Novel bronchodilators in asthma

The Saudi initiative for asthma - 2024 update: Guidelines for the diagnosis and management of asthma in adults and children

The Saudi Initiative for Asthma 2024 (SINA-2024) is the sixth version of asthma guidelines for the diagnosis and management of asthma for adults and children that was developed by the SINA group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up-to-date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA Panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is aligned for age groups: adults, adolescents, children aged 5-12 years, and children aged <5 years. SINA guidelines have focused more on personalized approaches reflecting a better understanding of disease heterogeneity with the integration of recommendations related to biologic agents, evidence-based updates on treatment, and the role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and the current situation at national and regional levels. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Evaluating the Safety and Efficacy of Ketamine as a Bronchodilator in Pediatric Patients With Acute Asthma Exacerbation: A Review

Ketamine has emerged as a potential treatment option for pediatric patients with acute asthma exacerbation who do not respond to standard therapy. This review aims to evaluate the safety and efficacy of ketamine in this population and provide an overview of the current literature. A comprehensive search was conducted in PubMed and Google Scholar, resulting in the identification of four relevant studies. The studies demonstrated that ketamine administration led to improvements in respiratory parameters, including a decrease in clinical asthma scores (CASs) and respiratory rates, and an increase in peak expiratory flow and oxygen saturation. Ketamine infusion also showed promise in obviating the need for intubation in patients with severe wheezing due to bronchiolitis. The most common side effects observed were increased tracheobronchial secretions and hallucinations, which were manageable through discontinuation or additional medication. No significant changes in heart rate and blood pressure were reported, indicating hemodynamic stability. Long-term complications of ketamine use were minimal, with no reports of nightmares or dysphoria. In conclusion, ketamine shows potential as a bronchodilator for pediatric patients with acute asthma exacerbation, although further research is needed to fully evaluate its effectiveness and long-term effects. The use of ketamine should be considered in carefully selected cases and closely monitored for adverse events.

Ultra-LABAs for the treatment of asthma

The term ultra-LABA indicates once-daily β2-AR agonists (abediterol, indacaterol, olodaterol and vilanterol) that are single enantiomers of the (R)-configuration. All have a near full-agonist profile at human β2-AR. They can be prescribed in asthmatics only when associated with an with ICS, although further confirmations need to clarify what really these agents add if used in association to ICS and in what asthmatic patients this association may have more value. They are also under development in triple inhalers that include an ultra-LABA, a LAMA and an ICS. The once-daily posology might increase adherence in long-term treatment of asthma but superiority to twice-daily LABAs has not yet been fully demonstrated. In any case, still no ultra-LABA can be recommended as preferred.

The Saudi Initiative for Asthma - 2019 Update: Guidelines for the diagnosis and management of asthma in adults and children

This is the fourth version of the updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of the SINA is to have guidelines that are up to date, simple to understand, and easy to use by healthcare workers dealing with asthma patients. To facilitate achieving the goals of asthma management, the SINA panel approach is mainly based on the assessment of symptom control and risk for both adults and children. The approach to asthma management is now more aligned for different age groups. The guidelines have focused more on personalized approaches reflecting better understanding of disease heterogeneity with integration of recommendations related to biologic agents, evidence-based updates on treatment, and role of immunotherapy in management. The medication appendix has also been updated with the addition of recent evidence, new indications for existing medication, and new medications. The guidelines are constructed based on the available evidence, local literature, and current situation at national and regional levels. There is also an emphasis on patient–doctor partnership in the management that also includes a self-management plan.

