Mind the gaps: Clinical trial concepts to address unanswered questions in aeroallergen immunotherapy-An NIAID/AHRQ Workshop

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.

Cost-effectiveness Analysis of Inferior Turbinate Reduction and Immunotherapy in Allergic Rhinitis

BACKGROUND

Allergic rhinitis (AR) is a common condition that is frequently associated with atopic inferior turbinate hypertrophy (ITH) resulting in nasal obstruction. Current guidelines support the use of subcutaneous allergen immunotherapy (SCIT) when patients fail pharmacologic management. However, there is a lack of consensus regarding the role of inferior turbinate reduction (ITR), a treatment that we hypothesize is cost-effective compared with other available treatments.

METHODS

We conducted a cost-effectiveness analysis comparing the following treatment combinations over a 5-year time horizon for AR patients presenting with atopic nasal obstruction who fail initial pharmacotherapy: (1) continued pharmacotherapy alone, (2) allergy testing and SCIT, (3) allergy testing and SCIT and then ITR for SCIT nonresponders, and (4) ITR and then allergy testing and SCIT for ITR nonresponders. Results were reported as incremental cost-effectiveness ratios (ICERs).

RESULTS

For patients who fail initial pharmacotherapy, prioritizing ITR, either by microdebrider-assisting submucous resection or radiofrequency ablation, before SCIT was the most cost-effective strategy. Probabilistic sensitivity analysis demonstrated that prioritizing ITR before SCIT was the most cost-effective option in 95.4% of scenarios. ITR remained cost-effective even with the addition of concurrent septoplasty.

CONCLUSION

For many AR patients who present with nasal obstruction secondary to atopic inferior turbinate hypertrophy that is persistent despite pharmacotherapy, ITR is a cost-effective treatment that should be considered prior to immunotherapy.

LEVEL OF EVIDENCE

NA - Laryngoscope, 2023 Laryngoscope, 134:1572-1580, 2024.

Efficacy and safety of subcutaneous immunotherapy in asthmatic children allergic to house dust mite: a meta-analysis and systematic review

Background

Subcutaneous immunotherapy (SCIT) has been proved to be effective and safe in adult asthma. But it is still controversial in children.

Object

To evaluate the efficacy and safety of SCIT in asthmatic children with allergy to house dust mite.

Method

We searched the databases of Cochrane Library, EMBASE and MEDLINE (from 1 January 1990 to 1 December 2022). Two reviewers independently screened studies, extracted data and critically appraised the risk of bias. We used the Revman 5 to synthesize the effect sizes.

Results

We finally selected 38 eligible studies including 21 randomized controlled trials to evaluate the efficacy and safety of SCIT and 17 observational studies to assess the safety. The results revealed that short-term asthma symptom scores were declined with a standardized mean difference (SMD) of -1.19 (95% CI: -1.87, -0.50) in 12 researches with high heterogeneity. Short-term asthma medication scores were decreased with SMD -1.04 (95% CI: -1.54, -0.54) in 12 heterogeneous researches. One study showed no significant reduction in combined symptom and medication scores without providing details. No studies we reviewed reported long-term efficacy. SCIT resulted in an obviously increased risk of adverse reactions compared with placebo. For secondary outcomes, SCIT improved life quality and reduced the numbers of annual asthma attacks and allergen-specific airway hyperreactivity, but without significant improvement in pulmonary function, asthma control or hospitalization.

Conclusions

SCIT can reduce the short-term symptom scores and medication scores regardless of different treatment duration or mono/polysensitization, but with an increased incidence of local and systemic adverse effects. Further studies on pediatric asthma are needed to evaluate the long-term efficacy, and clarify the effectiveness of SCIT in specific population using mix allergen extracts or with severe asthma. Overall, it is recommended for children with mild-moderate HDM-driven allergic asthma.

INMUNOCAT study: The impact of molecular diagnosis on immunotherapy prescription in pollen polysensitized patients from Catalonia

BACKGROUND

Recognition of specific allergens triggering immune response is key for the appropriate prescription of allergen-specific immunotherapy (SIT). This study aimed at evaluating the impact of using the commercially available microarray ImmunoCAP^TM ISAC 112 (Thermo Fisher Scientific) on the etiological diagnosis and SIT prescription compared to the conventional diagnostic methods in patients with allergic rhinitis/rhinoconjunctivitis and/or asthma.

METHODS

300 patients with respiratory allergic disease, sensitized to three or more pollen aeroallergens from different species, as assessed by a skin prick test (SPT) and specific IgE assays (sIgE), were included in this multicentric, prospective observational study. SPT and a blood test were performed to all patients. Total serum IgE and sIgE (ImmunoCAPTM) for allergens found positive in the SPT and sIgE allergen components (ImmunoCAPTM ISAC 112) were measured.

