Pharmacological mechanisms leading to synergy in fixed-dose dual bronchodilator therapy

Use of human airway smooth muscle in vitro and ex vivo to investigate drugs for the treatment of chronic obstructive respiratory disorders

Isolated airway smooth muscle has been extensively investigated since 1840 to understand the pharmacology of airway diseases. There has often been poor predictability from murine experiments to drugs evaluated in patients with asthma or chronic obstructive pulmonary disease (COPD). However, the use of isolated human airways represents a sensible strategy to optimise the development of innovative molecules for the treatment of respiratory diseases. This review aims to provide updated evidence on the current uses of isolated human airways in validated in vitro methods to investigate drugs in development for the treatment of chronic obstructive respiratory disorders. This review also provides historical notes on the pioneering pharmacological research on isolated human airway tissues, the key differences between human and animal airways, as well as the pivotal differences between human medium bronchi and small airways. Experiments carried out with isolated human bronchial tissues in vitro and ex vivo replicate many of the main anatomical, pathophysiological, mechanical and immunological characteristics of patients with asthma or COPD. In vitro models of asthma and COPD using isolated human airways can provide information that is directly translatable into humans with obstructive lung diseases. Regardless of the technique used to investigate drugs for the treatment of chronic obstructive respiratory disorders (i.e., isolated organ bath systems, videomicroscopy and wire myography), the most limiting factors to produce high-quality and repeatable data remain closely tied to the manual skills of the researcher conducting experiments and the availability of suitable tissue.

Is it preferable to administer a bronchodilator once- or twice-daily when treating COPD?

Nocturnal and early morning symptoms are common and uncomfortable in many patients with COPD, and are likely to affect their long-term outcomes. However, it is still debated whether it is better to give long-acting bronchodilators once- or twice-daily to symptomatic COPD patients. The functional link between circadian rhythms of autonomic tone and airway calibre explains why the timing of administration of bronchodilators in chronic airway diseases can induce different effects when taken at different biological (circadian) times. However, the timing also depends on the pharmacological characteristics of the bronchodilator to be used. Because the profile of bronchodilation produced by once-daily vs. twice-daily long-acting bronchodilators differs throughout 24 h, selecting long-acting bronchodilators may be customized to specific patient preferences based on the need for further bronchodilation in the evening. This is especially helpful for people who experience respiratory symptoms at night or early morning. Compared to placebo, evening bronchodilator administration is consistently linked with persistent overnight improvements in dynamic respiratory mechanics and inspiratory neural drive. The current evidence indicates that nocturnal and early morning symptoms control is best handled by a LAMA taken in the evening. In contrast, it seems preferable to use a LABA for daytime symptoms. Therefore, it can be speculated that combining a LAMA with a LABA can improve bronchodilation and control symptoms better. Both LAMA and LABA must be rapid in their onset of action. Aclidinium/formoterol, a twice-daily combination, is the most studies of the available LAMA/LABA combinations in terms of impact on daytime and nocturnal symptoms.

Real-world comparative effectiveness of three single-inhaler dual bronchodilators for the treatment of COPD

BACKGROUND

Single-inhaler dual bronchodilators are now recommended as initial treatment of COPD for patients with multiple exacerbations or with moderate or severe dyspnoea. It is unclear whether there are differences in effectiveness among commonly used dual bronchodilators.

METHODS

We identified a cohort of COPD patients, aged ≥40 years, treated during 2017-2020, from the UK Clinical Practice Research Datalink, a real-world practice setting. Inhaled corticosteroid-naïve patients initiating vilanterol-umeclidinium (VIL-UME) were compared with those initiating olodaterol-tiotropium (OLO-TIO) or indacaterol-glycopyrronium (IND-GLY) dual bronchodilators primarily on the incidence of moderate and severe COPD exacerbation over 1 year, and corresponding hazard ratios (HRs), after adjustment by propensity score weighting.

RESULTS

The cohort included 15 224 initiators of VIL-UME, 5536 initiators of OLO-TIO and 5059 initiators of IND-GLY. The HR of a moderate or severe exacerbation with VIL-UME was 0.91 (95% CI 0.85-0.97) compared with OLO-TIO and 0.96 (95% CI 0.89-1.03) compared with IND-GLY. The risk of severe exacerbation was not different for VIL-UME when compared with OLO-TIO (HR 1.04, 95% CI 0.86-1.26) and IND-GLY (HR 1.05, 95% CI 0.86-1.28). All-cause mortality was lower with VIL-UME compared with IND-GLY (HR 0.82, 95% CI 0.68-0.98), but not compared with OLO-TIO (HR 0.87, 95% CI 0.72-1.04).

CONCLUSION

In a real-world setting of COPD treatment, the three dual bronchodilator combinations were similarly effective on the risk of a severe exacerbation of COPD. However, the VIL-UME and IND-GLY combinations may confer slightly superior effectiveness than OLO-TIO on the risk of moderate or severe exacerbation. The potential lower mortality with VIL-UME warrants further investigation.

Revisiting asthma pharmacotherapy: where do we stand and where do we want to go?

Several current guidelines/strategies outline a treatment approach to asthma, which primarily consider the goals of improving lung function and quality of life and reducing symptoms and exacerbations. They suggest a strategy of stepping up or down treatment, depending on the patient's overall current asthma symptom control and future risk of exacerbation. While this stepwise approach is undeniably practical for daily practice, it does not always address the underlying mechanisms of this heterogeneous disease. In the last decade, there have been attempts to improve the treatment of severe asthma, such as the addition of a long-acting antimuscarinic agent to the traditional inhaled corticosteroid/long-acting β2-agonist treatment and the introduction of therapies targeting key cytokines. However, despite such strategies several unmet needs in this population remain, motivating research to identify novel targets and develop improved therapeutic and/or preventative asthma treatments. Pending the availability of such therapies, it is essential to re-evaluate the current conventional "one-size-fits-all" approach to a more precise asthma management. Although challenging, identifying "treatable traits" that contribute to respiratory symptoms in individual patients with asthma may allow a more pragmatic approach to establish more personalised therapeutic goals.

Experimental drugs in clinical trials for COPD: Artificial Intelligence via Machine Learning approach to predict the successful advance from early-stage development to approval

INTRODUCTION

Therapeutic advances in drug therapy of chronic obstructive pulmonary disease (COPD) really effective in suppressing the pathological processes underlying the disease deterioration are still needed. Artificial Intelligence (AI) via Machine Learning (ML) may represent an effective tool to predict clinical development of investigational agents.

AREAL COVERED

Experimental drugs in Phase I and II development for COPD from early 2014 to late 2022 were identified in the ClinicalTrials.gov database. Different ML models, trained from prior knowledge on clinical trial success, were used to predict the probability that experimental drugs will successfully advance toward approval in COPD, according to Bayesian inference as follows: ≤25% low probability, >25% and ≤ 50% moderate probability, >50% and ≤ 75% high probability, and > 75% very high probability.

EXPERT OPINION

The Artificial Neural Network and Random Forest ML models indicated that, among the current experimental drugs in clinical trials for COPD, only the bifunctional muscarinic antagonist - β₂-adrenoceptor agonists (MABA) navafenterol and batefenterol, the inhaled corticosteroid (ICS)/MABA fluticasone furoate/batefenterol, and the bifunctional phosphodiesterase (PDE) 3/4 inhibitor ensifentrine resulted to have a moderate to very high probability of being approved in the next future, however not before 2025.

Might It Be Appropriate to Anticipate the Use of Long-Acting Muscarinic Antagonists in Asthma?

A growing number of clinical trials are documenting that adding a long-acting muscarinic antagonist (LAMA) to established asthma treatment with an inhaled corticosteroid (ICS) and a long-acting β₂-agonist (LABA) is a treatment option that improves the health of patients with uncontrolled severe asthma even when therapy is optimized. These favorable results are the reason why the leading guidelines recommend triple therapy with ICS + LABA + LAMA in patients with asthma uncontrolled by medium- to high-dose ICS-LABA. However, we suggest adding LAMAs to ICS-LABAs at an earlier clinical stage. Such action could positively influence airflow limitation, exacerbations, and eosinophilic inflammation, conditions that are associated with acetylcholine (ACh) activity. It could also interrupt the vicious cycle related to a continuous release of ACh leading to the progressive expansion of neuronal plasticity resulting in small airway dysfunction. The utility of an earlier use of triple therapy in asthma should, in any case, be confirmed by statistically powered trials.