Tiotropium for the treatment of asthma in adolescents

INTRODUCTION

Asthma is a prevalent disease affecting millions of individuals. Despite receiving guideline therapy with inhaled corticosteroids (ICS) with or without a long-acting β₂-agonist (LABA), a proportion of patients remain symptomatic or have suboptimal lung function. There is therefore an unmet need for additional therapies to improve asthma control. The long-acting anticholinergic tiotropium, delivered via the Respimat inhaler, is approved for the treatment of asthma in the EU, the USA, and other countries. Phase III investigation in adults has demonstrated that tiotropium improves lung function and asthma control, with a safety profile comparable with that of placebo. Areas covered: Clinical trials in adolescent patients (aged 12-17 years) with moderate or severe symptomatic asthma have shown that tiotropium Respimat as add-on to ICS, with or without other maintenance therapies, is a well-tolerated and efficacious bronchodilator showing trends toward improved asthma control, similar to data in adult patients. Expert opinion: Tiotropium Respimat may be of benefit as add-on maintenance therapy to medium- or high-dose ICS with or without LABA; however, further data are needed to directly compare the efficacy of ICS plus tiotropium versus ICS plus LABA in adolescents with symptomatic asthma, and to establish the long-term effects on airway modeling.

Olodaterol for the treatment of asthma

INTRODUCTION

Long-acting β-agonist (LABA)/inhaled corticosteroid (ICS) combinations are still the mainstay of asthma therapy but there is a pressing need to increase adherence to the prescribed treatment achievable in general by reducing the dose frequency. Consequently, there is considerable interest within the pharmaceutical industry in the discovery of once-daily β2-agonists (ultra-LABAs) to be used as a part of a combination therapy for treating asthma.

AREAS COVERED

The authors review the preclinical and clinical development of olodaterol, a new ultra-LABA characterized by an improved selectivity for β2-adrenoceptors and a rather high intrinsic efficacy profile, in asthma. The clinical results were generated by 4 Phase 2 trials, which have enrolled 731 asthmatic patients.

EXPERT OPINION

The available results indicate that olodaterol is able to induce an effective 24-h bronchodilation and is safe. However, one cannot formulate a solid conclusion on the best dose and/or dose frequency to be used in asthma because trials were not powered to assess the differences between doses and dose frequencies. Apparently, there is no Phase 3 trial planned or ongoing for olodaterol monotherapy in patients with asthma and also no attempt to combine olodaterol with an ICS, which is surprising.

The Saudi Initiative for Asthma - 2016 update: Guidelines for the diagnosis and management of asthma in adults and children

This is an updated guideline for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have guidelines that are up to date, simple to understand and easy to use by nonasthma specialists, including primary care and general practice physicians. SINA approach is mainly based on symptom control and assessment of risk as it is the ultimate goal of treatment. The new SINA guidelines include updates of acute and chronic asthma management, with more emphasis on the use of asthma control in the management of asthma in adults and children, inclusion of a new medication appendix, and keeping consistency on the management at different age groups. The section on asthma in children is rewritten and expanded where the approach is stratified based on the age. The guidelines are constructed based on the available evidence, local literature, and the current situation in Saudi Arabia. There is also an emphasis on patient-doctor partnership in the management that also includes a self-management plan.

Dose-finding evaluation of once-daily treatment with olodaterol, a novel long-acting β2-agonist, in patients with asthma: results of a parallel-group study and a crossover study

BACKGROUND

Olodaterol is a novel, inhaled long-acting β2-agonist (LABA) with >24-hour duration of action investigated in asthma and chronic obstructive pulmonary disease.

METHODS

Two multicentre studies examined the efficacy and safety of 4 weeks' once-daily (QD) olodaterol (2, 5, 10 and 20 μg, with background inhaled corticosteroids) in patients with asthma. One randomised, double-blind, parallel-group study (1222.6; 296 patients) administered treatment in the morning. Pulmonary function tests (PFTs) were performed pre-dose (trough) and ≤3 hours post-dose (weeks 1 and 2), and ≤6 hours post-dose after 4 weeks; primary end point was trough forced expiratory volume in 1 second (FEV1) response (change from baseline mean FEV1) after 4 weeks. A second randomised, double-blind, placebo- and active-controlled (formoterol 12 μg twice-daily) incomplete-block crossover study (1222.27; 198 patients) administered QD treatments in the evening. PFTs were performed over a 24-hour dosing interval after 4 weeks; primary end point was FEV1 area under the curve from 0-24 hours (AUC0-24) response (change from study baseline [mean FEV1] after 4 weeks).

