Cost-Effectiveness of Bronchial Thermoplasty, Omalizumab, and Standard Therapy for Moderate-to-Severe Allergic Asthma

Comparing bronchial thermoplasty with biologicals for severe asthma: Systematic review and network meta-analysis

BACKGROUND

Bronchial thermoplasty (BT) has shown favorable safety and efficacy in several randomized controlled trials (RCTs), but has not been directly compared to biological therapies.

METHODS

Electronic literature searches were performed on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, to retrieve RCTs of BT or FDA-approved biologicals against controls in patients with severe asthma. Six outcomes were analyzed: Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), the number of patients experiencing ≥1 asthma exacerbation, annualized exacerbation rate ratio (AERR), oral corticosteroid dose reduction (OCDR), and morning peak expiratory flow rate (amPEF). Random-effects, Frequentist network meta-analysis (NMA) were performed, and therapies were ranked using P-scores.

RESULTS

Twenty-nine RCTs (15,547 patients) were included. Fewer patients treated with BT experienced ≥1 asthma exacerbation (risk ratio [RR] = 0.66, 95%CI = 0.45-0.98) compared to control. AERR of BT versus control was non-significant, but significant improvements in ACQ score (mean difference [MD] -0.41, 95%CI -0.63 to -0.20), AQLQ score (MD = 0.54, 95%CI = 0.30-0.77), amPEF and OCDR were found. No significant differences between BT and biologics were seen across indirect comparisons of all studies.

CONCLUSIONS

Despite the lack of head-to-head comparative trials, this NMA suggests that BT is non-inferior to biologicals in terms of quality-of-life scores, and represents a promising alternative for patients with severe asthma.

Incremental net monetary benefit of biologic therapies in moderate to severe asthma: a systematic review and meta-analysis of economic evaluation studies

OBJECTIVES

This meta-analysis was conducted to quantitatively pool the incremental net benefit (INB) of using biologic therapies as an add-on treatment to standard therapy in patients with moderate to severe asthma.

METHODS

We performed a comprehensive search in several databases published until April 2022. Studies were included if they were cost-effectiveness analyses reporting cost per quality-adjusted life-year or life-year on any biologic therapies as an add-on treatment for moderate to severe asthma in patients of all ages. Various monetary units were converted to purchasing power parity, adjusted to 2021 US dollars. The INBs were pooled across studies using a random-effects model, stratified by country income level (high-income countries (HICs) and low- and middle-income countries (LMICs)) and perspectives (health care or payer perspective (HCPP) and societal perspective (SP)) and age group (>12 years and 6-11 years). Heterogeneity was assessed using the I² statistic.

RESULTS

A total of 32 comparisons from 25 studies were included. Pooled INB indicated that the use of omalizumab as an add-on treatment to standard therapy in those aged >12 years was not cost-effective in HICs from the HCPP (n = 8, INB, -6,341 (95% CI, -$25,000 to $12,210), I²=86.18%) and SP (n = 5, -$14,000 (-$170,000 to $140,000), I²=75.64%). A similar finding was observed in those aged 6-11 years from the HCPP in LMICs (n = 2, -$45,000 (-$73,000 to $17,000), I²=00.00%). Subgroup analyses provided no explanations of the potential sources of heterogeneity.

CONCLUSION

The use of biologic therapies in moderate to severe asthma is not cost-effective compared to standard treatment alone.

Which Endoscopic Procedure to Use and in What Patient? Valves, Coils, Foam, and Heat in COPD and Asthma

Despite the latest developments in therapeutic agents targeting airway endotypes, a significant proportion of patients with asthma and chronic obstructive pulmonary disease (COPD) remain symptomatic. Endoscopic therapies have a complementary role in the management of these airway diseases. The sustained efficacy of bronchial thermoplasty (BT) among patients with asthma over 10 years has been encouraging, as it has been shown to improve symptom control and reduce hospital admissions and exacerbations. Studies suggest that BT helps ameliorate airway inflammation and reduce airway smooth muscle thickness. While studies suggest that it is as effective as biologic agents, its role in the management of severe asthma has yet to be clearly defined and GINA 2022 still suggests limiting its use to patients with characteristics of the various populations studied. Conversely, bronchoscopic lung volume reduction has shown promise among patients with advanced COPD. Rigorous patient selection is important. Patients with minimal collateral ventilation (CV) and higher heterogeneity index have shown to benefit the most from endobronchial valve (EBV) therapy. For those with ongoing CV, endobronchial coils would be more appropriate. Both therapeutic modalities have demonstrated improved quality of life, effort tolerance, and lung function indices among appropriately selected patients. The emerging evidence suggests that endoscopic procedures among airway disease still have a substantial role to play despite the development of new therapeutic options.

Airway autoimmunity, asthma exacerbations, and response to biologics

Biologic therapies in asthma are indicated in severe disease, and they are directed against specific inflammatory modulators that contribute to pathogenesis and severity. Currently approved biologics target T2 cytokines (IgE, IL-5, IL-4/IL-13, and TLSP) and have demonstrated efficacy in clinical outcomes such as exacerbation rate and oral corticosteroid dose reductions, blood and airway eosinophil depletion, and lung function improvement. However, a proportion of these patients may show inadequate responses to biologics, with either initial lack of improvement or clinical and functional worsening after an optimal initial response. Exacerbations while on a biologic may be due to several reasons, including imprecise identification of the dominant effector pathway contributing to severity, additional inflammatory pathways that are not targeted by the biologic, inaccuracies of the biomarker used to guide therapy, inadequate dosing schedules, intercurrent airway infections, anti-drug neutralizing antibodies, and a novel phenomenon of autoimmune responses in the airways interfering with the effectiveness of the monoclonal antibodies. This review, illustrated using case scenarios, describes the underpinnings of airway autoimmune responses in driving exacerbations while patients are being treated with biologics, device a strategy to evaluate such exacerbations, an algorithm to switch between biologics, and perhaps to consider two biologics concurrently.

Cost-effectiveness of single-inhaler extrafine beclometasone dipropionate/formoterol fumarate/glycopyrronium in patients with uncontrolled asthma in England

BACKGROUND

In patients with asthma that is uncontrolled by a medium- or high-dose inhaled corticosteroid (ICS) plus long-acting β₂-agonist (LABA), a maintenance therapy option is the addition of a long-acting muscarinic agonist, either via multiple inhalers, or single-inhaler triple therapy (SITT). One SITT is the extrafine formulation of beclometasone dipropionate/formoterol fumarate/glycopyrronium (BDP/FF/G). We used data from two 52-week clinical trials (TRIMARAN and TRIGGER), both conducted in adults with asthma uncontrolled by ICS/LABA, to investigate the cost-effectiveness of BDP/FF/G.

METHODS

A Markov cohort state transition model (focusing on exacerbations) was used to investigate the cost-effectiveness of medium- or high-dose BDP/FF/G vs medium- or high-dose BDP/FF, and high-dose BDP/FF/G vs high-dose BDP/FF + tiotropium. The model analysed cost, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER), and was developed from the England National Health Service perspective (2020 costs). Uncertainty of the inputs was estimated using one-way and probabilistic sensitivity analyses.