Comparison of Clinical Outcomes Among Different Fixed-Dose Combinations of Long-Acting Muscarinic Antagonists and Long-Acting β2-Agonists in Patients With COPD

BACKGROUND

Researchers have yet to obtain conclusive evidence differentiating among fixed-dose combinations (FDCs) of long-acting muscarinic antagonists (LAMAs) and long-acting beta-agonists (LABAs) for COPD in terms of real-world clinical outcomes.

RESEARCH QUESTION

What are the differences between available LAMA/LABA FDCs on the risk of acute exacerbation (AE) and cardiovascular events?

STUDY DESIGN AND METHODS

This retrospective cohort study based on a national insurance claims database included patients with COPD ≥ 40 years of age who were newly prescribed glycopyrronium (GLY)/indacaterol (IND), umeclidinium (UMEC)/vilanterol (VI), or tiotropium (TIO)/olodaterol (OLO) FDC between January 1, 2015, and June 30, 2019. Propensity score matching and Cox regression models were used to compare outcomes of AE and cardiovascular events associated with LAMA/LABA FDC treatment.

RESULTS

Among the 44,498 patients identified and included, 15,586 received GLY/IND, 20,460 received UMEC/VI, and 8,452 received TIO/OLO. Baseline characteristics were well balanced after 1:1 matching of UMEC/VI and GLY/IND, 2:1 matching of UMEC/VI and TIO/OLO, and 2:1 matching of GLY/IND and TIO/OLO. Risk of severe AE was lower among patients treated with UMEC/VI or GLY/IND than among those who received TIO/OLO (UMEC/VI vs TIO/OLO: 17.85 vs 29.32 per 100 person-years; hazard ratio, 0.76; 95% CI, 0.68-0.84; GLY/IND vs TIO/OLO: 15.54 vs 25.53 per 100 person-years; hazard ratio, 0.77; 95% CI, 0.67-0.88). In addition, GLY/IND users tended to have a lower risk of cardiovascular events than TIO/OLO users, but the difference dissipated when restricting follow up to a shorter duration.

INTERPRETATION

Our results revealed that the risk of severe AE was lower among patients with COPD receiving UMEC/VI or GLY/IND than among those receiving TIO/OLO, whereas the incidence of cardiovascular events was similar across groups but was slightly lower in GLY/IND users when compared with TIO/OLO users. Further research will be required to confirm these findings.

An Unexpected Deuterium-Induced Metabolic Switch in Doxophylline

Precision deuteration has become part of the medicinal chemist's toolbox, but its usefulness can be undermined by unpredictable metabolic switch effects. Herein we report the deuteration of doxophylline, a drug used in the treatment of asthma and COPD that undergoes extensive oxidative metabolism. Labeling of the main metabolic soft spots triggered an unexpected multidirectional metabolic switch that, while not improving the pharmacokinetic parameters, changed the metabolic scenario and, in turn, the pharmacodynamic features in two murine models of lung injury.

Optimizing asthma management: Role of long-acting muscarinic antagonists

Patients with asthma who are suboptimally responsive to inhaled corticosteroids (ICS) and long-acting β₂-agonists (LABAs) are frequently exposed to oral corticosteroids and high-dose ICS, which can lead to significant side effects. Long-acting muscarinic antagonists (LAMAs) have demonstrated efficacy and safety in a subset of these patients. This review summarizes the results of key studies using LAMAs in patients with asthma aged 12 years or older. LAMA as an add-on treatment improved lung function and asthma control in patients with uncontrolled asthma across studies. The efficacy of LAMAs as an add-on to ICS was superior to that of placebo and ICS dose escalation and comparable with that of LABAs. LAMA plus ICS plus LABA provided modest improvements in bronchodilation and increased the time to first severe exacerbation versus ICS plus LABA. Single-inhaler triple therapy was associated with decreased health care resource utilization and improved cost-effectiveness versus multiple inhalers. LAMAs were generally well tolerated; asthma exacerbations, bronchitis, and nasopharyngitis were common adverse events with LAMA in combination with ICS alone or ICS plus LABA. Thus, the overall evidence presented in this review supports the use of add-on LAMA treatment as a reasonable option in patients with asthma uncontrolled with ICS plus LABA or ICS alone.

The 5T approach in asthma: Triple Therapy Targeting Treatable Traits

Using a therapeutic strategy that is free from traditional diagnostic labels and based on the identification of "treatable traits" (TTs), which are influential in clinical presentations in each patient, might overcome the difficulties in identifying and validating asthma phenotypes and endotypes. Growing evidence is documenting the importance of using the triple therapy with ICS, LABA, and LAMAs in a single inhaler (SITT) in cases of asthma not controlled by ICS/LABA and in the prevention of exacerbations. The identification of TTs may overcome the possibility of using SITT without considering the specific needs of the patient. In effect, it allows a treatment strategy that is closer to the precision strategy now widely advocated for the management of patients with asthma. There are different TTs in asthma that may benefit from treatment with SITT, regardless of guideline recommendations. The airflow limitation and small airway dysfunction are key TTs that are present in different phenotypes/endotypes, do not depend on the degree of T2 inflammation, and respond better than other treatments to SITT. We suggest that the 5T (Triple Therapy Targeting Treatable Traits) approach should be applied to the full spectrum of asthma, not just severe asthma, and, consequently, SITT should begin earlier than currently recommended.

An update on the currently available and emerging synthetic pharmacotherapy for uncontrolled asthma

INTRODUCTION

: The treatment of uncontrolled asthma has improved because of triple therapy that includes a long-acting muscarinic antagonist (LAMA) and biological drugs, but several patients are resistant to corticosteroids and/or cannot achieve adequate asthma control using such therapies.

AREAS COVERED

: Herein, the authors review the current and emerging synthetic pharmacotherapy for uncontrolled asthma to overcome obstacles and limitations of biological therapies. The authors also provide their expert perspectives and opinion on the treatment of uncontrolled asthma.

EXPERT OPINION

: LAMAs should be added to inhaled corticosteroid/long-acting β₂-agonist combinations much earlier than currently recommended by the Global Initiative for Asthma strategy because they can influence the course of small airways disease, reducing lung hyperinflation and improving asthma control. Biological therapies are a major advance in the treatment of severe asthma, but their use is still very limited for several reasons. An alternative to overcome the use of biological therapies is to synthesise compounds that target inflammation-signalling pathways. Several pathways have been identified as potential targets to design either therapeutic or prophylactic drugs against asthma. Some new compounds have already been tested in humans, but results have often been disappointing probably because existing phenotypic and endotypic variants may unpredictably limit the therapeutic value of blocking a specific pathway in most asthmatics, although there may be a substantial benefit for a subgroup of patients.

Dual bronchodilation for the treatment of COPD - From bench to bedside

Because there is a solid pharmacological rationale based on positive interactions between long-acting muscarinic receptor antagonists (LAMAs) and long-acting β-agonists (LABAs) for their ability to relax human airway smooth muscle in vitro alongside several randomised controlled trials (RCTs) and real-world observational studies that support the use of LAMA/LABA fixed-dose combinations (FDCs) for the treatment of patients with COPD, in this narrative review we discuss the preclinical and clinical proofs supporting the use of LAMA+LABA therapy in COPD and why this therapeutic approach optimises bronchodilation. Robust evidence indicates that all LAMA/LABA FDCs are consistently more effective than LAMA or LABA administered alone in improving lung function, dyspnoea, quality of life, and exercise capacity in patients with COPD. However, the ability of dual bronchodilation with FDCs of LAMA/LABA to prevent or reduce the risk of COPD exacerbations remains unclear due to conflicting data from large RCTs, despite several mechanisms explaining why such combinations should be of value in decreasing the frequency of COPD exacerbations. Both LABAs and LAMAs mechanistically can affect the cardiovascular system, but from clinical studies to date, LAMA/LABA FDCs have an acceptable cardiovascular safety profile, at least in the COPD population enrolled in RCTs. Indirect evidence suggests that some FDCs may even exert a protective role against serious cardiovascular adverse events compared to monotherapies. Consequently, several LAMA/LABA FDCs have been developed and approved for clinical use as treatments for patients with COPD. However, to date, there are unfortunately very few head-to-head studies comparing the safety and efficacy of different LAMA/LABA FDCs making it difficult to choose the most appropriate combination, although the use of meta-analyses has provided some information in this regard.

