In vitro pharmacological characterization of vilanterol, a novel long-acting β2-adrenoceptor agonist with 24-hour duration of action

Phamacology of fluticasone furoate and vilanterol trifenatate combination therapy for asthma

INTRODUCTION

Fluticasone furoate (FF) is a novel inhaled corticosteroid (ICS). Vilanterol trifenate (VI) is a new inhaled, selective, long - acting β2 adrenergic agonist (LABA). It is now also marketed as a novel once daily combined ICS/LABA indicated for treatment of moderate and severe asthma.

AREAS COVERED

FF has a highly specific, fast association and slow dissociation from the glucocorticoid receptor, with a 24 hr duration of action. This, combined with a slow transport out of respiratory cells, creates a long tissue retention period. Vilanterol trifenate (VI) is a new inhaled, selective, long - acting β2 adrenergic agonist, also with a rapid onset of action with a maximal effect within 6 mins and prolonged lung retention with effects on lung function over 24 hours. Expert commentary: Multiple Phase I-III efficacy studies performed on FF and VI have shown an improvement in spirometry as well as symptom control in asthma. The development of once daily ICS/LABA combinations may potentially improve adherence to asthma therapy, but this has yet to be demonstrated.

Randomised, double-blind, placebo-controlled, cross-over single dose study of the bronchodilator duration of action of combination fluticasone furoate/vilanterol inhaler in adult asthma

BACKGROUND

Fluticasone furoate (FF)/vilanterol (VI) is a once-daily maintenance treatment for asthma and chronic obstructive pulmonary disease. The duration of bronchodilation beyond 24 h has not been determined previously.

METHODS

Adults aged 18-65 (n = 32), with asthma and reversibility to salbutamol (≥15% and ≥200 mL increase in forced expiratory volume in 1 s [FEV₁]) participated in a double-blind, placebo-controlled, crossover study. Patients were admitted to a clinical trials unit for 72 h, and inhaled, in random order, placebo or FF/VI 100/25 mcg via ELLIPTA dry powder inhaler on two occasions 7-14 days apart. FEV₁ was measured at baseline, 15 and 30 min, 1, 2, 4, 12, 24, 36, 48, 60, and 72 h. The differences in change in FEV₁ from baseline between treatments and corresponding two-sided 95% confidence intervals (CI) were calculated at each time point.

FINDINGS

FF/VI produced a rapid onset of bronchodilation (adjusted mean difference in change from baseline in FEV₁ versus placebo at 15 min, 252 mL [95% CI 182-322]). Maximum bronchodilation was observed at 12 h (adjusted mean difference in the change from baseline in FEV₁, 383 mL [95% CI 285-481]). Bronchodilation was maintained throughout the 72-h assessment period (adjusted mean difference in the change in FEV₁ from baseline at 72 h, 108 mL (95% CI 15-200]). FF/VI was well tolerated and no serious side effects were reported.

INTERPRETATION

A single dose of FF/VI 100/25 mcg showed evidence of a 72-h bronchodilator duration of action in adults with asthma.

Cell membranes… and how long drugs may exert beneficial pharmacological activity in vivo

The time course of the beneficial pharmacological effect of a drug has long been considered to depend merely on the temporal fluctuation of its free concentration. Only in the last decade has it become widely accepted that target-binding kinetics can also affect in vivo pharmacological activity. Although current reviews still essentially focus on genuine dissociation rates, evidence is accumulating that additional micro-pharmacokinetic (PK) and -pharmacodynamic (PD) mechanisms, in which the cell membrane plays a central role, may also increase the residence time of a drug on its target. The present review provides a compilation of otherwise widely dispersed information on this topic. The cell membrane can intervene in drug binding via the following three major mechanisms: (i) by acting as a sink/repository for the drug; (ii) by modulating the conformation of the drug and even by participating in the binding process; and (iii) by facilitating the approach (and rebinding) of the drug to the target. To highlight these mechanisms, we focus on drugs that are currently used in clinical therapy, such as the antihypertensive angiotensin II type 1 receptor antagonist candesartan, the atypical antipsychotic agent clozapine and the bronchodilator salmeterol. Although the role of cell membranes in PK-PD modelling is gaining increasing interest, many issues remain unresolved. It is likely that novel biophysical and computational approaches will provide improved insights in the near future.

Pharmacodynamic and pharmacokinetic assessment of fluticasone furoate + vilanterol for the treatment of asthma

INTRODUCTION

The pharmacokinetic (PK) and pharmacodynamic (PD) effects of long-acting β2-agonists and mostly inhaled corticosteroids (ICSs) shape the efficacy and safety of these agents in the treatment of asthma. In fact, the PK and PD characteristics of the drug largely determine the degree of pulmonary targeting Areas covered. In this review, we summarize the PK and PD properties of inhaled fluticasone furoate (FF) and vilanterol trifenatate (VI) and their fixed-dose combination (FDC) for the treatment of asthma Expert opinion. It is difficult to interpret the data that we have described because the preclinical and clinical development of FF/VI FDC was not really based on solid information on quantitative PK/PD approach. Unfortunately, for both FF and VI we only know concentrations in systemic blood, a compartment that is downstream of both target and non-target respiratory tissue. This lack of information does not allow us to understand the temporal relationship between the delivered dose and the drug concentration at the sites of action within the lungs. In addition, all studies performed with FF and VI did not address the fundamental issue that asthma can significantly alter lung deposition, absorption and also clearance of inhaled medicines.

Fluticasone furoate/Vilanterol 92/22 μg once-a-day vs Beclomethasone dipropionate/ Formoterol 100/6 μg b.i.d.: a 12-week cost analysis in mild-to-moderate asthma

Background

Asthma is a disease with high cost for the National Health Service. Two of the most recent LABA/ICS combinations for persistent bronchial asthma are Beclomethasone dipropionate/Formoterol (B/F) delivered via the Nexthaler device and Fluticasone furoate/Vilanterol (F/V) delivered via the Ellipta device. No comparison has been carried out yet in terms of cost analysis in asthma, to our knowledge. Aim of the present monocentric, observational, retrospective study was to calculate and compare the costs of mild-to-moderate asthma patients assuming B/F 100/6 μg b.i.d. to those of patients assuming F/V 92/22 μg once-a-day over a 12-week treatment period from the Italian National Health Service perspective.