RESULTS

Both medium- and high-dose BDP/FF/G were cost-effective vs BDP/FF, with ICERs of £12,224 and £15,587 per QALY gained. High-dose BDP/FF/G was dominant vs BDP/FF + tiotropium, as it was both cheaper and gained QALYs. Sensitivity analyses were consistent with the base model: medium- and high-dose BDP/FF/G had 94.3% and 88.3% likelihoods to be cost-effective vs BDP/FF; high-dose BDP/FF/G had 100% likelihood to be a dominant strategy vs BDP/FF + tiotropium.

CONCLUSIONS

Both medium- and high-dose BDP/FF/G were cost-effective vs medium- and high-dose BDP/FF in adults with asthma that was uncontrolled by ICS/LABA. In addition, high-dose BDP/FF/G was a dominating strategy to high-dose BDP/FF + tiotropium.

CLINICALTRIALS

GOV: NCT02676076 and NCT02676089.

Cost Utility of Bronchial Thermoplasty for Severe Asthma: Implications for Future Cost-Effectiveness Analyses Based on Phenotypic Heterogeneity

Background

Asthma is a disease with tremendous phenotypic heterogeneity, and the patients who are most severely impacted by the disease are high utilizers of the United States healthcare system. In the past decade, there has been many advances in asthma therapy for those with severe disease, including the use of a procedure called bronchial thermoplasty (BT) and the use of biologic therapy for certain phenotypes, but questions remain regarding the long-term durability and cost effectiveness of these therapies. The purpose of this analysis was (1) to assess the cost utility of BT relative to usual care (base case) and (2) to assess the cost utility of BT relative to usual care plus biologic therapy (omalizumab) (scenario analysis) based on updated 10-year clinical trial outcomes.

Methods

A Markov cohort model was developed and used to estimate the cost utility of BT to estimate the costs and quality-of-life impact of BT versus the comparisons over a 10-year time frame using a limited societal perspective, which included both direct health utilization costs and indirect costs associated with missed days of work, among those with severe persistent asthma.

Results

In the base case and the scenario analysis, BT was the dominant treatment strategy compared to usual care alone and usual care plus biologic therapy. The net monetary benefit for BT was $483,555.49 over a 10-year time horizon.

Conclusion

Cost-utility models are central to policy decisions dictating coverage, and can be extended to inform the patient and provider, during clinical decision-making, of the relative trade-offs of therapy, assessing long-term clinical and cost outcomes. Phenotypic classification of severe asthma is central to patient management and should also be integrated into economic analysis frameworks, particularly as new biologic agents are developed that are specific to a phenotype. Despite a larger upfront cost of BT therapy, there is a durable clinical and economic benefit over time for those with severe asthma.

Bronchial thermoplasty: State of the art

Since the publication of a sham-controlled, randomized trial (AIR2) and subsequent marketing approval by the US Food and Drug Administration, we have significantly advanced our understanding of bronchial thermoplasty (BT)'s scientific basis, long-term safety, clinical efficacy and cost-effectiveness. In particular, the last 2 years have witnessed multiple research publications on several of these counts. In this review, we critically appraise our evolving understanding of BT's biologic underpinnings and clinical impact, offer an evidence-based patient workflow guide for the busy pulmonologist and highlight both current challenges as well as potential solutions for the researcher and the clinician.

Endobronchial treatment of severe asthma and severe emphysema with hyperinflation

PURPOSE OF REVIEW

The field of interventional pulmonology has ushered in a wave of innovations for individuals with obstructive airways disease in whom established medical therapies have failed. Leading the charge are bronchial thermoplasty for severe refractory asthma and uni-directional valves for severe emphysema with hyperinflation: both have received regulatory approvals in the United Kingdom and United States. With the commissioning of these novel treatments comes new challenges relating to implementation, positioning within therapeutic algorithms, honing of patient selection, and establishing long-term safety and benefits beyond 5 years.

RECENT FINDINGS

This review summarises the evidence for their safety and efficacy, predictors of therapeutic response, mechanism(s) of action and emerging data supporting the durability of outcomes out to at least ten years.

SUMMARY

It is anticipated the experience of treating increasing numbers of patients, the adoption of international registries, and ongoing research evaluations will serve to optimise these therapies for future generations of patients.

Bronchial thermoplasty guided by hyperpolarised gas magnetic resonance imaging in adults with severe asthma: a 1-year pilot randomised trial

Patient-specific localisation of ventilation defects using hyperpolarised gas magnetic resonance imaging (MRI) introduces the possibility of regionally targeted bronchial thermoplasty (BT) for the treatment of severe asthma. We aimed to demonstrate that BT guided by MRI to ventilation defects reduces the number of radiofrequency activations while resulting in improved asthma quality-of-life and control scores that are non-inferior to standard BT. In a 1-year pilot randomised controlled trial, 14 patients with severe asthma who were clinically eligible to receive BT underwent hyperpolarised gas MRI to characterise ventilation defects and were randomised to MRI-guided or standard BT. End-points were improved Asthma Quality of Life Questionnaire (AQLQ) and Asthma Control Questionnaire (ACQ) scores, the proportion of AQLQ and ACQ responders and the number of radiofrequency activations and bronchoscopy sessions. Participants who underwent MRI-guided BT received 53% fewer radiofrequency activations than those who had standard BT (p=0.003). At 12 months, the mean improvement from baseline was similar between the MRI-guided group (n=5) and the standard group (n=7) for AQLQ score (MRI-guided: 1.8, 95% CI 0.1-3.5, p=0.04; standard: 0.7, 95% CI -0.9-2.3, p=0.30) (p=0.25) and ACQ-5 score (MRI-guided: -1.4, 95% CI -2.6- -0.2, p=0.03; standard: -0.7, 95% CI -1.3-0.0, p=0.04) (p=0.17). A similar proportion of participants in both groups achieved a clinically relevant improvement in AQLQ score (MRI-guided: 80%; standard: 71%) and ACQ-5 score (MRI-guided: 80%; standard: 57%). Hyperpolarised gas MRI-guided BT reduced the number of radiofrequency activations, and resulted in asthma quality of life and control improvements at 12 months that were non-inferior to standard BT.

The economics of precision health: preventing air pollution-induced exacerbation in asthma

The demonstrable value of precision medicine, in the context of common environmental exposures, has scarcely been explored. This study evaluated the cost effectiveness of a preventive personalised intervention to reduce the adverse effect of air pollution in the context of asthma.

A decision–analytic model was used to conduct a cost-utility analysis of prevention interventions in case of acute exposure to air pollution in mild asthma. Three different strategies, as follows, were compared: no preventive intervention; precision health strategy based on information from genotype testing, followed with treating high-risk patients; and prescribing additional medication to all mild asthmatics as a preventive intervention. The costs and quality-adjusted life years (QALYs) in the base case and alternative scenarios were obtained through probabilistic analysis.

The results showed that the precision prevention intervention (anticipatory intervention for asthmatics, guided by relevant genetic abnormality, in the face of acute air pollution) is a cost-effective strategy compared with no such intervention, with an incremental cost-effectiveness ratio of CAD 49 555 per QALY. Furthermore, this strategy is a dominant strategy compared with an intervention that prescribes medication indiscriminately to all asthmatics.

