Standardized quality (SQ) house dust mite sublingual immunotherapy tablet (ALK) reduces inhaled corticosteroid use while maintaining asthma control: a randomized, double-blind, placebo-controlled trial

Real-world evidence of allergen immunotherapy

PURPOSE OF REVIEW

The full understanding of the long-term effectiveness and safety of allergen immunotherapy (AIT) for allergic respiratory diseases cannot be achieved through randomized controlled trials (RCTs) alone. However, real-world studies designed as registries can complement RCTs.

RECENT FINDINGS

The significance of registries is highlighted by their potential to reassess contraindications and collect data on adult and pediatric patients with multiple comorbidities who are often excluded from RCTs.

SUMMARY

AIT is the sole disease-modifying therapeutic approach capable of inducing tolerance and offering a long-term response to allergens. AIT has been shown to play a role in arresting the 'allergic march' in young people, which reduces the risk of developing asthmatic clinical manifestations. Although RCTs are considered the gold standard for evaluating the efficacy and safety of AIT, their duration is usually too short (seldom lasting more than 1 year) to assess the long-term effects of AIT. Several long-term studies show that AIT's effect depends strongly on its use duration.

The evidence for commercial house dust mite immunotherapy products: A pragmatic systematic review with narrative synthesis

House dust mite (HDM) allergen immunotherapy (AIT) has an established role in the treatment of perennial allergic rhinitis (AR) and allergic asthma (AA) triggered by HDM sensitization. We aimed to identify all double-blind, randomized, placebo-controlled trials of HDM AIT for the treatment of AR and AA in humans and to summarize the evidence for AIT products that are currently manufactured and available for clinical use. A total of 56 eligible double-blind, randomized, placebo-controlled trials of HDM AIT for the treatment of AA and/or AR in humans fit the inclusion criteria and investigated a total of 14 commercial AIT products; together, the 56 studies enrolled a total of 14,619 patients. Of the 56 studies, 39 studies investigated the current manufacturer-recommended maintenance dose (MRMD) of the product, and 17 investigated other doses. We identified 39 studies (12,539 patients randomized) for 8 sublingual immunotherapy (SLIT) products and 17 studies (2,080 patients randomized) for subcutaneous immunotherapy products. For AR, 3 products, the ALK 12 standardized-quality (SQ-HDM) SLIT tablet, the ALK 6 SQ-HDM tablet, and the SG 300 index of reactivity SLIT tablet, had both dose-finding studies (DFSs) and phase III definitive studies (DSs) to demonstrate efficacy of the MRMD of the product. For AA, 2 products, the ALK 12 SQ-HDM SLIT tablet and the ALK 6 SQ-HDM tablet, had both DFSs and DSs for the MRMD. No subcutaneous immunotherapy product had a paired DFS and DS supporting the MRMD. A total of 30 studies of products no longer commercially manufactured were excluded. This study will help to inform clinical care and product selection for the treatment of HDM-induced AR and AA.

Sublingual allergen immunotherapy prevents house dust mite inhalant type 2 immunity through dendritic cell-mediated induction of Foxp3+ regulatory T cells

Sublingual allergen immunotherapy (SLIT) is an emerging treatment option for allergic asthma and a potential disease-modifying strategy for asthma prevention. The key cellular events leading to such long-term tolerance remain to be fully elucidated. We administered prophylactic SLIT in a mouse model of house dust mite (HDM)-driven allergic asthma. HDM extract was sublingually administered over 3 weeks followed by intratracheal sensitization and intranasal challenges with HDM. Prophylactic SLIT prevented allergic airway inflammation and hyperreactivity with a low lab-to-lab variation. The HDM-specific T helper (Th)2 (cluster of differentiation 4 Th) response was shifted by SLIT toward a regulatory and Th17 response in the lung and mediastinal lymph node. By using Derp1-specific cluster of differentiation 4+ T cells (1-DER), we found that SLIT blocked 1-DER T cell recruitment to the mediastinal lymph node and dampened IL-4 secretion following intratracheal HDM sensitization. Sublingually administered Derp1 protein activated 1-DER T cells in the cervical lymph node via chemokine receptor7+ migratory dendritic cells (DC). DCs migrating from the oral submucosa to the cervical lymph node after SLIT-induced Foxp3+ regulatory T cells. When mice were sensitized with HDM, prior prophylactic SLIT increased Derp1 specific regulatory T cells (Tregs) and lowered Th2 recruitment in the lung. By using Foxp3-diphtheria toxin receptor mice, Tregs were found to contribute to the immunoregulatory prophylactic effect of SLIT on type 2 immunity. These findings in a mouse model suggest that DC-mediated functional Treg induction in oral mucosa draining lymph nodes is one of the driving mechanisms behind the disease-modifying effect of prophylactic SLIT.

Allergen immunotherapy in asthma

Allergen immunotherapy (AIT), including SCIT and SLIT, is a treatment that involves the administration of allergens to which patients with allergic diseases have been sensitized. HDM-SCIT for asthma is indicated in cases of HDM-sensitized allergic asthma with normal lung function. HDM-SCIT improves asthma symptoms and AHR, and decreases the medication dose. Importantly, AIT can improve other allergic diseases complicated by asthma, such as allergic rhinitis, which can also contribute to the improvement of asthma symptoms. Several studies have suggested that HDM-SLIT also attenuates the risk of asthma exacerbations, and improves lung function in asthma cases with allergic rhinitis. Furthermore, AIT can modify the natural course of allergic diseases, including asthma. For example, the effects of AIT are maintained for at least several years after treatment discontinuation. AIT can prevent the onset of asthma when introduced in allergic rhinitis, and can also inhibit or reduce new allergen sensitizations. Recent data have suggested that AIT may suppress non-targeted allergen-induced immune responses in addition to targeted allergen-induced responses, and suppress infections of the lower respiratory tract by enhancing IFN responses.

The combination of allergen immunotherapy and biologics for inhalant allergies: Exploring the synergy

The development of monoclonal antibodies that selectively target IgE and type 2 immunity has opened new possibilities in the treatment of allergies. Although they have been used mainly as single therapies found to have efficacy in the management of asthma and other T2-mediated diseases, there is a growing interest in using these monoclonal antibodies in combination with allergen immunotherapy (AIT). AIT has transformed the treatment of allergic diseases by aiming to modify the underlying immune response to allergens rather than just providing temporary symptom relief. Despite the proven efficacy and safety of AIT, unmet needs call for further research and innovation. Combination strategies involving biologics and AIT exhibit potential in improving short-term efficacy, reducing adverse events, and increasing immunologic tolerance. Anti-IgE emerges as the most promising therapeutic strategy, not only enhancing AIT's safety and tolerability but also providing additional evidence of efficacy compared with AIT alone. Anti-interleukin-4 receptor offers a reduction in adverse effects and an improved immunologic profile when combined with AIT; however, its impact on short-term efficacy seems limited. The combination of cat dander subcutaneous immunotherapy with anti-thymic stromal lymphopoietin was synergistic with enhanced efficacy and altered immune responses that persisted for 1 year after discontinuation compared with AIT alone. Long-term studies are needed to evaluate the sustained benefits and safety profiles of combination strategies.

Impact of liquid sublingual immunotherapy on asthma onset and progression in patients with allergic rhinitis: a nationwide population-based study (EfficAPSI study)

Background

The only disease-modifying treatment currently available for allergic rhinitis (AR) is allergen immunotherapy (AIT). The main objective of the EfficAPSI real-world study (RWS) was to evaluate the impact of liquid sublingual immunotherapy (SLIT-liquid) on asthma onset and evolution in AR patients.

Methods

An analysis with propensity score weighting was performed using the EfficAPSI cohort, comparing patients dispensed SLIT-liquid with patients dispensed AR symptomatic medication with no history of AIT (controls). Index date corresponded to the first dispensation of either treatment. The sensitive definition of asthma event considered the first asthma drug dispensation, hospitalisation or long-term disease (LTD) for asthma, the specific one omitted drug dispensation and the combined one considered omalizumab or three ICS ± LABA dispensation, hospitalisation or LTD. In patients with pre-existing asthma, the GINA treatment step-up evolution was analysed.

Findings

In this cohort including 112,492 SLIT-liquid and 333,082 controls, SLIT-liquid exposure was associated with a significant lower risk of asthma onset vs. control, according to all definitions (combined: HR [95% CI] = 0.62 [0.60-0.63], sensitive: 0.77 [0.76-0.78], and specific: 0.67 [0.61-0.72]). Exposure to SLIT was associated with a one-third reduction in GINA step-up regardless baseline steps.

