Should Airway Hyper-Responsiveness Be Included in the Definition of Clinical Remission With Biologic Therapy in Severe Asthma

Airway hyper-responsiveness (AHR) is a tenet of the persistent asthma phenotype along with reversible airway obstruction and type 2 (T2) inflammation. Indirect acting challenges such as mannitol are more closely related to the underlying T2 inflammatory process as compared with direct challenges. In this review article, we summarise the current literature and explore the future role of mannitol AHR in clinical remission with biologics.

Budesonide/Formoterol or Budesonide/Albuterol as Anti-Inflammatory Reliever Therapy for Asthma

Overuse of reliever as short-acting beta-agonist and associated underuse of controller as inhaled corticosteroid (ICS) administered via separate inhalers results in worse asthma outcomes. Such discordance can be obviated by combining both controller and reliever in the same inhaler. So-called anti-inflammatory reliever (AIR) therapy comprises the use of a single inhaler containing an ICS such as budesonide (BUD) in conjunction with a reliever as either albuterol (ALB) or formoterol (FORM), to be used on demand, with variable dosing driven by asthma symptoms in a flexible patient-centered regimen. Global guidelines now support the use of BUD-ALB as AIR therapy to reduce exacerbations, either on its own in mild asthma or in conjunction with fixed-dose maintenance ICS-long-acting beta-agonist in moderate to severe asthma. Using BUD-FORM on its own allows patients to seamlessly move in an intuitive flexible fashion between AIR and maintenance and reliever therapy, by stepping up and down the dosing escalator across a spectrum of asthma severities. Head-to-head clinical studies are indicated to compare BUD-FORM versus BUD-ALB as AIR in mild asthma, and also BUD-FORM as maintenance and reliever therapy versus BUD-ALB as AIR plus maintenance ICS-long-acting beta-agonist in moderate to severe asthma. Patients should be encouraged to make an informed decision in conjunction with their health care professional regarding the best therapeutic option tailored to their individual needs, which in turn is likely to result in long-term compliance and associated optimal asthma control.

Eosinophil depletion with benralizumab is associated with attenuated mannitol airway hyperresponsiveness in severe uncontrolled eosinophilic asthma

BACKGROUND

Airway hyperresponsiveness (AHR) and eosinophilia are hallmarks of persistent asthma.

OBJECTIVE

We investigated whether eosinophil depletion with benralizumab might attenuate indirect mannitol AHR in severe uncontrolled asthma using a pragmatic open-label design.

METHODS

After a 4-week run-in period with provision of usual inhaled corticosteroids and/or long-acting β-agonist (baseline), adults with mannitol-responsive uncontrolled severe eosinophilic asthma received 3 doses of open-label benralizumab 30 mg every 4 weeks, followed by 16 weeks' washout after the last dose. The primary outcome was doubling difference (DD) in provocative dose of mannitol required to decrease FEV₁ by 10% (PD₁₀) at the end point after 12 weeks, powered at 90% with 18 patients required to detect 1 DD. Secondary outcomes included measures assessed by the asthma control questionnaire and mini-asthma quality of life questionnaire.

RESULTS

Twenty-one patients completed 12 weeks' benralizumab therapy at the end point at week 12. Mean (SEM) age was 53 (4) years, and FEV₁ 80.2% (4.1%) inhaled corticosteroid dose was 1895 (59) μg, with 12 receiving long-acting muscarinic antagonist and 13 leukotriene receptor antagonists. Improvement in AHR was significant by 8 weeks, with a mean 2.1 DD (95% confidence interval 1.0, 3.3; P < .01) change in PD₁₀ at week 12, while mean changes in asthma control questionnaire and mini-asthma quality of life questionnaire were significant by week 2 and sustained over 12 weeks, both exceeding the minimal important difference. Peripheral blood eosinophils were depleted by 2 weeks (439 to 6 cells/μL). No significant improvement occurred in lung function after 12 weeks. Domiciliary peak flow and symptoms also improved with benralizumab.

CONCLUSION

Eosinophil depletion results in clinically meaningful attenuated AHR in severe uncontrolled asthma patients.

Nodules, nodes and non-functioning macrophages: A risk with ibrutinib therapy

We describe the case of a 70-year-old never smoker with chronic lymphocytic leukaemia, treated with single agent ibrutinib therapy. Chest imaging noted nodular change and mediastinal lymphadenopathy, which showed avid uptake on positron emission tomography and guided subsequent biopsies (bronchoscopy using endobronchial ultrasound, mediastinoscopy). Despite negative aspergillus blood immunology tests, he was found to have invasive aspergillosis, which is a known risk with ibrutinib therapy. He has since been successfully treated with antifungal therapy.

Randomized controlled trial of triple versus dual inhaler therapy on small airways in smoking asthmatics

BACKGROUND

Smoking worsens underlying asthma inflammation and also induces resistance to inhaled corticosteroids (ICS). Small airways dysfunction measured by impulse oscillometry (IOS) is associated with worse control.

