Peter T. Daley-Yates

Introduction Asthma treatment guidelines classify inhaled corticosteroid (ICS) regimens as low, medium, or high dose. However, efficacy and safety are not independently assessed accordingly. Moreover, differences in ICS duration of action are not considered when a dose regimen is selected. We investigated the efficacy and safety implications of these limitations for available ICS molecules. Methods Published pharmacodynamic and pharmacokinetic parameters were used, alongside physiological and pharmacological principles, to estimate the efficacy and safety of available ICS molecules. Extent and duration of glucocorticoid receptor (GR) occupancy in the lung (efficacy) and cortisol suppression (systemic exposure and safety) were estimated. Results Some ICS regimens (e.g., fluticasone furoate, fluticasone propionate, and ciclesonide) rank high for efficacy but low for systemic exposure, contrary to how ICS dose equivalence is currently viewed. Differences in dose–response relationships for efficacy and systemic exposure were unique for each ICS regimen and reflected in their therapeutic indices. Notably, even low doses of most ICSs can generate high GR occupancy (≥ 90%) across the entire dose interval at steady state, which may explain previously reported difficulties in obtaining dose responses within the clinical dose range and observations that most clinical benefit typically occurs at low doses. The estimated post dose duration of lung GR occupancy for ICS molecules was categorized as 4–6 h (short), 14–16 h (medium), 25–40 h (long), or > 80 h (ultra-long), suggesting potentially large differences in anti-inflammatory duration of action. Conclusion In a real-world clinical setting where there may be poor adherence to prescribed therapy, our findings suggest a significant therapeutic advantage for longer-acting ICS molecules in patients with asthma.

Introduction Pharmacological asthma management focuses on the use of inhaled corticosteroid (ICS)-containing therapies, which reduce airway inflammation and provide bronchoprotection, improving symptom control and reducing exacerbation risk. ICS underuse due to poor adherence is common, leading to poor clinical outcomes including increased risk of mortality. This article reviews efficacy versus systemic activity profiles for various adherence patterns and dosing regimens of fluticasone furoate (FF)-containing and budesonide (BUD)-containing asthma therapies in clinical trials and real-world studies. Methods We performed a structured literature review (1 January 2000–3 March 2022) and mathematical modelling analysis of FF-containing and BUD-containing regular daily dosing in patients with mild-to-severe asthma, as-needed BUD/formoterol (FOR) in mild asthma, and BUD/FOR maintenance and reliever therapy (MART) dosing in moderate-to-severe asthma, to assess efficacy (bronchoprotection) and systemic activity (cortisol suppression) profiles of dosing patterns of ICS use in multiple adherence scenarios. Results A total of 22 manuscripts were included in full-text review and 18 in the model simulations. Focusing on FF-containing or BUD-containing treatments at comparable adherence rates, regular daily FF or FF/vilanterol (VI) dosing provided more prolonged bronchoprotection and fewer systemic effects than daily BUD, daily BUD/FOR, or BUD/FOR MART dosing, especially in low adherence scenarios. In model simulations and the real-world setting, FF/VI generally provided longer bronchoprotection, lower systemic activity, and greater clinical benefits over BUD/FOR as well as consistently higher adherence. Conclusion In this literature review and modelling analysis, FF/VI was found to show clinical advantages on asthma control over BUD/FOR. These findings have implications for helping clinicians select the most suitable inhaled therapy for their patients with asthma.

A bioanalytical method for detecting the ultra‐long‐acting beta₂‐agonist (U‐LABA) inhaled vilanterol and its metabolites, GSK932009 and GW630200, in urine was developed to potentially monitor permitted therapeutic versus prohibited supratherapeutic use in sport. The World Anti‐Doping Agency (WADA) has established urinary concentration thresholds for the beta₂‐agonists salbutamol and formoterol. Therapeutic use of vilanterol (25 μg once daily) was recently permitted by WADA; however, there is no established decision limit for adverse analytical findings due to insufficient urine concentration data. In this study, we validated an assay to detect vilanterol in urine collected from four healthy male and female athletes 0–72 h who received inhaled corticosteroid fluticasone furoate/U‐LABA vilanterol (800/100 μg) combination, four times the normal therapeutic dose. After administration, subjects performed 1 h of bike ergometer exercise. The experiment was conducted again after repeat dosing for 1 week. Our method utilised liquid chromatography with tandem mass spectrometry and was validated over urine concentrations of 5–5000 (vilanterol) and 50–50,000 pg/ml (GSK932009 and GW630200). Plasma samples were analysed for vilanterol, using a previously validated assay. The peak concentration values for urine vilanterol, GSK932009 and GW630200 were 9.5, 10.4 and 0.17 ng/ml, for single dosing, and 18.6, 19.5 and 0.20 ng/ml, for repeat dosing. Urine samples from four volunteers using the final validated method are reported, demonstrating this assay has sensitivity to detect vilanterol or GSK932009 in urine for ≥72 h post single or repeat dosing with 800/100 μg fluticasone furoate/vilanterol, whereas GW630200 was quantifiable ≤4 h post dose.