Interpretation

In this national RWS with the largest number of person-years of follow-up to date in the field of AIT, SLIT-liquid was associated with a significant reduction in the risk of asthma onset or worsening. The use of three definitions (sensitive or specific) and GINA step-up reinforced the rigorous methodology, substantiating SLIT-liquid evidence as a causal treatment option for patients with respiratory allergies.

Funding

Stallergenes Greer.

Allergen Immunotherapy: The Evidence Supporting the Efficacy and Safety of Subcutaneous Immunotherapy and Sublingual Forms of Immunotherapy for Allergic Rhinitis/Conjunctivitis and Asthma

Allergen immunotherapy (AIT) is a recognized key therapeutic modality for the treatment of allergic respiratory disease. Definitive studies have provided evidence-based data to demonstrate its effectiveness in allergic rhinitis and asthma due to the inhalation of proteinaceous allergic substances from specific seasonal pollens, dust mites, animal allergens, and certain mold spores. Over the ensuing decades, laboratory investigations have provided objective evidence to demonstrate immunologic changes, including production of protective IgG antibody, suppression of IgE antibody, upregulation of regulatory T cells, and induction of a state of immune tolerance to the offending allergen(s). Tangential to this work were carefully designed clinical studies that defined allergen dose and duration of treatment, established the importance of preparing extracts with standardized allergens (or well-defined extracts) based on major protein moieties, and used allergen provocation models to demonstrate efficacy superior to placebo. In the United States, the use of subcutaneous immunotherapy extracts for AIT was grandfathered in by the Food and Drug Administration based on expert literature review. In contrast, sublingual tablet immunotherapy underwent formal clinical development programs (phase I-III clinical trials) that provided the necessary clinical evidence for safety and efficacy that led to regulatory agency approvals for the treatment of allergic rhinitis in properly characterized patients with allergy. The allergy specialist's treatment options currently include traditional subcutaneous AIT and specific sublingual tablets approved for grass, ragweed, house dust mites, trees belonging to the birch-homologous group, and Japanese cedar. Tangential to this are sublingual drops that are increasingly being used off-label (albeit not approved by the Food and Drug Administration) in the United States. This article will review the evidence-based literature supporting the use of these forms of AIT, as well as focus on several current controversies and gaps in our knowledge base that have relevance for the appropriate selection of patients for treatment with specific AIT.

Long-term efficacy of house dust mite sublingual immunotherapy on clinical and pulmonary function in patients with asthma and allergic rhinitis

Background

A previous study reported that house dust mite (HDM) sublingual immunotherapy (SLIT) for 48 weeks was effective as add-on treatment for allergic asthma; however, data regarding its long-term efficacy are scarce.

Objective

We sought to evaluate the effect of HDM SLIT on asthma control, pulmonary function, and airway inflammation and remodeling throughout the 5-year treatment period.

Methods

A total of 140 patients with asthma and allergic rhinitis sensitized to HDM were randomized to receive either drugs alone or drugs plus SLIT for 5 years. The 5-item Asthma Control Questionnaire (ACQ-5), Asthma Quality of Life Questionnaire (AQLQ), Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ), spirometry, quantitative computed tomography, and type 2 biomarkers were assessed.

Results

An improvement in the ACQ-5, AQLQ, and RQLQ scores was observed in the SLIT group compared with the control group. HDM SLIT increased lung function and reduced the percentage of airway wall area. The levels of fractional exhaled nitric oxide (Feno), blood eosinophil, serum specific IgE for HDM, and total IgE decreased and were sustained during the 5 years. The change in type 2 biomarkers correlated with change in the AQLQ score. On the basis of receiver-operating characteristic analysis for predicting responders, the area under the receiver-operating characteristic curve in FEV1% predicted, airway wall area, Feno, and specific IgE was high. Multivariate regression analysis showed that the strongest predictor of responders was Feno.

Conclusions

HDM SLIT continued to provide sustained efficacy, improve lung function, and prevent progression of airway inflammation and remodeling in asthma throughout the 5-year treatment period.

Hot topics in allergen immunotherapy, 2023: Current status and future perspective

The importance of allergen immunotherapy (AIT) is multifaceted, encompassing both clinical and quality-of-life improvements and cost-effectiveness in the long term. Key mechanisms of allergen tolerance induced by AIT include changes in memory type allergen-specific T- and B-cell responses towards a regulatory phenotype with decreased Type 2 responses, suppression of allergen-specific IgE and increased IgG1 and IgG4, decreased mast cell and eosinophil numbers in allergic tissues and increased activation thresholds. The potential of novel patient enrolment strategies for AIT is taking into account recent advances in biomarkers discoveries, molecular allergy diagnostics and mobile health applications contributing to a personalized approach enhancement that can increase AIT efficacy and compliance. Artificial intelligence can help manage and interpret complex and heterogeneous data, including big data from omics and non-omics research, potentially predict disease subtypes, identify biomarkers and monitor patient responses to AIT. Novel AIT preparations, such as synthetic compounds, innovative carrier systems and adjuvants, are also of great promise. Advances in clinical trial models, including adaptive, complex and hybrid designs as well as real-world evidence, allow more flexibility and cost reduction. The analyses of AIT cost-effectiveness show a clear long-term advantage compared to pharmacotherapy. Important research questions, such as defining clinical endpoints, biomarkers of patient selection and efficacy, mechanisms and the modulation of the placebo effect and alternatives to conventional field trials, including allergen exposure chamber studies are still to be elucidated. This review demonstrates that AIT is still in its growth phase and shows immense development prospects.

Genetic and T2 biomarkers linked to the efficacy of HDM sublingual immunotherapy in asthma

BACKGROUND

Hypersensitivity to house dust mite (HDM) allergens is a common cause of allergic asthma symptoms and can be effectively treated with allergy immunotherapy (AIT).

OBJECTIVE

To investigate whether genetic and type 2 (T2) inflammatory biomarkers correlate with disease severity in subjects with allergic asthma, and whether this can be modified by AIT.

METHODS

MITRA (NCT01433523) was a phase III, randomised, double-blind, placebo-controlled trial of HDM sublingual immunotherapy (SLIT)-tablets in adults with HDM allergic asthma. Post hoc analyses of the study population (N=742) evaluated associations between T2 inflammatory (blood eosinophils, eosinophil cationic protein (ECP), total IgE and tryptase) and genetic (single-nucleotide polymorphisms, SNP) biomarkers (n=582) for the primary study endpoint (time to first moderate/severe asthma exacerbation). SNP associations were verified in HDM-positive subgroup from an independent 3-year Severe Asthma Research Programme (SARP3) subject cohort.

RESULTS

An increased asthma exacerbation risk in subjects homozygous for SNP rs7216389 (chromosomal locus 17q12-21) was reduced (p=0.037) by treatment with HDM SLIT (HR=0.37 (95% CI 0.22 to 0.64), p<0.001). The associations between exacerbation risk and 17q12-21 SNPs were replicated in the SARP3 HDM-positive subgroup. High levels of T2 biomarkers were associated with increased risk of asthma exacerbations in the placebo group. HDM SLIT-tablet treatment reduced this risk (blood eosinophils: HR=0.50 (95% CI 0.30 to 0.85); ECP: HR=0.45 (95% CI 0.29 to 0.87); tryptase: HR=0.45 (95% CI 0.25 to 0.80)). The treatment effect was higher (p=0.006) for subjects with a higher number of elevated T2 biomarkers.

CONCLUSIONS

HDM SLIT-tablet AIT is efficacious in HDM-sensitised asthma subjects with a genetic asthma predisposition and/or an underlying T2 endotype.

TRIAL REGISTRATION NUMBER

NCT01433523.

Clinical Practice Guideline: Immunotherapy for Inhalant Allergy

OBJECTIVE

Allergen immunotherapy (AIT) is the therapeutic exposure to an allergen or allergens selected by clinical assessment and allergy testing to decrease allergic symptoms and induce immunologic tolerance. Inhalant AIT is administered to millions of patients for allergic rhinitis (AR) and allergic asthma (AA) and is most commonly delivered as subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT). Despite its widespread use, there is variability in the initiation and delivery of safe and effective immunotherapy, and there are opportunities for evidence-based recommendations for improved patient care.