Methods

Data were obtained automatically and anonymously from the institutional database of the Lung Unit of the Specialist Medical Centre (CEMS), Verona, Italy, UNI EN ISO 9001-2008 validated. FEV₁ values, number of relapses, healthcare resources as hospitalizations due to asthma relapses, days of hospitalization, general practitioner (GP), specialist visits, and days of inactivity, were recorded over the study period together with the use of extra medications (systemic steroids and antibiotics). In order to compare the outcomes achieved in both groups, the propensity score matching method was used in STATA, and statistical significance was accepted for p < 0.05.

Results

Clinical data of 77 patients treated with B/F b.i.d (Group A) and of 40 patients treated with F/V 92/22 μg once-a-day (Group B) were selected. The PS-matching process, designed as matching on the baseline covariates, gender, age, FEV₁ and comorbidities, returned a cohort of 40 group A patients of the entire cohort matched with 40 patients of group B, fully comparable for demographics and clinical characteristics. In the PS-matched cohort, the mean (±SE) number of relapses per patient during the follow-up was 0.53 (±0.12) in group A and 0.28 (±0.07) in group B. In group A, n = 25 (62.50 %), n = 9 (22.50 %), and n = 6 (15 %) patients had 0, 1, 2 relapses, respectively. In group B, n = 29 (72.50 %), and n = 11 (27.50 %) had 0 and 1 relapse, respectively. Over the study period, the average number of hospitalizations per patient was 0.15 (±0.06), with 0.28 (±0.12) days of hospitalization in group A, and 0.08 (±0.04) with 0.08 (±0.04) days of hospitalization in group B, respectively. The difference between the two groups in terms of FEV₁(L) improvement vs baseline was 0.11 in favour of group B (p = 0.007). When results were compared, the improvement in lung function obtained in group B proved significantly higher both in terms of absolute FEV₁ and of FEV₁ % predicted.

The mean (±SE) cost of hospitalizations per patient was € 345.30 (±133.23) in group A and € 172.65 (±98.18) in group B, respectively, with a mean not significant difference of - € 172.65 in favour of group B (p = 0.9). In particular, the mean (±SE) cost for visits per patient was € 26.82 (±3.73) in group A and € 11.36 (±2.30) in group B (p = 0.002), and the mean cost for rescue medications per patient was € 35.24 (±6.93) in group A, and € 18.73 (±3.38) in group B, respectively (p = 0.05).

Conclusions

Even if both ICS/LABA combinations were checked over a limited period of time, they seem characterized by a different profile in terms of effect on lung function and economic impact on mild-to-moderate asthma. The once-daily inhalation of combined Fluticasone furoate/Vilanterol 92/22 μg showed the potential for enhanced clinical outcomes and reduced costs when compared to Beclomethasone dipropionate/Formoterol 100/6 μg b.i.d.

Vilanterol trifenatate for the treatment of COPD

INTRODUCTION

Currently the treatment of chronic obstructive pulmonary disease (COPD) has limited effectiveness and there is a need to develop new drugs. International guidelines recommend the use of long-acting bronchodilators (β2 agonists and anti-cholinergics/muscarinics), inhaled steroids and associations between these drugs in the maintenance treatment of moderate-to-severe COPD.

AREA COVERED

Vilanterol trifenate is a new once-daily highly selective β2-agonist available in USA and Europe in association with umeclidinium bromide (a long-acting anti-muscarnic agent) and fluticasone furoate (an inhaled corticosteroid) for the once-daily maintenance treatment of COPD. Vilanterol combined in fixed-dose treatments has been tested in numerous clinical trials involving thousands of patients. Expert commentary: These new once-daily formulations have the potential to improve compliance to long-term inhaled therapy. This paper will review the clinical and experimental data regarding vilanterol use in the regular treatment of COPD as well as provide a critical discussion of possible future treatment settings.

Randomised trial of once-daily vilanterol in children with asthma on inhaled corticosteroid therapy

BACKGROUND

Inhaled corticosteroids (ICS) are effective maintenance treatments for childhood asthma; however, many children remain uncontrolled. Vilanterol (VI) is an inhaled long-acting beta-2 agonist which, in combination with the ICS fluticasone furoate, is being explored as a once-daily treatment for asthma in children. We evaluated the dose-response, efficacy, and safety of once-daily VI (6.25 μg, 12.5 μg and 25 μg) administered in the evening over 4 weeks, on background fluticasone propionate (FP) in children with asthma inadequately controlled on ICS.

METHODS

This was a Phase IIb, multicentre, randomised, double-blind, parallel-group, placebo-controlled study in children ages 5-11 years with persistent asthma on ICS and as-needed short-acting beta-agonist. The study comprised a 4-week run-in, 4-week treatment period, and 1-week follow-up. From study start, children replaced their current ICS with open-label FP 100 μg twice daily. Children were randomised to receive placebo, VI 6.25 μg, VI 12.5 μg or VI 25 μg once daily. Primary endpoint was treatment difference between VI 25 and placebo groups in mean change from baseline in evening peak expiratory flow averaged over the 4-week treatment. Secondary endpoints included change from baseline in trough forced expiratory volume in one second (FEV1) at Week 4 and change from baseline in percentage of rescue-free and symptom-free 24-h periods. Safety assessments included incidence of adverse events (AEs) and asthma exacerbations.

RESULTS

In total, 456 children comprised the intention-to-treat population. The adjusted treatment difference between VI 25 and placebo groups for the primary endpoint was not statistically significant (p = 0.227) so no statistical inference was made for other VI dose comparisons or other endpoints. No difference in change from baseline in trough FEV1 was observed for any VI treatments versus placebo; however, VI 25 resulted in an additional 0.6 rescue-free days and 0.7 symptom-free days per week versus placebo. The incidence of AEs was slightly higher in the VI groups (28-33 %) versus placebo (22 %). Nine children experienced asthma exacerbations during the treatment period.

CONCLUSION

VI plus FP did not result in significant improvements in lung function versus placebo plus FP, but was well tolerated at all doses assessed.

TRIAL REGISTRATION

NCT01573767 (ClinicalTrials.gov).

Striving for optimal bronchodilation: focus on olodaterol

β2-agonists were introduced in the 1940s as bronchodilators to be used in obstructive respiratory diseases. Long-acting β2-agonists have been a mainstay of bronchodilating treatment for decades. Recently, agents extending their effect to 24 hours and thus allowing the once-daily administration were introduced, defined as very-long-acting β2-agonists. Olodaterol is a new very-long-acting β2-agonist that has been shown, in controlled trials, to improve lung function as well as clinical outcomes and quality of life. Most of these trials included patients with moderate, severe, or very severe chronic obstructive pulmonary disease (COPD). Olodaterol has a rapid onset of action (comparable to formoterol) and provides bronchodilation over 24 hours. In controlled trials, olodaterol was shown to be as effective as formoterol twice daily, but significantly superior in terms of quality of life in patients with COPD. The safety profile of olodaterol was very good, with a rate of adverse events, including the cardiac events that are particularly important for β2-agonists, comparable to placebo. Also, the efficiency of the Respimat(®) device concurs to the effectiveness of treatment.