OBJECTIVES

We investigated the effects on small airways of adding long-acting beta-agonist (LABA) alone or with long-acting muscarinic antagonist (LAMA) to ICS in asthmatic smokers.

METHODS

Sixteen current smokers were enrolled: mean age 44 year, FEV1 84%, FEF25-75 47%, R5 158%, ACQ 1.69, 20 pack year . Patients were converted to a reference ICS as HFA-BDP during initial run-in at median dose of 800 µg/day. Open label olodaterol 5 µg od (OLO) or olodaterol 5 µg/tiotropium 5 µg od (OLO/TIO) was added to HFA-BDP for median duration of 3 weeks in a randomized cross over design, including run-in and washout periods on HFA-BDP. IOS and spirometry were measured after each treatment (BDP/OLO/TIO or BDP/OLO) and at baseline after run-in and washout (BDP).

RESULTS

After chronic dosing, IOS outcomes at trough except for R20 were all significantly improved with OLO/TIO compared to OLO. For the primary end-point of total airway resistance (as R5), the mean difference (95%CI) at trough was 0.06 (0.015-0.10) kPa/l/s, peripheral airways resistance (as R5-R20) 0.03 (0.003-0.06) kPa/l/s, peripheral lung reactance area (as AX) 0.38 (0.08-0.68) kPa/l and resonant frequency (as RF) 2.28 (0.45-4.12) Hz. FEF25-75 at trough was also better with OLO/TIO vs TIO: 0.93 (0.86 - 0.95) l/s while FEV1 was not different.

CONCLUSIONS

ICS/LABA/LAMA was superior to ICS/LABA on trough small airway outcomes in asthma patients who smoke.

Pragmatic Clinical Perspective on Biologics for Severe Refractory Type 2 Asthma

Patients with severe refractory asthma present a challenging clinical conundrum for practicing clinicians. Biologics that target key mediators in the type 2 inflammation cascade, including IL-4, IL-5, IL-13, and IgE, can be effective strategies for these patients. However, with various biologics available, choosing the optimal one for a particular patient becomes a nuanced decision. We propose a pragmatic algorithm that identifies the optimal biologic class for patients who have specific type 2 disease endotypes. Patients with eosinophilic endotypes fare well with anti-IL-5(rα) medications, comprising mepolizumab, benralizumab, and reslizumab because they have been shown to reduce exacerbations in severe eosinophilic asthma by approximately 50%. In patients with fractional exhaled nitric oxide-high endotypes, anti-IL-4rα such as dupilumab is deemed to be most effective and has demonstrated a 47% reduction in asthma exacerbations. For patients with severe uncontrolled allergic asthma, anti-IgE (omalizumab) is effective and has been shown to confer a 25% reduction in asthma exacerbations. Type 2 comorbidities including chronic rhinosinusitis with nasal polyps, atopic dermatitis, chronic idiopathic urticaria, and eosinophilic esophagitis are important to bear in mind before the prescription of biologics. Further head-to-head studies are indicated to compare biologics in patients with mixed endotypes according to peripheral blood eosinophils, fractional exhaled nitric oxide, and allergic status. The evidence strongly supports endotype-driven prescribing of biologics to achieve clinically relevant outcomes in severe refractory asthma and related comorbidities.

Emerging pharmacotherapy for COVID-19

Broadly speaking, pharmacological treatments for COVID-19 can be divided into those acting on upstream pathways early on in the disease process via suppression of viral replication or by inhibiting cell entry, and those acting on downstream pathways later on via selective attenuation of the adaptive immune cytokine-mediated inflammatory response. The antiviral drug remdesivir has been shown to shorten duration of disease while interferon beta-1b may speed up viral clearance. The results with hydroxychloroquine have thus far been rather disappointing. Trials with selective cytokine blockers including anti-interleukin-1 (anti-IL-1) and anti-interleukin-6 (anti-IL-6), have shown some promise in more severe cases, with further confirmation being required from large-scale phase-3 randomised controlled trials. The likelihood is that combination therapy addressing both upstream and downstream pathways may be required to prevent progression of severe COVID-19 infection in susceptible older patients with comorbidities and we believe further studies are now warranted to specifically target such at-risk groups who are more prone to worse outcomes.

Does unified allergic airway disease impact on lung function and type 2 biomarkers?

The concept of the unified allergic airway disease (UAD) recognises the association between allergic inflammation in the upper and lower airways. Patients with asthma and concomitant allergic rhinitis experience more asthma-related primary and secondary care visits. We therefore aimed to determine differences in asthma control (asthma control questionnaire ACQ-6), lung function (spirometry) and T2 biomarkers (FeNO and Eos) in relation to the presence of allergic rhinitis in patients with allergic asthma. Retrospectively, we evaluated a cohort of 60 consecutive patients with persistent asthma attending our research unit for screening into clinical trials. All included subjects were receiving inhaled corticosteroids (ICS) and had a positive skin prick test (SPT) to at least one common aeroallergen to fulfil the criterion of allergic asthma. Patients with UAD had a diagnosis of allergic asthma in addition to established concomitant allergic rhinitis. T2 biomarkers were significantly higher in patients with allergic rhinitis in contrast to those without. FEV₁ % predicted and FEF_25-75 % predicted were also significantly lower in patients with concomitant allergic rhinitis. However, there was no difference in ACQ-6 observed between groups. In summary, patients with allergic asthma, the presence of concomitant allergic rhinitis is associated with worse lung function and higher type 2 biomarkers.