RESULTS

Study 1222.6 showed a statistically significant increase in trough FEV1 response with olodaterol 20 μg (0.147 L; 95 % confidence interval [CI]: 0.059, 0.234; p = 0.001) versus placebo, with more limited efficacy and no evidence of dose response compared to placebo across the other olodaterol doses (2, 5 and 10 μg). Study 1222.27 demonstrated increases in FEV1 AUC0-24 responses at 4 weeks with all active treatments (p < 0.0001); adjusted mean (95 % CI) differences from placebo were 0.140 (0.097, 0.182), 0.182 (0.140, 0.224), 0.205 (0.163, 0.248) and 0.229 (0.186, 0.272) L for olodaterol 2, 5, 10 and 20 μg, respectively, and 0.169 (0.126, 0.211) for formoterol, providing evidence of increased efficacy with higher olodaterol dose. Olodaterol was generally well tolerated, with a few events associated with known sympathomimetic effects, mainly with 20 μg.

CONCLUSIONS

The LABA olodaterol has >24-hour duration of action. In patients with asthma, evidence of bronchodilator efficacy was demonstrated with statistically and clinically significant improvements in the primary end point of trough FEV1 response measured in clinics over placebo for the highest administered dose of 20 μg in Study 1222.6, and statistically and clinically significant improvements versus placebo in FEV1 AUC0-24 responses at 4 weeks for all doses tested in Study 1222.27, which also exhibited a dose response. Bronchodilator efficacy was seen over placebo for all olodaterol doses for morning and evening peak expiratory flow in both studies. All doses were well tolerated.

TRIAL REGISTRATIONS

NCT00467740 (1222.6) and NCT01013753 (1222.27).

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.

Development of small molecules to target the IgE:FcεRI protein-protein interaction in allergies

The protein-protein interaction (PPI) between IgE and its high-affinity receptor (FcεRI) is a key component of the allergic response. Inhibiting the IgE:FcεRI PPI is an attractive strategy for therapeutic intervention and the development of allergy treatments. This PPI has been validated as a viable target by the monoclonal anti-IgE antibody omalizumab (Xolair(®)), which has demonstrated clinical efficacy when prescribed to treat moderate-to-severe asthma and hay fever, but small molecules would be a more convenient form of treatment. Cyclic peptides, small proteins and a natural product have all been developed to target the IgE:FcεRI PPI, and these will be discussed in this review. Targeting the IgE:FcεRI complex with small molecules presents various challenges, some of which are inherent in all PPI targets but some of which are unique to this system, which presents great opportunities for the development of new therapeutics for the treatment of allergies.

Sports doping: emerging designer and therapeutic β2-agonists

Beta2-adrenergic agonists, or β2-agonists, are considered essential bronchodilator drugs in the treatment of bronchial asthma, both as symptom-relievers and, in combination with inhaled corticosteroids, as disease-controllers. The use of β2-agonists is prohibited in sports by the World Anti-Doping Agency (WADA) due to claimed anabolic effects, and also, is prohibited as growth promoters in cattle fattening in the European Union. This paper reviews the last seven-year (2006-2012) literature concerning the development of novel β2-agonists molecules either by modifying the molecule of known β2-agonists or by introducing moieties producing indole-, adamantyl- or phenyl urea derivatives. New emerging β2-agonists molecules for future therapeutic use are also presented, intending to emphasize their potential use for doping purposes or as growth promoters in the near future.

