomarker to demonstrate GSK2269557 target engagement, as indicated by reduced levels of PIP3 in GSK2269557 treated subjects. Downstream of PIP3, reduced levels of p-FOXO1 and increased L-selectin cell surface expression were consistent with PI3K inhibition and support the PIP3 results.

Chronic obstructive pulmonary disease (COPD) has a significant negative impact on quality of life and increases the risk of premature death. Umeclidinium is a long-acting muscarinic receptor antagonist in development for the treatment of COPD with the aim to broaden treatment options for clinicians and patients by providing improved symptom control.

Introduction: GSK2269557 was investigated in a single centre, double blind, placebo controlled trial in healthy male subjects and smokers. Safety, tolerability and PK data were collected following single (25-6400 µg) and repeat dose (3200 µg b.i.d. for 7 days) in healthy and biomarker cohorts (400 and 6400 µg single doses) in smokers (ERS abstract ref 850263). Plasma PK and lung PK data (from bronchoalveolar lavage) were calculated. Lung PK are expressed as the concentrations in epithelial lining fluid (ELF) using [urea] as a marker of lavage dilution. Results: Adverse Events (AE’s) were few and mostly of mild to moderate intensity. 5 withdrawals occurred with 1 deemed study drug related (an inability to tolerate administration of 6400 µg). After single dosing plasma C max (T max at approx 5 min) dropped rapidly ( 1/2 was 19-42h. Dose proportionality was observed and plasma PK was unaffected by smoking status. Mean plasma C max and AUC (0-24h) values were 0.06 to 4.3 ng/mL (50 to 6400 µg) and 0.38 to 34 ng.h/mL (200 to 6400 µg) respectively. Twice daily dosing for 7 days showed accumulation in plasma with peak and trough levels increased by 2.4-fold and 6-fold respectively. Derived mean ELF concentration at 3h was 598 ng/mL (lung:plasma ratio 440:1). Conclusions: GSK2269557 was well tolerated in healthy male subjects. There was a low incidence of AE’s and plasma PK was well defined with ELF data confirming high levels of drug within the lung compared to plasma.

Background GSK233705 is an inhaled, long-acting muscarinic antagonist in development for the treatment of chronic obstructive pulmonary disease (COPD). This study was performed to see if the addition of GSK233705 to salmeterol would provide greater bronchodilation than salmeterol or tiotropium alone in COPD. Methods In an incomplete-block, three-period, crossover design, dually responsive patients received three of the following five treatments: GSK233705 20 μg plus salmeterol 50 μg twice-daily; GSK233705 50 μg plus salmeterol 50 μg twice-daily; salmeterol 50 μg or placebo, each twice-daily; and tiotropium 18 μg or placebo once-daily for 7 days. Each treatment period was separated by a 14-day washout. The primary efficacy endpoint was morning (trough) forced expiratory volume in 1 second (FEV1) on Day 8, following 7 days of treatment. Secondary endpoints included pulmonary function, plethysmography, pharmacokinetics of GSK233705 and salmeterol, adverse events (AEs), electrocardiograms (ECGs), vital signs, and laboratory parameters. Results A total of 47 patients were randomized. The mean % predicted normal postbronchodilator FEV1 was 55% at screening. Compared with placebo (n = 24), the adjusted mean change from baseline in trough FEV1 on Day 8 was 215 mL higher with GSK233705 20 μg + salmeterol (n = 23) and 203 mL higher with GSK233705 50 μg + salmeterol (n = 27), whereas with salmeterol (n = 27) and tiotropium (n = 28) the changes were 101 mL and 118 mL higher, respectively. The primary efficacy results were supported by the results from the other secondary lung function assessments. AEs were reported by similar proportions of patients across the treatment groups, with headache the most frequently reported treatment-related AE reported by one subject receiving each of GSK233705 20 μg + salmeterol, tiotropium, and placebo. No significant differences were seen in vital signs, ECGs, or laboratory parameters between the groups. Conclusion The addition of GSK233705 to salmeterol in partially reversible COPD patients resulted in greater bronchodilation than salmeterol or tiotropium alone and was well tolerated.

Introduction: GSK573719 is a new long-acting muscarinic antagonist offering sustained 24-hour bronchodilation in development for the treatment of chronic obstructive pulmonary disease (COPD). Objectives: To investigate the safety, tolerability, PD and PK of single inhaled doses of GSK573719. Methods: This double-blind, placebo-controlled, crossover, dose-escalation study randomised 20 ipratropium-responsive healthy male subjects to GSK573719 (10–350μg), tiotropium bromide (TB; 18μg) and placebo. Results: Eighteen subjects completed all 5 treatment periods. Adverse events (AEs) were mainly mild-to-moderate; no serious AEs were reported. One severe non-drug related AE was reported (increased creatine phosphokinase). 95% confidence intervals were assessed for statistical significance of PD data. Significantly higher specific airways conductance (sG aw ) was observed, versus placebo, for GSK573719 100 and 250μg at 12h, and for GSK573719 350μg and TB at 12h and 24h. FEV 1 values were also significantly greater than placebo for GSK573719 100 and 350μg at 12h and 24h and for TB at 24h. GSK573719 plasma C max (maximum plasma concentration) occurred at a median t max of 5min, followed by a rapid decline to below the lower limit of quantification by 6h. Between subjects C max variability was moderate-to-high (38–57%). Conclusion: In this first-in-human study, GSK573719 demonstrated adequate safety, tolerability and prolonged bronchodilation, suggesting the potential for once-daily administration in COPD. Funded by GSK (AC4105209)