PURPOSE

The purpose of this clinical practice guideline (CPG) is to identify quality improvement opportunities and provide clinicians trustworthy, evidence-based recommendations regarding the management of inhaled allergies with immunotherapy. Specific goals of the guideline are to optimize patient care, promote safe and effective therapy, reduce unjustified variations in care, and reduce the risk of harm. The target patients for the guideline are any individuals aged 5 years and older with AR, with or without AA, who are either candidates for immunotherapy or treated with immunotherapy for their inhalant allergies. The target audience is all clinicians involved in the administration of immunotherapy. This guideline is intended to focus on evidence-based quality improvement opportunities judged most important by the guideline development group (GDG). It is not intended to be a comprehensive, general guide regarding the management of inhaled allergies with immunotherapy. The statements in this guideline are not intended to limit or restrict care provided by clinicians based on their experience and assessment of individual patients.

ACTION STATEMENTS

The GDG made a strong recommendation that (Key Action Statement [KAS] 10) the clinician performing allergy skin testing or administering AIT must be able to diagnose and manage anaphylaxis. The GDG made recommendations for the following KASs: (KAS 1) Clinicians should offer or refer to a clinician who can offer immunotherapy for patients with AR with or without AA if their patients' symptoms are inadequately controlled with medical therapy, allergen avoidance, or both, or have a preference for immunomodulation. (KAS 2A) Clinicians should not initiate AIT for patients who are pregnant, have uncontrolled asthma, or are unable to tolerate injectable epinephrine. (KAS 3) Clinicians should evaluate the patient or refer the patient to a clinician who can evaluate for signs and symptoms of asthma before initiating AIT and for signs and symptoms of uncontrolled asthma before administering subsequent AIT. (KAS 4) Clinicians should educate patients who are immunotherapy candidates regarding the differences between SCIT and SLIT (aqueous and tablet) including risks, benefits, convenience, and costs. (KAS 5) Clinicians should educate patients about the potential benefits of AIT in (1) preventing new allergen sensitizations, (2) reducing the risk of developing AA, and (3) altering the natural history of the disease with continued benefit after discontinuation of therapy. (KAS 6) Clinicians who administer SLIT to patients with seasonal AR should offer pre- and co-seasonal immunotherapy. (KAS 7) Clinicians prescribing AIT should limit treatment to only those clinically relevant allergens that correlate with the patient's history and are confirmed by testing. (KAS 9) Clinicians administering AIT should continue escalation or maintenance dosing when patients have local reactions (LRs) to AIT. (KAS 11) Clinicians should avoid repeat allergy testing as an assessment of the efficacy of ongoing AIT unless there is a change in environmental exposures or a loss of control of symptoms. (KAS 12) For patients who are experiencing symptomatic control from AIT, clinicians should treat for a minimum duration of 3 years, with ongoing treatment duration based on patient response to treatment. The GDG offered the following KASs as options: (KAS 2B) Clinicians may choose not to initiate AIT for patients who use concomitant beta-blockers, have a history of anaphylaxis, have systemic immunosuppression, or have eosinophilic esophagitis (SLIT only). (KAS 8) Clinicians may treat polysensitized patients with a limited number of allergens.

Short-term and long-term efficacy of sublingual immunotherapy in different courses for house dust mite-induced allergic rhinitis

PURPOSE

Sublingual immunotherapy (SLIT) has been proven to be an effective and safe treatment for patients with house dust mite (HDM)-induced allergic rhinitis (AR) to achieve short-term and long-term efficacy. This study aimed to investigate the relationship between SLIT duration and long-term efficacy.

MATERIALS AND METHODS

This study involved 134 patients who underwent SLIT between 2019 and 2021 (in the 2-year group), between 2018 and 2021(in the 3-year group), or between 2017 and 2021 (in the 4-year group). The total nasal symptoms score (TNSS), total medication score (TMS), visual analogue scale (VAS), the Mini Rhinoconjunctivitis Quality of Life Questionnaire (MiniRQLQ) and adverse events (AEs) were assessed at baseline, after treatment (2021) and one year after the treatment completion (2022). The correlation between MiniRQLQ and other indicators was also analyzed.

RESULTS

After SLIT, patients in all three groups showed significant improvements in TNSS, TMS, VAS and MiniRQLQ scores (all p < 0.001). These improvements were sustained even one year after SLIT. Patients who received 3-4 years of SLIT showed significant improvement compared with those who received 2 years of SLIT in all clinical outcomes (all p < 0.01). The analysis showed positive correlations between the MiniRQLQ and TNSS, TMS, and VAS (all p < 0.001). No significant difference was observed in the AE rate in all three groups (p > 0.05).

CONCLUSION

Different duration of HDM SLIT could generate various short-term and long-term clinical efficacy. The MiniRQLQ could be applied to evaluate SLIT efficacy in clinical practice.

The pharmacotherapeutic management of allergic rhinitis in people with asthma

INTRODUCTION

Up to 90% of asthmatic patients have comorbid allergic rhinitis (AR). Although appropriate therapy of AR can improve asthma symptoms and management, AR is often underdiagnosed and under-treated in asthmatics.A non-systematic literature research was conducted on AR as a comorbidity and risk factor of asthma. Latest international publications in medical databases, international guidelines, and the Internet were reviewed.

AREAS COVERED

Based on the conducted literature research there is proved evidence of the necessity of diagnosis and treatment of AR in patients with asthma because it affects health care utilization. Therefore, it is recommended in national and global guidelines.

EXPERT OPINION

AR increases the risk of asthma development and contributes to the severity of an existing asthma. Early treatment of AR with drugs as intranasal steroids, antihistamines, leukotriene receptor antagonists, and especially allergen-specific immunotherapy can reduce the risk of asthma development and the concomitant medication use in addition to severity of symptoms in AR and asthma.

The KAAACI Guidelines for Sublingual Immunotherapy

Allergen immunotherapy is regarded as the only disease-modifying treatment option for various allergic conditions, including allergic rhinitis and asthma. Among the routes of administration of allergens, sublingual immunotherapy (SLIT) has gained clinical interest recently, and the prescription of SLIT is increasing among patients with allergies. After 30 years of SLIT use, numerous pieces of evidence supporting its efficacy, safety, and mechanism allows SLIT to be considered as an alternative option to subcutaneous immunotherapy. Based on the progressive development of SLIT, the current guideline from the Korean Academy of Asthma, Allergy, and Clinical Immunology aims to provide an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. This guideline addresses the use of SLIT, including 1) mechanisms of action, 2) appropriate patient selection for SLIT, 3) the currently available SLIT products in Korea, and 4) updated information on its efficacy and safety. This guideline will facilitate a better understanding of practical considerations for SLIT.

Allergen Immunotherapy for Asthma

Allergen immunotherapy is a disease-modifying treatment for IgE-mediated allergies reducing disease burden and symptoms in patients with allergic rhinitis, with or without asthma. The growing evidence that allergen immunotherapy also has the potential to facilitate achieving asthma control in patients with allergic asthma resulted in its acknowledgment by international bodies (Global Initiative for Asthma and European Academy of Allergy and Clinical Immunology) as add-on treatment for mild/moderate asthma. Although there have been promising developments in biomarkers for patient selection and for allergen immunotherapy efficacy evaluation in patients with asthma, a lot more data are still required.

Prevention Is Better than Cure: Impact of Allergen Immunotherapy on the Progression of Airway Disease

Allergen immunotherapy is highly effective for seasonal pollinosis. Three years of treatment results in long-term efficacy. This disease modification is accompanied by downregulation of allergen-specific Th2 responses and the induction of persistent specific IgG- and IgA-associated IgE-blocking activity. In children with seasonal rhinitis, both subcutaneous and sublingual pollen immunotherapy have been shown to reduce the development of asthma symptoms and asthma medication requirements. House dust mite tablet allergen immunotherapy has been shown to be effective for perennial mite-driven rhinitis in adults and children and may suppress asthma exacerbations, whereas its long-term efficacy has yet to be explored. The success of primary prevention of peanut allergy in childhood by introduction of peanut into the diet during infancy provides a strong rationale to explore whether primary prevention of inhalant allergies and asthma may also be possible. House dust mite allergy is a major risk factor for developing asthma. Preliminary data in at-risk children suggest that sublingual house dust mite immunotherapy initiated during infancy could reduce the onset of multiple allergen sensitizations and prevent the development of asthma at age 6 years. This possibility should now be explored in an adequately powered, prospectively randomized controlled trial.