Once-daily fluticasone furoate/vilanterol versus twice daily combination therapies in asthma-mixed treatment comparisons of clinical efficacy

Background

Fluticasone furoate (FF)/vilanterol (VI) is a once-daily inhaled corticosteroid (ICS)/long-acting beta₂ agonist (LABA) combination. FF/VI, 92/22mcg and 184/22mcg, are approved in Europe as maintenance therapy in persistent asthma. We report data from mixed treatment comparisons (MTC) of once-daily FF/VI against established twice-daily ICS/LABA combination therapies on clinical efficacy outcomes.

Methods

Data from 31 parallel-group randomised controlled trials (RCTs) of ICS/LABA, of ≥8 weeks’ duration in patients aged ≥12 years with asthma, identified by systematic review, were analysed using covariate-adjusted Bayesian hierarchical models for four efficacy outcomes (primary analysis). Lung function, assessed by change from baseline morning peak expiratory flow (PEF) (n = 18 studies) and forced expiratory volume in 1 s (FEV₁) (n = 28), was the outcome of primary interest. Secondary objectives were assessment of relative efficacy in terms of exacerbation rates (n = 6) and health status (n = 7). Overall, 24 different treatment arms were included in the MTC; we report findings comparing FF/VI (92/22mcg and 184/22mcg) with fluticasone propionate/salmeterol (FP/SAL) (250/50mcg and 500/50mcg) and budesonide/formoterol (BUD/FORM) (320/9mcg and 640/18mcg).

Results

For PEF (margin = 12 l/min), FF/VI 92/22mcg demonstrated ≥94 % probability and FF/VI 184/22mcg >99 % probability of non-inferiority to corresponding doses of both FP/SAL and BUD/FORM. For FEV₁ (margin = 100 ml), FF/VI demonstrated ≥98 % (92/22mcg) and >99 % (184/22mcg) probability of non-inferiority to both FP/SAL and BUD/FORM. Findings for exacerbations were inconclusive due to lack of data: FF/VI 92/22mcg demonstrated 74 % and 82 % probability of non-inferiority (margin = 10 %) to FP/SAL 250/50mcg and BUD/FORM 320/9mcg, respectively. For Asthma Quality of Life Questionnaire (AQLQ) score, FF/VI 92/22mcg demonstrated >99 % and 90 % probability of non-inferiority (margin = 0.25) to FP/SAL 250/50mcg and BUD/FORM 320/9mcg. Data were unavailable to assess non-inferiority of FF/VI 184/22mcg on exacerbations or AQLQ.

Conclusions

Both strengths of once-daily FF/VI in asthma were comparable with corresponding doses of twice-daily FP/SAL and BUD/FORM in terms of lung function in this MTC analysis. FF/VI 92/22mcg was comparable with FP/SAL and BUD/FORM on AQLQ, but exacerbation results were inconclusive. Model limitations include disconnected treatment networks and variability across studies. Our data support previous RCT findings suggesting that the efficacy of once-daily FF/VI in improving lung function and health status in asthma is comparable with twice-daily ICS/LABAs.

Electronic supplementary material

The online version of this article (doi:10.1186/s40733-015-0016-0) contains supplementary material, which is available to authorized users.

Comparison of early effects of budesonide/formoterol maintenance and reliever therapy with fluticasone furoate/vilanterol for asthma patients requiring step-up from inhaled corticosteroid monotherapy

BACKGROUND

If asthma patients fail to achieve symptom control using a medium dose of inhaled corticosteroid (ICS) alone, addition of a long-acting β2 agonist (LABA) is the preferred treatment. Currently, there are several combinations of ICS/LABA that are available, each of which has a different property. Here, we aimed to compare the early effects of budesonide/formoterol (BUD/FM; Symbicort(®)) for maintenance and reliever therapy (SMART) with a fixed dose of fluticasone furoate/vilanterol (FF/VI; Relvar(®)).

METHODS

Inadequately controlled asthma patients (defined as having an Asthma Control Questionnaire, 5-item version [ACQ5] score≥1.5) with a fractional exhaled nitric oxide (FeNO) value > 35 ppb, who had been treated with a medium dose of ICS alone, were enrolled. Patients were randomized into two groups and treated with two inhalations twice-daily of BUD/FM 160/4.5 μg plus as-needed BUD/FM (SMART group, n = 15) or one inhalation once-daily of FF/VI 100/25 μg plus as-needed procaterol (FF/VI group, n = 15) for 4 weeks. Outcomes including FeNO, impulse oscillometry (IOS) parameters and ACQ5 scores were measured at 0, 2 and 4 weeks.

RESULTS

Both groups showed improvement in airway inflammation, pulmonary function and symptoms from baseline to 2 weeks. From 2 to 4 weeks, the SMART group exhibited continuous improvement in most measured parameters, whereas improvement in the FF/VI group seemed to reach a plateau transiently. Consequently, the SMART group showed significant improvement in the FeNO, IOS parameters (resonance frequency and integrated area of low frequency reactance) and ACQ5 score as compared with the FF/VI group at 4 weeks.

CONCLUSION

As compared with the FF/VI group, the SMART group achieved a greater improvement in FeNO, small airway parameters regarding IOS and ACQ score, in patients with airway inflammation and uncontrolled symptoms treated with a medium dose of ICS alone. In this 4-week study, these two ICS/LABA combination therapies showed different treatment outcomes; they must be investigated further to clarify suitable patient characters and the long term efficacies for each combination.

