Randomized controlled trial of a ragweed allergy immunotherapy tablet in North American and European adults. J Allergy Clin Immunol. 2013;131:1342-9.e6. [PMID: 23622121 DOI: 10.1016/j.jaci.2013.03.019]

Shared decision making for the allergist

OBJECTIVE

Shared decision making (SDM) is becoming more commonly appreciated and used in medical practice as a way to empower patients who are facing treatment preference-sensitive conditions, such as allergic rhinitis, atopic dermatitis, food allergy, and persistent asthma. The purpose of this review is to educate the allergy health care provider about how SDM works and provide practical advice and allergist-specific SDM resources.

DATA SOURCES

PubMed and online patient decision aid resources.

STUDY SELECTIONS

Studies and reviews relevant to SDM and patient decision aids relevant to the allergy health care provider were selected for discussion.

RESULTS

There are ethical, practical, economic, and psychological imperatives for the implementation of quality SDM, particularly for chronic diseases. Many benefits and barriers of SDM have been identified and models have been developed to encourage implementation of quality SDM. For the allergy health care provider, SDM for asthma has been shown to improve adherence, outcomes, and patient satisfaction with care. Patient decision aids are useful tools for SDM and have recently been developed for allergen immunotherapy, severe asthma, and atopic dermatitis.

CONCLUSION

Effective SDM has been shown to improve adherence and lead to better outcomes. SDM should be universally implemented as a key component of patient-centered health care. Allergy health care providers should work with their patients to reach treatment decisions that align with their values and preferences.

Recent advances in allergic rhinitis

Allergic rhinitis affects 20 to 30% of adults in both the United States and Europe and perhaps a somewhat higher percentage of children. In addition to nasal and ocular symptoms directly related to the allergic process, interference of these symptoms with sleep leads to daytime sleepiness and impaired quality of life. Patients miss work because of symptoms but an even greater problem is interference with work productivity, or presenteeism, which has been reported to be the biggest contributor to the total economic cost of allergic rhinitis. There has been increasing awareness that many patients with either seasonal or perennial symptoms but negative skin and in vitro tests for allergen sensitivity have local nasal allergy, diagnosable by the presence of allergen-specific IgE in their nasal secretions or a positive nasal allergen challenge or both. The pharmaceutical management of allergic rhinitis rests on symptomatic treatment with antihistamines that perhaps are more effectively administered intranasally than orally and intranasal corticosteroids. Allergen immunotherapy is very effective, even for local allergic rhinitis, and the shortcomings of subcutaneous immunotherapy of inconvenience and safety are reduced by the introduction of sublingual immunotherapy (SLIT). Use of the latter is currently somewhat limited by the lack of appropriate dosing information for SLIT liquids and the limited number of allergens for which SLIT tablets are available.

New approaches to allergen immunotherapy

OBJECTIVE

New insights into mechanisms should enable strategic improvement of allergen immunotherapy, aiming to make it safer, faster, more effective, and able to induce long-term tolerance. We review novel approaches with potential to translate into clinical use.

DATA SOURCES

Database searches were conducted in PubMed, Scopus, and Google Scholar.

STUDY SELECTIONS

Search terms were based on current and novel approaches in immunotherapy. Literature was selected primarily from recent randomized double-blinded placebo-controlled trials and meta-analyses.

RESULTS

Alum, microcrystalline tyrosine, and calcium phosphate are adjuvants in current use. Toll-like receptor-4 agonists combined with allergen have potential to shorten duration of treatment. Other novel adjuvants, nanoparticles, and virus-like particles in combination with allergen have shown early promise. Omalizumab lessens systemic side effects but does not improve efficacy. Intralymphatic immunotherapy for aeroallergens, epicutaneous immunotherapy for food allergens, and use of modified allergens (allergoids), recombinant allergens (and hypoallergenic variants), and T- and B-cell peptide approaches have shown evidence of efficacy and permitted shortened courses but have only rarely been compared with conventional extracts.

CONCLUSION

Novel routes of immunotherapy, use of modified allergens, and combination of allergens with immunostimulatory adjuvants or immune modifiers have been developed to augment downregulation of T-helper cell type 2 immunity and/or induce "protective" blocking antibodies. Although these strategies have permitted shortened courses, confirmatory phase 3 trials are required to confirm efficacy and safety and head-to-head trials are required for comparative efficacy. Currently, subcutaneous and sublingual immunotherapies using in-house standardized crude extracts remain the only approaches proved to induce long-term tolerance.

