DElaying Disease Progression In COPD with Early Initiation of Dual Bronchodilator or Triple Inhaled PharmacoTherapy (DEPICT): A Predictive Modelling Approach.

INTRODUCTION: Clinical studies demonstrate an accelerated decline in lung function in patients with moderate chronic obstructive pulmonary disease (COPD) (Global Initiative for Chronic Obstructive Lung Disease [GOLD] grade 2) versus severe and very severe COPD (GOLD grades 3 and 4). This predictive modelling study assessed the impact of initiating pharmacotherapy earlier versus later on long-term disease progression in COPD. METHODS: The modelling approach used data on decline in forced expiratory volume in 1 s (FEV1) extracted from published studies to develop a longitudinal non-parametric superposition model of lung function decline with progressive impact of exacerbations from 0 per year to 3 per year and no ongoing pharmacotherapy. The model simulated decline in FEV1 and annual exacerbation rates from age 40 to 75 years in COPD with initiation of long-acting anti-muscarinic antagonist (LAMA)/long-acting beta2-agonist (LABA) (umeclidinium (UMEC)/vilanterol (VI)) or triple (inhaled corticosteroid (ICS)/LAMA/LABA; fluticasone furoate (FF)/UMEC/VI) therapy at 40, 55 or 65 years of age. RESULTS: Model-predicted decline in FEV1 showed that, compared with 'no ongoing' therapy, initiation of triple or LAMA/LABA therapy at age 40, 55 or 65 years preserved an additional 469.7 mL or 236.0 mL, 327.5 mL or 203.3 mL, or 213.5 mL or 137.5 mL of lung function, respectively, by the age of 75. The corresponding average annual exacerbation rates were reduced from 1.57 to 0.91, 1.06 or 1.23 with triple therapy or to 1.2, 1.26 and 1.4 with LAMA/LABA therapy when initiated at 40, 55 or 65 years of age, respectively. CONCLUSIONS: This modelling study suggests that earlier initiation of LAMA/LABA or triple therapy may have positive benefits in slowing disease progression in patients with COPD. Greater benefits were demonstrated with early initiation therapy with triple versus LAMA/LABA.

Pharmacology Versus Convenience: A Benefit/Risk Analysis of Regular Maintenance Versus Infrequent or As-Needed Inhaled Corticosteroid Use in Mild Asthma.

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.

Therapeutic index of inhaled corticosteroids in asthma: A dose-response comparison on airway hyperresponsiveness and adrenal axis suppression.

AIMS: To compare the airway potency, systemic activity and therapeutic index of three inhaled corticosteroids that differ in glucocorticoid receptor binding affinity, physicochemical and pharmacokinetic properties. METHODS: This escalating-dose, placebo-controlled, cross-over study randomised adults with asthma to 1 or 2 treatment periods with ≥25 days washout in-between. Each treatment period comprised five 7-day dose escalations (µg/d): fluticasone furoate (FF; 25 → 100 → 200 → 400 → 800), fluticasone propionate (FP; 50 → 200 → 500 → 1000 → 2000), budesonide (BUD; 100 → 400 → 800 → 1600 → 3200) or placebo. Airway hyperresponsiveness to adenosine-5'-monophosphate (AMP PC20 ) was assessed on day 8. Plasma cortisol was assessed on day 1 (predose baseline) and from pre-PM dose on day 6 to pre-PM dose day 7 (24-h weighted mean). RESULTS: Fifty-four subjects were randomised. FF showed greater airway potency than FP and BUD (AMP PC20 dose at which 50% of the maximum effect is achieved [ED50 ] values: 48.52, 1081.27 and 1467.36 µg/d, respectively). Systemic activity (cortisol suppression) ED50 values were 899.99, 1986.05 and 1927.42 µg/d, respectively. The therapeutic index (ED50 cortisol suppression/ED50 AMP PC20 ) was wider for FF (18.55) than FP (1.84) and BUD (1.31). FF 100 µg/d and 200 µg/d were both comparable in terms of airway potency with high doses of FP (≥1000 µg twice daily [BID]) and BUD (≥1500 µg/BID). The systemic activity of FF 100 µg/d and 200 µg/d (cortisol suppression: 7.41% and 14.28%, respectively) was comparable with low doses of FP (100 µg/BID and 250 µg/BID) and BUD (100 µg/BID and 200 µg/BID). CONCLUSION: This study provides evidence that FF can provide more protection against airway hyperresponsiveness, with less systemic activity, than FP or BUD. This suggests that all inhaled corticosteroids are not therapeutically similar and may differ in their therapeutic index. (203162; NCT02991859).