RESULTS

According to SPT results, the most prevalent pollen sensitizers in our population were Olea europaea followed by grass, Platanus acerifolia and Parietaria judaica. The molecular diagnosis (MD) revealed Ole e 1 as the most prevalent pollen sensitizer, followed by Cup a 1, Phl p 1, Cyn d 1, Par j 2, Pla a 1, 2, and 3 and Phl p 5. Immunotherapy prescription changed, due to MD testing, in 51% of the cases, with an increase of prescription of SIT from 39% to 65%.

CONCLUSION

The identification of the allergen eliciting the respiratory disease is essential for a correct immunotherapy prescription. The advances in allergen characterization using methods, such as the commercial microarray ImmunoCAP^TM ISAC 112, can help clinicians to improve SIT prescription.

Subcutaneous allergen immunotherapy in the treatment of allergic respiratory disease

Subcutaneous immunotherapy is recognized as a cornerstone in the management of allergic respiratory disease in patients who are properly characterized with allergy and with allergic rhinoconjunctivis and/or well-controlled asthma, and who are willing to adhere to the rigorous treatment program. A key tenet is that it affords the opportunity to effect long-term clinical remission through its disease-modifying properties. Furthermore, it has the potential to prevent the progression of allergic rhinitis to asthma, prevent new allergen sensitivities, and improve a patient's quality of life.

Preventive Effect of Allergen Immunotherapy on Asthma and New Sensitizations

Allergen immunotherapy (AIT) is a disease-modifying treatment for some IgE-mediated allergic diseases with the potential to have important preventive effects. Children with allergic rhinitis have a high risk of developing asthma, and treating allergic rhinitis with AIT may interfere with disease progression and prevent onset of asthma. Although the evidence is limited due to relatively few and heterogeneous studies, data nevertheless suggest that AIT has a preventive effect on development of asthma especially in children with rhinitis due to grass pollen allergy. AIT may also affect the development of new sensitizations. Both the degree of sensitization and the specific sensitization pattern may influence future disease severity and development of comorbidities. Hitherto, the indication for AIT for prevention of development of asthma in grass/birch pollen allergic children has been the same as for treatment of allergic rhinitis. Probably, AIT should be applied in the early stage of the allergic disease to have the greatest preventive effect on disease progression. Consequently, in the future, the potential preventive effects should influence the timing of initiating AIT. The window of opportunity to prevent asthma may primarily exist in young children with mild symptoms and a low degree of sensitization.

Compromising between European and US allergen immunotherapy schools: Discussions from GUIMIT, the Mexican immunotherapy guidelines

Background

Allergen immunotherapy (AIT) has a longstanding history and still remains the only disease-changing treatment for allergic rhinitis and asthma. Over the years 2 different schools have developed their strategies: the United States (US) and the European. Allergen extracts available in these regions are adapted to local practice. In other parts of the world, extracts from both regions and local ones are commercialized, as in Mexico. Here, local experts developed a national AIT guideline (GUIMIT 2019) searching for compromises between both schools.

Methods

Using ADAPTE methodology for transculturizing guidelines and AGREE-II for evaluating guideline quality, GUIMIT selected 3 high-quality Main Reference Guidelines (MRGs): the European Academy of Allergy, Asthma and Immunology (EAACI) guideines, the S2k guideline of various German-speaking medical societies (2014), and the US Practice Parameters on Allergen Immunotherapy 2011. We formulated clinical questions and based responses on the fused evidence available in the MRGs, combined with local possibilities, patient's preference, and costs. We came across several issues on which the MRGs disagreed. These are presented here along with arguments of GUIMIT members to resolve them. GUIMIT (for a complete English version, Supplementary data) concluded the following.

Results

Related to the diagnosis of IgE-mediated respiratory allergy, apart from skin prick testing complementary tests (challenges, in vitro testing and molecular such as species-specific allergens) might be useful in selected cases to inform AIT composition. AIT is indicated in allergic rhinitis and suggested in allergic asthma (once controlled) and IgE-mediated atopic dermatitis. Concerning the correct subcutaneous AIT dose for compounding vials according to the US school: dosing tables and formula are given; up to 4 non-related allergens can be mixed, refraining from mixing high with low protease extracts. When using European extracts: the manufacturer's indications should be followed; in multi-allergic patients 2 simultaneous injections can be given (100% consensus); mixing is discouraged. In Mexico only allergoid tablets are available; based on doses used in all sublingual immunotherapy (SLIT) publications referenced in MRGs, GUIMIT suggests a probable effective dose related to subcutaneous immunotherapy (SCIT) might be: 50-200% of the monthly SCIT dose given daily, maximum mixing 4 allergens. Also, a table with practical suggestions on non-evidence-existing issues, developed with a simplified Delphi method, is added. Finally, dissemination and implementation of guidelines is briefly discussed, explaining how we used online tools for this in Mexico.