Phenotyping airways disease: an A to E approach

The airway diseases asthma and chronic obstructive pulmonary disease (COPD) are heterogeneous conditions with overlapping pathophysiological and clinical features. It has previously been proposed that this heterogeneity may be characterized in terms of five relatively independent domains labelled from A to E, namely airway hyperresponsiveness (AHR), bronchitis, cough reflex hypersensitivity, damage to the airways and surrounding lung parenchyma, and extrapulmonary factors. Airway hyperresponsiveness occurs in both asthma and COPD, accounting for variable day to day symptoms, although the mechanisms most likely differ between the two conditions. Bronchitis, or airway inflammation, may be predominantly eosinophilic or neutrophilic, with different treatments required for each. Cough reflex hypersensitivity is thought to underlie the chronic dry cough out of proportion to other symptoms that can occur in association with airways disease. Structural changes associated with airway disease (damage) include bronchial wall thickening, airway smooth muscle hypertrophy, bronchiectasis and emphysema. Finally, a variety of extrapulmonary factors may impact upon airway disease, including rhinosinusitis, gastroesophageal reflux disease, obesity and dysfunctional breathing. This article discusses the A to E concept in detail and describes how this framework may be used to assess and treat patients with airway diseases in the clinic.

Are inhaled longacting β2 agonists detrimental to asthma?

Possible adverse effects of adrenergic bronchodilators in asthma have been the subject of discussion for more than half a century, with recent intense debate about the safety of longacting β agonists (LABAs). In this Debate, we consider the issues of bronchodilator and bronchoprotective tolerance resulting from the frequent use of bronchodilators, which is noted particularly with shortacting drugs, but has also been shown to occur quicker and to a greater extent with LABAs. Increased allergen responsiveness and masking allowing inflammation to increase, while symptoms and lung function remain apparently controlled, have also been observed. Studies in which LABAs were used as monotherapy were associated with increased mortality. However, several studies have shown the benefits of adding LABAs to inhaled corticosteroids (ICS). Meta-analyses of asthma clinical trials involving LABAs showed that, when given with mandatory ICS, LABAs were not associated with an increased risk of death, intubations, or hospital admission for exacerbations when compared with use of the same dose of ICS only. Withdrawal of LABA therapy once symptom control is achieved is often associated with subsequent loss of symptom control. When used for appropriate indications, LABAs should be combined with ICS in one inhaler so that monotherapy is not possible.

Cosuspensions of microcrystals and engineered microparticles for uniform and efficient delivery of respiratory therapeutics from pressurized metered dose inhalers

Engineered porous phospholipid microparticles with aerodynamic diameters in the respirable range of 1-2 μm were cosuspended in 1,1,1,2-tetrafluoroethane, a propellant, with microcrystals of glycopyrrolate, formoterol fumarate dihydrate, or Mometasone furoate-three drugs with different solubilities in the propellant, and different physical, chemical, and pharmacological attributes. The drug microcrystals were added individually, in pairs, or all three together to prepare different cosuspensions, contained in a pressurized metered dose inhaler (pMDI). The drug microcrystals irreversibly associated with the porous particles, and the resultant cosuspensions possessed greatly improved suspension stability compared with suspensions of drug microcrystals alone. In general, all cosuspensions showed efficient dose delivery of the drugs, with fine particle fractions of more than 60% for a wide range of doses, including those as low as 300 ng per inhaler actuation. In the cosuspension pMDIs, comparable fine particle fractions were delivered for all tested drugs, whether or not they were emitted from an inhaler containing one, two, or three drugs. We demonstrate that the cosuspension approach solves at least three long-standing problems in the clinical development of pMDI-based products: (1) dose and drug dependent delivery efficiency, (2) inability to formulate dose strengths below 1 μg to fully explore drug efficacy and safety, and (3) combination suspensions delivering a different fine particle fraction than individual drug suspensions.

