Tolerability of short-term, high-dose formoterol in healthy volunteers and patients with asthma

Redefining approaches to asthma: developing targeted biologic therapies

Asthma is a chronic respiratory disorder canonically associated with type 2 airway inflammation as characterized by elevated levels of eosinophils, immunoglobulin E, and cytokines including interleukin (IL) 4, IL5, IL9, and IL13 and tumor necrosis factor (TNF) α. However, mounting evidence has shown that considerable heterogeneity exists in human asthma in terms of the nature and intensity of airway inflammation. While many asthma patients achieve acceptable control of symptoms with standard-of-care therapies such as β₂-adrenergic agonists and inhaled corticosteroids, a minority remains symptomatic despite maximal standard-of-care therapy and constitutes a significant unmet medical need. A growing number of investigational therapeutics under clinical development for asthma are biologic therapies that specifically target mediators of type 2 airway inflammation. In this chapter, we consider the biological functions of therapeutic targets in asthma and data from clinical trials of biologic agents directed against these targets. We discuss recent clinical trial results in terms of four key components of drug development: target selection, molecule selection, outcome selection, and patient selection, with particular attention paid to the emerging role of biomarkers in clinical development for asthma.

Tolerability of high cumulative doses of the HFA modulite beclomethasone dipropionate/formoterol combination inhaler in asthmatic patients

The corticosteroid beclomethasone dipropionate (BDP) has been formulated with the long acting beta agonist formoterol (BDP/formoterol 100 microg/6 microg, Foster) in a single inhaler using Modulite technology. We have investigated the acute tolerability of high, cumulative doses of BDP/formoterol compared to formoterol alone and placebo. This was a double blind, 3-way cross-over comparison of 10 puffs of BDP/formoterol 100 microg/6 microg or formoterol 6 microg or placebo during maintenance treatment with BDP/formoterol two puffs per day. Pharmacokinetics over 12h during maintenance treatment was measured on day 7. High cumulative doses were then administered on three separated days. Eighteen patients with asthma were recruited (mean FEV(1) 65% predicted). The primary endpoint was serum potassium over the 12h period after high doses. QTc, blood pressure and heart rate over 12h, and plasma lactate and glucose over 3h following dosing were assessed. Formoterol caused a significantly greater decrease in serum potassium than BDP/formoterol or placebo (difference in mean minimum concentrations; 0.11 and -0.15 mmol/l, respectively, p<0.05 for both comparisons). No significant differences in serum potassium parameters were found between BDP/formoterol and placebo. QTc, plasma lactate and vital signs values observed with the combination were not statistically different from those with formoterol alone. For glucose, the mean maximum increase after formoterol treatment was 0.4 mmol/l (p<0.01 compared to placebo), while BDP/formoterol treatment caused a maximum increase of 0.7 mmol/l (p<0.01 compared to formoterol and placebo). The active metabolite of BDP is beclomethasone-17-monopropriate (B17MP), which reached Cmax at 0.25 h, with an elimination half-life of 3.7 h. Formoterol also reached Cmax at 0.25 h, and concentrations were measurable up to 12 h. High doses of BDP/formoterol did not significantly reduce serum potassium, while formoterol alone did to a greater extent. The BDP/formoterol combination was well tolerated, and exhibited a safety profile generally similar to formoterol alone when administered in high doses to stable asthmatic patients.

Tolerability profiles of leukotriene receptor antagonists and long-acting beta2-adrenoceptor agonists in combination with inhaled corticosteroids for treatment of asthma: a review

Inhaled corticosteroids, long-acting beta2-adrenoceptor agonists, and leukotriene receptor antagonists are widely used for treatment of asthma. Inhaled corticosteroids are recommended as first-line therapy, whereas long-acting beta2-adrenoceptor agonists and leukotriene receptor antagonists are indicated as add-on therapy in patients not adequately controlled with corticosteroids alone. A number of studies have investigated the efficacy of combinations of these drugs in asthma, but several issues concerning the safety of these treatments are highly debated. This review provides a critical appraisal of the tolerability profiles of long-acting beta2-agonists and leukotriene receptor antagonists used in combination with inhaled corticosteroids for the treatment of asthma.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

A randomized, double-blind, double-dummy, single-dose, efficacy crossover trial comparing formoterol-HFA (pMDI) versus formoterol-DPI (Aerolizer) and placebo (pMDI or Aerolizer) in asthmatic patients

BACKGROUND

Chlorofluorocarbons (CFCs) have traditionally been used as propellants in pressurized metered-dose inhalers (pMDIs), which are often used to deliver drugs to the lungs for the treatment of reversible obstructive airways diseases. However, CFCs are harmful to the environment and need to be phased out. Hydrofluoroalkanes (HFAs), such as HFA-134a, represent a safe alternative to CFC propellants for use with pMDIs. Formoterol fumarate has been recently formulated in an HFA-134a-containing pMDI and is undergoing clinical testing with the aim of providing an effective, safe and environmentally-friendly alternative to currently existing formulations.

OBJECTIVES

The study objective was to demonstrate the non-inferiority (clinical equivalence) of the HFA-134a-propelled formoterol pMDI versus the formoterol Aerolizer dry powder inhaler (DPI).

METHODS

The study was a single dose, double-blind, double-dummy, randomized, placebo and reference product controlled, three-periods, crossover trial in 49 patients with moderate-to-severe stable asthma. The active treatments involved a single 12-microg dose of formoterol delivered from an HFA-134a-propelled pMDI and an Aerolizer DPI. The primary efficacy parameter was the average 12-hour forced expiratory volume in 1 s (FEV1), calculated as area under the 12-hour post-morning dose FEV1 time curve divided by time (hours).

RESULTS

Mean 12-hour average FEV1 was 2.28 liters for placebo, 2.60 liters for formoterol pMDI and 2.60 liters for the formoterol DPI. Contrast analysis showed that the HFA-propelled formoterol pMDI was significantly superior to placebo in terms of 12-hour average FEV1. Further statistical analysis confirmed bronchodilation with the pMDI formoterol formulation which was clinically equivalent to that seen with the DPI formoterol formulation. All treatments were well tolerated.

CONCLUSIONS

The bronchodilatory effect of a 12-microg dose of formoterol inhaled from a CFC-free, HFA-propelled pMDI is significantly superior to placebo and equivalent to a commercially available formoterol DPI.

Long-acting beta(2)-agonists in the management of asthma exacerbations

PURPOSE OF REVIEW

Asthma exacerbations are a major cause of morbidity in the United States. Although long-acting beta2-agonists have a defined role in maintenance therapy, their potential use in exacerbations remains largely undetermined. This paper reviews recent literature on long-acting beta2-agonists in the context of the management of acute asthma.

RECENT FINDINGS

Although clinical experience with long-acting beta2-agonists now approaches 20 years, their applicability in asthma exacerbations has only recently been explored. Formoterol, with a rapid onset of action similar to albuterol, has already been approved in Europe as a reliever medication and there are emerging data to support its use in the outpatient management of mild exacerbations of asthma. Salmeterol added to conventional therapy has been found to be safe and potentially beneficial in patients hospitalized for an exacerbation.

SUMMARY

Long-acting beta2-agonists have proved to be useful in the chronic management of asthma and the prevention of exacerbations. Recent data suggest a role for patient-guided management using adjustable dosing of long-acting beta2-agonists with inhaled corticosteroids during periods of worsening asthma. Further research to evaluate the potential role of long-acting beta2-agonists in the management of acute asthma is needed.