Fluticasone furoate/vilanterol: a review of its use in patients with asthma

Fluticasone furoate/vilanterol (Relvar(®)) is a once-daily, fixed combination of an inhaled corticosteroid (ICS) and a long-acting β2-adrenoreceptor agonist (LABA), delivered via a dry powder inhaler (Ellipta(®)). It is approved for the treatment of asthma in the EU and Japan, and is the first once-daily ICS/LABA to be available for this indication. Fluticasone furoate is an enhanced-affinity glucocorticoid receptor agonist, with potent anti-inflammatory activity. Vilanterol produces rapid and prolonged bronchodilation. In phase III trials in adolescents and adults with various levels of asthma uncontrolled on ICS and/or ICS/LABA, fluticasone furoate/vilanterol 100/25 or 200/25 µg once daily (approved dosages in the EU) significantly improved pulmonary function compared with placebo or equivalent dosages of fluticasone furoate alone (in some trials) or fluticasone propionate. In similar trials, fluticasone furoate/vilanterol 100/25 µg once daily was as effective as fluticasone propionate/salmeterol 250/50 µg twice daily in improving pulmonary function and significantly reduced the risk of severe asthma exacerbation relative to fluticasone furoate alone. In clinical trials, fluticasone furoate/vilanterol was generally well tolerated with fewer than 15 % of patients experiencing treatment-related adverse events, the most common of which were oral/oropharyngeal candidiasis, dysphonia, extrasystoles and cough. The tolerability profile of fluticasone furoate/vilanterol was generally similar to that of fluticasone propionate/salmeterol. Thus, fluticasone furoate/vilanterol is an effective and generally well tolerated ICS/LABA option for the treatment of uncontrolled asthma.

In vitro and in vivo preclinical profile of abediterol (LAS100977), an inhaled long-acting β2-adrenoceptor agonist, compared with indacaterol, olodaterol and vilanterol

Abediterol is a novel long-acting β2-adrenoceptor agonist (LABA) currently in development for once-daily combination maintenance therapy of asthma and COPD. This study investigated the preclinical profile of abediterol in terms of affinity, potency, selectivity, duration of action and cardiac effects in comparison to the marketed once-daily LABAs indacaterol, olodaterol and vilanterol. Abediterol was the compound with the highest in vitro potency for dog, guinea pig and human β2-adrenoceptors. In electrical field stimulated guinea pig trachea, abediterol demonstrated 5-, 44- and 77-fold greater potency than olodaterol, indacaterol and vilanterol, respectively. In anaesthetised guinea pigs, inhaled abediterol was also the most potent compound, with 5-20 times higher bronchoprotective potency than other once-daily LABAs against acetylcholine. The bronchoprotective half-life of abediterol in guinea pigs was 36h compared with 51h for indacaterol, 47h for olodaterol, and 18h for vilanterol. In anaesthetised dogs, abediterol also inhibited acetylcholine-induced bronchoconstriction, with higher potency than olodaterol and vilanterol [ID40 (dose inhibiting bronchoconstriction by 40%) of 0.059µg/kg, 0.180µg/kg and 2.870µg/kg, respectively]. In parallel, effects on heart rate in dogs were also measured. Abediterol showed greater safety index (defined as the ratio of the maximal dose without effect on heart rate and the ID40) than olodaterol and vilanterol (10.5 versus 4.9 and 2.4, respectively). Taken together, these data suggest that abediterol offers potent bronchodilation and a sustained duration of action suited to once-daily dosing, plus a reduced potential for class-related cardiac side effects.

A comparison of the efficacy of once-daily fluticasone furoate/vilanterole with twice-daily fluticasone propionate/salmeterol in asthma-COPD overlap syndrome

BACKGROUND

Asthma-chronic obstructive pulmonary disease overlap syndrome (ACOS) is important because patients with ACOS have significantly worse outcomes compared with those with asthma or chronic obstructive pulmonary disease (COPD) alone. Inhaled corticosteroids (ICS), together with a long-acting β2 agonist (LABA), are recommended, but no therapeutic studies for ACOS have been conducted. Recently, fluticasone furoate/vilanterole (FF/VI) has been approved as the first once-daily ICS/LABA combination therapy for asthma and COPD.

METHODS

A 12-week, randomized, open-label cross-over study was conducted in 16 patients with ACOS to compare the effectiveness of once-daily FF/VI 200/25 μg vs. twice-daily fluticasone propionate/salmeterol (FP/SAL) 500/50 μg. The study period included a 4-week run-in, the first 4-week treatment, and the second 4-week treatment. Respiratory functions, including forced expiratory volume in 1 s (FEV1) and respiratory impedance using the forced oscillation technique (FOT), were measured, as was fractional exhaled nitric oxide (FeNO). A COPD assessment test (CAT) scores and asthma control test (ACT) scores were recorded 0, 4, and 8 weeks after randomization.

RESULTS

The mean values for the FEV1 were 1.33 (±0.29) L in the run-in period, 1.38 (±0.39) L after the FP/SAL treatment period, and 1.47 (±0.38) L after the FF/VI treatment period. The FEV1 value after the FF/VI treatment was significantly greater than the value after the run-in period (p < 0.01). FOT parameters, FeNO levels, CAT scores, ACT scores, and other blood tests were not significantly different during the run-in period, the FP/SAL treatment period, and the FF/VI treatment period.

CONCLUSIONS

FF/VI, the first once-daily ICS/LABA, can provide substantial improvement in lung functions, indicating that FF/VI should be considered for the regular treatment of ACOS.

Umeclidinium/vilanterol: a review of its use as maintenance therapy in adults with chronic obstructive pulmonary disease

Umeclidinium/vilanterol (Anoro(®) Ellipta™; Laventair™) is an inhaled fixed-dose combination of a long-acting muscarinic receptor antagonist and a long-acting β2-adrenoceptor agonist. It is available in several countries, including Japan, the USA, Canada and those of the EU, where it is indicated for oral inhalation in adults with chronic obstructive pulmonary disease (COPD). Umeclidinium/vilanterol is administered once daily using the Ellipta™ multi-dose dry powder inhaler, which is regarded as easy to use. Umeclidinium/vilanterol (62.5/25 µg once daily, equivalent to a delivered dose of 55/22 µg once daily) was effective and well tolerated in adult patients with COPD participating in large, multicentre trials of up to 24 weeks' duration. Umeclidinium/vilanterol improved pulmonary function to a significantly greater extent than placebo and each of the individual components. Moreover, umeclidinium/vilanterol was significantly more effective than once-daily tiotropium bromide monotherapy and a twice-daily fixed combination of salmeterol/fluticasone propionate at improving pulmonary function. Umeclidinium/vilanterol also had beneficial effects on dyspnoea, use of rescue medication, exacerbations, health-related quality of life and, in one study, exercise endurance. Umeclidinium/vilanterol is generally well tolerated in patients with COPD, with the most common adverse events in clinical trials being headache and nasopharyngitis. Umeclidinium/vilanterol was not associated with a clinically relevant increased risk of cardiovascular adverse events in patients with COPD, when data from several clinical trials were pooled. Thus, inhaled umeclidinium/vilanterol extends the treatment options currently available for the maintenance treatment of adults with COPD and has the convenience of once-daily administration.