The global development and clinical efficacy of sublingual tablet immunotherapy for allergic diseases

Allergy immunotherapy (AIT) is a treatment option for respiratory allergy that is complementary to pharmacotherapy, with a distinct mechanism of action. Alternative methods to subcutaneous administration of AIT that enable patients to safely self-administer AIT is considered an unmet clinical need. The sublingual immunotherapy tablet (SLIT-tablet) is an orally disintegrating pharmaceutical formulation (oral lyophilisate) containing standardized allergens. SLIT-tablets have been developed for sublingual immunotherapy (SLIT) of cedar-pollen, grass-pollen, ragweed-pollen, tree-pollen, and house dust mite allergies. It is a once-daily tablet treatment to be self-administered after the first dose has been provided under the supervision of a physician with experience in the diagnosis and treatment of allergic diseases. Once the first dose is adequately tolerated, subsequent doses may be self-administered. SLIT-tablets have proven efficacy for allergic rhinitis (AR) with and without conjunctivitis (C) and allergic asthma (AA) in adults, children, and poly-sensitized allergic patients. Meta-analyses indicate that SLIT-tablets have superior or similar efficacy compared with anti-allergic pharmacotherapies for seasonal AR and superior efficacy for perennial AR. SLIT-tablets have also demonstrated clinically relevant improvements of asthma, with significant reductions in the following: daily inhaled corticosteroid use, risk of asthma exacerbations, and asthma symptoms. SLIT-tablets are generally well tolerated, with a low risk of systemic allergic reactions. The most common treatment-related adverse events are mild-moderate oral reactions. Current evidence supports SLIT-tablets to be considered as an alternative or add-on treatment to pharmacotherapy for AR/C and asthma. Future SLIT developments may include early intervention to prevent the development or progression of allergic disease in children.

Adjuvants for allergy immunotherapeutics

Allergic diseases are reaching epidemic proportions in developed countries. In particular, food allergy is increasing in prevalence and severity, thus becoming an important socioeconomic burden. Numerous cell types and cell populations, which form an intricate and balanced network, are involved in an immune response. This balance is occasionally disturbed, leading to the onset of different diseases, such as allergic diseases. Antihistamines and corticosteroids provide some degree of relief from the symptoms of allergic conditions. However, the only treatment that can revert the disease is immunotherapy. Nevertheless, specific immunotherapy has at least 2 major drawbacks: it is time-consuming, and it can produce local and even systemic allergic side effects. Immunotherapy's potential goes beyond our current knowledge of the immune response; nevertheless, we can still design strategies to reach a safer immune modulation for treating allergies. This review deals with the use of adjuvants to reduce the undesirable side effects associated with specific allergen immunotherapy. For example, nanoparticles used as immunoadjuvants are offering promising results in preclinical assays.

Ragweed Pollen Allergy: Burden, Characteristics, and Management of an Imported Allergen Source in Europe

Ambrosia artemisiifolia, also known as common or short ragweed, is an invasive annual flowering herbaceous plant that has its origin in North America. Nowadays, ragweed can be found in many areas worldwide. Ragweed pollen is known for its high potential to cause type I allergic reactions in late summer and autumn and represents a major health problem in America and several countries in Europe. Climate change and urbanization, as well as long distance transport capacity, enhance the spread of ragweed pollen. Therefore ragweed is becoming domestic in non-invaded areas which in turn will increase the sensitization rate. So far 11 ragweed allergens have been described and, according to IgE reactivity, Amb a 1 and Amb a 11 seem to be major allergens. Sensitization rates of the other allergens vary between 10 and 50%. Most of the allergens have already been recombinantly produced, but most of them have not been characterized regarding their allergenic activity, therefore no conclusion on the clinical relevance of all the allergens can be made, which is important and necessary for an accurate diagnosis. Pharmacotherapy is the most common treatment for ragweed pollen allergy but fails to impact on the course of allergy. Allergen-specific immunotherapy (AIT) is the only causative and disease-modifying treatment of allergy with long-lasting effects, but currently it is based on the administration of ragweed pollen extract or Amb a 1 only. In order to improve ragweed pollen AIT, new strategies are required with higher efficacy and safety.

Ragweed sublingual tablet immunotherapy: part II - practical considerations and pertinent issues

Sublingual allergen immunotherapy (SLIT) has been demonstrated to be both efficacious and safe for the treatment of respiratory allergies such as allergic rhinoconjunctivitis or allergic asthma. Based on the clinical documentation of SLIT ragweed tablets, they have gained marketing authorization in the USA by the US FDA in 2014 for adult patients. Following clinical data from (pivotal) multicenter Phase II and III trials as performed in the USA and Canada and real life experience after registration in 2014, SLIT ragweed tablets can be recommended as efficacious and safe treatment option with disease modifying potential when adequately indicated and performed. Therefore, several practical issues should be considered for treating ragweed allergic patients with these tablets. This second part of a thorough review on ragweed SLIT tablets addresses important clinical questions which should be taken into account by the subscribing practitioner before initiation and during the treatment.