The incorporation of genomic testing to stratify risk of asthmatics to pollution-driven exacerbations, and then tailoring a preventive intervention accordingly, may be cost effective relative to untailored methods. These results lend plausibility to the use of precision medicine for limiting asthma exacerbation in the context of air pollution and, potentially, other exposures.

Glutathione-S-transferase genotyping to determine the use of preventive asthma medication in the face of air pollution is cost effective in this model. Precision prevention in the setting of common environmental exposures may be used in other contexts.https://bit.ly/35Lab4b

Economic burden of asthma in Singapore

Background and objective

Up-to-date economic burden of asthma in Singapore is currently unknown.

Methods

We quantify the per capita and total annual costs of asthma for adults and children by level of symptom control (uncontrolled, partly controlled, and well controlled) via a cross-sectional online survey administered to a national web panel. Participants were asked about healthcare utilisation, days missed from work, and reduced productivity due to their symptoms. These values were then monetised and multiplied by prevalence estimates of adult and child asthmatics to generate total costs.

Results

A total of 300 adults and 221 parents of children with asthma were included in analysis. The total annual cost of adult asthma was estimated to be SGD 1.74 billion (US$1.25 billion) with 42% coming from the uncontrolled group, 45% from the partly controlled group, and 13% from the well-controlled group. For children, the total cost is SGD 0.35 billion (US$0.25 billion), with 64%, 26% and 10% coming from each group respectively. Combined, the annual economic burden of asthma in Singapore is SGD 2.09 billion (US$1.50 billion) with 79% due to productivity losses.

Conclusion

Poorly controlled asthma imposes a significant economic burden. Therefore, better control of disease has the potential to generate not only health improvements, but also medical expenditure savings and productivity gains.

Cost-effectiveness of bronchial thermoplasty for severe asthmatic patients in Japan

Bronchial thermoplasty (BT) is an interventional endoscopic treatment for severe bronchial asthma. Some studies have shown the clinical efficacy of this intervention, but its cost-effectiveness is unclear. The aim of this study was to evaluate the cost-effectiveness of BT. We collected data from the medical records of 16 Japanese patients who were treated with BT between February 2015 and April 2017, and compared asthma-related medical expenses between the year preceding and the year following BT. Four patients were Global Initiative for Asthma (GINA) treatment step 4, and 12 were step 5. In 8 patients who had a successful response to BT, the annual asthma-related medical expenses decreased because of a reduction in hospitalization and emergency outpatient visits due to asthma attacks, and termination of the use of biologics. Most patients in the non-responder group had increased asthma-related medical costs postoperatively. The main reason for the increase in medical costs was the add-on treatment of biologics. BT was cost-effective in the responder group. If its effects continue for more than 10 years, BT will be a cost-effective treatment. Medical costs will be reduced if those who respond to BT can be identified prior to commencement of treatment.

Cost-effectiveness analysis of double low-dose budesonide and low-dose budesonide plus montelukast among pediatric patients with persistent asthma receiving Step 3 treatment in China

AIMS

For children aged 1-5 years with persistent asthma, double low-dose inhaled corticosteroids (ICS) are recommended as the preferred Step 3 treatment and low-dose ICS plus leukotriene receptor antagonists (LTRA) as an alternative. Budesonide inhalation suspension (0.5 mg daily) and montelukast (4.0 mg daily) are commonly used low-dose ICS and LTRA, respectively, among children in China. This study compared the cost-effectiveness of double low-dose budesonide vs. low-dose budesonide plus montelukast from a Chinese healthcare payer's perspective.

METHODS

A Markov model was constructed with four health states (i.e. no exacerbation, mild exacerbation, moderate-to-severe exacerbation, and death). Transition probabilities were estimated based on exacerbation rates, case-fatality of hospitalized patients due to exacerbation, and natural mortality. Treatment adherence was considered and assumed to impact both drug costs and exacerbation rates. Costs (in 2019 Chinese Yuan [¥]) included drug costs and exacerbation management costs. Cost inputs and utilities for each health state were obtained from a public database and the literature. In-depth interviews were conducted with a health economics expert to validate the model, and a clinical expert to verify inputs and assumptions related to clinical practice. Costs and quality-adjusted life-years (QALYs) were estimated over a year. Deterministic and probabilistic sensitivity analyses were performed.

RESULTS

Compared with low-dose budesonide plus montelukast, double low-dose budesonide was associated with lower costs (¥1,534 vs. ¥2,327), fewer exacerbation events (0.43 vs. 1.67) and slightly better QALYs (0.98 vs. 0.97). Sensitivity analyses supported the robustness of the results and the generalizability of findings across geographic regions in China.

CONCLUSION

The cost-effectiveness analysis suggests that double low-dose budesonide is a dominant Step 3 treatment strategy compared with low-dose budesonide plus montelukast for patients aged 1-5 years with persistent asthma in China.

The cost-effectiveness of low-dose budesonide as a Step 2 treatment for pediatric asthma in China

Aim: To compare the cost-effectiveness of low-dose budesonide versus montelukast among patients aged 1-5 years from a Chinese patient and healthcare payer perspective. Materials & methods: A Markov model based on exacerbation states was developed. Exacerbation was defined as the need for rescue therapy (mild exacerbation) or hoscopitalization (moderate-to-severe exacerbation). Inputs including efficacy (i.e., exacerbation rates), mortality, utilities, costs and treatment adherence were obtained from literature. Results: Compared with montelukast, low-dose budesonide led to fewer exacerbation events (1.44 vs 2.15), lower costs (¥3675 vs 4130) and slightly more quality-adjusted life years (0.974 vs 0.967) over 1 year. Conclusion: These findings may improve the use of low-dose budesonide, an economically and clinically preferable treatment to montelukast in pediatric patients.

Bronchial thermoplasty: Redefining its role

In this review, we trace (i) the origins of bronchial thermoplasty, (ii) the development of a solid evidence base for efficacy and safety, (iii) the emerging understanding of the pathophysiological mechanisms of action and (iv) the place in therapy today. Future challenges are then discussed.

Health and economic consequences of applying the United States' PM2.5 automobile emission standards to other nations: a case study of France and Italy

OBJECTIVES

The US has among the world's strictest automobile emission standards, but it is now loosening them. It is unclear where a nation should draw the line between the associated cost burden imposed by regulations and the broader societal benefits associated with having cleaner air. Our study examines the health benefits and cost-effectiveness of introducing stricter vehicle emission standards in France and Italy.

STUDY DESIGN

Quasi-experimental study.

METHODS

We used cost-effectiveness modeling to measure the incremental quality-adjusted life years (QALYs) and cost (Euros) of adopting more stringent US vehicle emission standards for PM2.5 in France and Italy.

RESULTS

Adopting Obama era US vehicle emission standards would likely save money and lives for both the French and Italian populations. In France, adopting US emission standards would save €1000 and increase QALYs by 0.04 per capita. In Italy, the stricter standards would save €3000 and increase QALYs by 0.31. The results remain robust in both the sensitivity analysis and probabilistic Monte Carlo simulation model.

CONCLUSIONS

Adopting more stringent emission standards in France and Italy would save money and lives.