Umeclidinium/vilanterol combination inhaler efficacy and potential impact on current chronic obstructive pulmonary disease management guidelines

INTRODUCTION

Umeclidinium bromide (UM) with vilanterol (VI) is the first once-daily long-acting muscarinic antagonist/long-acting β2 agonist (LAMA/LABA) combination approved for use in the treatment of chronic obstructive pulmonary disease (COPD) in the USA. Prior to this, only combinations of short-acting bronchodilators and short-acting muscarinic antagonists were available in the USA as a single inhaler and they required frequent dosing. LAMA or LABA therapy is the recommended first choice for moderate-to-very severe COPD with combination therapy added if monotherapy fails to control patients' symptoms. This allows lower dosing of individual medications, which may limit adverse effects. It could also have the additional benefit of improving patient compliance by making medication regimens less laboring.

AREAS COVERED

A comprehensive literature search of journal articles and abstracts looking for trials that evaluated both the efficacy and the safety of UM/VI revealed that UM/VI improves patients' lung function and overall health status, while maintaining excellent safety and tolerability profiles compared to placebo and other bronchodilators.

EXPERT OPINION

Given the clinical efficacy, favorable safety profile and ease of use, clinicians may recommend UM/VI to patients with moderate-to-very severe COPD - a shift that could have significant impact on the management of COPD.

Positioning new pharmacotherapies for COPD

COPD imposes considerable worldwide burden in terms of morbidity and mortality. In recognition of this, there is now extensive focus on early diagnosis, secondary prevention, and optimizing medical management of the disease. While established guidelines recognize different grades of disease severity and offer a structured basis for disease management based on symptoms and risk, it is becoming increasingly evident that COPD is a condition characterized by many phenotypes and its control in a single patient may require clinicians to have access to a broader spectrum of pharmacotherapies. This review summarizes recent developments in COPD management and compares established pharmacotherapy with new and emerging pharmacotherapies including long-acting muscarinic antagonists, long-acting β-2 sympathomimetic agonists, and fixed-dose combinations of long-acting muscarinic antagonists and long-acting β-2 sympathomimetic agonists as well as inhaled cortiocosteroids, phosphodiesterase inhibitors, and targeted anti-inflammatory drugs. We also review the available oral medications and new agents with novel mechanisms of action in early stages of development. With several new pharmacological agents intended for the management of COPD, it is our goal to familiarize potential prescribers with evidence relating to the efficacy and safety of new medications and to suggest circumstances in which these therapies could be most useful.

Translational models of lung disease

The 2nd Cross Company Respiratory Symposium (CCRS), held in Horsham, U.K. in 2012, brought together representatives from across the pharmaceutical industry with expert academics, in the common interest of improving the design and translational predictiveness of in vivo models of respiratory disease. Organized by the respiratory representatives of the European Federation of Pharmaceutical Industries and Federations (EFPIA) group of companies involved in the EU-funded project (U-BIOPRED), the aim of the symposium was to identify state-of-the-art improvements in the utility and design of models of respiratory disease, with a view to improving their translational potential and reducing wasteful animal usage. The respiratory research and development community is responding to the challenge of improving translation in several ways: greater collaboration and open sharing of data, careful selection of the species, complexity and chronicity of the models, improved practices in preclinical research, continued refinement in models of respiratory diseases and their sub-types, greater understanding of the biology underlying human respiratory diseases and their sub-types, and finally greater use of human (and especially disease-relevant) cells, tissues and explants. The present review highlights these initiatives, combining lessons from the symposium and papers published in Clinical Science arising from the symposium, with critiques of the models currently used in the settings of asthma, idiopathic pulmonary fibrosis and COPD. The ultimate hope is that this will contribute to a more rational, efficient and sustainable development of a range of new treatments for respiratory diseases that continue to cause substantial morbidity and mortality across the world.

Therapeutic novelties of inhaled corticosteroids and bronchodilators in asthma

Orally inhaled agents are a key therapeutic class for treatment of asthma. Inhaled corticosteroids (ICS) are the most effective anti-inflammatory treatment for asthma thus representing the first-line therapy and bronchodilators complement the effects of ICSs. A significant body of evidence indicates that addition of a β2-agonist to ICS therapy is more effective than increasing the dose of ICS monotherapy. In this paper, pharmacological features of available ICSs and bronchodilators will be reviewed with a focus on fluticasone propionate/formoterol fumarate combination which represents the one of the most powerful ICS acting together with the most rapid active LABA.

Fluticasone furoate/vilanterol: a review of its use in chronic obstructive pulmonary disease

Fluticasone furoate/vilanterol (Relvar(®), Breo(®), Revinty(®)) is a fixed combination of a corticosteroid and a long-acting β2-adrenergic agonist (LABA) for once-daily use via a dry powder inhaler (Ellipta(®)). Fluticasone furoate/vilanterol 100/25 µg is approved for the treatment of chronic obstructive pulmonary disease (COPD) in several countries. This article reviews the clinical use of the combination in COPD and summarises pharmacological properties. Fluticasone furoate has enhanced affinity for the glucocorticoid receptor compared with other clinically used inhaled corticosteroids (ICS) and longer lung retention than fluticasone propionate. Vilanterol is highly selective for β2-adrenoreceptors and provides a rapid and prolonged duration of action. In phase 3 trials in patients with moderate to very severe COPD, overall, once-daily fluticasone furoate/vilanterol 100/25 µg improved pulmonary function more than placebo and fluticasone furoate alone and improved exacerbation rates more than vilanterol alone. With regard to pulmonary function, once-daily fluticasone furoate/vilanterol 100/25 μg was more effective than twice-daily fluticasone propionate/salmeterol 250/50 µg and similarly effective as twice-daily fluticasone propionate/salmeterol 500/50 μg. In 12-month trials, fluticasone furoate/vilanterol was generally well tolerated, and in 12- and 24-week trials, the incidence of adverse events was similar overall to that associated with the individual components or fluticasone propionate/salmeterol. However, as with the long-term use of all ICS agents, 12-month data indicate an increase in the risk of pneumonia with fluticasone furoate/vilanterol. In conclusion, fluticasone furoate/vilanterol is an effective and generally well tolerated additional LABA/ICS agent for the treatment of COPD with the added convenience of once-daily administration, which may improve treatment adherence in some patients.