SLIT's Prevention of the Allergic March

PURPOSE OF REVIEW

The progression of atopic disorders from atopic dermatitis in infants to allergic rhinitis and asthma in children, adolescents, and adults defines the allergy march. Allergen immunotherapy is the only causal treatment altering the immunological mechanism underlying the allergic diseases. The sublingual administration route is more acceptable than the subcutaneous one in pediatric age.

RECENT FINDINGS

Several studies show the efficacy and safety profile of sublingual immunotherapy (SLIT) for the treatment of respiratory allergy diseases, but few data are available on its effect of primary and secondary prevention of allergic disease. The purpose of this manuscript is to review the latest studies addressing the effect of SLIT on the development of new sensitizations in not sensitized or already sensitized patients and progression of the allergy march.

Ragweed sublingual tablet immunotherapy: part I - evidence-based clinical efficacy and safety

Sublingual tablet immunotherapy provides an attractive alternative approach to allergen immunotherapy, as the allergen is administered as a rapidly dissolving sublingual tablet. Part I of this two-part series on the ragweed sublingual tablet describes the dose-ranging clinical work, the safety studies and the clinical outcomes from the pivotal trials which provide clear evidence for statistically significant and clinically meaningful benefit in the treatment of patients suffering from ragweed-induced seasonal allergic rhinitis-conjunctivitis with or without milder asthma. The robust results observed in the clinical trials performed with the ragweed sublingual tablet are defined by the quality of their study design, their use of a standardized allergen extract, their consistent reproducibility in demonstrating therapeutic efficacy and their properly quantified and graded safety data.

EAACI Guidelines on Allergen Immunotherapy: Allergic rhinoconjunctivitis

Allergic rhinoconjunctivitis (AR) is an allergic disorder of the nose and eyes affecting about a fifth of the general population. Symptoms of AR can be controlled with allergen avoidance measures and pharmacotherapy. However, many patients continue to have ongoing symptoms and an impaired quality of life; pharmacotherapy may also induce some side-effects. Allergen immunotherapy (AIT) represents the only currently available treatment that targets the underlying pathophysiology, and it may have a disease-modifying effect. Either the subcutaneous (SCIT) or sublingual (SLIT) routes may be used. This Guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on AIT for AR and is part of the EAACI presidential project "EAACI Guidelines on Allergen Immunotherapy." It aims to provide evidence-based clinical recommendations and has been informed by a formal systematic review and meta-analysis. Its generation has followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included involvement of the full range of stakeholders. In general, broad evidence for the clinical efficacy of AIT for AR exists but a product-specific evaluation of evidence is recommended. In general, SCIT and SLIT are recommended for both seasonal and perennial AR for its short-term benefit. The strongest evidence for long-term benefit is documented for grass AIT (especially for the grass tablets) where long-term benefit is seen. To achieve long-term efficacy, it is recommended that a minimum of 3 years of therapy is used. Many gaps in the evidence base exist, particularly around long-term benefit and use in children.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Sublingual Immunotherapy Dosing Regimens: What Is Ideal?

Sublingual immunotherapy (SLIT) is a treatment for allergic respiratory diseases that has demonstrated efficacy and safety. Several formulations of SLIT are now available worldwide for treatment of allergic rhinitis (AR). Grass tablets containing 15 to 25 μg of group 5 major allergen reduced combined AR symptoms and medication use by 23% to 41% in 3 treatment years and 2 follow-up years. Ragweed pollen tablets (12 μg of Ambrosia artemisiifolia 1) and liquid extracts (50 μg of Ambrosia artemisiifolia 1) reduced combined AR symptoms and medication use by 26% and 43%, respectively. House dust mite tablets containing 300 index of reactivity (16 μg of Dermatophagoides pteronyssinus 1 and 68 μg of Dermatophagoides farinae 1) reduced AR symptoms by 17.9% and 17.0% in 1 treatment year and 1 follow-up year, respectively. A different house dust mite tablet (12 standardized quality house dust mite) was able to reduce the risk of asthma exacerbation compared with placebo (hazard ratio, 0.69; 95% CI, 0.50-0.96). Most adverse events were local and mild to moderate in severity. For SLIT products reviewed herein, effective doses range from 1.12 to 84 μg of major allergen(s). However, allergen content is not uniformly standardized, can be expressed in arbitrary or proprietary units (depending on the manufacturer), and assays for determination of allergen content are highly variable. Thus, results from one study of a given product cannot be extrapolated to other products. Despite these limitations, this Clinical Management Review aims to provide practitioners with relevant information on the dosing of selected SLIT formulations in the treatment of allergic respiratory disease.