A single inhaler triple therapy fluticasone furoate/umeclidinium/vilanterol for the treatment of COPD

INTRODUCTION

: Single inhaler triple therapy (SITT) with an inhaled corticosteroid, a long-acting β₂-agonist, and a long-acting muscarinic antagonist is an effective and attractive therapeutic option codified in the recommendations of guidelines and treatment strategies for the management of COPD.

AREAS COVERED

: The preclinical and clinical development in COPD of fluticasone furoate (FF)/umeclidinium (UMEC)/vilanterol (VI) SITT and its use in the real world.

EXPERT OPINION

: Findings from phase III/IV trials and the use of FF/UMEC/VI in the real-world setting support the view that it may be a useful, safe, and cost-effective option for the maintenance treatment of COPD, especially when dealing with patients who are not adequately controlled with dual ICS/LABA or LAMA/LABA therapy. Only direct head-to-head comparisons will be able to establish whether FF/UMEC/VI may be preferable to the other SITTs approved for COPD due to its pharmacokinetic and pharmacodynamic characteristics and especially the fact that it is the only one that can be taken once-daily. In addition, there is a need for further studies, especially in the real world, to optimize the positioning of FF/UMEC/VI in the treatment of COPD, also considering the availability of FF/VI and UMEC/VI and the need for better differentiation between the three treatments.

Drug interaction and chronic obstructive respiratory disorders

Chronic obstructive respiratory disorders uncontrolled by monotherapy should be given combinations of drugs that act by distinct mechanisms of action. The rationale for combining different classes of drugs should be to elicit a synergistic interaction, lower the dose of the single components in the combinations and, thus, reduce the risk of adverse events.

The aim of this systematic review was to investigate the combined effect of drugs acting on human airways, by including studies that used a validated method for assessing the nature of drug interaction.

Current evidence indicates that drug combinations modulating the bronchial contractility induce a synergistic relaxant effect when the individual components are combined at isoeffective concentrations. There are several mechanisms of action underlying drug interactions. Pharmacological research has been directed to elucidate what causes the synergism between long-acting β₂-adrenoceptor (β₂-AR) agonists (LABAs), long-acting muscarinic antagonist (LAMAs), and inhaled corticosteroids (ICS) administered as dual or triple combination. Conversely, the mechanisms behind the additive interaction between phosphodiesterase 3 and 4 inhibitors and LAMAs, and the synergistic interaction between proliferator-activated receptor gamma ligands and β₂ agonists have been only hypothesized. Overall, the synergism elicited by combined drugs for the treatment of chronic respiratory disorders is an effect of class, rather than specific for drug combinations. Optimal synergy can be achieved only when the single agents are combined at isoeffective concentrations, and when monocomponents are given concurrently to reach together the same levels of the bronchial tree.

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Drug interaction should be identified with validated pharmacological models.

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Synergistic efficacy is the rationale for combining drugs for respiratory diseases.

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Synergy is favored when combined agents act by distinct mechanisms of action.

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Optimal synergy is achieved when drugs are combined at isoeffective concentrations.

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Synergy is a class effect and is not specific for single drug combinations.

Inhaled β2 Adrenergic Agonists and Other cAMP-Elevating Agents: Therapeutics for Alveolar Injury and Acute Respiratory Disease Syndrome?

Inhaled long-acting β-adrenergic agonists (LABAs) and short-acting β-adrenergic agonists are approved for the treatment of obstructive lung disease via actions mediated by β2 adrenergic receptors (β2-ARs) that increase cellular cAMP synthesis. This review discusses the potential of β2-AR agonists, in particular LABAs, for the treatment of acute respiratory distress syndrome (ARDS). We emphasize ARDS induced by pneumonia and focus on the pathobiology of ARDS and actions of LABAs and cAMP on pulmonary and immune cell types. β2-AR agonists/cAMP have beneficial actions that include protection of epithelial and endothelial cells from injury, restoration of alveolar fluid clearance, and reduction of fibrotic remodeling. β2-AR agonists/cAMP also exert anti-inflammatory effects on the immune system by actions on several types of immune cells. Early administration is likely critical for optimizing efficacy of LABAs or other cAMP-elevating agents, such as agonists of other Gs-coupled G protein-coupled receptors or cyclic nucleotide phosphodiesterase inhibitors. Clinical studies that target lung injury early, prior to development of ARDS, are thus needed to further assess the use of inhaled LABAs, perhaps combined with inhaled corticosteroids and/or long-acting muscarinic cholinergic antagonists. Such agents may provide a multipronged, repurposing, and efficacious therapeutic approach while minimizing systemic toxicity. SIGNIFICANCE STATEMENT: Acute respiratory distress syndrome (ARDS) after pulmonary alveolar injury (e.g., certain viral infections) is associated with ∼40% mortality and in need of new therapeutic approaches. This review summarizes the pathobiology of ARDS, focusing on contributions of pulmonary and immune cell types and potentially beneficial actions of β2 adrenergic receptors and cAMP. Early administration of inhaled β2 adrenergic agonists and perhaps other cAMP-elevating agents after alveolar injury may be a prophylactic approach to prevent development of ARDS.

Multi-walled carbon nanotubes induce airway hyperresponsiveness in human bronchi by stimulating sensory C-fibers and increasing the release of neuronal acetylcholine

OBJECTIVES

The potential of multi-walled carbon nanotubes (MWCNTs) in inducing airway hyperresponsiveness (AHR) was investigated in human airways.

METHODS

Human isolated bronchi were exposed to MWCNTs and the contractility to electrical field stimulation (EFS) was measured. Neuronal acetylcholine (ACh) and cyclic adenosine monophosphate (cAMP) were quantified. Some tissues were desensitized by consecutive administrations of capsaicin.

RESULTS

MWCNTs (100 ng/ml - 100 µg/ml) induced AHR (overall contractile tone vs. negative control: +83.43 ± 11.13%, P < 0.01). The potency was significantly (P < 0.05) greater when airways were stimulated at low frequency (EFS_3Hz) then at medium-to-high frequencies (EFS_10Hz and EFS_25Hz) (delta potency: +2.13 ± 0.74 and +2.40 ± 0.65 logarithms, respectively). In capsaicin-desensitized airways, the AHR to MWCNTs 100 ng/ml was abolished. MWCNTs increased the release of ACh, an effect prevented by capsaicin-desensitization (-90.17 ± 18.59%, P < 0.05). MWCNTs did not alter the level of cAMP.

CONCLUSION

MWCNTs administered at low concentrations elicit AHR in human airways by activating sensory C-fibers and, in turn, increasing the release of neuronal ACh. Our results suggest that work is required to understand the impact of MWCNTs in patients at risk of AHR, such as those suffering from chronic obstructive respiratory disorders.

Indacaterol, glycopyrronium, and mometasone: pharmacological interaction and anti-inflammatory profile in hyperresponsive airways

LABA/ICS and LABA/LAMA/ICS combinations elicit beneficial effects in asthma. Specific evidence concerning the impact of combining indacaterol acetate (IND), glycopyrronium bromide (GLY), and mometasone furoate (MF) on human airway hyperresponsiveness (AHR) and airway inflammation is still missing. The aim of this study was to characterize the synergy of IND/MF and IND/GLY/MF combinations, both once-daily treatments for asthma, in hyperresponsive airways. Passively sensitized human medium and small airways were stimulated by histamine and treated with IND/MF (molar ratio: 100/45, 100/90) and IND/GLY/MF (molar ratio: 100/37/45, 100/37/90). The effect on contractility and airway inflammation was tested. Drug interaction was assessed by Bliss Independence equation and Unified Theory. IND/MF 100/90 elicited middle-to-very strong synergistic relaxation in medium and small airways (+≈20-30% vs. additive effect, P<0.05), for IND/MF 100/45 the synergy was middle-to-very strong in small airways (+≈20% vs. additive effect, P<0.05), and additive in medium bronchi (P>0.05 vs. additive effect). IND/GLY/MF 100/37/45 and 100/37/90 induced very strong synergistic relaxation in medium and small airways (+≈30-50% vs. additive effect, P<0.05). Synergy was related with significant (P<0.05) reduction in IL-4, IL-5, IL-6, IL-9, IL-13, TNF-α, TSLP, NKA, SP, and non-neuronal ACh, and enhancement in cAMP. IND/MF and IND/GLY/MF combinations synergistically interact in hyperresponsive medium and small airways and modulate the levels of cytokines, neurokinins, ACh, and intracellular cAMP. The concentrations of MF in the combinations modulate the effects in the target tissue.