The 2023 Prohibited List issued by the World Anti‐Doping Agency (WADA) permits athletes to inhale the beta₂‐agonist vilanterol at a standard dose of 25 μg daily. However, given limited data on urine pharmacokinetics, vilanterol has no urinary threshold or decision limit to discriminate therapeutic from supratherapeutic use. We investigated urine concentrations of vilanterol and its main metabolites GSK932009 and GW630200 over 0–72 h following inhalation of therapeutic (25 μg) or supratherapeutic (100 μg) doses and repeat‐dose administration for 7 days of 25 or 100 μg·day⁻¹ in 25 trained men and women. Vilanterol administration was followed by 1 h of exercise. GW630200 urine concentrations were low and insufficient for threshold purposes, and while GSK932009 had higher urine concentrations, it could not discriminate between therapeutic and supratherapeutic use. Mean (range) maximum urine concentrations of parent vilanterol were 1.2 (0.2–4.1) and 6.2 (1.4–14.3) ng·ml⁻¹ for single‐dose 25 and 100 μg vilanterol, respectively, and 2.0 (0.3–4.8) and 22.4 (6.4–42.1) ng·ml⁻¹ for repeat‐dose 25 and 100 μg·day⁻¹ vilanterol. In 333 samples collected 6 h post‐administration and considering WADA TD2022DL, a 3.1 ng·ml⁻¹ vilanterol cut‐off showed 30% sensitivity in detecting supratherapeutic use at 100 μg versus therapeutic use at 25 μg. Considering inter‐ and intra‐individual variability and guard bands in doping analysis, a 6 ng·ml⁻¹ decision limit, which could be shifted upwards in samples with specific gravity >1.018, appears sufficiently high to minimize risk of samples exceeding the decision limit after therapeutic use of vilanterol, while demonstrating the ability to detect supratherapeutic use at 100 μg.

Background: Fluticasone furoate/vilanterol trifenatate (FF/VI) is an inhaled therapy for the treatment of asthma, with a prolonged duration of anti-inflammatory and bronchodilatory action. This study investigated the global metabolomic and lipidomic profile following treatment with FF/VI or placebo and assessed whether changes correlated with exhaled nitric oxide levels as a measure of airway inflammation. Methods: This was a single-center, randomized, double-blind, placebo-controlled, two-period, crossover, repeat-dose study. Adults with asthma (forced expiratory volume in 1 s ≥ 60% predicted; fraction of exhaled nitric oxide [FeNO] > 40 parts per billion) received once-daily FF/VI 100 µg/25 µg or placebo for 14 days, followed by a 21-day washout period. Serum samples were taken at pre-dose (T1), and 15 and 21 days (T2 and T3, respectively) post dose in each period. The metabolomic and lipidomic profiles were analyzed by liquid chromatography with tandem mass spectrometry and polar liquid chromatography platforms, and ions were matched to a library of standards for metabolite identification and quantification. FeNO values at each timepoint were evaluated for correlations with the biochemical data. Results: Of 27 randomized participants (mean age 24.5 years, 63% male), 26 provided serum samples for metabolomic analysis. A total of 1969 metabolites were identified, 1634 of which corresponded to a named structure in a reference library. Treatment-related changes in the metabolome were generally subtle, with a modest increase in metabolite perturbations across timepoints. The percentage of metabolites with significant changes (p < 0.05 for all) (increases↑/decreases↓) versus placebo were: 2.1% (1.1%↑/1.0%↓), 6.7% (0.46%↑/6.2%↓) and 11.8% (0.86%↑/10.9%↓) at T1, T2 and T3, respectively. Treatment with FF/VI reduced FeNO levels by 60%, whereas the systemic intermediates involved in NO biosynthesis remained unaffected. Evidence of systemic anti-inflammatory activity was seen in complex lipid pathways, suggesting reduced phospholipase-A2 activity, but without downstream impact on free fatty acids or inflammatory mediators. Consistent with the pathogenesis of asthma, there was evidence of higher fatty acid β-oxidation and lower glycolysis in the placebo arm; this pattern was reversed in the treatment arm. Conclusions: Despite the prolonged airway anti-inflammatory action of FF/VI, this was accompanied by only subtle systemic metabolomic and lipidomic changes. Trial registration Prospectively registered on ClinicalTrials.gov registry number NCT02712047