'Partial' competition of heterobivalent ligand binding may be mistaken for allosteric interactions: a comparison of different target interaction models

BACKGROUND AND PURPOSE

Non-competitive drugs that confer allosteric modulation of orthosteric ligand binding are of increasing interest as therapeutic agents. Sought-after advantages include a ceiling level to drug effect and greater receptor-subtype selectivity. It is thus important to determine the mode of interaction of newly identified receptor ligands early in the drug discovery process and binding studies with labelled orthosteric ligands constitute a traditional approach for this. According to the general allosteric ternary complex model, allosteric ligands that exhibit negative cooperativity may generate distinctive 'competition' curves: they will not reach baseline levels and their nadir will increase in par with the orthosteric ligand concentration. This behaviour is often considered a key hallmark of allosteric interactions.

EXPERIMENTAL APPROACH

The present study is based on differential equation-based simulations.

KEY RESULTS

The differential equation-based simulations revealed that the same 'competition binding' pattern was also obtained when a monovalent ligand binds to one of the target sites of a heterobivalent ligand, even if this process is exempt of allosteric interactions. This pattern was not strictly reciprocal when the binding of each of the ligands was recorded. The prominence of this phenomenon may vary from one heterobivalent ligand to another and we suggest that this phenomenon may take place with ligands that have been proposed to bind according to 'two-domain' and 'charnière' models.

CONCLUSIONS AND IMPLICATIONS

The present findings indicate a familiar experimental situation where bivalency may give rise to observations that could inadvertently be interpreted as allosteric binding. Yet, both mechanisms could be differentiated based on alternative experiments and structural considerations.

Pharmacology of novel treatments for COPD: are fixed dose combination LABA/LAMA synergistic?

Bronchodilators are mainstay for the symptomatic treatment of chronic obstructive pulmonary disease (COPD) and the introduction of long-acting bronchodilators has led to an improvement in the maintenance treatment of this disease. Various clinical trials have evaluated the effects of fixed dose long-acting β2-agonists (LABA)/long-acting anti-muscarinics (LAMA) combinations and documented greater improvements in spirometry but such improvements do not always translate to greater improvements in symptom scores or reduction in the rates of exacerbation compared with a single component drug. An analysis of whether this significantly greater change in spirometry with combination therapy is additive or synergistic was undertaken and is the subject of this review. Bronchodilators are not disease modifiers and whilst glucocorticosteroids have been shown to reduce rates of exacerbation in moderate to severe COPD, the increase risk of pneumonia and bone fractures is a motivation enough to warrant developing novel anti-inflammatory and disease-modifying drugs and with the expectation of positive outcomes.

Fluticasone furoate and vilanterol inhalation powder for the treatment of chronic obstructive pulmonary disease

Fluticasone furoate/vilanterol (FF/VI) is a novel inhaled corticosteroid/long-acting β₂-agonist (ICS/LABA) fixed dose combination that, by simplifying the dosing schedule, allows, for the first time in a member of the ICS/LABA class, a shift from twice-daily to once-daily treatment. FF/VI is delivered via a novel, single-step activation, multi-dose dry powder inhaler for oral inhalation, Ellipta. Regrettably, there are no head-to-head trials that have shown superiority in the safety or efficacy of FF versus other ICSs, but evidence shows that VI has a quicker onset of effect versus salmeterol. However, the clinical utility of this effect in a maintenance medication is still questionable. Furthermore, benefits of FF/VI over twice-daily ICS/LABA comparator have not been shown yet and, in addition, its adverse event profile is generally consistent with the known class effects of an ICS/LABA fixed dose combination. In particular, there is an increase in the risk of pneumonia among patients treated with FF/VI relative to VI, mainly among those who benefit most from FF/VI. Nevertheless, the interesting pharmacological profiles of both FF and VI, the possibility that FF/VI can be administered once-daily, and the attractive characteristics of Ellipta are important features that could help FF/VI to be a successful combination in the treatment of chronic obstructive pulmonary disease.

Update on ultra-long-acting β agonists in chronic obstructive pulmonary disease

INTRODUCTION

For the last two decades, long-acting β agonists (LABAs) have been a cornerstone in the management of chronic obstructive pulmonary disease (COPD). They relax airway smooth muscle and augment expiratory airflow, which reduces hyperinflation and improves dyspnea, functional capacity and quality of life. In recent years, Indacaterol, a LABA with an ultra-long duration of action (ultra-LABA), which only requires once-daily dosing, was approved by the FDA. The clinical efficacy of indacaterol is comparable, and, in some aspects better, than the currently available LABAs.

AREAS COVERED

This article reviews the pharmacological properties, clinical efficacy, safety and potential role of the ultra-LABAs in COPD management.

EXPERT OPINION

Ultra-LABAs are effective bronchodilators with a prolonged duration of action. By decreasing dosing frequency, ultra-LABAs potentially may improve respiratory medication adherence, which is associated with better survival and less healthcare utilization. In addition to their salubrious benefits, β agonists may produce untoward effects. Increased mortality and hospitalizations among patients with left ventricular heart failure, who were treated with β agonists, has caused concern about their use in patients with COPD and heart disease. Further experience and testing will determine the optimal role of ultra-LABAs in the management of COPD.

Current and novel bronchodilators in respiratory disease

PURPOSE OF REVIEW

β2-Agonists and muscarinic antagonists are widely used to treat asthma and chronic obstructive pulmonary disease (COPD), and a number of novel drug targets are being investigated for potential clinical utility. This review will summarize current developments in the field.

RECENT FINDINGS

The clinical effectiveness of a number of once a day inhaled β2-agonists and muscarinic antagonists is a major advance providing sustained bronchodilation in asthma and COPD. The identification of novel targets (e.g. bitter taste receptor TASR2), the demonstration of clinical effectiveness of others [e.g. phosphodiesterase (PDE)3/4] and exploring the potential of inverse agonists/biased agonists are evidence of continuing interest in the development of novel bronchodilators.

SUMMARY

Novel long-acting β2-agonists (e.g. indacaterol, vilanterol, olodaterol and carmoterol) and muscarinic antagonists (e.g. tiotropium, aclidinium, glycopyrronium and umeclidinium bromide) document sustained bronchodilation and their combination provides additional benefits over monotherapy. Not surprisingly, inhaled long-acting β2-agonist and long-acting muscarinic antagonists remain the drugs of choice for maintenance bronchodilation. However, there is a continued interest in developing novel bronchodilators illustrated by the clinical effectiveness of long acting mixed PDE3/4 inhibitors, vasointestinal peptide adenylyl cyclase agonists and inverse agonists/biased agonists for the β2-adrenoceptor, and the identification of intracellular (e.g. Rho kinase, exchange proteins activated by cyclic AMP) and cell surface (e.g. TAS2R, natriuretic peptide receptor) targets.