Efficacy and safety of treatment with biologicals (benralizumab, dupilumab and omalizumab) for severe allergic asthma: A systematic review for the EAACI Guidelines - recommendations on the use of biologicals in severe asthma

Allergic asthma is a frequent asthma phenotype. Both IgE and type 2 cytokines are increased, with some degree of overlap with other phenotypes. Systematic reviews assessed the efficacy and safety of benralizumab, dupilumab and omalizumab (alphabetical order) vs standard of care for patients with uncontrolled severe allergic asthma. PubMed, Embase and Cochrane Library were searched to identify RCTs and health economic evaluations, published in English. Critical and important asthma-related outcomes were evaluated. The risk of bias and the certainty of the evidence were assessed using GRADE. All three biologicals reduced with high certainty the annualized asthma exacerbation rate: benralizumab incidence rate ratios (IRR) 0.63 (95% CI 0.50 - 0.81); dupilumab IRR 0.58 (95%CI 0.47 - 0.73); and omalizumab IRR 0.56 (95%CI 0.42 - 0.73). Benralizumab and dupilumab improved asthma control with high certainty and omalizumab with moderate certainty; however, none reached the minimal important difference (MID). Both benralizumab and omalizumab improved QoL with high certainty, but only omalizumab reached the MID. Omalizumab enabled ICS dose reduction with high certainty. Benralizumab and omalizumab showed an increase in drug-related adverse events (AEs) with low to moderate certainty. All three biologicals had moderate certainty for an ICER/QALY value above the willingness to pay threshold. There was high certainty that in children 6-12 years old omalizumab decreased the annualized exacerbation rate [IRR 0.57 (95%CI 0.45-0.72)], improved QoL [relative risk 1.43 (95%CI 1.12 -1.83)], reduced ICS [mean difference (MD) -0.45 (95% CI -0.58 to -0.32)] and rescue medication use [ MD -0.41 (95%CI -0.66 to -0.15)].

Bronchial Thermoplasty

Bronchial thermoplasty is an advanced therapy for severe asthma. It is a bronchoscopic procedure in which radiofrequency energy is applied to the airway wall, resulting in decreased airway smooth muscle burden. Human trials have shown that bronchial thermoplasty may reduce asthma exacerbations and improve quality of life in patients with severe uncontrolled asthma. It has been demonstrated to be a safe procedure, with most adverse events being early and mild. More studies are required to understand the precise effects of bronchial thermoplasty on the asthmatic airway and optimal parameters to appropriately select patients for this novel procedure.

Cost-effectiveness of implementing objective diagnostic verification of asthma in the United States

BACKGROUND

Asthma diagnosis in the community is often made without objective testing.

OBJECTIVE

The aim of this study was to evaluate the cost-effectiveness of implementing a stepwise objective diagnostic verification algorithm among patients with community-diagnosed asthma in the United States.

METHODS

We developed a probabilistic time-in-state cohort model that compared a stepwise asthma verification algorithm on the basis of spirometry testing and a methacholine challenge test against the current standard of care over 20 years. Model input parameters were informed from the literature and with original data analyses when required. The target population was US adults (≥15 years old) with physician-diagnosed asthma. The final outcomes were costs (in 2018 dollars) and quality-adjusted life years (QALYs), discounted at 3% annually. Deterministic and probabilistic analyses were undertaken to examine the effect of alternative assumptions and uncertainty in model parameters on the results.

RESULTS

In a simulated cohort of 10,000 adults with diagnosed asthma, the stepwise algorithm resulted in removal of the diagnosis of 3,366. This was projected to be associated with savings of $36.26 million in direct costs and a gain of 4,049.28 QALYs over 20 years. Extrapolating these results to the US population indicated an undiscounted potential savings of $56.48 billion over 20 years. The results were robust against alternative assumptions and plausible changes in values of input parameters.

CONCLUSION

Implementation of a simple diagnostic testing algorithm to verify asthma diagnosis might result in substantial savings and improvement in patients' quality of life.

Recent Developments In Bronchial Thermoplasty For Severe Asthma

PURPOSE

Bronchial thermoplasty is approved in many countries worldwide as a non-pharmacological treatment for severe asthma. This review summarizes recent publications on the selection of patients with severe asthma for bronchial thermoplasty, predictors of a beneficial response and developments in the procedure and discusses specific issues about bronchial thermoplasty including effectiveness in clinical practice, mechanism of action, cost-effectiveness, and place in management.

RESULTS

Bronchial thermoplasty is a treatment option for patients with severe asthma after assessment and management of causes of difficult-to-control asthma, such as nonadherence, poor inhaler technique, comorbidities, under treatment, and other behavioral factors. Patients treated with bronchial thermoplasty in clinical practice have worse baseline characteristics and comparable clinical outcomes to clinical trial data. Bronchial thermoplasty causes a reduction in airway smooth muscle mass although it is uncertain whether this effect explains its efficacy since other mechanisms of action may be relevant, such as alterations in airway epithelial, gland, and/or nerve function; improvements in small airway function; or a placebo effect. The cost-effectiveness of bronchial thermoplasty is greater in countries where the costs of hospitalization and emergency department are high. The place of bronchial thermoplasty in the management of severe asthma is not certain, although some experts propose that bronchial thermoplasty should be considered for patients with severe asthma associated with non-type 2 inflammation or who fail to respond favorably to biologic therapies targeting type 2 inflammation.

CONCLUSION

Bronchial thermoplasty is a modestly effective treatment for severe asthma after assessment and management of causes of difficult-to-control asthma. Asthma morbidity increases during and shortly after treatment. Follow-up studies provide reassurance on the long-term safety of the procedure. Uncertainties remain about predictors of response, mechanism(s) of action, and place in management of severe asthma.

New Therapies for Emerging Endotypes of Asthma

The presentation, pathobiology, and prognosis of asthma are highly heterogeneous and challenging for clinicians to diagnose and treat. In addition to the adaptive immune response that underlies allergic inflammation, innate immune mechanisms are increasingly recognized to be critical mediators of the eosinophilic airway inflammation present in most patients with asthma. Efforts to classify patients by severity and immune response have identified a number of different clinical and immune phenotypes, indicating that the innate and adaptive immune responses are differentially active among patients with the disease. Advances in the detection of these subgroups using clinical characteristics and biomarkers have led to the successful development of targeted biologics. This has moved us to a more personalized approach to managing asthma. Here we review the emerging endotypes of asthma and the biologics that have been developed to treat them.