Objective: The aim of this study was toidentify dose-related systemic effects of inhaled glucocorticoids (GCs) on the global metabolome. Design and methods: Metabolomics/lipidomic analysis from plasma was obtained from 54 subjects receiving weekly escalating doses (µg/day) of fluticasone furoate (FF; 25, 100, 200, 400 and 800), fluticasone propionate (FP; 50, 200, 500, 1000 and 2000), budesonide (BUD; 100, 400, 800, 1600 and 3200) or placebo. Samples (pre- and post-dose) were analysed using ultrahigh-performance liquid chromatography-tandem mass spectroscopy and liquid chromatography-mass spectrometry. Ions were matched to library standards for identification and quantification. Statistical analysis involved repeated measures ANOVA, cross-over model, random forest and principal component analysis using log-transformed data. Results: Quantifiable metabolites (1971) had few significant changes (% increases/decreases; P < 0.05) vs placebo: FF 1.34 (0.42/0.92), FP 1.95 (0.41/1.54) and BUD 2.05 (0.60/1.45). Therapeutic doses had fewer changes: FF 0.96 (0.36/0.61), FP 1.66 (0.44/1.22) and BUD 1.45 (0.56/0.90). At highest/supratherapeutic doses, changes were qualitatively similar: reduced adrenal steroids, particularly glucuronide metabolites of cortisol and cortisone and pregnenolone metabolite DHEA-S; increased amino acids and glycolytic intermediates; decreased fatty acid β-oxidation and branched-chain amino acids. Notable qualitative differences were lowered dopamine metabolites (BUD) and secondary bile acid profiles (BUD/FF), suggesting CNS and gut microbiome effects. Conclusions: Dose-dependent metabolomic changes occurred with inhaled GCs but were seen predominately at highest/supratherapeutic doses, supporting the safety of low and mid therapeutic doses. At comparable therapeutic doses (FF 100, FP 500 and BUD 800 µg/day), FF had the least effect on the most sensitive markers (adrenal steroids) vs BUD and FP.

Inhaled corticosteroid (ICS)-containing therapies are the mainstay of pharmacological management of asthma. They can be administered alone or in combination with a long-acting bronchodilator, depending on asthma severity, and may also be supplemented with short-acting bronchodilators for as-needed rescue medication. Adherence to asthma therapies is generally poor and characterized by underuse of ICS therapies and over-reliance on short-acting bronchodilators, which leads to poor clinical outcomes. This article reviews efficacy versus systemic activity profiles for various dosing regimens of budesonide (BUD) and fluticasone propionate (FP). We performed a structured literature review of BUD and FP regular daily dosing, and BUD/formoterol (FOR) as-needed dosing, to explore the relationship between various dosing patterns of ICS regimens and the risk–benefit profile in terms of the extent of bronchoprotection and cortisol suppression. In addition, we explored how adherence could potentially affect the risk–benefit profile, in patients with mild, moderate, and moderate-to-severe asthma. With a specific focus on BUD or FP-containing treatments, we found that regular daily ICS and ICS/long-acting β₂-agonist (LABA) dosing had a greater degree of bronchoprotection than as-needed BUD/FOR dosing or BUD/FOR maintenance and reliever therapy (MART) dosing, and still maintained low systemic activity. We also found that the benefits of regular daily ICS dosing regimens were diminished when adherence was low (50%); the shorter duration of bronchoprotection observed was similar to that seen with typical as-needed BUD/FOR usage. These findings have implications for aiding clinicians with selecting the most suitable treatment option for asthma management, and subsequent implications for the advice clinicians give their patients.