Asthma and COPD: A Focus on β-Agonists - Past, Present and Future

Asthma has been recognised as a respiratory disorder for millennia and the focus of targeted drug development for the last 120 years. Asthma is one of the most common chronic non-communicable diseases worldwide. Chronic obstructive pulmonary disease (COPD), a leading cause of morbidity and mortality worldwide, is caused by exposure to tobacco smoke and other noxious particles and exerts a substantial economic and social burden. This chapter reviews the development of the treatments of asthma and COPD particularly focussing on the β-agonists, from the isolation of adrenaline, through the development of generations of short- and long-acting β-agonists. It reviews asthma death epidemics, considers the intrinsic efficacy of clinical compounds, and charts the improvement in selectivity and duration of action that has led to our current medications. Important β2-agonist compounds no longer used are considered, including some with additional properties, and how the different pharmacological properties of current β2-agonists underpin their different places in treatment guidelines. Finally, it concludes with a look forward to future developments that could improve the β-agonists still further, including extending their availability to areas of the world with less readily accessible healthcare.

Standardization of clinical outcomes used in allergen immunotherapy in allergic asthma: An EAACI position paper

INTRODUCTION

In allergic asthma patients, one of the more common phenotypes might benefit from allergen immunotherapy (AIT) as add-on intervention to pharmacological treatment. AIT is a treatment with disease-modifying modalities, the evidence for efficacy is based on controlled clinical trials following standardized endpoint measures. However, so far there is a lack of a consensus for asthma endpoints in AIT trials. The aim of a task force (TF) of the European Academy of Allergy and Clinical Immunology (EAACI) is evaluating several outcome measures for AIT in allergic asthma.

METHODS

The following domains of outcome measures in asthmatic patients have been evaluated for this position paper (PP): (i) exacerbation rate, (ii) lung function, (iii) ICS withdrawal, (iv) symptoms and rescue medication use, (v) questionnaires (PROMS), (vi) bronchial/nasal provocation, (vii) allergen exposure chambers (AEC) and (viii) biomarkers.

RESULTS

Exacerbation rate can be used as a reliable objective primary outcome; however, there is limited evidence due to different definitions of exacerbation. The time after ICS withdrawal to first exacerbation is considered a primary outcome measure. Besides, the advantages and disadvantages and clinical implications of further domains of asthma endpoints in AIT trials are elaborated in this PP.

CONCLUSION

This EAACI-PP aims to highlight important aspects of current asthma measures by critically evaluating their applicability for controlled trials of AIT.

Efficacy of Sublingual Immunotherapy in Allergic Rhinitis Patients with Asthma: A Systematic Review and Meta-Analysis

OBJECTIVE

Sublingual immunotherapy (SLIT) has been widely applied to treat patients with allergic rhinitis (AR). However, meta-analyses on the efficacy of SLIT in AR patients with asthma are still limited.

METHODS

Literature without language limitation published before October 28, 2022, were retrieved from PubMed, EMBASE, and Cochrane Library. STATA 16.0 software was used for the meta-analysis of the extracted data. The results reported were symptom scores, drug scores, adverse effects rates, and cost of treatment.

RESULTS

Ten studies involving 1722 patients met the inclusion criteria. The total rhinitis score (TRSS) (weighted mean difference [WMD] = -1.23, 95% CI: -1.39--1.06, P < .001) and total asthma symptom score (TASS) (WMD = -1.00, 95% CI: -1.12-0.89, P < .001) were significantly lower in the SLIT group than the placebo group. The SLIT group had higher rates of treatment-related adverse events (relative risk [RR] = 2.82, 95% CI: 1.77-4.48, P < .001) and total costs of treatment (standardized mean difference [SMD] = 0.71, 95% CI: 0.45-0.97, P < .001). There was no significant difference in inhaled corticosteroids (ICS) dose (P = .195), fractional exhaled nitric oxide (FeNO) (P = .158), forced expiratory volume in 1 s (FEV1) (P = .237), and direct costs of treatment (P = .630) between the SLIT and placebo groups.

CONCLUSION

SLIT may be a therapeutic method for improving rhinitis symptoms and asthma symptoms in AR patients with asthma. However, as there was significant heterogeneity in results, more high-quality and well-designed studies are needed in the future to elucidate the efficacy of SLIT.

KAAACI Guidelines for Allergen Immunotherapy

Allergen immunotherapy (AIT) is a causative treatment for various allergic diseases such as allergic rhinitis, allergic asthma, and bee venom allergy that induces tolerance to offending allergens. The need for uniform practice guidelines in AIT is continuously growing because of the increasing discovery of potential candidates for AIT and evolving interest in new therapeutic approaches. This guideline is an updated version of the Korean Academy of Asthma Allergy and Clinical Immunology recommendations for AIT published in 2010. This updated guideline proposes an expert opinion by allergy, pediatrics, and otorhinolaryngology specialists with an extensive literature review. The guideline deals with basic knowledge and methodological aspects of AIT, including mechanisms, clinical efficacy, patient selection, allergens extract selection, schedule and doses, management of adverse reactions, efficacy measurements, and special consideration in pediatrics. The guidelines for sublingual immunotherapy will be covered in detail in a separate article.

Advancing precision medicine in asthma: Evolution of treatment outcomes

The article discusses the historical evolution of asthma treatment and highlights recent advancements in personalized medicine, specifically the use of biologics in severe asthma therapy and its potential combination with allergen immunotherapy (AIT). One of the major breakthroughs of biologics is their potential effect on airway remodeling, a crucial aspect of asthma chronicity. The article introduces the concept of disease-modifying antiasthmatic drugs, which aim to modify the course of asthma and possibly modulate or prevent airway remodeling. Furthermore, the critical importance of patient-centered outcome measures to evaluate the efficacy and effectiveness of asthma treatments is emphasized, with the innovative concept of asthma remission introduced as a potential outcome. Recent studies suggest that AIT can be used as an additional therapy to biologic agents for the treatment of allergic asthma. The combination of these treatments has been shown to induce improved clinical outcomes. However, AIT is actually not recommended for use in patients with severe asthma, but encouraging results from studies investigating the combined use of AIT and biologics indicate a novel approach to exploring these treatment modalities. In conclusion, the introduction of biologics and AIT has changed the scenario of respiratory allergy treatment, from a "one size fits all" approach to embracing "individual treatments."

[Diagnosis and treatment of asthma: a guideline for respiratory specialists 2023 - published by the German Respiratory Society (DGP) e. V.]

The management of asthma has fundamentally changed during the past decades. The present guideline for the diagnosis and treatment of asthma was developed for respiratory specialists who need detailed and evidence-based information on the new diagnostic and therapeutic options in asthma. The guideline shows the new role of biomarkers, especially blood eosinophils and fractional exhaled NO (FeNO), in diagnostic algorithms of asthma. Of note, this guideline is the first worldwide to announce symptom prevention and asthma remission as the ultimate goals of asthma treatment, which can be achieved by using individually tailored, disease-modifying anti-asthmatic drugs such as inhaled steroids, allergen immunotherapy or biologics. In addition, the central role of the treatment of comorbidities is emphasized. Finally, the document addresses several challenges in asthma management, including asthma treatment during pregnancy, treatment of severe asthma or the diagnosis and treatment of work-related asthma.

How can we improve our use of allergen immunotherapy as a treatment option for asthma and severe asthma?

INTRODUCTION

In patients suffering from allergic asthma, especially in the pediatric age-group, allergen immunotherapy (AIT) could be of benefit and has the potential of long-term disease modification.

AREAS COVERED

We reviewed the evidence for a beneficial effect of AIT in allergic asthma. A correct selection of the possible candidates for AIT is crucial. We define the comprehensive allergic asthma diagnosis: confirming asthma, confirming allergic sensitization and having symptoms on exposure to the relevant allergens.We analyze why the first trials on AIT for asthma were contradictory; we consider the results of systematic reviews and discuss the high degree of heterogeneity often found in meta-analysis. We assess recent, double-blind, placebo-controlled trials in sublingual AIT that provide robust evidence for a reduction in acute asthma exacerbations and a decrease in the use of inhaled corticosteroids. Further, we demonstrate how real-world trials and large pharmacy data-based analyses confirm these findings for SLIT and SCIT. Finally, we explore the option of AIT in severe asthma patients, once well-controlled on biologic therapy.

EXPERT OPINION

Clear indications for AIT in asthma guidelines would benefit allergic asthmatics. AIT is a therapeutic option in appropriately selected asthmatics. Three years treatment has the potential for long-term tolerance, with persisting benefits years after discontinuation.