Umeclidinium bromide and vilanterol trifenatate inhalation powder

Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The June 2014 monograph topics are apremilast, metreleptin, five pollen allergen extract, evolocumab, and miltefosine. The DUE/MUE is on apremilast.

Efficacy and safety of once-daily fluticasone furoate/vilanterol (100/25 mcg) versus twice-daily fluticasone propionate/salmeterol (250/50 mcg) in COPD patients

BACKGROUND

Fluticasone furoate/vilanterol (FF/VI) is an inhaled corticosteroid/long-acting beta2-agonist (ICS/LABA), recently approved as once-daily maintenance therapy for COPD. We compared the lung function effects of FF/VI with those of twice-daily fluticasone propionate/salmeterol (FP/SAL).

METHODS

Three 12 week studies comparing FF/VI and FP/SAL were conducted. Patients aged ≥40 years with moderate-to-very severe COPD were randomized to receive double-blind, double-dummy FF/VI 100/25 mcg once-daily, or FP/SAL 250/50 mcg twice-daily for 12 weeks following a 2 week placebo run-in period. The primary endpoint of each study was change from baseline trough in 0-24 h weighted mean FEV(1) (wmFEV(1)) on Day 84. Safety was also assessed.

RESULTS

In Study 1 (HZC113109) (intent-to-treat n: FF/VI = 260; FP/SAL = 259), the increase from baseline in 0-24 h wmFEV(1) was significantly greater with FF/VI than FP/SAL (Δ80 mL, P < 0.001). In Study 2 (HZC112352) (intent-to-treat n: FF/VI = 259; FP/SAL = 252) and Study 3 (RLV116974) (intent-to-treat n: FF/VI = 412; FP/SAL = 416), the increase from baseline in 0-24 h wmFEV(1) was not significantly greater with FF/VI than FP/SAL (Δ29 mL, P = 0.267; Δ25 mL, P = 0.137). The treatment difference was statistically but not clinically significant in a pooled analysis (Δ41 mL, P < 0.001). Pooled adverse events (FF/VI 27%; FP/SAL 28%) and serious adverse events (FF/VI 2%; FP/SAL 3%) were similar between treatments.

CONCLUSIONS

Our data suggest that once-daily FF/VI 100/25 mcg provides FEV(1) improvement in COPD that is at least comparable with that conferred by twice-daily FP/SAL 250/50 mcg, although interpretation is limited by differences in individual study outcomes. The safety profiles of FF/VI 100/25 mcg and FP/SAL 250/50 mcg are similar.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov: NCT01323634; NCT01323621; NCT01706328. GlaxoSmithKline study codes: HZC113109; HZC112352; RLV116974.

Comparison of vilanterol, a novel long-acting beta2 agonist, with placebo and a salmeterol reference arm in asthma uncontrolled by inhaled corticosteroids

Background

Current maintenance therapies for asthma require twice-daily dosing. Vilanterol (VI) is a novel long-acting beta₂ agonist, under development in combination with fluticasone furoate, a new inhaled corticosteroid (ICS). Findings from a previous 4-week study suggested that VI has inherent 24-hour activity and is therefore suitable for once-daily dosing. The study described here was a double-blind, double-dummy, randomised, placebo-controlled trial, the aim of which was to assess the efficacy of once-daily VI compared with placebo in patients with persistent asthma. The primary endpoint was change from baseline in 24-hour weighted mean forced expiratory volume in 1 second after 12 weeks of treatment vs. placebo. An active control arm received salmeterol (SAL) twice daily. All patients were maintained on a stable background dose of ICS.

Results

Patients (n = 347) received VI, placebo or SAL (1:1:1). For the primary endpoint, substantial improvements in lung function were seen with VI (359 ml), SAL (283 ml) and placebo (289 ml). There were no statistically significant treatment differences between either the VI (70 ml, P = 0.244) or SAL (-6 ml, P = 0.926) groups and placebo. Both active treatments were well tolerated, with similarly low rates of treatment-related adverse events compared with placebo. No treatment-related serious adverse events occurred.

Conclusions

This study failed to show a treatment difference between VI and placebo for the primary endpoint, in the presence of a placebo response of unforeseen magnitude. Because the placebo response was so large, it is not possible to draw meaningful conclusions from the data. The reason for this magnitude of effect is unclear but it may reflect increased compliance with the anti-inflammatory therapy regimen during the treatment period.

Trial registration

NCT01181895 at ClinicalTrials.gov.

Umeclidinium bromide and vilanterol in combination for the treatment of chronic obstructive pulmonary disease

Drugs from the two major classes of bronchodilator; umeclidinium, a long-acting muscarinic antagonist (LAMA), and vilanterol, a long-acting β2 agonist (LABA), have been combined in a single inhaler device for once-daily use in chronic obstructive pulmonary disease (COPD). These drugs have been proven safe and well tolerated in patients with COPD and show an enhanced improvement in FEV1 when compared to either drug in isolation and when compared with an established LAMA drug. In this article, we discuss the data supporting this combination inhaler and also review alternative combined LAMA/LABA options. We discuss where these agents are likely to find a place in the current therapy of COPD and where the future is likely to lead with these and other therapies.

Formoterol and budesonide inhibit rhinovirus infection and cytokine production in primary cultures of human tracheal epithelial cells

BACKGROUND

Long-acting β(2) agonists (LABAs) and inhaled corticosteroids (ICSs) reduce the frequency of exacerbations of chronic obstructive pulmonary disease and bronchial asthma. However, inhibitory effects of LABAs and ICSs on the replication of rhinovirus (RV), the major cause of exacerbations, have not been demonstrated.

METHODS

Primary cultures of human tracheal epithelial cells were infected with a major group RV, type 14 rhinovirus (RV14), to examine the effects of formoterol and budesonide on RV infection and infection-induced airway inflammation.