Allergen immunotherapy for allergic rhinoconjunctivitis: A systematic review and meta-analysis

BACKGROUND

The European Academy of Allergy and Clinical Immunology (EAACI) is in the process of developing Guidelines on Allergen Immunotherapy (AIT) for Allergic Rhinoconjunctivitis. To inform the development of clinical recommendations, we undertook a systematic review to assess the effectiveness, cost-effectiveness, and safety of AIT in the management of allergic rhinoconjunctivitis.

METHODS

We searched nine international biomedical databases for published, in-progress, and unpublished evidence. Studies were independently screened by two reviewers against predefined eligibility criteria and critically appraised using established instruments. Our primary outcomes of interest were symptom, medication, and combined symptom and medication scores. Secondary outcomes of interest included cost-effectiveness and safety. Data were descriptively summarized and then quantitatively synthesized using random-effects meta-analyses.

RESULTS

We identified 5960 studies of which 160 studies satisfied our eligibility criteria. There was a substantial body of evidence demonstrating significant reductions in standardized mean differences (SMD) of symptom (SMD -0.53, 95% CI -0.63, -0.42), medication (SMD -0.37, 95% CI -0.49, -0.26), and combined symptom and medication (SMD -0.49, 95% CI -0.69, -0.30) scores while on treatment that were robust to prespecified sensitivity analyses. There was in comparison a more modest body of evidence on effectiveness post-discontinuation of AIT, suggesting a benefit in relation to symptom scores.

CONCLUSIONS

AIT is effective in improving symptom, medication, and combined symptom and medication scores in patients with allergic rhinoconjunctivitis while on treatment, and there is some evidence suggesting that these benefits are maintained in relation to symptom scores after discontinuation of therapy.

The SQ House Dust Mite SLIT-Tablet Is Well Tolerated in Patients with House Dust Mite Respiratory Allergic Disease

BACKGROUND

The SQ house dust mite (HDM) SLIT-tablet (ALK, Denmark) addresses the underlying cause of HDM respiratory allergic disease, and a clinical effect has been demonstrated for both HDM allergic rhinitis and allergic asthma. Here, we present pooled safety data from an adult population with HDM respiratory allergy, with particular focus on the impact of asthma on the SQ HDM SLIT-tablet tolerability profile.

METHODS

Safety data from 2 randomised double-blind, placebo-controlled clinical trials were included: MT-04: 834 adults with HDM allergic asthma not well controlled by inhaled corticosteroids and with HDM allergic rhinitis, and MT-06: 992 adults with moderate-to-severe HDM allergic rhinitis despite the use of allergy pharmacotherapy and with or without asthma.

RESULTS

The proportion of subjects experiencing adverse events (AEs) was greater in the active treatment group (12 SQ-HDM; 73% of subjects) compared to placebo (53%). The most common treatment-related AEs were local allergic reactions. No AEs were reported as systemic allergic reactions. Regardless of asthma status, most AEs were mild or moderate (>97% of AEs) and the frequency of serious AEs was low. Subgroup analysis revealed no statistically significant difference in the risk of experiencing moderate or severe treatment-related AEs for subjects with asthma compared to subjects without asthma (p = 0.88). In addition, subjects with partly controlled or uncontrolled asthma were no more likely to experience moderate or severe treatment-related AEs than subjects with controlled asthma (p = 0.42).

CONCLUSION

The SQ HDM SLIT-tablet is well tolerated, and the safety profile was comparable for subjects with HDM respiratory allergic disease irrespective of asthma status.

An update on ocular allergy

PURPOSE OF REVIEW

The update reviews prevalence, classification, cause, and treatment options for allergic eye disease.

RECENT FINDINGS

The incidence of allergic eye disease is underreported but may affect almost all patients with allergic rhinitis. Increased rates of oculonasal symptoms have been reported in the United States resulting in significant economic expenditures. The spectrum of allergic conjunctivitis and its differential considerations include seasonal and perennial conjunctivitis, vernal and atopic keratoconjunctivitis, and giant papillary conjunctivitis. Patients with allergic conjunctivitis have classic immunoglobulin E-mediated pathophysiology and treatments directed at allergen avoidance, traditional pharmacotherapy with oral antihistamines, topical dual-acting antihistamine/mast cell stabilizer agents, and treatment of tear film dysfunction are first-line management strategies. Immunotherapy is an effective treatment option and refractory cases may require ophthalmology comanagement for consideration of topical ester-based corticosteroid therapy and consideration of topical immunomodulators.