Potential Effects of AIT on Nonspecific Allergic Immune Responses or Symptoms

Allergen immunotherapy (AIT) is a treatment in which clinically corresponding allergens are administered to patients with allergic diseases, either by subcutaneous immunotherapy (SCIT) or sublingual immunotherapy (SLIT), or by oral immunotherapy (OIT) in the case of food allergy. Since etiological allergens are administered to patients, AIT is presumed to modify mainly allergen-specific immune responses. In bronchial asthma, AIT with house dust mites (HDM) alleviates clinical symptoms, suppresses airway hyperresponsiveness, and reduces medication doses of HDM-sensitive asthmatics. Moreover, AIT can suppress the symptoms of other allergic diseases associated with asthma including allergic rhinitis. However, AIT sometimes reduces allergic symptoms not induced by the responsible allergens, such as non-targeted allergens, in clinical settings. Furthermore, AIT can suppress the spread of sensitization to new allergens that are not targeted allergens by AIT, suggesting the suppression of allergic immune responses in an allergen-nonspecific manner. In this review, the nonspecific suppression of allergic immune responses by AIT is discussed. AIT has been reported to increase regulatory T cells that produce IL-10, transforming growth factor-β, and IL-35, IL-10-producing regulatory B cells, and IL-10-producing innate lymphoid cells. These cells can suppress type-2 mediated immune responses mainly through the production of anti-inflammatory cytokines or a cell-cell contact mechanism, which may be involved in the nonspecific suppression of allergic immune responses by AIT.

Allergen immunotherapy: progress and future outlook

INTRODUCTION

Allergy, the immunological hypersensitivity to innocuous environmental compounds, is a global health problem. The disease triggers, allergens, are mostly proteins contained in various natural sources such as plant pollen, animal dander, dust mites, foods, fungi and insect venoms. Allergies can manifest with a wide range of symptoms in various organs, and be anything from just tedious to life-threatening. A majority of all allergy patients are self-treated with symptom-relieving medicines, while allergen immunotherapy (AIT) is the only causative treatment option.

AREAS COVERED

This review will aim to give an overview of the state-of-the-art allergy management, including the use of new biologics and the application of biomarkers, and a special emphasis and discussion on current research trends in the field of AIT.

EXPERT OPINION

Conventional AIT has proven effective, but the years-long treatment compromises patient compliance. Moreover, AIT is typically not offered in food allergy. Hence, there is a need for new, effective and safe AIT methods. Novel routes of administration (e.g. oral and intralymphatic), hypoallergenic AIT products and more effective adjuvants holds great promise. Most recently, the development of allergen-specific monoclonal antibodies for passive immunotherapy may also allow treatment of patients currently not treated or treatable.

Allergen immunotherapy for allergic asthma: The future seems bright

Allergen specific immunotherapy (AIT) is the only causal therapeutic option for allergic airway diseases including asthma and allergic rhinitis. AIT has been shown to restore the allergen immune tolerance, can modify both the early and late-onset allergen-specific airway hyperreactivity, helps to achieve disease control/remission and prevents new sensitisations. Recent real life data on long-term effectiveness of house dust mite (HDM) AIT in a large group of patients with HDM-driven asthma further underscored its unique therapeutic potential as well as confirmed previous data with pollen AIT. More widespread use of this causal treatment in select patient populations should further move this promising therapeutic field. In this mini-review, we discuss updates on new insights based on real world patient data.

Asthma

Asthma is one of the most common chronic non-communicable diseases worldwide and is characterised by variable airflow obstruction, causing dyspnoea and wheezing. Highly effective therapies are available; asthma morbidity and mortality have vastly improved in the past 15 years, and most patients can attain good asthma control. However, undertreatment is still common, and improving patient and health-care provider understanding of when and how to adjust treatment is crucial. Asthma management consists of a cycle of assessment of asthma control and risk factors and adjustment of medications accordingly. With the introduction of biological therapies, management of severe asthma has entered the precision medicine era-a shift that is driving clinical ambitions towards disease remission. Patients with severe asthma often have co-existing conditions contributing to their symptoms, mandating a multidimensional management approach. In this Seminar, we provide a clinically focused overview of asthma; epidemiology, pathophysiology, diagnosis, and management in children and adults.

Approaches to Management of Asthma: Guidelines for Stepped Care and Self-Monitoring

While the twentieth century brought rapid changes to the diagnosis and management of asthma, consensus guidelines did not exist until the mid-1980s. Over the subsequent four decades, guidelines evolved from expert-based recommendations to comprehensive, evidenced-based references. The main two guidelines to be discussed in this chapter are the expert panel reports (EPR) published by the United States National Heart, Lung, and Blood Institute (NHLBI) and the Global Strategy for Asthma Management and Prevention Report (GINA) published by the NHLBI and World Health Organization (WHO). While these guidelines both focus on evidence-based approaches to the diagnosis and management of asthma, there are significant differences in both organization and recommendations. Just as the introduction of evidence-based guidelines was revolutionary to asthma management over the last 20 years, we anticipate further development of recommendations specific to precision medicine based on ongoing cutting-edge clinical research.

Allergen immunotherapy effectively reduces the risk of exacerbations and lower respiratory tract infections in both seasonal and perennial allergic asthma: a nationwide epidemiological study

BACKGROUND

Allergic asthma is associated with increased risk of respiratory tract infections and exacerbations. It remains unclear whether this susceptibility is conditioned by seasonal or by perennial allergy.

AIM

To investigate perennial allergy compared with seasonal allergy as a risk factor for lower respiratory tract infections and exacerbations in asthma and whether this risk can be reduced by allergen immunotherapy (AIT).

METHODOLOGY

This is a prospective register-based nationwide study of 18-44-year-olds treated with AIT during 1995-2014. Based on the type of AIT and use of anti-asthmatic drugs, patients were subdivided into two groups: perennial allergic asthma (PAA) versus seasonal allergic asthma (SAA). Data on antibiotics against lower respiratory tract infections (LRTI) and oral corticosteroids for exacerbations were analysed before starting AIT (baseline) and 3 years after completing AIT (follow-up).

RESULTS

We identified 2688 patients with asthma treated with AIT, of whom 1249 had PAA and 1439 had SAA. At baseline, patients with SAA had more exacerbations (23.8% versus 16.5%, p≤0.001), but there were no differences in LRTI. During the 3-year follow-up, we observed a highly significant reduction of exacerbations with an average decrease of 57% in PAA and 74% in SAA. In addition, we observed a significant reduction of LRTI in both PAA and SAA: 17% and 20% decrease, respectively.

CONCLUSION

AIT effectively reduced the risk of exacerbations and lower respiratory tract infections in both seasonal and perennial allergic asthma. Perennial allergy is seemingly not a stronger risk factor for respiratory infections and exacerbations than seasonal allergy.

Allergen immunotherapy: past, present and future

Allergen immunotherapy is a form of therapeutic vaccination for established IgE-mediated hypersensitivity to common allergen sources such as pollens, house dust mites and the venom of stinging insects. The classical protocol, introduced in 1911, involves repeated subcutaneous injection of increasing amounts of allergen extract, followed by maintenance injections over a period of 3 years, achieving a form of allergen-specific tolerance that provides clinical benefit for years after its discontinuation. More recently, administration through the sublingual route has emerged as an effective, safe alternative. Oral immunotherapy for peanut allergy induces effective ‘desensitization’ but not long-term tolerance. Research and clinical trials over the past few decades have elucidated the mechanisms underlying immunotherapy-induced tolerance, involving a reduction of allergen-specific T helper 2 (T_H2) cells, an induction of regulatory T and B cells, and production of IgG and IgA ‘blocking’ antibodies. To better harness these mechanisms, novel strategies are being explored to achieve safer, effective, more convenient regimens and more durable long-term tolerance; these include alternative routes for current immunotherapy approaches, novel adjuvants, use of recombinant allergens (including hypoallergenic variants) and combination of allergens with immune modifiers or monoclonal antibodies targeting the T_H2 cell pathway.

Durham and Shamji review the history and future of allergen immunotherapy for established IgE-mediated hypersensitivity to common allergens. They describe the mechanisms of immunotherapy-induced tolerance and the new strategies being explored to achieve safer, more effective, long-term tolerance.

Cost-effectiveness analysis of house dust mite allergen immunotherapy in children with allergic asthma

BACKGROUND

Cost-effectiveness studies evaluating allergen immunotherapy (AIT) in children are limited but needed to drive clinical and policy-making decisions such as reimbursement of new interventions. In this study, we compared the cost effectiveness of subcutaneous (SCIT) and sublingual immunotherapy (SLIT) tablets to the standard of care (SOC) treatment in children with house dust mite-driven (HDM) allergic asthma.