The Saudi initiative for asthma - 2012 update: Guidelines for the diagnosis and management of asthma in adults and children

This an updated guidelines for the diagnosis and management of asthma, developed by the Saudi Initiative for Asthma (SINA) group, a subsidiary of the Saudi Thoracic Society. The main objective of SINA is to have updated guidelines, which are simple to understand and easy to use by non-asthma specialists, including primary care and general practice physicians. This new version includes updates of acute and chronic asthma management, with more emphasis on the use of Asthma Control Test in the management of asthma, and a new section on "difficult-to-treat asthma." Further, the section on asthma in children was re-written to cover different aspects in this age group. The SINA panel is a group of Saudi experts with well-respected academic backgrounds and experience in the field of asthma. The guidelines are formatted based on the available evidence, local literature, and the current situation in Saudi Arabia. There was an emphasis on patient-doctor partnership in the management that also includes a self-management plan. The approach adopted by the SINA group is mainly based on disease control as it is the ultimate goal of treatment.

An update on bronchodilators in Phase I and II clinical trials

INTRODUCTION

Inhaled bronchodilators are the mainstay of the current management of COPD at all stages of the disease, and are critical in the symptomatic management of asthma. Therefore, there is still considerable interest in finding novel classes of broncholytic drugs or, at least, in improving the existing classes of bronchodilator.

AREAS COVERED

This review paper mainly focuses on bronchodilators that are in Phase I and II clinical trials.

EXPERT OPINION

To date, finding new classes of bronchodilators has proved difficult. Consequently, many research groups have sought to improve the existing classes of bronchodytic drugs. The majority of programs in development for novel bronchodilators are focused on developing new ligands that interact with β(2)-adrenoceptors and/or muscarinic acetylcholine receptors in a manner that enhances their bronchodilator effectiveness and duration of action, which allows only one administration per day, although the twice-daily dosing of bronchodilators is still considered a useful approach to the symptomatic treatment of COPD, and improving their safety profiles. Moreover, the current opinion is that it is advantageous to develop inhalers containing combinations of long-acting bronchodilator drugs in an attempt to simplify treatment regimes as much as possible. Another goal is to develop novel combinations of one or two classes of long-acting bronchodilators along with inhaled corticosteroids.

Emerging drugs for asthma

INTRODUCTION

Current drug treatments for asthma relieve bronchospasm and airway inflammation but do not offer a cure, and symptoms return when treatment is stopped. Asthma management guidelines emphasize the importance of effective asthma treatment to achieve and maintain asthma control. However, despite widely available and effective treatments, achieving asthma control is still an unmet need for many patients.

AREAS COVERED

Remarkable efforts have been made to identify the characteristic features of difficult-to-control (usually severe) asthma that are different from those described for mild-to-moderate asthma, setting the stage for the development of new and even individualized therapies. The most fascinating options of the new asthma treatments are biologic therapies, in particular monoclonal antibodies. In addition, some novel once-daily combinations of long-acting β(2)-agonist and inhaled corticosteroids are under development.

EXPERT OPINION

Asthma is a complex syndrome made up of a number of disease variants or asthma phenotypes, with different underlying pathophysiology. As different drugs target different pathways, it is necessary to determine the individual profile of pathophysiological abnormalities for each patient. Several cytokines have been implicated in the inflammatory cascades leading to the different asthma phenotypes, and the most relevant ones are discussed. The challenge in treating asthma resides precisely in its heterogeneity.