SUMMARY

Ocular allergy involving specific modifiable and treatable environmental sensitizations is common and often underrecognized. It can impair quality of life to varying degrees. Some cases are quite refractory to management and may require multidisciplinary coordination of care between allergy and ophthalmology specialists. Understanding classification, triggers, and treatment options is important in designing the most appropriate patient-tailored management plans.

Differences and similarities between sublingual immunotherapy of allergy and oral tolerance

Allergen immunotherapy is the only treatment altering the natural course of IgE-mediated allergies. Whereas the subcutaneous route for immunotherapy (SCIT) has been historically considered as a reference, we discuss herein the relative advantages of the sublingual and oral routes as alternatives to SCIT in order to elicit allergen-specific tolerance. The buccal and gut immune systems are similarly organized to favor immune tolerance to antigens/allergens, due to the presence of tolerogenic dendritic cells and macrophages promoting the differentiation of CD4⁺ regulatory T cells. Sublingual immunotherapy (SLIT) is now established as a valid treatment option, with clinical efficacy demonstrated in allergic rhinoconjunctivitis (to either grass, tree, weed pollens or mite allergens) and encouraging results obtained in the management of mild/moderate allergic asthma. While still exploratory, oral immunotherapy (OIT) has shown promising results in the desensitization of patients with food allergies. We review at both biological and clinical levels the perspectives currently pursued for those two mucosal routes.

Allergen Immunotherapy Clinical Trial Outcomes and Design: Working Toward Harmonization of Methods and Principles

Progress has been made in the harmonization of efficacy and safety outcome measures for allergen immunotherapy (AIT) trials, but unresolved issues still remain. Furthermore, there are discrepancies in recommendations from professional medical societies and regulatory agencies regarding requirements for AIT trials. In this article, we reviewed published recommendations and current data from recent clinical trials, as well as the criteria applied by regulatory authorities for approval of AIT products, to provide updated considerations for conducting phase 3 AIT trials. Topics discussed include analysis of outcomes and trial designs for pediatric and asthma indications, as well as trial designs for perennial allergic rhinoconjunctivitis. In addition, the need for harmonization of safety reporting is emphasized. Considerations presented in this article may further effort to find common ground among professional medical societies and government agencies in developing future recommendations for AIT trial design.

Specific immunotherapy in allergic rhinitis

Allergic rhinitis is a common condition, with significant impact on quality of life depending on severity and quality of control. Allergen-specific immunotherapy (allergen-SIT) is the only known treatment able to alter the natural course of allergic rhinitis. Although well known to allergologists, it has yet to be fully adopted by the ENT community. This review, based on the most recent meta-analyses and clinical studies, shows that SIT significantly reduces symptoms and medication requirements (nasal corticosteroids, H1-antihistamines) in allergic rhinitis. It can reduce the risk of progression to asthma and, if initiated early enough, of developing new sensitizations. Immunobiological analysis shows an altered inflammatory profile following SIT, with immune tolerance involving T-regulatory lymphocyte induction and IgG production. Sublingual SIT with drops is as effective as subcutaneous SIT and is simpler to use, with less anaphylactic risk. Standardization of trial protocols in terms of treatment response assessment and side effect grading is recommended to improve comparative studies. Sublingual SIT with tablets has recently been introduced, providing a good opportunity for ENT practitioners to adopt the SIT approach in rhinitis triggered by allergy to pollens and, in the near future, to house dust mites.

Allergen-Specific Immunotherapy for Respiratory Allergy in Children: Unmet Needs and Future Goals

Allergen-specific immunotherapy for the treatment of respiratory allergy is currently supported, at least for selected products, by evidence of efficacy and effectiveness in the pediatric age. However, unmet needs remain in terms of administration regimens, duration of treatment, biomarkers, and preventive effects. These knowledge gaps need to be urgently addressed to provide pediatricians and pediatric allergists with more definite recommendations for the use of this treatment in children. This article critically appraises the most relevant debated issues on allergen-specific immunotherapy in children, focusing on allergen standardization procedures, heterogeneity of clinical studies, and regulatory and pharmacoeconomic aspects.