METHODS

We developed a hypothetical Markov model based on the Global Initiative for Asthma (GINA) severity steps to compare the three strategies over a 10-year horizon divided by cycles of 6 months. SOC was used as a reference to calculate the incremental cost-effectiveness ratio (ICER). Deterministic and probabilistic sensitivity analyses were used to assess models' uncertainty. Other scenarios were evaluated to strengthen the presentation of results.

RESULTS

The ICER for SCIT and SLIT tablets was 1281€ and 7717€, respectively. The cost-effectiveness threshold for Portugal was 18,482.80€; both treatment approaches were below this limit. The major contributors to these results were the AIT effects on reducing moderate and severe exacerbations and asthma controller medication. In the sensitivity analysis, SCIT revealed a higher probability of cost-effectiveness than SLIT. When including allergic rhinitis as comorbidity, ICER values reduced markedly, especially for SCIT intervention.

CONCLUSIONS

AIT was cost effective in children with HDM-driven allergic asthma, especially when given by the subcutaneous route. The high probability of cost effectiveness, especially for SCIT, may drive future policy decisions and AIT-prescribing habits. AIT adherence greatly influenced the results highlighting the value of implementing strategies to promote adherence rates.

Barriers to accessing aeroallergen immunotherapy in paediatrics

BACKGROUND

Allergen immunotherapy (AIT) is a safe, effective and disease-modifying treatment for allergic rhinitis. It is indicated for children with moderate to severe disease whose symptoms persist despite conventional therapy. There is a high prevalence of allergic rhinitis amongst Irish children; however, levels of AIT prescribing in Ireland are lower than neighbouring countries.

AIMS

The aims of this study are to describe current patterns of AIT prescribing and referrals amongst Irish paediatricians and to identify barriers to accessing AIT in Ireland.

METHODS

An electronic questionnaire was distributed to all paediatricians and paediatric trainees caring for children with allergic rhinitis.

RESULTS

A lack of knowledge of AIT clinical criteria was the most frequently reported barrier with 50.5% (50/99) of general paediatricians unaware of the indications for referral compared to 27.3% (3/11) of respiratory physicians and 0% (0/8) of allergists. Accessibility is the next most cited barrier with 31.4% (37/118) of respondents unsure where to refer and 19.5% (23/118) reporting a lack of local services. Cost was reported to be a barrier by 12.7% (15/118). Paediatricians with an allergy or respiratory subspecialisation reported seeing significantly higher numbers of children with allergic rhinitis and were more likely to prescribe or refer a child for AIT.

CONCLUSIONS

This study demonstrated positive attitudes towards AIT amongst all grades and specialities of paediatricians in Ireland. The main barriers to more widespread use are difficulties with the identification of suitable candidates by general paediatricians and a lack of local AIT services and referral pathways.

Long-term efficacy of the sublingual and subcutaneous routes in allergen immunotherapy

Allergen immunotherapy is highly effective in selected patients with allergic rhinitis, allergic asthma, and Hymenoptera venom allergy. Unlike anti-allergic drugs, both subcutaneous and sublingual immunotherapies have been shown to modify the underlying cause of the disease, with proved long-term clinical benefits after treatment cessation. In this review, we analyzed 10 randomized, double-blind, placebo controlled clinical trials of allergen immunotherapy that included blinded follow-up for at least 1 year after treatment withdrawal. Three studies of pollen subcutaneous immunotherapy provided evidence that a sustained, tolerogenic effect of subcutaneous immunotherapy can be achieved after 3 years of treatment. Six trials of sublingual immunotherapy provided robust evidence for long-term clinical benefit and persistent immunologic changes after grass pollen, house-dust mite, or Japanese cedar immunotherapy, whereas a clinical trial of both sublingual and subcutaneous grass pollen immunotherapies showed that 2 years of immunotherapy were efficacious but insufficient to induce long-term tolerance. These studies strongly supported international guidelines that recommend at least 3 years of allergen immunotherapy of proven value to achieve disease modification and sustained clinical and immunologic tolerance.

Delivery options for sublingual immunotherapy for allergic rhinoconjunctivitis: clinical considerations for North America

Background: Sublingual immunotherapy (SLIT) can be delivered via tablets (SLIT-T) or aqueous drops (SLIT-D). SLIT-D dosing recommendations using North American extracts were published in 2015. We review the 2015 recommendations in the context of recent research, and compare and contrast dosing, efficacy, safety, adherence, and cost of SLIT-T and SLIT-D for allergic rhinoconjunctivitis (ARC) in North America. Methods: Randomized controlled trials (RCT) of SLIT-D and SLIT-T trials were identified by a systematic PubMed search through March 1, 2022. Results: Dose-finding studies have been conducted for all approved SLIT-T; efficacy in North American populations was demonstrated in 11 RCTs. Approved SLIT-T are uniform internationally. Few dose-finding studies for SLIT-D have been conducted using North American extracts; efficacy was demonstrated in 2 RCTs. Extrapolation of dosing from SLIT-D studies conducted with extracts from other geographic regions is unreliable. Since the 2015 SLIT-D dosing recommendations, no new RCTs of SLIT-D have been conducted with North American extracts, whereas 6 SLIT-T RCTs have since been conducted in North America. Local allergic reactions are the most common adverse events with SLIT-T and SLIT-D, but both can induce systemic allergic reactions. Adherence to SLIT-D and SLIT-T remains a challenge. Patients must pay for SLIT-D directly, whereas SLIT-T is usually covered by insurance. Conclusion: As part of shared decision-making, patients should be informed about the scientific evidence supporting the use of SLIT-T and SLIT-D for ARC.

Immunotherapy for Asthma

Asthma represents one of the biggest global health concerns with increasing prevalence and influence on global health. Several distinct asthma phenotypes have been identified with one of the most common, earliest recognized, and described being the allergic asthma phenotype, in which allergens trigger asthma through mechanisms involving allergen-specific immunoglobulin E (IgE). Allergen-specific immunotherapy (AIT), in the forms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT), has been used for many decades as a tool for reducing IgE-mediated sensitization and controlling symptoms of allergic disease, most commonly for allergic rhinitis, and it remains the only currently available disease modifying therapy in atopic patients. AIT has been studied for use in mild to moderate allergic asthma. While the data are often inconsistent, and utilize a multitude of different methods, antigens, and outcome measures, in general, AIT may have several beneficial effects on asthma disease control, quality of life, and requirement for medication. These benefits are notable when immunotherapy is used as an adjunct to pharmacologic treatment in carefully selected and monitored patients with mild to moderate persistent asthma. Patients with severe asthma are excluded from these trials. Importantly, patients with asthma, and in particular severe asthma, may have a higher rate of systemic adverse reactions to SCIT, including anaphylaxis, however, these events are overall rare. Future research in the area is needed to definitively assess the benefit of SCIT and SLIT for patients with asthma, comparing outcomes with different methods, addressing the role of AIT in severe asthma, significance of multiallergen AIT in allergic asthma, and safety concerns in asthma.

Efficacy of a house dust mite sublingual immunotherapy tablet as add-on dupilumab in asthma with rhinitis

BACKGROUND

HDM SLIT is one of the disease-modifying treatment for allergic asthma, and has demonstrated efficacy in clinical trials. Dupilumab, blocks IL-4 and IL-13 signaling, key drivers of type 2 inflammation, and is approved for patients with uncontrolled, moderate-to-severe asthma. The aim of this study was to evaluate outcomes after HDM SLIT initiation in asthma with rhinitis not optimally controlled with dupilumab in a real-world setting.

METHODS

At baseline and 48 weeks after treatment, asthma control questionnaire (ACQ)-5, asthma quality of life questionnaire (AQLQ) and rhinoconjunctivitis quality of life questionnaire (RQLQ) were assessed. Spirometry, type 2 inflammatory biomarkers and quantitative computed tomographic parameters of airway remodeling were also collected.

RESULTS

Of 47 patients received HDM SLIT and 41 completed the study. Combined HDM SLIT and dupilumab improved ACQ-5 (p < 0.05), AQLQ (p < 0.05), RQLQ (p < 0.05), and increased lung function and reduced FeNO (p < 0.05) and airway percentage wall area, and wall thickness (each, p < 0.05). The change in ACQ-5 and AQLQ score correlated with both changes in FeNO and FEV₁ percent predicted. Multiple regression analysis showed that the change in FEV₁ percent predicted was independent factor for improvement of AQLQ (r² = 0.510, p = 0.012). Based on ROC analysis for predicting SLIT responders, the baseline area under the curves in serum HDM specific-IgE, total IgE and FEV₁ percent predicted were high (>0.8).