Current long-acting muscarinic antagonists for the treatment of asthma

INTRODUCTION

The role of long-acting muscarinic antagonists (LAMAs) is well established in uncontrolled asthma, but not in milder stages.

AREAS COVERED

This review examines the main randomized controlled trials (RCTs) that have investigated LAMAs administered as monotherapy or in combination to asthmatic patients, according to the different phenotypes. It offers an overview of the role of LAMAs or their fixed dose combinations (FDCs) in the treatment across all the different stages of asthma.

EXPERT OPINION

Tiotropium is now widely recognized as treatment for moderate to severe uncontrolled asthma (step 4-5) in adults and children. The most recent new evidence is: a) in adults, three different LAMA/long-acting β₂-agonist (LABA)/inhaled corticosteroid (ICS) FDCs have been recently approved, extending the treatment options for these patients; b) therapy with LAMAs does not depend on patient's Th2 status and justifies the indication regardless of patient's phenotyping; c) in the milder stages, the high variability of response to LAMAs and the lack of a good phenotyping of patients represents the main obstacle in prescribing LAMAs. A better characterization of parasympathetic tone activity could improve LAMAs prescription.

Long-acting muscarinic antagonists and small airways in asthma: Which link?

Involvement of small airways, those of <2 mm in internal diameter, is present in all stages of asthma and contributes substantially to its pathophysiologic expression. Therefore, small airways are a potential target to achieve optimal asthma control. Airway tone, which is increased in asthma, is mainly controlled by the vagus nerve that releases acetylcholine (ACh) and activates muscarinic ACh receptors (mAChRs) post-synaptically on airway smooth muscle (ASM). In small airways, M₃ mAChRs are expressed, but there is no vagal innervation. Non-neuronal ACh released from the epithelial cells that may express choline acetyltransferase in response to inflammatory stimuli, as well as from other structural cells in the airways, including fibroblasts and mast cells, can activate mAChRs. By antagonizing M₃ mAChR, the contraction of the ASM is prevented and, potentially, local inflammation can be reduced and the progression of remodeling may be averted. In fact, ACh also contributes to inflammation and remodeling of the airways and regulates the growth of ASM. Several experimental studies have demonstrated the potential benefit derived from the use of mAChR antagonists, mainly long-acting mAChR antagonists (LAMAs), on small airways in asthma. However, there are several confounding factors that may cause a wrong estimation of the relationship between LAMAs and small airways in asthma. Further studies are needed to differentiate broncholytic and anti-inflammatory effects of LAMAs and to better understand the interaction between LAMAs and corticosteroids, also in the context of a triple therapy that includes a β₂ -AR agonist, at different levels of the bronchial tree.

Aclidinium bromide/formoterol fumarate as a treatment for COPD: an update

Introduction: Aclidinium/formoterol is a long-acting muscarinic antagonist (LAMA) and long-acting β₂-agonist (LABA) dual bronchodilator used as a maintenance treatment for patients with chronic obstructive pulmonary disease (COPD). The efficacy of aclidinium/formoterol has been demonstrated consistently in patients with moderate-to-severe COPD versus placebo and monocomponents, with a comparable safety profile.Areas covered: This review examines recent research findings that expand our understanding of the impact of aclidinium/formoterol on the burden of COPD. Reviewed outcomes include improvements in lung function, respiratory symptoms, health-related quality of life, exercise tolerance, exacerbation rates, and clinically important deteriorations. In addition, the reported cardiovascular safety of aclidinium and current LAMA/LABA treatment recommendations are discussed.Expert opinion: Aclidinium/formoterol reduces disease burden in patients with COPD, including those that are treatment-naïve, without a significant increase in safety risk compared with monotherapies. Furthermore, evidence supports an improvement in lung function over a 24-hour period with aclidinium/formoterol treatment versus monotherapy and placebo, which may offer an advantage over some once-daily LAMA/LABA combinations. In summary, the recent evidence discussed in this review adds weight to the use of LAMA/LABA combinations as an initial therapy for certain patients newly diagnosed with COPD.

Ceiling effect of beclomethasone/formoterol/glycopyrronium triple fixed-dose combination in COPD: A translational bench-to-bedside study

BACKGROUND

Currently, data on the possible synergy of adding a LAMA to ICS/LABA combination are missing and no studies assessed whether triple therapy may induce ceiling bronchodilator effect. A translational study was performed to investigate the interaction between glycopyrronium bromide (GB) and beclomethasone dipropionate (BDP)/formoterol fumarate (FF) combination in human isolated airways and the effect on FEV₁ and small airway resistance of BDP/FF/GB in COPD.

METHODS

The interaction of adding GB to BDP/FF combination was tested in vitro in medium and small airways via Bliss, Loewe, and Highest Single Agent models. The peak and trough effect on FEV₁ and R5-R19 of salbutamol on top of BDP/FF/GB 100/6/12.5 μg FDC via extrafine formulation was investigated in severe COPD patients after two weeks of treatment.

RESULTS

GB plus BDP/FF elicited significant synergistic bronchorelaxation in medium and small isolated airways (overall maximal effect: +32% vs. additive effect). No significant (P > 0.05) improvement in R5-R19 was detected when salbutamol was administered on top of BDP/FF/GB 100/6/12.5 μg FDC (peak -0.12 ± 0.22 cmH₂O/L/s, trough -0.23 ± 0.25 cmH₂O/L/s). Salbutamol significantly (P < 0.01) increased FEV₁ when administered on top of triple FDC (peak +145 ± 119 ml, trough +221 ± 111 ml).

CONCLUSION

The synergistic interaction detected in vitro when adding GB to BDP/FF combination may lead to ceiling bronchorelaxation of small airways in vivo, an effect that may improve hyperinflation in subjects with small airway disease and, thus, explain the substantial clinical benefits of triple combination therapy administered via extrafine formulation in severe COPD patients.

STUDY REGISTRATION

ISRCTN94089001.

Comparative studies of dual bronchodilation in COPD

Dual bronchodilation therapy is becoming the cornerstone for the treatment of COPD because the clinical benefits of LABA/LAMA fixed-dose combinations (FDCs) are now extensively established. Therefore, it not surprising that a number of LAMA/LABA combinations in a single inhaler have now been approved for clinical use as treatments for patients with COPD. Regrettably, very few head-to-head studies between all of the available LABA/LAMA FDCs have been carried out. This makes choosing the most appropriate FDC difficult. Comparative effectiveness research that also uses conventional meta-analyses to compare different care strategies can help generate useful information. A bidimensional comparative analysis across LAMA/LABA FDCs has suggested constant superiority for tiotropium/olodaterol. However, considering that there is not an equivalent amount of evidence on efficacy outcomes for all LAMA/LABA FDCs, a proper comparison between the different LAMA/LABA FDCs cannot be made yet, and the information available is still rather inconsistent.

Synergy across the drugs approved for the treatment of asthma

INTRODUCTION

Inhaled corticosteroids are the cornerstone for the treatment of stable asthma, however, when disease severity increases, escalating therapy to combinations of drugs acting on distinct signalling pathways is required. It is advantageous to providing evidence of a synergistic interaction across drug combinations, as it allows optimizing bronchodilation while lowering the dose of single agents. In the respiratory pharmacology field, two statistical models are accepted as gold standard to characterize drug interactions, namely the Bliss Independence criterion and the Unified Theory. In this review, pharmacological interactions across drugs approved for the treatment of asthma have been systematically assessed.

EVIDENCE ACQUISITION

A comprehensive literature search was performed in MEDLINE for studies that used a validated pharmacological method for assessing drug interaction. The results were extracted and reported via qualitative synthesis.

EVIDENCE SYNTHESIS

Overall, 45 studies were identified from literature search and 5 met the inclusion criteria. Current evidence coming from ex vivo models of asthma indicates that drug combinations modulating bronchial contractility induce a synergistic bronchorelaxant effect. In murine models of lung inflammation, the combination between inhaled corticosteroids and β2- adrenoceptor agonists synergistically improve lung function and the inflammatory profile.

CONCLUSIONS

There is still limited knowledge regarding the mechanistic basis underlying pharmacological interactions across drugs approved for asthma. The synergism elicited by combined agents is an effect of class. Specifically designed clinical trials are needed to confirm the results coming from preclinical evidence, but also to establish the minimal dose for combined agents to induce a synergistic interaction and maximize bronchodilation.