Introduction This study compared the bronchoprotective and benefit/risk profiles of various inhaled corticosteroid (ICS) dosing regimens in mild asthma. Methods A pharmacokinetic/pharmacodynamic model was developed and validated describing the relationship between ICS dose and time-course for airway bronchoprotection, [provocative concentration of adenosine monophosphate (AMP) causing ≥ 20% decline in forced expiratory volume in 1 s (FEV₁) (AMP PC₂₀)], for fluticasone furoate (FF), fluticasone propionate (FP) and budesonide (BUD). For regular ICS maintenance therapy (100% and 50% adherence) and infrequent or as-needed use (dosing 3–4 times per week), treatment effectiveness was expressed as percent time during 28 days when bronchoprotection exceeded either the threshold for a treatment-related bronchoprotective effect (AMP PC₂₀ ≥ 0.25 doubling dose) or the threshold for a clinically significant bronchoprotective effect (AMP PC₂₀ ≥ 1.0 doubling dose). This value was divided by the total ICS dose administered expressed in prednisolone equivalents to give a therapeutic index (TI). Results The model-predicted time course of ICS-induced bronchoprotection with regular daily maintenance dosing and 100% adherence showed that all ICS at the highest recommended doses for mild asthma exceeded the threshold for clinically significant bronchoprotective effect for all or most of the 28-day dosing period, mean (90% CI); 100% (96.1–100), 99.9% (8.0–100) and 100% (58.2–100) with TI values of 16.9, 6.6 and 5.4 for FF 100 µg OD, FP 200 µg BID and BUD 200 µg BID, respectively. For simulated poor adherence (50%) to regular daily maintenance therapy, corresponding mean (90% CI) values were; 75.7% (39.4–89.1), 52.3% (0.7–69.2) and 51.3% (28.6–58.3) with TI values of 25.7, 6.9 and 5.6. For simulated infrequent/as needed use the corresponding values were; 77.0% (37.6–87.0), 25.5% (0.0–38.0) and 26.2% (14.3–31.5) with TI values of 26.1, 6.7 and 5.7. For all regimen/scenarios, FF had the most sustained efficacy and favourable TI followed by FP and BUD. Conclusions At doses recommended for mild asthma, all ICS regimens provide sustained bronchoprotective efficacy when dosed regularly with high adherence. With poor adherence or use 3–4 times per week (infrequent/as needed), longer-acting ICS molecules will more likely provide sustained protection and a better TI versus shorter duration of action molecules (FF > FP ≥ BUD). These data highlight the benefits of using ICS as regular daily maintenance dosing in mild asthma and the potential risks of under-treatment with ICS (which may occur with ICS/formoterol as-needed approach in mild persistent asthma) associated with reduced levels of bronchoprotection.

Intranasal corticosteroid (INCS) therapy is the preferred treatment option for allergic rhinitis (AR). Although all INCSs for the treatment of AR are considered safe and effective, differences in potency, molecular structure features and physicochemical and pharmacokinetic properties could result in differences in clinical efficacy and safety. Higher glucocorticoid receptor (GR) binding affinity of INCS is associated with higher lipophilicity, nasal tissue retention and topical potency. Higher topical potency is also accompanied by low oral bioavailability and high systemic clearance conferring low systemic exposure, reduced potential for systemic adverse effects and an improved therapeutic index. It has been shown that adverse events related to systemic exposure of INCSs in children are low. Although INCSs mostly produce low systemic effects, use of an INCS with low systemic exposure in patients on multiple corticosteroid (CS) therapies could help reduce the total systemic burden of CS therapy. Despite differences in topical potency, physicochemical and pharmacokinetic properties between INCSs, clinical studies of INCSs in the treatment of AR generally show no clinically important differences between these compounds, and poor correlation between INCS topical potency and clinical response. However, the lack of head-to-head comparisons of INCSs in clinical studies conducted in more severe AR patients should be noted. This narrative review provides an assessment of the therapeutic relevance of topical potency and the physicochemical and pharmacokinetic properties of INCSs and describes for the first time the relationship between topical potency and therapeutic index using pharmacological features of INCSs. It concludes that higher GR binding affinity and topical potency can potentially improve the therapeutic index of an INCS. Therefore, both efficacy and systemic exposure profiles should be considered when comparing INCS regimens in terms of therapeutic equivalence, to aid clinical decision-making and avoid the assumption that all INCS formulations are the same when considering treatment options.