CONCLUSIONS

These results support the benefits of adding HDM SLIT to pharmacotherapy plus dupilumab in uncontrolled asthma with rhinitis.

EAACI position paper on the clinical use of the bronchial allergen challenge: Unmet needs and research priorities

Allergic asthma (AA) is a common asthma phenotype, and its diagnosis requires both the demonstration of IgE-sensitization to aeroallergens and the causative role of this sensitization as a major driver of asthma symptoms. Therefore, a bronchial allergen challenge (BAC) would be occasionally required to identify AA patients among atopic asthmatics. Nevertheless, BAC is usually considered a research tool only, with existing protocols being tailored to mild asthmatics and research needs (eg long washout period for inhaled corticosteroids). Consequently, existing BAC protocols are not designed to be performed in moderate-to-severe asthmatics or in clinical practice. The correct diagnosis of AA might help select patients for immunomodulatory therapies. Allergen sublingual immunotherapy is now registered and recommended for controlled or partially controlled patients with house dust mite-driven AA and with FEV1 ≥ 70%. Allergen avoidance is costly and difficult to implement for the management of AA, so the proper selection of patients is also beneficial. In this position paper, the EAACI Task Force proposes a methodology for clinical BAC that would need to be validated in future studies. The clinical implementation of BAC could ultimately translate into a better phenotyping of asthmatics in real life, and into a more accurate selection of patients for long-term and costly management pathways.

Efficacy and Safety of House Dust Mite Sublingual Immunotherapy Tablet in Allergic Asthma: A Systematic Review of Randomized Controlled Trials

BACKGROUND

House dust mite sublingual immunotherapy (HDM SLIT) effectively treats allergic rhinitis (AR). However, the evidence of HDM SLIT for allergic asthma remained limited.

OBJECTIVE

To systematically review the efficacy and safety of HDM SLIT tablets in patients with allergic asthma.

METHODS

We performed a systematic search through PubMed, Scopus, EMBASE, Web of Science, the Cochrane Center of Controlled Trials, and Google Scholar for randomized controlled trials (RCTs) that addressed the efficacy and safety of HDM SLIT tablets compared with placebo or no intervention in allergic asthma from their inception date until September 2021. The primary outcome was the reduction in inhaled corticosteroids (ICS) dose. Additional outcomes were asthma control, exacerbation, lung function, quality-of-life, and adverse events.

RESULTS

There were 7 RCTs, 5 studies in allergic asthma (4 in adults and 1 in children), and 2 in AR with or without asthma. The 6 standardized quality (SQ) HDM effectively reduced ICS dose in well- to partly controlled mild-to-moderate asthma in 1 RCT. Two RCTs evaluated the efficacy of 6 SQ and 12 SQ HDM in reducing asthma exacerbation in partly controlled moderate-to-severe asthma, and their results were inconsistent. One study in children with mild-to-moderate asthma found no benefit of HDM SLIT. Two RCTs in AR with or without mild-to-moderate asthma showed improvement of asthma symptoms. Adverse events were primarily local, and anaphylaxis treated with epinephrine was reported in 3 patients.

CONCLUSIONS

The HDM SLIT tablets tend to effectively reduce ICS use in adults and adolescents with well- to partly controlled mild-to-moderate allergic asthma with a favorable safety profile.

The SQ HDM SLIT-Tablet is safe and well tolerated in patients with House Dust Mite allergic rhinitis with or without asthma: A "real-life" French study

Background

The SQ House Dust Mite (HDM) SubLingual ImmunoTherapy (SLIT)‐Tablet (Acarizax) is the only allergen immunotherapy authorized by European regulatory authorities to treat HDM‐induced allergic asthma (AA) that is not well‐controlled by inhaled corticosteroids and associated with mild‐to‐severe HDM allergic rhinitis (AR). The aim of this study was to add evidence on the safety of the SQ HDM SLIT‐Tablet in patients with AR, alone or with AA, under real‐life conditions.

Methods

This was a French “real‐life”, multicenter, non‐comparative, longitudinal, prospective study. It included patients initiating the SQ HDM SLIT‐Tablet for either persistent moderate‐to‐severe HDM AR or AA not well‐controlled by inhaled corticosteroids and associated with mild‐to‐severe HDM AR. Adverse Events (AEs) were collected at the first intake and throughout the study. Logistic regression was used to compare safety according to asthma control before treatment initiation.

Results

Between May 09, 2018 and May 29, 2019, 1526 patients were enrolled at 185 sites and 1483 were included in the safety population (SAF). Of them, 33.6% had suspected clinical manifestations of AA. Asthma was uncontrolled for 18.2% of the patients, partially controlled for 27.9% and well‐controlled for 53.8%. Overall, 31.9% of the SAF patients experienced at least one AE. The percentage of patients with AEs was 29.9% among patients with AR alone and 35.9% among those with AA (p = 0.0193). No significant difference was observed in the rate of AE or SAE depending on asthma control at inclusion (2.2% of SAEs reported for patients with uncontrolled asthma, 1.4% for partly controlled and 1.1% for well‐controlled).

Conclusions

The overall results indicate a good SQ HDM SLIT‐Tablet safety profile consistent with that reported in previous studies, regardless of asthma control.

Long-term real-world effectiveness of allergy immunotherapy in patients with allergic rhinitis and asthma: Results from the REACT study, a retrospective cohort study

BACKGROUND

Allergen immunotherapy (AIT) is the only causal treatment for respiratory allergy. Long-term real-life effectiveness of AIT remains to be demonstrated beyond the evidence from randomised controlled trials (RCTs).

METHODS

REACT (Real world effectiveness in allergy immunotherapy) is a retrospective cohort study using claims data between 2007 and 2017. Study eligibility was a confirmed diagnosis of allergic rhinitis (AR), with or without asthma, and AIT. To ensure comparable groups, AIT-treated subjects were propensity score matched 1:1 with control subjects, using characteristic and potential confounding variables. Outcomes were analysed as within (pre vs post AIT) and between (AIT vs control) group differences across 9 years of follow-up (ClinicalTrial.gov: NCT04125888).

FINDINGS

46,024 AIT-treated subjects were matched with control subjects and 14,614 were included in the pre-existing asthma cohort. AIT-treated subjects were 29·5 (16·3) years and 53% were male. Compared to pre-index year, AIT was consistently associated with greater reductions compared to control subjects in AR and asthma prescriptions, including both asthma controller and reliever prescriptions. Additionally, the AIT group had significantly greater likelihood of stepping down asthma treatment (P <0·0001). In addition to the reduction in asthma treatment in the AIT group, a greater reduction in severe asthma exacerbations was demonstrated (P<0·05). Reductions in pneumonia with antibiotic prescriptions, hospitalisations, and duration of inpatients stays were all in favour of AIT.

INTERPRETATION

The study extends the existing RCT evidence for AIT by demonstrating longer-term and sustained effectiveness of AIT in the real world. Additionally, in patients with concurrent asthma, AIT was associated with reduced likelihood of asthma exacerbations and pneumonia.

FUNDING

The study was funded by ALK A/S.

Allergen Release Profiles of Fast-Dissolving Freeze-Dried Orodispersible Sublingual Allergy Immunotherapy Tablets

Background

Sublingual allergy immunotherapy tablets (SLIT-tablets) provide a well-tolerated and clinically efficacious treatment for allergic disease such as allergic rhinitis and allergic asthma. In SLIT, uptake of allergen by immune-competent cells in the oral mucosa activates the immune system and leads to tolerance toward the sensitizing allergen. The ability to deliver the full allergen content into solution within the recommended sublingual holding time is therefore an essential quality of SLIT-tablets that must be supported by the tablet formulation for all relevant allergen sources. SLIT-tablets based on a fast-dissolving orodispersible freeze-dried formulation (Zydis) are currently available for 5 of the most prevalent allergens: tree (birch and related species from the birch-homologous group), grass, ragweed, Japanese cedar, and house dust mite.

Objectives

The purpose of this study was to examine the allergen release properties of three freeze-dried SLIT-tablets containing tree, ragweed, and Japanese cedar extracts, respectively. The correlation between SLIT-tablet allergen release and the level of allergen-specific T-cell activation was examined for the tree SLIT-tablet.