Pharmacokinetic/pharmacodynamic approaches to drug delivery design for inhalation drugs

Introduction: Inhaled drugs are important in the treatment of many lung pathologies, but to be therapeutically effective they must reach unbound concentrations at their effect site in the lung that are adequate to interact with their pharmacodynamic properties (PD) and exert the pharmacological action over an appropriate dosing interval. Therefore, the evaluation of pharmacokinetic (PK)/PD relationship is critical to predict their possible therapeutic effect.Areas covered: We review the approaches used to assess the PK/PD relationship of the major classes of inhaled drugs that are prescribed to treat pulmonary pathologies.Expert opinion: There are still great difficulties in producing data on lung concentrations of inhaled drugs and interpreting them as to their ability to induce the desired therapeutic action. The structural complexity of the lungs, the multiplicity of processes involved simultaneously and the physical interactions between the lungs and drug make any PK/PD approach to drug delivery design for inhalation medications extremely challenging. New approaches/methods are increasing our understanding about what happens to inhaled drugs, but they are still not ready for regulatory purposes. Therefore, we must still rely on plasma concentrations based on the axiom that they reflect both the extent and the pattern of deposition within the lungs.

A randomized controlled trial of long-acting muscarinic antagonist and long-acting β2 agonist fixed-dose combinations in patients with chronic obstructive pulmonary disease

Background

In chronic obstructive pulmonary disease (COPD) patients, combination treatment with long-acting muscarinic antagonist (LAMA) and long-acting β2 agonist (LABA) increases forced expiratory volume in one second and reduces symptoms compared to monotherapy. In Japan, three different once-daily fixed-dose combinations (FDCs) have been prescribed since 2015, although a direct comparison of these FDCs has never been performed. The objective of the present study was to compare the effectiveness, preference, and safety of three LAMA/LABA FDCs—glycopyrronium/indacaterol (Gly/Ind), umeclidinium/vilanterol (Ume/Vil), and tiotropium/olodaterol (Tio/Olo)—in patients with COPD.

Methods

We enrolled 75 COPD outpatients (male:female ratio, 69:6; 77.4 ± 6.9 years). A prospective, randomized, crossover study was conducted on three groups using three FDCs: Gly/Ind; Ume/Vil; and Tio/Olo. Each medication was administered for 4 weeks before crossover (total 12 weeks). After each FDC administration, a respiratory function test and questionnaire survey were conducted. A comparative questionnaire survey of all three LAMA/LABA FDCs was conducted after 12 weeks (following administration of final FDC).

Results

No significant differences in COPD Assessment Test or modified Medical Research Council dyspnea questionnaire were reported in the surveys completed after each FDC administration; no significant differences in spirometric items were observed. In the final comparative questionnaire survey, patients reported better actual feeling of being able to inhale following Gly/Ind administration compared with Tio/Olo, although no significant differences in adverse events or other evaluations were reported.

Conclusions

The three LAMA/LABA FDCs administered to COPD patients show similar effects and safety, although some minor individual preference was reported.

Trial registration This study retrospectively registered with the University Hospital Medical Information Network Clinical Trials Registry (number UMIN000041342, registered on August 6, 2020).

Long-Acting Muscarinic Antagonists Under Investigational to Treat Chronic Obstructive Pulmonary Disease

Introduction

Bronchodilators are the cornerstone of chronic obstructive pulmonary disease (COPD) therapy and long-acting muscarinic antagonists (LAMAs) as a mono or combination treatment play a pivotal role. Several LAMAs are already available on the market in different formulations, but developing a new compound with a higher M3 receptor selectivity and a lower affinity to M2 receptors to increase the therapeutic effect and minimize the adverse effects is still a goal. Moreover, new formulations could improve adherence to therapy.

Areas Covered

This systematic review assesses investigational long-acting muscarinic antagonist in Phase I and II clinical trials over the last decade. It offers insights on whether LAMAs and/or their new formulations in clinical development can become effective treatments for COPD in the future.

Expert Opinion

Research on LAMA seems to have come to a standstill, the few new molecules under study do not show distinctive characteristics compared to the previous ones. Muscarinic antagonist/β2-agonist (MABAs) appear to be the major innovation currently under investigation, and they could theoretically open new research frontiers on the effect between adrenergic and muscarinic interaction in the same cell.

First-Line Treatment with Tiotropium/Olodaterol Improves Physical Activity in Patients with Treatment-Naïve Chronic Obstructive Pulmonary Disease

Background

Comparative effects on physical activity of mono and dual bronchodilators remain unclear in patients with treatment-naïve chronic obstructive pulmonary disease (COPD). We sought to compare the changes in physical activity before and after tiotropium and tiotropium/olodaterol treatment in treatment-naïve COPD patients.

Methods

A prospective, multicenter, randomized, open-labeled, and parallel interventional study was conducted. Eighty Japanese patients with treatment-naïve COPD were randomized to receive either tiotropium or tiotropium/olodaterol treatment for 12 weeks. Spirometry and dyspnea index were assessed, and COPD assessment test (CAT) and the 6-minute walk distance (6MWD) were conducted before and after treatment. Evaluation of physical activity was assessed by a triaxle accelerometer over a 2-week period before and after treatment.

Results

There were no differences in the mean age (69.8 vs 70.4 years), body mass index (BMI) (22.5 vs 22.6 kg/m²) and mean % forced expiratory volume in 1 second (%FEV1) at baseline (61.5 vs 62.6%) between the two groups. Changes in FEV1 (mean±standard error, 242.8±28.8 mL) and transient dyspnea index (TDI) (2.4±0.3 points) before and after tiotropium/olodaterol treatment were greater than with tiotropium treatment (104.1±31.9 mL, p<0.01 and 1.5±0.3, p=0.02, respectively). Changes in the duration of physical activity with 1.0–1.5 metabolic equivalents (METs) estimated in the sedentary position following tiotropium/olodaterol treatment (−38.7±14.7 min) tended to be reduced more than with tiotropium treatment (−4.6±10.6 min) (p=0.06), although those with ≥2.0 METs numerically increased with both treatments (+10.8±7.6 min for tiotropium/olodaterol vs +8.3±7.6 min for tiotropium, p=0.82). Tiotropium/olodaterol treatment reduced the duration of physical activity with 1.0–1.5 METs (regression coefficient, −43.6 [95% CI −84.1, −3.1], p=0.04) in a multiple regression model adjusted for cofounding factors such as age, FEV1, total CAT scores, 6MWD, and TDI.

Conclusion

This is the first study to report the impact of dual bronchodilator on physical activity in treatment-naïve COPD patients of Japanese with low BMI.

Pharmacology and Therapeutics of Bronchodilators Revisited

Bronchodilators remain the cornerstone of the treatment of airway disorders such as asthma and chronic obstructive pulmonary disease (COPD). There is therefore considerable interest in understanding how to optimize the use of our existing classes of bronchodilator and in identifying novel classes of bronchodilator drugs. However, new classes of bronchodilator have proved challenging to develop because many of these have no better efficacy than existing classes of bronchodilator and often have unacceptable safety profiles. Recent research has shown that optimization of bronchodilation occurs when both arms of the autonomic nervous system are affected through antagonism of muscarinic receptors to reduce the influence of parasympathetic innervation of the lung and through stimulation of β ₂-adrenoceptors (β ₂-ARs) on airway smooth muscle with β ₂-AR-selective agonists to mimic the sympathetic influence on the lung. This is currently achieved by use of fixed-dose combinations of inhaled long-acting β ₂-adrenoceptor agonists (LABAs) and long-acting muscarinic acetylcholine receptor antagonists (LAMAs). Due to the distinct mechanisms of action of LAMAs and LABAs, the additive/synergistic effects of using these drug classes together has been extensively investigated. More recently, so-called "triple inhalers" containing fixed-dose combinations of both classes of bronchodilator (dual bronchodilation) and an inhaled corticosteroid in the same inhaler have been developed. Furthermore, a number of so-called "bifunctional drugs" having two different primary pharmacological actions in the same molecule are under development. This review discusses recent advancements in knowledge on bronchodilators and bifunctional drugs for the treatment of asthma and COPD. SIGNIFICANCE STATEMENT: Since our last review in 2012, there has been considerable research to identify novel classes of bronchodilator drugs, to further understand how to optimize the use of the existing classes of bronchodilator, and to better understand the role of bifunctional drugs in the treatment of asthma and chronic obstructive pulmonary disease.