Conclusions

Countries where European and American AIT extracts are available should adjust AIT according to which school is followed.

Clinical Practice of Allergen Immunotherapy for Allergic Rhinoconjunctivitis and Asthma: An Expert Panel Report

Allergen immunotherapy (AIT) reduces symptoms and medication use associated with allergic rhinitis with or without conjunctivitis and allergic asthma. Although several AIT guidelines exist, there remain unanswered questions about AIT that are relevant to everyday practice. Our objective was to prepare an evidence-based overview addressing the practical aspects of AIT in clinical practice based on published evidence and the experience of international experts in the field. Topics covered include interpretation and translation of clinical trial data into everyday clinical practice (eg, allergen doses and treatment duration), assessment of risk and treatment of local and systemic allergic reactions, recommendations for improvement of AIT guidelines, and identification of appropriate data for seeking regulatory approval, to name a few. Many informational gaps in AIT practice need further evaluation as products and practices evolve.

ARIA 2019, Allerjik Rinite Tedavi Yaklaşımı-Türkiye

Gerçek yaşamda, çevresel maruziyetlerin de etkilediği rinit ve astım mültimorbidite durumlarında, dijitalleşmiş ve kişiye odaklanan tedaviler için bütünleştirilmiş tedavi yollarının değerlendirilmesi önerilmektedir. Gerçek yaşamdaki bu durum mültisipliner bir yaklaşımla basamaklandırılıp, rehberilerinde ülkelerdeki gereksinimlere göre değiştilmesini gerektirebilir. Allerjik rinitte hem farmakoterapi hem immünoterapi açısından acil yeni yaklaşımlara ihtiyaç olduğu görülmüştür. 3. Aralık 2018'de Paris'te bir toplantı yapılmış ve iki ayrı belge hazırlanmıştır. Bu yayında bunlara ait bir özet sunulup, ülkeye ve sağlık sistemine uygun kullanımın çerçevesi oluşturulmak istenmiştir.

ARIA guideline 2019: treatment of allergic rhinitis in the German health system

Background: The number of patients affected by allergies is increasing worldwide. The resulting allergic diseases are leading to significant costs for health care and social systems. Integrated care pathways are needed to enable comprehensive care within the national health systems. The ARIA (Allergic Rhinitis and its Impact on Asthma) initiative develops internationally applicable guidelines for allergic respiratory diseases. Methods: ARIA serves to improve the care of patients with allergies and chronic respiratory diseases. In collaboration with other international initiatives, national associations and patient organizations in the field of allergies and respiratory diseases, real-life integrated care pathways have been developed for a digitally assisted, integrative, individualized treatment of allergic rhinitis (AR) with comorbid asthma. In the present work, these integrated care pathways have been adapted to the German situation and health system. Results: The present ICP (integrated care pathway) guideline covers key areas of the care of AR patients with and without asthma. It includes the views of patients and other healthcare providers. Discussion: A comprehensive ICP guideline can reflect real-life care better than traditional guideline models.

2019 ARIA Care pathways for allergen immunotherapy

Allergen immunotherapy (AIT) is a proven therapeutic option for the treatment of allergic rhinitis and/or asthma. Many guidelines or national practice guidelines have been produced but the evidence-based method varies, many are complex and none propose care pathways. This paper reviews care pathways for AIT using strict criteria and provides simple recommendations that can be used by all stakeholders including healthcare professionals. The decision to prescribe AIT for the patient should be individualized and based on the relevance of the allergens, the persistence of symptoms despite appropriate medications according to guidelines as well as the availability of good-quality and efficacious extracts. Allergen extracts cannot be regarded as generics. Immunotherapy is selected by specialists for stratified patients. There are no currently available validated biomarkers that can predict AIT success. In adolescents and adults, AIT should be reserved for patients with moderate/severe rhinitis or for those with moderate asthma who, despite appropriate pharmacotherapy and adherence, continue to exhibit exacerbations that appear to be related to allergen exposure, except in some specific cases. Immunotherapy may be even more advantageous in patients with multimorbidity. In children, AIT may prevent asthma onset in patients with rhinitis. mHealth tools are promising for the stratification and follow-up of patients.