Pharmacology and therapeutics of bronchodilators

Bronchodilators are central in the treatment of of airways disorders. They are the mainstay of the current management of chronic obstructive pulmonary disease (COPD) and are critical in the symptomatic management of asthma, although controversies around the use of these drugs remain. Bronchodilators work through their direct relaxation effect on airway smooth muscle cells. at present, three major classes of bronchodilators, β(2)-adrenoceptor (AR) agonists, muscarinic receptor antagonists, and xanthines are available and can be used individually or in combination. The use of the inhaled route is currently preferred to minimize systemic effects. Fast- and short-acting agents are best used for rescue of symptoms, whereas long-acting agents are best used for maintenance therapy. It has proven difficult to discover novel classes of bronchodilator drugs, although potential new targets are emerging. Consequently, the logical approach has been to improve the existing bronchodilators, although several novel broncholytic classes are under development. An important step in simplifying asthma and COPD management and improving adherence with prescribed therapy is to reduce the dose frequency to the minimum necessary to maintain disease control. Therefore, the incorporation of once-daily dose administration is an important strategy to improve adherence. Several once-daily β(2)-AR agonists or ultra-long-acting β(2)-AR-agonists (LABAs), such as indacaterol, olodaterol, and vilanterol, are already in the market or under development for the treatment of COPD and asthma, but current recommendations suggest the use of LABAs only in combination with an inhaled corticosteroid. In addition, some new potentially long-acting antimuscarinic agents, such as glycopyrronium bromide (NVA-237), aclidinium bromide, and umeclidinium bromide (GSK573719), are under development, as well as combinations of several classes of long-acting bronchodilator drugs, in an attempt to simplify treatment regimens as much as possible. This review will describe the pharmacology and therapeutics of old, new, and emerging classes of bronchodilator.

Pharmacological characterization of abediterol, a novel inhaled β(2)-adrenoceptor agonist with long duration of action and a favorable safety profile in preclinical models

Abediterol is a novel potent, long-acting inhaled β(2)-adrenoceptor agonist in development for the treatment of asthma and chronic obstructive pulmonary disease. Abediterol shows subnanomolar affinity for the human β(2)-adrenoceptor and a functional selectivity over β(1)-adrenoceptors higher than that of formoterol and indacaterol in both a cellular model with overexpressed human receptors and isolated guinea pig tissue. Abediterol is a full agonist at the human β(2)-adrenoceptor (E(max) = 91 ± 5% of the maximal effect of isoprenaline). The potency and onset of action that abediterol shows in isolated human bronchi (EC(50) = 1.9 ± 0.4 nM; t½ onset = 7-10 min) is not significantly different from that of formoterol, but its duration of action (t½ ∼ 690 min) is similar to that of indacaterol. Nebulized abediterol inhibits acetylcholine-induced bronchoconstriction in guinea pigs in a concentration-dependent manner, with higher potency and longer duration of action (t½ = 36 h) than salmeterol (t½ = 6 h) and formoterol (t½ = 4 h) and similar duration of action to indacaterol up to 48 h. In dogs, the bronchoprotective effect of abediterol is more sustained than that of salmeterol and indacaterol at doses without effects on heart rate, thus showing a greater safety margin (defined as the ratio of dose increasing heart rate by 5% and dose inhibiting bronchospasm by 50%) than salmeterol, formoterol, and indacaterol (5.6 versus 3.3, 2.2, and 0.3, respectively). In conclusion, our results suggest that abediterol has a preclinical profile for once-daily dosing in humans together with a fast onset of action and a favorable cardiovascular safety profile.

From libraries to candidate: the discovery of new ultra long-acting dibasic β₂-adrenoceptor agonists

Libraries of dibasic compounds designed around the molecular scaffold of the DA(2)/β(2) dual agonist sibenadet (Viozan™) have yielded a number of promising starting points that have been further optimised into novel potent and selective target molecules with required pharmacokinetic properties. From a shortlist, 31 was discovered as a novel, high potency, and highly efficacious β(2)-agonist with high selectivity and a duration of action commensurable with once daily dosing.