Pharmacodynamic Studies to Demonstrate Bioequivalence of Oral Inhalation Products.

In the session on "Pharmacodynamic studies to demonstrate efficacy and safety", presentations were made on methods of evaluating airway deposition of inhaled corticosteroids and bronchodilators, and systemic exposure indirectly using pharmacodynamic study designs. For inhaled corticosteroids, limitations of measuring exhaled nitric oxide and airway responsiveness to adenosine for anti-inflammatory effects were identified, whilst measurement of 18-h area under the cortisol concentration-time curve was recommended for determining equivalent systemic exposure. For bronchodilators, methacholine challenge was recommended as the most sensitive method of determining the relative amount of ß-agonist or anti-muscarinic agent delivered to the airways. Whilst some agencies, such as the Food and Drug Administration (FDA), do not require measuring systemic effects when pharmacokinetic measurements are feasible, the European Medicines Agency requires measurement of heart rate and serum potassium, and some require serial electrocardiograms when bioequivalence is not established by pharmacokinetic (PK) studies. The Panel Discussion focused on whether PK would be the most sensitive marker of bioequivalence. Furthermore, there was much discussion about the FDA draft guidance for generic fluticasone propionate/salmeterol. The opinion was expressed that the study design is not capable of detecting a non-equivalent product and would require an unfeasibly large sample size.

Clinical pharmacology of Cilomilast.

Chronic obstructive pulmonary disease (COPD) is a multicomponent, chronic inflammatory disease of the lungs with systemic complications. The majority of the inflammation occurs in the peripheral airways and lung parenchyma. It is a progressive disease, leading to disability and eventual death, despite conventional therapy. Inflammatory activity can be reduced by increasing intracellular cyclic adenosine-3',5'-monophosphate (cAMP) through inhibition of phosphodiesterase (PDE) IV, the principal PDE isoenzyme within pro-inflammatory cells, including eosinophils, mast cells, macrophages, lymphocytes, neutrophils and epithelial cells. PDE IV inhibition also has other effects, including relaxation of airway smooth muscle, suppression of smooth muscle mitogenesis and modulation of excitatory activity in pulmonary nerves. Cilomilast is a systemically available, second-generation, selective PDE IV inhibitor. It retains the therapeutic activity of the first-generation PDE IV inhibitors but lacks their profound emetic effect. Cilomilast is the first drug to demonstrate a reduction of tissue cells considered central to the ongoing inflammatory process (macrophages and CD8+ lymphocytes) in patients with stable COPD. Cilomilast is completely absorbed following oral administration and has negligible first-pass metabolism. It exhibits linear pharmacokinetics, with low between-subject variability. Cilomilast is highly protein bound (99.4%), but this binding is concentration-independent at clinically relevant doses, and it has a small volume of distribution at steady state (17L). Plasma clearance (approximately 2 L/h) is almost entirely metabolic, through multiple parallel pathways. Its terminal elimination half-life is approximately 6.5 hours and steady state is rapidly achieved with twice-daily administration. The most abundant metabolite, formed by the action of cytochrome P450 2C8, has <10% of the activity of the parent molecule. Cilomilast pharmacokinetics in COPD patients were consistent with those in healthy subjects. Smoking, age and ethnicity had no clinically relevant effects. Total plasma cilomilast pharmacokinetic parameters did not change significantly with renal or hepatic impairment, but concentrations of unbound cilomilast increased with declining renal or hepatic function. Cilomilast had no clinically relevant interactions with a range of drugs likely to be coadministered to patients with COPD, with the exception of erythromycin where concurrent administration with cilomilast was associated with an increased incidence of gastrointestinal adverse events, a pharmacodynamic interaction predicted by their secondary pharmacology. Nausea was the principal adverse reaction seen in healthy subjects taking cilomilast, but this was reduced by administration with food or by use of simple dose-escalation regimens. Cilomilast has not shown a propensity for any of the serious cardiac or neurological adverse effects associated with theophylline. Cilomilast exhibits favourable and predictable pharmacokinetics, has few clinically relevant drug-drug interactions and has demonstrated effects on measures of inflammation of potential benefit in the treatment of COPD. It is generally well tolerated and has not generated safety concerns in any clinical study.