Allergic conjunctivitis in Asia

Allergic conjunctivitis (AC), which may be acute or chronic, is associated with rhinitis in 30%-70% of affected individuals, hence the term allergic rhinoconjunctivitis (AR/C). Seasonal and perennial AC is generally milder than the more chronic and persistent atopic and vernal keratoconjunctivitis. Natural allergens like house dust mites (HDM), temperate and subtropical grass and tree pollen are important triggers that drive allergic inflammation in AC in the Asia-Pacific region. Climate change, environmental tobacco smoke, pollutants derived from fuel combustion, Asian dust storms originating from central/north Asia and phthalates may also exacerbate AR/C. The Allergies in Asia Pacific study and International Study of Asthma and Allergies in Childhood provide epidemiological data on regional differences in AR/C within the region. AC significantly impacts the quality of life of both children and adults, and these can be measured by validated quality of life questionnaires on AR/C. Management guidelines for AC involve a stepped approach depending on the severity of disease, similar to that for allergic rhinitis and asthma. Topical calcineurin inhibitors are effective in certain types of persistent AC, and sublingual immunotherapy is emerging as an effective treatment option in AR/C to grass pollen and HDM. Translational research predominantly from Japan and Korea involving animal models are important for the potential development of targeted pharmacotherapies for AC.

Sublingual immunotherapy tablets as a disease-modifying add-on treatment option to pharmacotherapy for allergic rhinitis and asthma

Allergic rhinitis (AR) with or without conjunctivitis (AR/C) is associated with a significant health and economic burden, and is often accompanied by asthma. Pharmacotherapies are the mainstay treatment options for AR and asthma, but guidelines also recommend allergy immunotherapy (AIT). Unlike pharmacotherapies, AIT has the ability to modify the underlying immunologic mechanisms of AR and asthma with the potential for long-term benefits after treatment is discontinued. Immunotherapy may also prevent progression of AR/C to asthma. Sublingual immunotherapy (SLIT)-tablets are a self-administered alternative to subcutaneous immunotherapy that provide the benefits of AIT without the cost and inconvenience of frequent office visits or the discomfort of injections. SLIT-tablets are also an option that can be utilized by primary care clinicians. Pharmacotherapies are generally effective in mild disease although a number of patients remain uncontrolled. SLIT-tablets have proven efficacy for AR in adults, children, and poly-sensitized allergic patients. Indirect comparisons indicate that SLIT-tablets have superior or comparable efficacy compared with traditional pharmacotherapies for seasonal AR, and superior efficacy for perennial AR. House dust mite (HDM) SLIT-tablets have also demonstrated clinically relevant benefits for asthma, with significant observed reductions in daily inhaled corticosteroid use, risk of asthma exacerbations, and asthma symptoms. SLIT-tablets are well tolerated, with minimal risk of systemic allergic reactions. The most common treatment-related adverse events are oral site reactions such as oral pruritus and throat irritation. Based on the favorable efficacy and safety profile, as well as the convenience of at-home oral administration and disease-modifying effects, SLIT-tablets should be considered as an alternative or add-on treatment to pharmacotherapy for AR/C, and as an add-on treatment for HDM allergic asthma.

A practical guide to the sublingual immunotherapy tablet adverse event profile: implications for clinical practice

OBJECTIVES

Treatment with allergy immunotherapy improves allergic rhinoconjunctivitis, but can also improve comorbidities associated with allergic rhinitis such as asthma. Sublingual immunotherapy (SLIT)-tablets are a convenient and efficacious method of allergy immunotherapy. They are self-administered after the first tablet has been provided under medical supervision. Therapy may elicit local reactions or, rarely, systemic allergic reactions. The objective of this report is to inform healthcare practitioners about the safety and tolerability profile of SLIT-tablets and use this information to provide practical guidance that may inform patients regarding potential adverse reactions and how to manage them.

METHODS

Pooled analyses of safety data from completed randomized, multicenter, double-blind, placebo-controlled phase 2 and phase 3 US and EU trials of timothy grass, short ragweed, and SQ house dust mite SLIT-tablets were conducted to characterize safety and tolerability.

RESULTS

SLIT-tablets are generally well tolerated. No life-threatening events, serious systemic allergic reactions, or events that compromised the airway have been reported. The most common treatment-related adverse events (AEs) are oral site reactions, most of which begin on day 1 of treatment, recur for less than 2 weeks, and resolve after approximately 30-60 minutes. Systemic allergic reactions have been managed with conventional pharmacotherapy. Reactions treated with epinephrine are uncommon, but have been reported. Treatment of AEs, treatment discontinuation considerations, and patient FAQs regarding SLIT-tablet safety/tolerability are discussed.

CONCLUSIONS

This report gives healthcare providers valuable information to educate patients regarding what to expect in terms of SLIT-tablet safety and tolerability. Practical guidance is also provided to ensure proper treatment of any adverse reactions.