Emerging therapies for severe asthma

Many patients with asthma have poorly controlled symptoms, and particularly for those with severe disease, there is a clear need for improved treatments. Two recent therapies licensed for use in asthma are omalizumab, a humanized monoclonal antibody that binds circulating IgE antibody, and bronchial thermoplasty, which involves the delivery of radio frequency energy to the airways to reduce airway smooth muscle mass. In addition, there are new therapies under development for asthma that have good potential to reach the clinic in the next five years. These include biological agents targeting pro-inflammatory cytokines such as interleukin-5 and interleukin-13, inhaled ultra long-acting β2-agonists and once daily inhaled corticosteroids. In addition, drugs that block components of the arachidonic acid pathway that targets neutrophilic asthma and CRTH2 receptor antagonists that inhibit the proinflammatory actions of prostaglandin D2 may become available. We review the recent progress made in developing viable therapies for severe asthma and briefly discuss the idea that development of novel therapies for asthma is likely to increasingly involve the assessment of genotypic and/or phenotypic factors.

Exploring lung physiology in health and disease with lung slices

The development of therapeutic approaches to treat lung disease requires an understanding of both the normal and disease physiology of the lung. Although traditional experimental approaches only address either organ or cellular physiology, the use of lung slice preparations provides a unique approach to investigate integrated physiology that links the cellular and organ responses. Living lung slices are robust and can be prepared from a variety of species, including humans, and they retain many aspects of the cellular and structural organization of the lung. Functional portions of intrapulmonary airways, arterioles and veins are present within the alveoli parenchyma. The dynamics of macroscopic changes of contraction and relaxation associated with the airways and vessels are readily observed with conventional low-magnification microscopy. The microscopic changes associated with cellular events, that determine the macroscopic responses, can be observed with confocal or two-photon microscopy. To investigate disease processes, lung slices can either be prepared from animal models of disease or animals exposed to disease invoking conditions. Alternatively, the lung slices themselves can be experimentally manipulated. Because of the ability to observe changes in cell physiology and how these responses manifest themselves at the level of the organ, lung slices have become a standard tool for the investigation of lung disease.

β(2) -adrenoceptor agonists: current and future direction

Despite the passionate debate over the use of β(2) -adrenoceptor agonists in the treatment of airway disorders, these agents are still central in the symptomatic management of asthma and COPD. A variety of β(2) -adrenoceptor agonists with long half-lives, also called ultra long-acting β(2) -adrenoceptor agonists (ultra-LABAs; indacaterol, olodaterol, vilanterol, carmoterol, LAS100977 and PF-610355) are currently under development with the hopes of achieving once-daily dosing. It is likely that the once-daily dosing of a bronchodilator would be a significant convenience and probably a compliance-enhancing advantage, leading to improved overall clinical outcomes. As combination therapy with an inhaled corticosteroid (ICS) and a LABA is important for treating patients suffering from asthma, and a combination with an inhaled long-acting antimuscarinic agent (LAMA) is important for treating COPD patients whose conditions are not sufficiently controlled by monotherapy with a β(2) -adrenoceptor agonist, some novel once-daily combinations of LABAs and ICSs or LAMAs are under development.

Inhalation by design: novel ultra-long-acting β(2)-adrenoreceptor agonists for inhaled once-daily treatment of asthma and chronic obstructive pulmonary disease that utilize a sulfonamide agonist headgroup

A novel series of potent and selective sulfonamide derived β(2)-adrenoreceptor agonists are described that exhibit potential as inhaled ultra-long-acting bronchodilators for the treatment of asthma and chronic obstructive pulmonary disease. Analogues from this series mediate very long-lasting smooth muscle relaxation in guinea pig tracheal strips. The sulfonamide agonist headgroup confers high levels of intrinsic crystallinity that could relate to the acidic sulfonamide motif supporting a zwitterionic form in the solid state. Optimization of pharmacokinetic properties was achieved through targeted introduction of a phenolic moiety to support rapid phase II clearance, thereby minimizing systemic exposure following inhalation and reducing systemically mediated adverse events. Compound 38 (PF-610355) is identified as a clinical candidate from this series, with in vivo duration of action studies confirming its potential for once-daily use in humans. Compound 38 is currently in advanced phase II clinical studies.