Efficacy of bronchial thermoplasty in patients with severe asthma

Objective: To investigate the efficacy and safety of bronchial thermoplasty (BT) in clinical practice in adults with severe, refractory asthma.Methods: Prospective, single-center, open, observational study comprising patients with uncontrolled asthma (asthma control questionnaire (ACQ) >1.5) and/or frequent exacerbations despite treatment with at least high dose inhaled corticosteroids plus a second controller. Efficacy outcomes was change from baseline 4, 8, 12 and 24 months in FEV₁, FVC and FEV₁/FVC ratio, asthma control questionnaire (ACQ) score and asthma quality of life score (mini-AQLQ). Results are presented as median with interquartile ranges (IQR). The following were recorded as adverse events: Un-scheduled health care contacts, rescue courses of oral corticosteroid (OCS) and/or antibiotics for exacerbation for exacerbations/respiratory tract infections (RTI).Results: Six-teen patients were enrolled (nine males, median age 50 years; 14 followed for 24 months). Compared to baseline, an improvement in FEV₁, FVC, FEV₁/FVC ratio, mini-AQLQ and ACQ was observed, i.e.FEV₁ (IQR) 1.98 L (1.65-2.45) vs. 2.45 L (2.09-2.93) (p = 0.006), FVC (IQR) 3.23 L (2.76-4.05) vs. 3.75 L (3.22-4.36) (p = 0.041), FEV₁/FVC 0.60 (IQR: 0.55-0.70) vs. 0.66 (IQR: 0.63-0.71) (p = 0.016), mini-AQLQ 4.0 (IQR: 3.2-4.9) vs. 5.6 (IQR 4.5-6.5) (p = 0.008, and ACQ 2.9 (IQR: 2.1-3.7) versus 1.5 (IQR 1.0-2.4) (p = 0.004). On the other hand, an increase was observed in unscheduled visits (p = 0.005), as well as use of OCS and antibiotics (p = 0.009 and p = 0.003, respectively).Conclusion: BT in adults with severe asthma improved ACQ, mini-AQLQ and lung function, but resulted in an increased frequency of unscheduled doctor-visits and rescue courses of OCS and antibiotics.

A Systematic Review of Decision-Analytic Models for Evaluating Cost-Effectiveness of Asthma Interventions

OBJECTIVE

To demonstrate the landscape of model-based economic studies in asthma and highlight where there is room for improvement in the design and reporting of studies.

DESIGN

A systematic review of the methodologies of model-based, cost-effectiveness analyses of asthma-related interventions was conducted. Models were evaluated for adherence to best-practice modeling and reporting guidelines and assumptions about the natural history of asthma.

METHODS

A systematic search of English articles was performed in MEDLINE, EMBASE, and citations within reviewed articles. Studies were summarized and evaluated based on their adherence to the Consolidated Health Economic Evaluation Reporting Standards (CHEERS). We also studied the underlying assumptions about disease progression, heterogeneity in disease course, comorbidity, and treatment effects.

RESULTS

Forty-five models of asthma were included (33 Markov models, 10 decision trees, 2 closed-form equations). Novel biological treatments were evaluated in 12 studies. Some of the CHEERS' reporting recommendations were not satisfied, especially for models published in clinical journals. This was particularly the case for the choice of the modeling framework and reporting on heterogeneity. Only 13 studies considered any subgroups, and 2 explicitly considered the impact of comorbidities. Adherence to CHEERS requirements and the quality of models generally improved over time.

CONCLUSION

It would be difficult to replicate the findings of contemporary model-based evaluations of asthma-related interventions given that only a minority of studies reported the essential parameters of their studies. Current asthma models generally lack consideration of disease heterogeneity and do not seem to be ready for evaluation of precision medicine technologies.

Incorporating adherence in cost-effectiveness analyses of asthma: a systematic review

Aims: Non-adherence is associated with poor clinical outcomes among patients with asthma. While cost-effectiveness analysis (CEA) is increasingly used to inform value assessment of the interventions, most do not take into account adherence in the analyses. This study aims to: (1) Understand the extent of studies considering adherence as part of the economic analyses, and (2) summarize the methods of incorporating adherence in the economic models. Materials and methods: A literature search was performed from the inception to February 2018 using four databases: PubMed, EMBASE, NHS EED, and the Tufts CEA registry. Decision model-based CEA of asthma were identified. Outcomes of interest were the number of studies incorporating adherence in the economic models, and the incorporating methods. All data were extracted using a standardized data collection form. Results: From 1,587 articles, 23 studies were decision model-based CEA of asthma, of which four CEA (17.4%) incorporated adherence in the analyses. Only the method of incorporating adherence by adjusting treatment effectiveness according to adherence levels was demonstrated in this review. Two approaches were used to derive the associations between adherence and effectiveness. The first approach was to apply a mathematical formula, developed by an expert panel, and the second was to extrapolate the associations from previous published studies. The adherence-adjusted effectiveness was then incorporated in the economic models. Conclusions: A very low number of CEA of asthma incorporated adherence in the analyses. All the CEA adjusted treatment effectiveness according to adherence levels, applied to the economic models.

Cost-effectiveness of omalizumab for the treatment of inadequately controlled severe allergic asthma in Chinese children

Objective: The addition of omalizumab to standard therapy has proven to be efficacious in children with severe allergic asthma. The goal of this study was to assess the cost-effectiveness of adding omalizumab to standard treatment for asthma in Chinese pediatric patients.Methods: A Markov model was constructed to project the health and economic outcomes in pediatric patients with severe allergic asthma. Model inputs were obtained from the literature. Cost and quality-adjusted life-years (QALYs) were measured over a five-year time horizon. One-way and probabilistic sensitivity analyses were conducted.Results: For the base-case analysis, the addition of omalizumab to standard therapy yielded an incremental cost of $49,047 for 0.232 incremental QALY, led to an incremental cost-effectiveness ratio of $211,217/QALY. Sensitivity analyses were robust for these results.Conclusions: This study found that the addition of omalizumab is not a cost-effective strategy compared with standard therapy for children with severe allergic asthma in China due to its high cost.

Improvement of exertional dyspnea and breathing pattern of inspiration to expiration after bronchial thermoplasty

Background

Bronchial thermoplasty (BT) is a bronchoscopic treatment that can ameliorate the symptoms of severe asthma. However, little is known about the mechanism by which BT improves exertional dyspnea without significantly changing the resting pulmonary function in asthmatics. To understand the mechanism, cardiopulmonary variables were investigated using cardiopulmonary exercise testing (CPET) in a patient with severe asthma before and after BT.

Case presentation

A 57-year-old Japanese man visited our hospital for consultation of the intractable asthma, which we managed with three treatment sessions of BT. Comparison of the findings pre-BT and at 1 year after BT demonstrated that (1) the resting tests for respiration showed no improvement in forced expiratory volume in 1 s, but the forced oscillation technique showed decreases in both inhalation and exhalation respiratory resistance values, and (2) the CPET results showed (i) improvement in exertional dyspnea, exercise endurance, and arterial oxygen saturation at the end of exercise; (ii) that the expiratory tidal volume exceeded the inspiratory tidal volume during exercise, which implied that a sufficient exhalation enabled longer inspiratory time and adequate oxygen absorption; and (iii) that an increase in respiratory frequency could be prevented throughout exercise.

Conclusions

This case report described a novel mechanism of BT in improving exertional dyspnea and exercise duration, which was brought about by ventilatory improvements related to the breathing pattern of inspiration to expiration.

Two decades with omalizumab: what we still have to learn

From its availability for clinical use nearly two decades ago for severe asthma, omalizumab has gained strong evidence of efficacy and safety in the treatment of severe asthma not controlled by standard-of-care therapy. It has been acknowledged by Global Initiative on Asthma guidelines as add-on therapy against severe uncontrolled asthma. Thanks to controlled trials supporting its efficacy, omalizumab has also been licensed for the treatment of chronic spontaneous urticaria. The optimal duration of treatment in either disease has not been established. Despite its high price, omalizumab appears to be cost-effective in severe uncontrolled asthma as well as in chronic urticaria. The literature suggests a wide range of applications for omalizumab in various disorders regardless of allergic or non-allergic pathophysiology.