A review of clinical efficacy, safety, new developments and adherence to allergen-specific immunotherapy in patients with allergic rhinitis caused by allergy to ragweed pollen (Ambrosia artemisiifolia)

Allergic rhinitis is a common health problem in both children and adults. The number of patients allergic to ragweed (Ambrosia artemisiifolia) is on the rise throughout Europe, having a significant negative impact on the patients' and their family's quality of life. Allergen-specific immunotherapy (AIT) has disease-modifying effects and can induce immune tolerance to allergens. Both subcutaneous immunotherapy and sublingual immunotherapy with ragweed extracts/preparations have clear positive clinical efficacy, especially over pharmacological treatment, even years after the treatment has ended. AIT also has very good safety profiles with extremely rare side effects, and the extracts/preparations used in AIT are commonly well tolerated by patients. However, patient adherence to treatment with AIT seems to be quite low, mostly due to the fact that treatment with AIT is relatively time-demanding and, moreover, due to patients not receiving adequate information and education about the treatment before it starts. AIT is undergoing innovations and improvements in clinical efficacy, safety and patient adherence, especially with new approaches using new adjuvants, recombinant or modified allergens, synthetic peptides, novel routes of administration (epidermal or intralymphatic), and new protocols, which might make AIT more acceptable for a wider range of patients and novel indications. Patient education and support (eg, recall systems) is one of the most important goals for AIT in the future, to further enhance treatment success.

Immunotherapy in allergic rhinitis and lower airway outcomes

Allergic rhinitis and asthma constitute two clinical expressions of a single-condition, respiratory allergy. Allergen immunotherapy (AIT) is a form of treatment specifically aimed at modifying the response to sensitizing allergens. The inherent potential benefit of AIT is the simultaneous treatment of all clinical expressions of respiratory allergy. Current data support the effectiveness of subcutaneous and sublingual immunotherapy in rhinitis. Studies also provide proof for a beneficial effect in allergic asthma. Even more, substantial evidence points to the preventive effect on the progression from rhinitis to asthma. Despite the current knowledge on the basic mechanisms underlying the immunological effect of AIT is vast, the specific mechanisms for the preventive effect of primary sensitization or new sensitizations are poorly understood. This review aimed to provide a critical overview of the current knowledge on the effectiveness of AIT and its potential role in secondary prevention of respiratory allergy progression.

THE CLINICAL EFFICACY OF SUBLINGUAL ALLERGEN-SPECIFIC IMMUNOTHERAPY IN CHILDREN AGED 3-5 YEARS

The aim of this study was to determine the efficacy of sublingual allergen–specific immunotherapy (SLIT) in Ukrainian children younger than 5 years old with allergic rhinitis and bronchial asthma sensitized to house dust mite allergens. Material and methods: Four hundred and fifty children aged 28 months up to 5 years with rhinitis or asthma were examined. One hundred and twenty five children sensitized to house dust mites Dermatophagoides pteronyssinus and/or Dermatophagoides farina were included. In vivo and in vitro tests were made with a standard inhalant allergens panel. Results: The high information value of molecular diagnostics methods applied prior to prescription of the given therapy in children is analyzed. It has been found that in children under 5 sensitized to allergens of house dust mites Dermatophagoides pteronyssinus and/or Dermatophagoides farinae the application of sublingual allergen–specific immunotherapy therapy allows gaining control over the symptoms of the disease during the first 6 months. Conclusion: The high safety of SLIT in children has been proven. Comparative analysis in the group of patients not receiving SLIT shows a high frequency of symptoms of the disease after “free-of-symptoms interval” against full or partial baseline therapy denial.

Epinephrine Use in Clinical Trials of Sublingual Immunotherapy Tablets

BACKGROUND

Allergy immunotherapy can result in systemic allergic reactions and even life-threatening anaphylaxis requiring epinephrine administration.

OBJECTIVE

The objective of this study was to describe epinephrine use in the clinical trial development programs of 3 rapidly dissolving sublingual immunotherapy tablets (SLIT-tablets; Merck & Co., Inc., Kenilworth, NJ/ALK, Hørsholm, Denmark/Torii Pharmaceutical Co., Ltd., Tokyo, Japan).

METHODS

Data on epinephrine use were collected from 13 timothy grass SLIT-tablet trials (MK-7243; ≤2800 bioequivalent allergen units/75,000 SQ-T dose, n = 2497; placebo, n = 2139), 5 short ragweed SLIT-tablet trials (MK-3641; ≤12 Amb a 1-U, n = 1725; placebo, n = 770), and 11 house dust mite (HDM) SLIT-tablet trials (MK-8237; ≤12 SQ-HDM; n = 3930; placebo, n = 2246).