Targeting IL-5 pathway against airway hyperresponsiveness: A comparison between benralizumab and mepolizumab

BACKGROUND AND PURPOSE

Airway hyperresponsiveness (AHR) is a central abnormality in asthma. IL-5 may modulate AHR in animal models of asthma, but the available data is inconsistent on the impact of targeting IL-5 pathway against AHR. The difference between targeting IL-5 or the IL-5 receptor, α subunit (IL-5Rα) in modulating AHR remains to be investigated in human airways. The aim of this study was to compare the role of the anti-IL-5Rα benralizumab and the anti-IL-5 mepolizumab against AHR and to assess whether these agents influence the levels of cAMP.

EXPERIMENTAL APPROACH

Passively sensitized human airways were treated with benralizumab and mepolizumab. The primary endpoint was the inhibition of AHR to histamine. The secondary endpoints were the protective effect against AHR to parasympathetic activation and mechanical stress, and the tissue modulation of cAMP.

KEY RESULTS

Benralizumab and mepolizumab significantly inhibited the AHR to histamine (maximal effect -134.14 ± 14.93% and -108.29 ± 32.16%, respectively), with benralizumab being 0.73 ± 0.10 logarithm significantly more potent than mepolizumab. Benralizumab and mepolizumab significantly inhibited the AHR to transmural stimulation and mechanical stress. Benralizumab was 0.45 ± 0.16 logarithm significantly more potent than mepolizumab against AHR to parasympathetic activation. The effect of these agents was significantly correlated with increased levels of cAMP.

CONCLUSION AND IMPLICATIONS

Targeting the IL-5/IL-5Rα axis is an effective strategy to prevent the AHR. Benralizumab was more potent than the mepolizumab and the concentration-dependent beneficial effects of both these monoclonal antibodies were related to improved levels of cAMP in hyperresponsive airways.

Investigational treatments in phase I and II clinical trials: a systematic review in chronic obstructive pulmonary disease (COPD)

Introduction. The current pharmacological treatments for the management of stable COPD permit the reduction of symptoms and frequency and severity of exacerbations, and the improvement of exercise tolerance and health status. However, they do not modify the long-term decline in lung function and patient health. Consequently, there is the strong need for 'highly innovative' medications that are focused on new targets and/or mechanisms for the treatment of COPD. Areas covered. This systematic review assesses investigational agents in Phase I and II clinical trials over the last six years. It offers insights on whether drugs and/or formulations in clinical development offer future effective treatments of COPD. Expert opinion. There is no evidence to suggest that current investigational agents can reduce lung function decline and cure COPD. However, looking forward, investigational, innovative treatments in combination with the therapies already recommended by the Global Initiative for Chronic Obstructive Lung Disease (GOLD) may provide future suitable tools to counteract the progression of COPD.

New perspectives on the role of muscarinic antagonists in asthma therapy

INTRODUCTION

There is increasing evidence that tiotropium, a long-acting muscarinic agent (LAMA), is useful in the presence of severe-uncontrolled asthma despite the optimization of therapy with inhaled corticosteroids (ICSs) and long-acting β₂ agonists (LABAs) as recommended by the current guidelines. Furthermore, in recent years there have been several  preclinical and clinical studies on the pharmacological and therapeutic impact of other LAMAs in asthma.

AREAS COVERED

We have conducted an extensive search on muscarinic antagonists in asthma therapy throughout several sources and discuss what has emerged in the last 3 years (January 2017-March 2020).

EXPERT OPINION

New evidence indicates that the effectiveness of adding a LAMA, at least tiotropium, is independent of the degree of the type 2 inflammation and age of patient. Therefore, tiotropium can be administered without the need for patient phenotyping. Umeclidinium and glycopyrronium also appear effective in asthma. Initial treatment with LAMA+ICS for those with mild asthma may be an equally effective therapeutic option as LABA+ICS but this hypothesis should be confirmed by statistically powered trials.

Anthelminthic medicinal plants in veterinary ethnopharmacology: A network meta-analysis following the PRISMA-P and PROSPERO recommendations

Medicinal plants may be effective against helminthic infestation in animals, but to date few studies have investigated the real impact of anthelminthic medicinal plants in veterinary ethnopharmacology.

The aim of this study was to assess the geographical use of anthelminthic medicinal plants in livestock in European Union (EU), and to quantify the anthelminthic efficacy of medicinal plants in comparison with anthelminthic drugs. Surveys on the use of anthelminthic traditional medicinal plants in livestock in the EU were included in the qualitative synthesis. Studies that investigated the efficacy of anthelminthic traditional medicinal plants in animals, compared with negative control and/or anthelminthic drugs, were included in the quantitative synthesis (network meta-analysis).

Twelve surveys (9 in Italy, 2 in Spain, 1 in Austria) reported the use of anthelminthic medicinal plants in livestock living in EU Countries. Data obtained from 256 animals and extracted from 6 studies were included in the network meta-analysis. Medicinal plants and drugs were more effective than negative control (standardized mean difference [SMD]: -0.60 95%CrI -0.88 to -0.31, -0.73 95%CrI -1.08 to -0.38, respectively, P < 0.001). Overall, no difference was detected between anthelminthic medicinal plants and anthelminthic drugs, namely albendazole, ivermectin, fenbendazole, and doramectin (SMD: 0.26 95%CrI -0.02 to 0.55, P > 0.05). The most effective anthelminthic medicinal plants were Artemisia absintihium, Allium sativum, and Duranta erecta.

There is the strong medical need of performing adequately powered randomized controlled trials in different livestock species aimed to improve the quality of the current evidence concerning the anthelminthic efficacy of medicinal plants compared to that of the currently available antiparasitic drugs.

Beclomethasone dipropionate, formoterol fumarate and glycopyrronium bromide: Synergy of triple combination therapy on human airway smooth muscle ex vivo

BACKGROUND AND PURPOSE

Combining inhaled corticosteroids (ICSs), long-acting β₂ -adrenoceptor agonists (LABAs) and long-acting muscarinic antagonists (LAMAs) is recommended to treat severe forms of asthma and chronic obstructive pulmonary disease (COPD). Clinical benefits have been demonstrated for ICS/LABA/LAMA combinations. This study characterized the interaction between the ICS beclomethasone dipropionate, the LABA formoterol fumarate and the LAMA glycopyrronium bromide in human airways.

EXPERIMENTAL APPROACH

Human passively sensitized airways and bronchi from COPD donors were stimulated with histamine or carbachol. Tissues were incubated overnight with beclomethasone and then treated with formoterol and glycopyrronium, alone or in triple combination. The interaction was assessed by using Bliss Independence and Unified Theory theorems.

KEY RESULTS

Beclomethasone/formoterol/glycopyrronium combination synergistically relaxed medium bronchi and small airways. Beclomethasone/formoterol/glycopyrronium combination at 100:6:12.5 combination ratio was a balanced drug mixture leading to very strong synergistic effect on relaxation of medium bronchi (Combination Index: from 0.042 to 0.96) and middle to very strong synergy in small airways (Combination Index: from 0.018 to 0.310). The synergy was related with the activation of intracellular glucocorticoid receptors and G_sα subunit G-protein of β₂ -adrenoceptors, leading to the modulation of cyclic AMP-dependent PKA pathway.

CONCLUSION

Triple beclomethasone/formoterol/glycopyrronium combination induces synergistic bronchorelaxant effect in medium and small human airways, at least in ex vivo experiments. Further research is needed to confirm these findings in clinical studies in patients with asthma or COPD.

A long-term clinical trial on the efficacy and safety profile of doxofylline in Asthma: The LESDA study

Doxofylline, an oral methylxanthine with bronchodilator and anti-inflammatory activities, offers a promising alternative to theophylline due to its superior efficacy/safety profile. No long-term studies on the efficacy and safety of doxofylline are currently available in asthma. The aim of the Long-term clinical trial on the Efficacy and Safety profile of Doxofylline in Asthma (LESDA) study was to investigate the safety and efficacy profile of doxofylline administered for one year in asthmatic patients. LESDA was a multicenter, open-label, Phase III, clinical trial in which adult asthmatic patients received the same treatment (oral doxofylline 400 mg t.i.d.) for one year. Efficacy was assessed through periodic pulmonary function tests and by having the subjects keep monthly records of asthma events rates and use of salbutamol as rescue medication. The rate of adverse events (AEs) was recorded during the study. Three-hundred nine patients were screened and allocated in the study. Doxofylline significantly improved the change from baseline in forced expiratory volume in 1 s (FEV₁) (+16.90 ± 1.81%, P < 0.001 vs. baseline). Doxofylline also significantly improved the rate of asthma events (events/day: -0.57 ± 0.18, P < 0.05 vs. baseline) and the use of salbutamol as rescue medication (puffs/day: -1.48 ± 0.25, P < 0.01 vs. baseline). The most common AEs were nausea (14.56%), headache (14.24%), insomnia (10.68%), and dyspepsia (10.03%). There were neither serious AEs nor deaths during or shortly after the study. Concluding, doxofylline is effective and well tolerated when administered chronically in asthmatic patients.