RESULTS

Treatment with formoterol and budesonide 72 h before and after RV14 infection reduced RV14 titers and cytokine concentrations, including interleukin (IL)-1β, IL-6 and IL-8, in supernatants and viral RNA within cells. Formoterol and budesonide reduced mRNA expression and protein concentration of intercellular adhesion molecule-1 (ICAM-1), the receptor for RV14. Formoterol reduced the number and fluorescence intensity of acidic endosomes through which RV RNA enters the cytoplasm. Formoterol and budesonide reduced the activation of the nuclear factor kappa-B protein p65 in nuclear extracts. The effects of formoterol plus budesonide were additive with respect to RV14 replication, cytokine production, ICAM-1 expression, acidic endosome fluorescence intensity, and p65 activation. The selective β(2)-adrenergic receptor antagonist, ICI 118551 [erythro-dl-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol], reversed the inhibitory effects of formoterol on RV14 titers and RNA levels, the susceptibility of cells to RV14 infection, cytokine production, acidic endosomes, ICAM-1 expression, and p65 activation.

CONCLUSIONS

Formoterol and budesonide may inhibit RV infection by reducing the ICAM-1 levels and/or acidic endosomes and modulate airway inflammation associated with RV infections.

Profile of fluticasone furoate/vilanterol dry powder inhaler combination therapy as a potential treatment for COPD

Currently, there is no cure for chronic obstructive pulmonary disease (COPD). The limited efficacy of current therapies for COPD indicates a pressing need to develop new treatments to prevent the progression of the disease, which consumes a significant amount of health care resources and is an important cause of mortality worldwide. Current national and international guidelines for the management of stable COPD patients recommend the use of inhaled long-acting bronchodilators, inhaled corticosteroids, and their combination for maintenance treatment of moderate to severe stable COPD. Once-daily fluticasone furoate/vilanterol dry powder inhaler combination therapy has recently been approved by the US Food and Drug Administration and the European Medicines Agency as a new regular treatment for patients with stable COPD. Fluticasone furoate/vilanterol dry powder inhaler combination therapy has been shown to be effective in many controlled clinical trials involving thousands of patients in the regular treatment of stable COPD. This is the first once-daily combination of ultra-long-acting inhaled β₂-agonists and inhaled glucocorticoids that is available for the treatment of stable COPD and has great potential to improve compliance to long-term regular inhaled therapy and hence to improve the natural history and prognosis of COPD patients.

Combination of fluticasone furoate and vilanterol for the treatment of chronic obstructive pulmonary disease

OBJECTIVE

To evaluate the efficacy and safety of the combination of fluticasone furoate/vilanterol (FF/VI) and compare it with other inhaled combination corticosteroid/long-acting β₂-receptor agonists for maintenance treatment of chronic obstructive pulmonary disease (COPD).

DATA SOURCES

A PubMed and EMBASE search in June 2013 using the MeSH terms fluticasone and vilanterol identified trials using this combination for COPD. Additional information was gathered from references cited in the identified publications, the manufacturer, and package insert as well as the ClinicalTrials.gov registry.

STUDY SELECTION/DATA EXTRACTION

Preference was given to randomized controlled clinical trials. Data from animal trials, clinical trials for asthma, and non-English sources were excluded.

DATA SYNTHESIS

Given once daily, FF/VI improves trough forced expiratory volume at 1 s by about 230 mL in a 28-day trial versus placebo. However, a more modest increase (100-130 mL) was seen in 2 longer 28-week trials. In the longest trial of 1 year, a slight but significant decrease in the yearly rate of moderate plus severe exacerbations, the time to first moderate or severe exacerbation, and the frequency of exacerbations requiring systemic corticosteroids was seen. There was no difference in the rate of exacerbations requiring hospitalization. The product appears to have the adverse effect profile typical of its class.

CONCLUSIONS

Of the inhaled corticosteroid/long-acting β₂ receptor agonist combinations, VI/FF is the first allowing once-daily dosing. Similar to the other combination products, it may slightly decrease the incidence of COPD exacerbations in the patient subset with Global Initiative for Chronic Obstructive Lung Disease risk category C or D. There are no direct safety or efficacy data comparing this with other available inhaled combination products. The once-daily dosing might improve adherence in select patients. The Ellipta delivery device may assist some who are unable to use other devices correctly.

New developments in the combination treatment of COPD: focus on umeclidinium/vilanterol

An increasing body of evidence suggests that the long-acting muscarinic antagonist (LAMA)/long-acting β2-agonist (LABA) combination appears to play an important role in maximizing bronchodilation, with studies to date indicating that combining different classes of bronchodilators may result in significantly greater improvements in lung function compared to the use of a single drug, and that these combinations are well tolerated in patients with moderate-to-severe chronic obstructive pulmonary disease (COPD). An inhaled, fixed-dose combination of two 24-hour bronchodilators, the LAMA umeclidinium and the LABA vilanterol, is under development as a once-daily treatment for COPD. The efficacy of both mono-components has already been demonstrated. The information currently available suggests that umeclidinium/vilanterol is an effective once-daily dual bronchodilator fixed-dose combination in the treatment of COPD. However, it remains to be seen if it compares favorably with current therapies. Moreover, the question remains whether umeclidinium/vilanterol fixed-dose combination, which significantly improves FEV1, is also associated with improvements in other outcome measures that are important to COPD patients.

β2-agonist therapy in lung disease

β2-Agonists are effective bronchodilators due primarily to their ability to relax airway smooth muscle (ASM). They exert their effects via their binding to the active site of β2-adrenoceptors on ASM, which triggers a signaling cascade that results in a number of events, all of which contribute to relaxation of ASM. There are some differences between β2-agonists. Traditional inhaled short-acting β2-agonists albuterol, fenoterol, and terbutaline provide rapid as-needed symptom relief and short-term prophylactic protection against bronchoconstriction induced by exercise or other stimuli. The twice-daily β2-agonists formoterol and salmeterol represent important advances. Their effective bronchodilating properties and long-term improvement in lung function offer considerable clinical benefits to patients. More recently, a newer β2-agonist (indacaterol) with a longer pharmacodynamic half-life has been discovered, with the hopes of achieving once-daily dosing. In general, β2-agonists have an acceptable safety profile, although there is still controversy as to whether long-acting β2-agonists may increase the risk of asthma mortality. In any case, they can induce adverse effects, such as increased heart rate, palpitations, transient decrease in PaO2, and tremor. Desensitization of β2-adrenoceptors that occurs during the first few days of regular use of β2-agonist treatment may account for the commonly observed resolution of the majority of these adverse events after the first few doses. Nevertheless, it can also induce tolerance to bronchoprotective effects of β2-agonists and has the potential to reduce bronchodilator sensitivity to them. Some novel once-daily β2-agonists (olodaterol, vilanterol, abediterol) are under development, mainly in combination with an inhaled corticosteroid or a long-acting antimuscarinic agent.