Methods

Allergen release kinetics and tablet disintegration times for the 3 freeze-dried SLIT-tablets were examined. For all 3 tablets, the magnitude of solubilized major allergen relative to time in solution was compared to external controls to achieve a measure of the total allergen release. Additional assessments of allergen release occurring after the initial timepoint (15 or 30 seconds in solution) were done independently of external controls by linear regression analyses. For the tree SLIT-tablet, the immunological potency of the released major allergen was assessed at each experimental timepoint by a Bet v-specific T-cell activation assay.

Results

All 3 SLIT-tablets disintegrated within 1 second after contact with assay buffer without any detectible residue. Complete release of major allergens (Bet v 1, Amb a 1, and Cry j 1, respectively) was seen at the earliest experimental time points (15 or 30 seconds). For the tree SLIT-tablet, full T-cell activation was achieved at 30 seconds (earliest experimental time point).

Conclusions

The freeze-dried SLIT-tablet formulation consistently provides rapid and complete release of allergen from a wide range of species in a standardized in vitro assay. Full release of the SLIT-tablet allergen content within the sublingual holding time is a prerequisite for maximal exposure of allergens to the sublingual mucosa immune system. The freeze-dried SLIT-tablet formulation examined here supports short sublingual holding times and furthermore offers a convenient administration form of allergy immunotherapy.

Allergen immunotherapy in treating allergic eosinophilic asthma

Currently, the approach to a patient with asthma is in accordance with personalized medicine wherein the decision on the treatment pathway is based on the type of asthmatic inflammation and other comorbidities that accompany asthma. For an allergic asthma patient, allergen immunotherapy (AIT), which has a disease-modifying effect and the potential to prevent further progression of allergic symptoms, is one of the treatment modalities. It is an effective treatment that, unlike pharmacotherapy, modifies the course of allergic respiratory diseases and induces allergen specific immune tolerance that persists for up to several years after treatment cessation. Therapeutic allergens of high quality, efficacy, and safety according to European regulatory authorities are an integral part of the treatment of respiratory allergies. It is a safe treatment option which still remains the only causal immuno¬modulatory therapy for allergic eosinophilic asthma.

Effectiveness and safety of oral lactococci-based vaccine encoding triple common allergens to prevent airway allergy in mice

Allergic airway disease is the most common chronic airway inflammatory disorder in developed countries. House dust mite, cockroach, and mold are the leading allergens in most tropical and subtropical countries, including Taiwan. As allergen avoidance is difficult for patients allergic to these perennial indoor allergens, allergen-specific immunotherapy (ASIT) is the only available allergen-specific and disease-modifying treatment. However, for patients sensitized to multiple allergens, ASIT using each corresponding allergen is cumbersome. In the present study, we developed a recombinant L. lactis vaccine against the three most common indoor aeroallergens and investigated its effectiveness for preventing respiratory allergy and safety in mice. Three recombinant clones of Der p 2 (mite), Per a 2 (roach), and Cla c 14 (mold) were constructed individually in pNZ8149 vector and then electroporated into host strain L.lactis NZ3900. BALB/c mice were fed with the triple vaccine 5 times per week for 4 weeks prior to sensitization. The effectiveness and safety profile were then determined. Oral administration of the triple vaccine significantly alleviated allergen-induced airway hyper-responsiveness in the vaccinated mice. The allergen-specific IgG2a was upregulated. IL-4 and IL-13 mRNA expressions as well as inflammatory cell infiltration in the lungs decreased significantly in the vaccinated groups. No body weight loss or abnormal findings in the liver and kidneys were found in any of the groups of mice. This is the first report to describe a triple-aeroallergen vaccine using a food-grade lactococcal expression system. We developed a convenient oral delivery system and intend to extend this research to develop a vaccination that can be self-administered at home by patients.

New insights in mite immunotherapy - sublingual tablets

PURPOSE OF REVIEW

Sublingual tablet immunotherapy has been demonstrated to be effective for allergies induced by exposure to grass, ragweed, specific trees (Japanese Cedar; birch homologous tree mix), and house dust mites (HDM). This review provides both an overview of the evidence-based clinical studies that address the use of the HDM SLIT-tablet for the treatment of HDM-induced allergic rhinitis/conjunctivitis and its appropriate use in carefully selected asthmatic patients and provides the clinician with practical management considerations.

RECENT FINDINGS

Solid evidence-based clinical studies have shown that the HDM SLIT-tablet is both well tolerated in patients with mild-to-moderate asthma and has demonstrated a meaningful improvement in exacerbations, need for rescue medication, quality of life, and asthma control.

SUMMARY

The HDM SLIT-tablet provides the allergy specialist with a well-tolerated treatment that has established superior safety to subcutaneous injection therapy, which can be administered easily as a sublingual dissolvable tablet, and which provides the opportunity to address one of the more difficult aspects in the management of an inducer of perennial allergic disease - that of persistent airway inflammation and allergic asthma.

Allergen Immunotherapy in Asthma

Allergen immunotherapy (AIT) is a specific treatment involving the administration of relevant allergens to allergic patients, with subtypes including subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT). In asthma, AIT using the house dust mite (HDM) alleviates clinical symptoms and decreases airway hyper responsiveness and medication dose. In addition, AIT can improve the natural course of asthma. For example, the effects of AIT can be preserved for at least a few years, even after ending treatment. AIT may increase the remission rate of asthma in children and suppress sensitization to new allergens. If AIT is introduced in pollinosis, AIT may prevent the development of asthma. Moreover, AIT can control other allergic diseases complicated by asthma, such as allergic rhinitis, which also improves the control of asthma. The indication of HDM-SCIT for asthma is mild-to-moderate HDM-sensitized allergic asthma in a patient with normal respiratory function. To date, HDM-SLIT is applicable in Japan for allergic rhinitis, not for asthma. However, the effect of SLIT on asthma has been confirmed internationally, and SLIT is available for asthma in Japan if allergic rhinitis is present as a complication.

2020 NAEPP Guidelines Update and GINA 2021-Asthma Care Differences, Overlap, and Challenges

The 2020 National Asthma Education and Prevention Program Coordinating Committee Expert Panel Working Group (NAEPP [2020 Focused Asthma Update]) guidelines and the Global Initiative for Asthma (GINA) 2021 strategy report are compared in this Rostrum article. The methodologies of each publication are described. Subsequently, 4 different selected pharmacological recommendations are compared in the 2 documents: step 1 for children 0 to 4 years of age with viral-induced wheezing, step 2 in ages 12 years and older with the intermittent use of inhaled corticosteroid, steps 3 and 4 with single-inhaler maintenance and reliever therapy with inhaled corticosteroids-formoterol (SMART), and steps 3, 4, and 5 with add-on long-acting muscarinic antagonist therapy. Nonpharmacological recommendations are also considered and contrasted, including for exhaled nitric oxide, environmental control, immunotherapy, and bronchial thermoplasty. Similarities and differences in these 2 documents are highlighted, and recommendations are made about harmonizing the approaches where possible.

How important is proper dosing for subcutaneous and sublingual allergy immunotherapy?

Background: Results of surveys report that allergists use a wide range of doses for allergy immunotherapy; however, results of randomized, double-blind, placebo controlled studies suggest that the range of the optimum effective dosing is relatively narrow. Objective: To review studies that established effective or less than fully effective doses for allergy immunotherapy. Methods: Studies were reviewed that established effective and ineffective subcutaneous and sublingual immunotherapy doses. Only those studies that expressed dosing in terms of the content of a major allergen in the maintenance doses were included in defining effective and ineffective doses. Results: Studies were identified that showed effective doses for subcutaneous injection, established in randomized, double-blind, placebo controlled trials, for short ragweed, timothy grass, house-dust mites, cat and dog dander, birch, and Alternaria. For short ragweed, timothy grass, Dermatophagoides pteronyssinus, and cat and dog dander, less-effective doses were determined, along with effective doses; the less-effective doses were only one-fifth to one-tenth less in allergen content than were the effective doses. Effective doses of cockroach and all fungal extracts except Alternaria have not been established. Information is available on the mean major allergen content of U.S. standardized and a few nonstandardized extracts, which allows the information on effective and ineffective dosing to be used in prescribing subcutaneous allergy immunotherapy. With sublingual allergy immunotherapy, all the approved tablets had multidose studies that determined the optimal dose. For the U.S. liquid extracts, to my knowledge, there are no studies to define effective doses except for ragweed. Conclusions: Although a wide range of doses are prescribed by U.S. allergists, analysis of available data suggests that effective doses fall within a narrow range and that use of doses one-fifth or one-tenth of the effective doses may sacrifice most or all of the potential efficacy of the treatment.