Optimizing the Development Strategy of Combination Therapy in Respiratory Medicine: From Isolated Airways to Patients

The current recommendations for the treatment of chronic obstructive pulmonary disease (COPD) are pushing towards triple combination therapy based on the combination of an inhaled corticosteroid (ICS) associated with two bronchodilator agents. However, dual bronchodilation remains the cornerstone for the treatment of most COPD patients. Combining a long-acting β₂ adrenoceptor agonist (LABA) with a long-acting muscarinic antagonist (LAMA) induces appreciable synergistic bronchorelaxant effect in human airways, especially when the medications are combined at isoeffective concentrations. Thus, each LABA/LAMA combination is characterized by a specific range of concentration-ratio at which the drug mixture may induce sustained synergistic interaction. Results of a recent randomized controlled trial (RCT, NCT00696020) and evidences from pre-clinical studies in human isolated airways poses the question whether combining tiotropium 5 μg with olodaterol 5 μg is the best combination option: tiotropium/olodaterol 5/5 μg has the same efficacy profile of tiotropium/olodaterol 5/2 μg, and it is less effective than tiotropium/olodaterol 5/10 μg. Furthermore, tiotropium/olodaterol 5/2 μg, 5/5 μg, and 5/10 μg combinations are generally characterized by the same safety profile. Indeed tiotropium/olodaterol 5/5 μg is effective and safe in COPD, but a different development strategy based on solid data obtained from human isolated airways would have driven towards a better-balanced FDC to be tested in Phase III RCTs. Accurate bench-to-bedside plans are needed also in the development of triple combination therapies for asthma and COPD, in which the presence of an ICS in the formulation may further modulate the beneficial interaction between the LABA and the LAMA.

Isolated airways in equine respiratory pharmacology: They never lie

Pre-clinical studies on human isolated bronchi have relevant translational value in human in vivo, conversely no investigation has been performed to assess whether data resulting from equine isolated airways can have any translational application in asthmatic horses. Thus, a meta-regression analysis via random-effect method was carried out to correlate the pharmacological characteristics of bronchodilators resulting from experiments performed in equine isolated bronchi with their impact on the lung function outcomes in asthmatic horses. Data on the potency of different bronchodilators were extracted from four ex vivo studies involving 68 horses, and related with the maximum change in transpulmonary pressure (ΔPpl_max), pulmonary resistance (R_L), and dynamic lung compliance (C_dyn) resulting from the meta-analysis of clinical trials aimed to assess the effect of different bronchodilator classes, namely antimuscarinic agents and β₂-adrenoreceptor (β₂-AR) agonists, on lung function of asthmatic horses. The potency (pEC₅₀) detected in equine isolated bronchi for each specific bronchodilator did not significantly (P > 0.05) influence the bronchorelaxant effect resulting from clinical trials. R_L was characterized by a flatter meta-regression line (slope 0.01, 95%CI -0.25 - 0.28) with respect to ΔPpl_max (slope 0.90, 95%CI -4.06 - 2.26) and C_dyn (slope 0.09, 95%CI -0.21 - 0.04). The quality of evidence was moderate for R_L and ΔPpl_max and low for C_dyn. This quantitative synthesis provides the indirect evidence that pre-clinical investigations performed by using equine isolated airways may produce useful data to predict the impact of bronchodilators on the R_L of asthmatic horses. Further translational studies are needed to directly confirm the results of this research.

A potential role of triple therapy for asthma patients

Introduction: The use of LAMAs in asthma is now supported by pharmacological and clinical evidence, whereas the effectiveness of therapy with ICS/LABA/LAMA fixed dose combinations in patients with asthma still remains to be determined. Areas covered: The pharmacological rationale that explains why it is possible to use triple therapy in asthma and the results of clinical studies that have explored the effects of this therapy in asthmatics is critically examined. A systematic search was conducted on 10 August 2019, and included six electronic databases: EMBASE, MEDLINE, Scopus, The Cochrane Library, Web of Science, and Google Scholar. Expert opinion: The real role of single inhaler triple therapy in asthma will be demonstrated when the various trials that are currently ongoing or are scheduled will be completed. We believe that it is appropriate to treat with triple therapy asthmatic patients who have smoked and remain symptomatic or suffer from frequent exacerbations despite initial inhaler therapy with ICS/LABA. However, we must establish when to step up or mainly step down triple therapy especially in patients who are well controlled, and what will be the cost of these combinations in the management of asthma.

Pharmacological treatment and current controversies in COPD

Bronchodilators, corticosteroids, and antibiotics are still key elements for treating chronic obstructive pulmonary disease in the 2019 Global Initiative for Chronic Obstructive Lung Disease (GOLD) recommendations and this is due in part to our current inability to discover new drugs capable of decisively influencing the course of the disease. However, in recent years, information has been produced that, if used correctly, can allow us to improve the use of the available therapies.

Eosinophil Inflammation and Hyperresponsiveness in the Airways as Phenotypes of COPD, and Usefulness of Inhaled Glucocorticosteroids

Background: The differential diagnosis in persistent airway limitation is sometimes not so clear in older adults. Airway eosinophilia and airway hyperresponsiveness may develop in some cases with chronic obstructive lung disease (COPD), independent of asthma. However, little is known about clinical significance of these phenotypes of COPD in detail. Aims and objectives: This clinical study was designed to examine prevalence of airway eosinophilia and airway hyperresponsiveness in COPD who have no symptom and no past history of asthma, and to examine involvement of these pathophysiological features of asthma in the management and therapy for COPD. Methods: Sputum examination via qualitative and quantitative procedures was performed in stable COPD (GOLD 1-3). When sputum eosinophils were qualitatively (≥+) or quantitatively assessed (≥3%), ciclesonide (inhaled glucocorticosteroids) was added on bronchodilators. In cases with FEV₁ ≥ 70% of predicted values, acetylcholine provocation test was examined for assessment of airway hyperresponsiveness. Therapeutic effect was evaluated using spirometry and COPD assessment test (CAT). Results: Sputum eosinophils were observed in 65 (50.4%) of 129 subjects using qualitative analysis; in contrast, lower grade (>0%) and higher grade (≥3%) were observed in 15 (20.3%) and 25 (33.8%) of 74 subjects using quantitative analysis. Airway hyperresponsiveness developed in 46.9% of these subjects with sputum eosinophils. Exacerbations occurred much more frequently in lower-grade airway eosinophilia without ciclesonide than in higher-grade airway eosinophilia with ciclesonide. Airway hyperresponsiveness significantly increased frequency of exacerbations in COPD with both lower and higher grade in airway eosinophilia. Addition of ciclesonide to indacaterol markedly improved lung function (FEV₁, IC), CAT score, and reliever use in these subjects with airway eosinophilia determined by qualitative analysis. However, ciclesonide was less effective in improving these values in subjects with airway hyperresponsiveness than in those without airway hyperresponsiveness. Conclusions: Airway eosinophilia and airway hyperresponsiveness are complicated with 25-50% of COPD that have no symptom and history for asthma. These phenotypes of COPD are closely related to symptom stability and reactivity to glucocorticosteroids. These phenotypes may play key roles for advancement of the management and therapy of this disease.

Clinical efficacy of bronchodilators in equine asthma: Looking for minimal important difference

BACKGROUND

Airway obstruction is the main trait of severe equine asthma that affects respiratory function and elicits detrimental effects on clinical presentation. Only few and underpowered clinical studies have investigated the impact of improvement in lung function induced by bronchodilators on the clinical signs of asthma-affected horses.

OBJECTIVES

To identify the minimal important difference (MID) in lung function elicited by bronchodilator leading to a meaningful improvement in clinical signs.

STUDY DESIGN

Pairwise meta-analysis and meta-regression analysis.