Cost Effectiveness of Pharmacological Treatments for Asthma: A Systematic Review

OBJECTIVE

The objective of this article was to summarize the findings of all the available studies on alternative pharmacological treatments for asthma and assess their methodological quality, as well as to identify the main drivers of the cost effectiveness of pharmacological treatments for the disease.

METHODS

A systematic review of the literature in seven electronic databases was conducted in order to identify all the available health economic evidence on alternative pharmacological treatments for asthma published up to April 2017. The reporting quality of the included studies was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement.

RESULTS

A total of 72 studies were included in the review, classified as follows: medications for acute asthma treatment (n = 5, 6.9%); inhaled corticosteroids (ICS) administered alone or in conjunction with long-acting β-agonists (LABA) or tiotropium for chronic asthma treatment (n = 38, 52.8%); direct comparisons between different combinations of ICS, ICS/LABA, leukotriene receptor antagonists (LTRA), and sodium cromoglycate for chronic asthma treatment (n = 14, 19.4%); and omalizumab for chronic asthma treatment (n = 15, 20.8%). ICS were reported to be cost effective when compared with LTRA for the management of persistent asthma. In patients with inadequately controlled asthma taking ICS, the addition of long-acting β-agonist (LABA) preparations has been demonstrated to be cost effective, especially when combinations of ICS/LABA containing formoterol are used for both maintenance and reliever therapy. In patients with uncontrolled severe persistent allergic asthma, omalizumab therapy could be cost effective in a carefully selected subgroup of patients with the more severe forms of the disease. The quality of reporting in the studies, according to the CHEERS checklist, was very uneven. The main cost-effectiveness drivers identified were the cost or rate of asthma exacerbations, the cost or rate of the use of asthma medications, the asthma mortality risk, and the rate of utilization of health services for asthma.

CONCLUSIONS

The present findings are in line with the pharmacological recommendations for stepwise management of asthma given in the most recent evidence-based clinical practice guidelines for the disease. The identified reporting quality of the available health economic evidence is useful for identifying aspects where there is room for improvement in future asthma cost-effectiveness studies.

Cost-Effectiveness of Biological Asthma Treatments: A Systematic Review and Recommendations for Future Economic Evaluations

BACKGROUND

Recently developed asthma biological therapies have been shown to provide relief for severe asthma patients not controlled by inhaled treatment. Given the relatively high costs of biological therapies, cost-effectiveness analyses (CEAs) may be required as a prerequisite for coverage and reimbursement.

OBJECTIVE

We aimed to systematically review published literature on the economic impact of biological asthma therapies and to identify key drivers that impact cost-effectiveness in order to provide recommendations for future economic evaluations.

METHODS

We conducted a systematic literature search in PubMed and Google Scholar. We included studies that assessed the cost-effectiveness of asthma biologics and were published in English between 2000 and 2018. The Quality of Health Economic Studies (QHES) instrument was used to evaluate quality.

RESULTS

Twenty asthma biological CEAs were identified. Nineteen studies analyzed the cost-effectiveness of omalizumab, and one study analyzed mepolizumab. Ten studies concluded that omalizumab was cost-effective in base-case scenarios, four studies concluded omalizumab was not cost-effective, and the remaining studies concluded omalizumab or mepolizumab was cost-effective only when targeted to specific severe subgroups or given considerable price discounts. Key drivers of cost-effectiveness included day-to-day health-related quality of life (HRQoL), asthma-related mortality, acquisition price of the biological therapy, and time horizon.

CONCLUSIONS

Most studies recommended carefully targeting biological therapy to specific populations such as responders or discounting acquisition price in order to further improve value. The quality of the studies was generally satisfactory, but improved evidence is needed linking HRQoL to utilities as well as understanding interventions' impact on asthma-related mortality. Key recommendations from this review may allow for greater comparability across future cost-effectiveness studies.

Biologics in pediatric lung disease

PURPOSE OF REVIEW

Although biologic therapies can provide outstanding efficacy in the management of lung disease, especially asthma, most of these agents have been approved only for adults. Recent findings provide new strategies for using these agents in children.

RECENT FINDINGS

Extensive evidence has consistently demonstrated the efficacy and safety of biologic therapy for asthma. In addition, some studies have documented potentially important secondary effects, such as improving response to respiratory virus infection in asthmatic patients. Additional strategies for improving asthma control using biologic therapy, such as seasonal administration, have been suggested, and may limit cost while still providing a high degree of efficacy.

SUMMARY

Many of the current biologics are able to readily establish control even in asthmatic patients for whom inhaled steroid and long-acting β agonist have failed. However, biologics currently have limited regulatory approval and availability in the pediatric age range, despite this age being disproportionately affected by asthma. In addition, successful biologics for asthma to date have largely been limited to the Th2-high endotype of asthma, and there is great need for similar medications to target the Th2-low endotype. Other pediatric lung disease might well benefit from the specificity allowed by biologic therapy.

Nonadherence in the era of severe asthma biologics and thermoplasty

Nonadherence to inhaled preventers impairs asthma control. Electronic monitoring devices (EMDs) can objectively measure adherence. Their use has not been reported in difficult asthma patients potentially suitable for novel therapies, i.e. biologics and bronchial thermoplasty.Consecutive patients with difficult asthma were assessed for eligibility for novel therapies. Medication adherence, defined as taking >75% of prescribed doses, was assessed by EMD and compared with standardised clinician assessment over an 8-week period.Among 69 difficult asthma patients, adherence could not be analysed in 13, due to device incompatibility or malfunction. Nonadherence was confirmed in 20 out of 45 (44.4%) patients. Clinical assessment of nonadherence was insensitive (physician 15%, nurse 28%). Serum eosinophils were higher in nonadherent patients. Including 11 patients with possible nonadherence (device refused or not returned) increased the nonadherence rate to 31 out of 56 (55%) patients. Severe asthma criteria were fulfilled by 59 out of 69 patients. 47 were eligible for novel therapies, with confirmed nonadherence in 16 out of 32 (50%) patients with EMD data; including seven patients with possible nonadherence increased the nonadherence rate to 23 out of 39 (59%).At least half the patients eligible for novel therapies were nonadherent to preventers. Nonadherence was often undetectable by clinical assessments. Preventer adherence must be confirmed objectively before employing novel severe asthma therapies.

The projected economic and health burden of sub-optimal asthma control in Canada

BACKGROUND

Achieving optimal control is the primary objective of asthma management. However, despite the existence of effective treatments, many patients experience periods of sub-optimal asthma control. The objective of this study was to quantify and project the future economic and health burden of sub-optimal asthma control in Canada.

METHODS

A probabilistic time-in-state model of asthma was created with inputs from published studies on the prevalence of asthma, levels of asthma control, and the impact of asthma control on costs and quality of life. In the primary analysis, we modeled the 20-year total direct costs (in 2014 Canadian dollars) and quality-adjusted life years (QALYs) from 2014 to 2033 in Canada. In the secondary analysis, we also incorporated indirect costs.