Feather duvet lung

A 43-year-old non-smoker was referred with a 3-month history of malaise, fatigue and breathlessness. Blood avian precipitins were strongly positive. Lung function testing confirmed a restrictive pattern with impaired gas transfer. A 'ground glass' mosaic pattern was seen on CT imaging, suggestive of hypersensitivity pneumonitis. Although he had no pet birds, on closer questioning he had recently acquired a duvet and pillows containing feathers. His symptoms, chest radiograph and lung function tests improved after removal of all feather bedding, and he was also started on oral corticosteroid therapy. Our case reinforces the importance of taking a meticulous exposure history and asking about domestic bedding in patients with unexplained breathlessness. Prompt recognition and cessation of antigen exposure may prevent the development of irreversible lung fibrosis.

Pragmatic evaluation of inhaled corticosteroid particle size formulations on asthma control

BACKGROUND

Extra-fine particle formulations of inhaled corticosteroid (ICS) are associated with improved lung delivery.

OBJECTIVES

A pragmatic study to assess patient-reported outcomes after switching from fine to extra-fine particle ICS in persistent asthma.

METHODS

Twenty-four patients (mean age 48 year, FEV₁ 84%, ACQ 1.67) received 4 weeks run-in with a constant dose of fine particle ICS (mean dose 710 µg), followed by switching to an equivalent dose of extra-fine particle hydrofluoroalkane beclomethasone dipropionate (mean dose 355µg). Asthma control questionnaire (ACQ), the primary outcome and mini asthma quality of life questionnaire (mAQLQ) were measured pre- and post-run-in (baseline) and after 4 weeks and 8 weeks of switching.

RESULTS

Comparing pre- vs post-run-in, there were no differences for ACQ: 1.67 vs 1.65 or AQLQ: 5.08 vs 5.34. There were mean (95%CI) improvements (P < 0.001) from baseline after 8 weeks for ACQ: -0.53 (-0.83, -0.23) and AQLQ: 0.69 (0.35, 1.04), which exceeded the minimal clinically important difference (MCID) of 0.5 for both. There were also differences (P < 0.05) in domiciliary symptoms and reliever use. There were no significant changes at 8 weeks in lung function, FeNO or blood eosinophils.

CONCLUSIONS

Pragmatic switching from fine to extra-fine particle ICS at half the dose was associated with clinically relevant improvements in asthma control and quality of life, but not lung function or type 2 biomarkers.

Scottish consensus statement on the role of FeNO in adult asthma

Fractional exhaled nitric oxide (FeNO) is the only available point of care test to assess type-2 inflammation in asthma. In making a diagnosis of asthma, FeNO should be used together with blood eosinophils and spirometry, alongside a history. Raised FeNO in conjunction with blood eosinophilia are treatable traits of type 2 inflammation in asthma, which in turn may guide personalised management. A FeNO suppression test can be used to assess adherence and device use with ICS therapy. Furthermore FeNO may be used to provide feedback to patients in response to ICS, especially when spirometry is normal. FeNO may facilitate appropriate referral to secondary care for more definitive specialist investigations. In summary, FeNO is cost effective in the diagnosis and management of asthma and should be incorporated into primary and secondary care as part of routine clinical practice.

Current appraisal of single inhaler triple therapy in COPD

A single inhaler containing inhaled corticosteroid (ICS)/long-acting beta-agonist (LABA)/long-acting muscarinic antagonist (LAMA) is a more convenient way of delivering triple therapy in patients with COPD. Single triple therapy has been shown to be superior at reducing exacerbations and improving quality of life compared to LABA/LAMA, especially in patients with a prior history of frequent exacerbations and blood eosinophilia, who have ICS responsive disease. The corollary is that patients with infrequent exacerbations who are noneosinophilic may be safely de-escalated from triple therapy to LABA/LAMA without loss of control. Pointedly, there is a substantially increased risk of pneumonia associated with the triple therapy containing fluticasone furoate but not beclometasone dipropionate or budesonide. Since triple therapy is also better than ICS/LABA at reducing exacerbations and improving lung function, symptoms, and quality of life, this brings into question the rationale for using ICS/LABA. Hence, we propose a simplified pragmatic decision process based on symptoms, prior to exacerbation history, and blood eosinophils to select which patients should be given a single triple inhaler or LABA/LAMA. Differences in patient preference of inhaler device, formulations and drugs will also determine which triple inhaler prescribers elect to use.