METHODS

Literature searches were performed for studies that investigated the effect of bronchodilator therapy on lung function and clinical condition of asthmatic horses. The relationship between the change in lung function variables and clinical score was analysed via random-effect meta-regression. One-point change of the Improved clinically Detectable Equine Asthma Scoring System (IDEASS) score was used to identify the MID.

RESULTS

A significant (P<0.05) relationship was found between the changes in IDEASS score and maximum change in transpulmonary pressure (ΔPpl_max ) or pulmonary resistance (R_L ). Since only the model resulting for R_L passed through the origin (Y-intercept when X = 0: -0.31, 95% CI -0.75 to 0.14), this variable was used to identify the MID correlated with a meaningful improvement in clinical signs. The resulting MID value was a change in R_L of 0.63 cm H₂ O/L/s (95% CI 0.33-0.94), representing the slope of meta-regression model (high quality of evidence).

MAIN LIMITATIONS

No long-term studies investigated the effect of bronchodilator agents on both lung function and clinical signs in asthmatic horses.

CONCLUSIONS

In conclusion, bronchodilator pharmacotherapy in equine asthma elicits clinically meaningful effect when R_L increases ≥1 cm H₂ O/L/s, a value indicating the MID. Assessing the MID based on change in R_L may improve the quality of evidence and the scientific impact of future clinical trials as it extends beyond the simple, and limiting, evaluation of statistical significance.

Long-term observational study on the impact of GLP-1R agonists on lung function in diabetic patients

INTRODUCTION

Preclinical research suggests a role of Glucagon Like Peptide-1 Receptors (GLP-1R) on the regulation of human bronchial tone. We investigated the effect of GLP-1R agonists on lung function of Type 2 Diabetes Mellitus (T2DM) population without co-existing chronic obstructive respiratory disorders.

METHODS

This was a prospective cohort study that examined change in lung function measurements over two years of T2DM patients (n = 32) treated with metformin monotherapy (control cohort), metformin plus GLP-1R agonists (GLP-1R agonists cohort), or metformin plus insulin (insulin cohort).

RESULTS

After 24 months of treatment, the forced expiratory volume in 1 s (FEV₁) significantly (p < 0.05) increased from baseline in the GLP-1R agonists cohort (218 ml [95%CI 88-246]), but not in the control and insulin cohorts (94 ml [95%CI -28 - 216] and 26 ml [95%CI -174 - 226], respectively; p > 0.05 vs. baseline). The average increase in FEV₁ in the GLP-1R agonists cohort was significantly greater than that in the control and insulin cohorts (delta: 110 ml [95%CI 18-202] and 177 ml [95%CI 85-270], respectively, p < 0.05). The forced vital capacity (FVC) also increased significantly more in the GLP-1R agonists cohort than in the control and insulin cohorts (overall delta FVC: 183 ml [95%CI 72-295], p < 0.05). The maximal expiratory flow at 50-75% significantly (p < 0.05) improved from baseline in the GLP-1R agonists cohort, but not in the control and insulin cohorts (p > 0.05).

CONCLUSION

Our preliminary results suggest a potential new therapeutic perspective to treat airway disorders with GLP-1R agonists.

Pharmacological Profile of AZD8871 (LAS191351), a Novel Inhaled Dual M3 Receptor Antagonist/β 2-Adrenoceptor Agonist Molecule with Long-Lasting Effects and Favorable Safety Profile

AZD8871 is a novel muscarinic antagonist and β ₂-adrenoceptor agonist in development for chronic obstructive pulmonary disease. This study describes the pharmacological profile of AZD8871 in in vitro and in vivo assays. AZD8871 is potent at the human M₃ receptor (pIC₅₀ in binding assays: 9.5) and shows kinetic selectivity for the M₃ (half-life: 4.97 hours) over the M₂ receptor (half-life: 0.46 hour). It is selective for the β ₂-adrenoceptor over the β ₁ and β ₃ subtypes (3- and 6-fold, respectively) and shows dual antimuscarinic and β ₂-adrenoceptor functional activity in isolated guinea pig tissue (pIC₅₀ in electrically stimulated trachea: 8.6; pEC₅₀ in spontaneous tone isolated trachea: 8.8, respectively), which are sustained over time. AZD8871 exhibits a higher muscarinic component than batefenterol in human bronchi, with a shift in potency under propranolol blockade of 2- and 6-fold, respectively, together with a persisting relaxation (5.3% recovery at 8 hours). Nebulized AZD8871 prevents acetylcholine-induced bronchoconstriction in both guinea pig and dog with minimal effects on salivation and heart rate at doses with bronchoprotective activity. Moreover, AZD8871 shows long-lasting effects in dog, with a bronchoprotective half-life longer than 24 hours. In conclusion, these studies demonstrate that AZD8871 is a dual-acting molecule with a high muscarinic component and a long residence time at the M₃ receptor; moreover, its preclinical profile in animal models suggests a once-daily dosing in humans and a favorable safety profile. Thus, AZD8871 has the potential to be a next generation of inhaled bronchodilators in respiratory diseases.

Inhaled therapies and cardiovascular risk in patients with chronic obstructive pulmonary disease

INTRODUCTION

Chronic obstructive pulmonary disease (COPD) therapy includes a multi-dimensional approach, taking into account both symptoms of the patient and the number of acute exacerbations of COPD (AECOPDs). There are three main pharmaceutical classes currently available including long-acting muscarinic antagonists (LAMA), long-acting β₂-agonists (LABA) and inhaled corticosteroids (ICS). COPD is a major risk factor for most cardiovascular diseases, and cardiac comorbidities are very common in COPD patients. Both LAMA and LABA have a considerable impact on cardiac function by stimulating cardiac β2-adrenergic receptors or inhibiting the heart M₂ muscarinic receptors. ICS alone or in combination has never been associated with a real cardiovascular risk.

AREAS COVERED

This review explores the data published on the safety of COPD therapy and the implications for current pharmacotherapy.

EXPERT OPINION

Several studies have confirmed the good safety profile of bronchodilators available both in monotherapy and in association with other bronchodilators of different classes or with ICS despite the device used. Cardiovascular events in clinical trials are generally low and balanced between groups. The actual cardiovascular risk of fixed-dose combinations (FDCs) in an unselected COPD population will need to be investigated through post-marketing surveillance studies and observational studies.

LABA/LAMA fixed-dose combinations in patients with COPD: a systematic review

OBJECTIVES

The aim of this study was to assess the current evidence for long-acting β2-agonist (LABA)/long-acting muscarinic antagonist (LAMA) fixed-dose combinations (FDCs) in the treatment of COPD.

MATERIALS AND METHODS

A systematic literature search of randomized controlled trials published in English up to September 2017 of LABA/LAMA FDCs vs LABA or LAMA or LABA/inhaled corticosteroid (ICS) FDCs in COPD patients was performed using PubMed, Embase, Scopus, and Google Scholar. Outcomes including forced expiratory volume in 1 second (FEV1), Transition Dyspnea Index (TDI) scores, St George's Respiratory Questionnaire (SGRQ) scores, exacerbations, exercise tolerance (endurance time [ET]), inspiratory capacity (IC), and rescue medication use were evaluated.

RESULTS

In total, 27 studies were included in the review. LABA/LAMA FDCs significantly improved lung function (FEV1) at 12 weeks compared with LABA or LAMA or LABA/ICS. These effects were maintained over time. Significant improvements with LABA/LAMA FDCs vs each evaluated comparator were also observed in TDI and SGRQ scores, even if significant differences between different LABA/LAMA FDCs were detected. Only the LABA/LAMA FDC indacaterol/glycopyrronium has shown superiority vs LAMA and LABA/ICS for reducing exacerbation rates, while olodaterol/tiotropium and indacaterol/glycopyrronium have been shown to improve ET and IC vs the active comparators. Rescue medication use was significantly reduced by LABA/LAMA FDCs vs the evaluated comparators. LABA/LAMA FDCs were safe, with no increase in the risk of adverse events with LABA/LAMA FDCs vs the monocomponents.

CONCLUSION

Evidence supporting the efficacy of LABA/LAMA FDCs for COPD is heterogeneous, particularly for TDI and SGRQ scores, exacerbation rates, ET, and IC. So far, indacaterol/glycopyrronium is the LABA/LAMA FDC that has the strongest evidence for superiority vs LABA, LAMA, and LABA/ICS FDCs across the evaluated outcomes. LABA/LAMA FDCs were safe; however, more data should be collected in a real-world setting to confirm their safety.