RESULTS

The undiscounted projected 20-year direct costs and QALYs lost attributable to sub-optimal asthma control were $24.40 billion and 1.82 million, respectively, from 2014 to 2033. The corresponding discounted values (at 3%) were $18.54 billion and 1.38 million. When indirect costs were considered, the total undiscounted and discounted costs of sub-optimal control were projected to be $280.49 billion, and $213.10 billion, respectively. A 10% reduction in prevalence of sub-optimal control in asthma was associated with 18% reduction in the economic and health burden of asthma over this time period.

DISCUSSION

Sub-optimal asthma control is associated with a substantial economic and health burden. Given that with evidence-based disease management asthma can be controlled in the majority of patients, strategies towards improving asthma management can be associated with a significant return on investment.

TRIAL REGISTRATION

not applicable.

Bronchial thermoplasty as a treatment for severe asthma: controversies, progress and uncertainties

INTRODUCTION

Bronchial thermoplasty is a licensed non-pharmacological treatment for severe asthma. Area covered: This article considers evidence for the efficacy and safety of bronchial thermoplasty from clinical trials and observational studies in clinical practice. Its place in the management of severe asthma, predictors of response and mechanisms of action are reviewed. Expert commentary: Bronchial thermoplasty improves quality of life and reduces exacerbations in moderate to severe asthma. Morbidity from asthma is increased during treatment. Overall, patients treated in clinical practice have worse baseline characteristics and comparable clinical outcomes to trial data. Follow-up studies provide reassurance on long-term safety. Despite some progress, future research needs to investigate uncertainties about predictors of response, mechanism of action and place in management of asthma.

Cost-effectiveness of tiotropium versus omalizumab for uncontrolled allergic asthma in US

BACKGROUND

A significant minority of asthma patients remain uncontrolled despite the use of inhaled corticosteroids (ICS) and long-acting beta-agonists (LABA). A number of add-on therapies, including monoclonal antibodies (namely omalizumab) and more recently tiotropium bromide have been recommended for this subgroup of patients. The purpose of this study was to assess the cost-effectiveness of tiotropium versus omalizumab as add-on therapies to ICS + LABA for patients with uncontrolled allergic asthma.

METHODS

A probabilistic Markov model of asthma was created. Total costs (in 2013 US $) and health outcomes of three interventions including standard therapy (ICS + LABA), add-on therapy with tiotropium, and add-on therapy with omalizumab, were calculated over a 10-year time horizon. Future costs and quality-adjusted life years (QALYs) were discounted at the rate of 3%. Multiple sensitivity analyses were conducted. Cost-effectiveness was evaluated at willingness-to-pay value of $50,000.

RESULTS

The 10-year discounted costs and QALYs for standard therapy were $38,432 and 6.79, respectively. The corresponding values for add-on therapy with tiotropium and with omalizumab were $41,535 and 6.88, and $217,847 and 7.17, respectively. The incremental cost-effectiveness ratios (ICER) of add-on therapy with tiotropium versus standard therapy, and omalizumab versus tiotropium were $34,478/QALY, and $593,643/QALY, respectively. The model outcomes were most sensitive to the costs of omalizumab but were robust against other assumptions.

CONCLUSIONS

Although omalizumab had the best health outcomes, add-on therapy with tiotropium was a cost-effective alternative to omalizumab and standard therapy for uncontrolled allergic asthma at willingness-to-pay of $50,000/QALY.

Usefulness of Bronchial Thermoplasty for Patients with a Deteriorating Lung Function

Bronchial thermoplasty is a novel procedure for patients with severe asthma showing a stable lung function. We herein report two cases with a deteriorating lung function. The lung function tended to improve in one case, while the other case discontinued mepolizumab medication after the procedure. Treatment was performed safely under general anesthesia in both cases. The use of bronchial thermoplasty may therefore be useful for the treatment of patients with a deteriorating lung function.

Bronchial Thermoplasty: A Nonpharmacologic Therapy for Severe Asthma

Bronchial thermoplasty is an innovative treatment for patients with severe asthma and chronic airflow obstruction with an established long-term efficacy and safety profile. This review focuses on the role of bronchial thermoplasty in severe asthma, its mechanism of action, appropriate patient selection, current evidence, and recent developments of this therapy.

Asthma Cost-Effectiveness Analyses: Are We Using the Recommended Outcomes in Estimating Value?

BACKGROUND

Asthma medication cost-effectiveness analyses (CEAs) lack the qualitative assessment regarding whether they capture the National Institutes for Health (NIH) 2012 recommended outcomes necessary to allow robust cross-study comparisons.

OBJECTIVE

We aimed to assess the current asthma outcomes used in CEAs and recommend a direction for improvement.

METHODS

We performed a systematic search using electronic databases including PubMed, EMBASE, Tufts CEA registry, Cochrane, and NHSEED from January 2010 through December 2015. Key words included (1) cost-effectiveness, cost-utility, economic evaluation, health economics, or cost-benefit AND (2) asthma. All CEA studies evaluating 1 or more asthma medication were included. Authors assessed each CEA study with respect to asthma-specific NIH outcome recommendations including core (hospitalizations, emergency department visits, outpatient visits, medication, interventions costs), supplemental (visit categories and work/school absence), and emerging (academic/job-related) asthma outcomes. Besides outcomes of each CEA, issues that could prevent robust cross-study comparison were identified and thematically summarized.

RESULTS

A total of 12 pre-NIH and 14 post-NIH recommendation CEAs were included. Eleven (91.7%) and 14 (100%) of the pre-/post-NIH studies included at least 1 core outcome, respectively. Of the 26 total studies, 7 (26.9%) included asthma-specific outpatient visit categories, 6 (23.1%) included asthma school or work absences, 5 (19.2%) included respiratory health care use, and none of the studies included emerging outcomes. Other issues that hamper cross-study comparison include lack of standardized cost data, time frames, quality-of-life measures, and incorporation of adherence.

CONCLUSIONS

Although the use of NIH-recommended asthma core outcomes has improved, there is still room for improvement in using supplemental and emerging outcomes. To allow robust cross-study comparisons, future work should focus on further standardizing of data sources and methods.

Bronchial thermoplasty and the role of airway smooth muscle: are we on the right direction?

Asthma is characterized by inflammation of the airways that includes eosinophils, basal membrane thickening, epithelial sloughing, vascular changes, smooth muscle hypertrophy and hyperplasia, and mucous gland hyperplasia. Recently, there have been studies on the role of hypersensitivity and inflammation in asthma, but the role of bronchial smooth muscle remains unclear. Bronchial thermoplasty is an endoscopic procedure that is approved by the US Food and Drug Administration (FDA) for the treatment of severe refractory asthma, based on the local delivery of radio frequency at 65°C to the airways, with the aim of controlling bronchospasm through a reduction of airway smooth muscle (ASM). Several recent studies have shown significant improvement in clinical outcomes of bronchial thermoplasty for asthma, including symptom control, reduction in exacerbation and hospitalization rates, improved quality of life, and reduction in number of working days or school days lost due to asthma. Data from these recent studies have shown reduction in ASM following bronchial thermoplasty and changes in inflammation patterns. It has also been argued that bronchial thermoplasty may have modulating effects on neuroendocrine epithelial cells, bronchial nerve endings, TRPV1 nerve receptors, and type-C unmyelinated fibers in the bronchial mucosa. This may involve interrupting the central and local reflexes responsible for the activation of bronchospasm in the presence of bronchial hyperreactivity. Several questions remain regarding the use of bronchial thermoplasty, mechanism of action, selection of appropriate patients, and long-term effects. In this review, the role of ASM in the pathogenesis of asthma and the key aspects of bronchial thermoplasty are discussed, with a focus on the potential clinical effects of this promising procedure, beyond the reduction in ASM.

Bronchial thermoplasty: implementing best practice in the era of cost containment

Increasing dependence on advanced technologies in the 21st century has created a dilemma between the practice and business of medicine. From information technology to robotic surgery, new technologies have expanded treatment possibilities and have potentially improved patient outcomes and safety. Simultaneously, their escalating costs limit access for certain patients and health care facilities. Nevertheless, medical decisions should not simply be based on cost. Input from physicians and other health care specialists as well as adherence to best practice position statements, are vital to implementing truly cost-effective strategies in medicine. Bronchial thermoplasty (BT), a US Food and Drug Administration approved bronchoscopy procedure in difficult-to-control persistent asthma, is a prime example of a new technology facing cost and implementation challenges. We discuss the specific indications and contraindications for BT and review recent real-world experiences that can provide the foundation for building a comprehensive asthma program that provides BT for difficult-to-control asthma patients who fail national guideline treatment recommendations after an adequate clinical trial of one. We also offer insight into the barriers to implementing a successful BT program and strategies for overcoming them.

Is bronchial thermoplasty cost-effective as treatment for problematic asthma patients? Singapore's perspective on a global model

BACKGROUND AND OBJECTIVE

Bronchial thermoplasty (BT) has been shown to be effective at reducing asthma exacerbations and improving asthma control for patients with severe persistent asthma but it is also expensive. Evidence on its cost-effectiveness is limited and inconclusive. In this study, we aim to evaluate the incremental cost-effectiveness of BT combined with optimized asthma therapy (BT-OAT) relative to OAT for difficult-to-treat and severe asthma patients in Singapore, and to provide a general framework for determining BT's cost-effectiveness in other healthcare settings.

METHODS

We developed a Markov model to estimate the costs and quality-adjusted life years (QALYs) gained with BT-OAT versus OAT from the societal and health system perspectives. The model was populated using Singapore-specific costs and transition probabilities and utilities from the literature. Sensitivity analyses were conducted to identify the main factors determining cost-effectiveness of BT-OAT.

RESULTS

BT-OAT is not cost-effective relative to OAT over a 5-year time horizon with an incremental cost-effectiveness ratio (ICER) of $US138 889 per QALY from the societal perspective and $US139 041 per QALY from the health system perspective. The cost-effectiveness of BT-OAT largely depends on a combination of the cost of the BT procedure and the cost of asthma-related hospitalizations and emergency department (ED) visits.

CONCLUSION

Based on established thresholds for cost-effectiveness, BT-OAT is not cost-effective compared with OAT in Singapore. Given its current clinical efficacy, BT-OAT is most likely to be cost-effective in a setting where the cost of BT procedure is low and costs of hospitalization and ED visits are high.

Pharmacoeconomics of Biologic Therapy

Novel biologic agents have allowed clinicians to achieve improved patient outcomes. Appropriate pharmacoceconomic analyses demand evaluation of all relevant costs, including the treatments, the disease and comorbidities, and costs of alternative treatments, including their short- and long-term side effects. Only with complete data can the value of therapies be correctly estimated. By assessing costs, pharmacoeconomic studies complement studies of efficacy and safety, helping to determine the relationships of treatment and outcome. This article provides a broad framework for understanding and evaluating published economic analyses and identifying the key costs and benefits caring for patients with asthma and other immune diseases.

Thermal ablation for asthma: current status and technique

Bronchial thermoplasty (BT) is a novel technique used in the treatment of severe asthma. A catheter is advanced through the bronchoscope and directed radiofrequency waves are applied to the segmental bronchi to reduce airway smooth muscle mass. Several randomized clinical trials demonstrate improvement in quality of life and reduction in exacerbation rates after treatment. BT is a safe and cost effective treatment option for severe asthma which is refractory to medical treatment. Further studies are needed in order to better describe the mechanism of action and the asthma subphenotype that was best benefit from this treatment.

Therapeutic interventions in severe asthma

The present paper addresses severe asthma which is limited to 5-10% of the overall population of asthmatics. However, it accounts for 50% or more of socials costs of the disease, as it is responsible for hospitalizations and Emergency Department accesses as well as expensive treatments. The recent identification of different endotypes of asthma, based on the inflammatory pattern, has led to the development of tailored treatments that target different inflammatory mediators. These are major achievements in the perspective of Precision Medicine: a leading approach to the modern treatment strategy. Omalizumab, an anti-IgE antibody, has been the only biologic treatment available on the market for severe asthma during the last decade. It prevents the linkage of the IgE and the receptors, thereby inhibiting mast cell degranulation. In clinical practice omalizumab significantly reduced the asthma exacerbations as well as the concomitant use of oral glucocorticoids. In the "Th2-high asthma" phenotype, the hallmarks are increased levels of eosinophils and other markers (such as periostin). Because anti-IL-5 in this condition plays a crucial role in driving eosinophil inflammation, this cytokine or its receptors on the eosinophil surface has been studied as a potential target for therapy. Two different anti-IL-5 humanized monoclonal antibodies, mepolizumab and reslizumab, have been proven effective in this phenotype of asthma (recently they both came on the market in the United States), as well as an anti-IL-5 receptor alpha (IL5Rα), benralizumab. Other monoclonal antibodies, targeting different cytokines (IL-13, IL-4, IL-17 and TSLP) are still under evaluation, though the preliminary results are encouraging. Finally, AIT, Allergen Immunotherapy, a prototype of Precision Medicine, is considered, also in light of the recent evidences of Sublingual Immunotherapy (SLIT) tablet efficacy and safety in mite allergic asthma patients. Given the high costs of these therapies, however, there is an urgent need to identify biomarkers that can predict the clinical responders.

Bronchial thermoplasty and biological therapy as targeted treatments for severe uncontrolled asthma

Although a small proportion of patients with asthma have severe disease, it accounts for the majority of morbidity related to the illness. Severe asthma comprises a heterogeneous group of phenotypes. Targeted treatments for these phenotypes represent a major advancement in the management of severe asthma. Omalizumab, a monoclonal antibody to IgE, improves asthma control in patients with a predominant allergic phenotype. Monoclonal antibodies targeted to interleukin 4α and interleukin 5 have shown substantial benefit in patients with the eosinophilic asthma phenotype; so too have monoclonal antibodies targeted to interleukin 13 in patients with a type 2 allergic phenotype. Bronchial thermoplasty, a new technique to reduce airway smooth muscle mass, improves symptoms and reduces exacerbations in patients with severe uncontrolled asthma and the chronic airflow obstruction phenotype. While awaiting comparative trials, we can now use a targeted approach with these phenotypes, guiding our treatment selection with the best evidence. This Review will focus on the latest developments in these new treatments and inform the clinician on how to select the appropriate patient for these treatments.