RESULTS

In grass SLIT-tablet trials, epinephrine was used 13 times (grass SLIT-tablet, n = 10; placebo, n = 3). Eight administrations were for grass SLIT-tablet-related adverse events (AEs): 4 for systemic allergic reactions and 4 for local mouth and/or throat swelling. In ragweed SLIT-tablet trials, epinephrine was used 9 times in 8 subjects (ragweed SLIT-tablet, n = 7; placebo, n = 1 [2 administrations for protracted anaphylaxis]). Four administrations were for ragweed SLIT-tablet-related AEs: 1 for systemic allergic reaction and 3 for local mouth and/or pharynx/throat swelling. In HDM SLIT-tablet trials, epinephrine was administered 13 times (HDM SLIT-tablet, n = 8; placebo, n = 5). Four administrations were for HDM SLIT-tablet-related AEs: 1 for systemic allergic reaction and 3 for local events. Of the 16 epinephrine administrations for events related to SLIT-tablet treatment, 11 occurred within the first week of treatment (7 administrations on day 1) and 5 were subject self-administered.

CONCLUSIONS

Epinephrine administrations in response to SLIT-tablet-related reactions in clinical trials are uncommon, typically occur within the first week of treatment, and are rarely self-administered. All SLIT-tablet-related events treated with epinephrine were nonserious.

Current Evidence on Safety and Practical Considerations for Administration of Sublingual Allergen Immunotherapy (SLIT) in the United States

Liquid sublingual allergen immunotherapy (SLIT) has been used off-label for decades, and Food and Drug Administration (FDA)-approved grass and ragweed SLIT tablets have been available in the United States since 2014. Potentially life-threatening events from SLIT do occur, although they appear to be very rare, especially for FDA-approved products. Practice guidelines that incorporate safety precautions regarding the use of SLIT in the United States are needed. This clinical commentary attempts to address unresolved issues including controversy regarding the FDA mandate for the prescription of epinephrine autoinjectors for patients on SLIT; how to approach polysensitized patients; optimal timing and duration of SLIT administration; how to address gaps in therapy; whether antihistamines can prevent local reactions, if certain patient populations (such as persistent asthmatics) should not receive SLIT; and when to instruct patients to self-administer epinephrine. Key points are that physicians should focus on educating patients regarding: (1) when not to administer SLIT; (2) how to recognize a potentially serious allergic reaction to SLIT; and (3) when to administer epinephrine and seek emergency care.

Subcutaneous Immunotherapy and Sublingual Immunotherapy: Comparative Efficacy, Current and Potential Indications, and Warnings--United States Versus Europe

Subcutaneous immunotherapy and sublingual immunotherapy are effective for allergic rhinitis and allergic asthma and with some support for use in selected patients with atopic dermatitis. The sequence of immunologic responses is the same, irrespective of the route of administration, and similar disease modification has been demonstrated. However, there are differences between the two approaches. The most important is the greatly reduced likelihood of sublingual immunotherapy producing systemic reactions. There are major drawbacks for sublingual immunotherapy in regard to dosing. Finally, there is the question of relative clinical efficacy, with the currently available data favoring subcutaneous immunotherapy.

Local Side Effects of Sublingual and Oral Immunotherapy

Sublingual immunotherapy (SLIT) is increasingly used worldwide, and several products have been recently registered as drugs for respiratory allergy by the European Medicine Agency and the Food and Drug Administration. Concerning inhalant allergens, the safety of SLIT is overall superior to that of subcutaneous immunotherapy in terms of systemic adverse events. No fatality has been ever reported, and episodes of anaphylaxis were described only exceptionally. Looking at the historical and recent trials, most (>90%) adverse events are "local" and confined to the site of administration. For this reason, a specific grading system has been developed by the World Allergy Organization to classify and describe local adverse events. There is an increasing amount of literature concerning oral desensitization for food allergens, referred to as oral immunotherapy. Also, in this case, local side effects are predominant, although systemic adverse events are more frequent than with inhalant allergens. We review herein the description of local side effects due to SLIT, with a special focus on large trials having a declared sample size calculation. The use of the Medical Dictionary for Regulatory Activities nomenclature for adverse events is mentioned in this context, as recommended by regulatory agencies. It is expected that a uniform classification/grading of local adverse events will improve and harmonize the surveillance and reporting on the safety of SLIT.

Efficacy of house dust mite sublingual immunotherapy tablet in North American adolescents and adults in a randomized, placebo-controlled trial

BACKGROUND

The house dust mite (HDM) sublingual immunotherapy (SLIT) tablet (MK-8237; Merck & Co, Kenilworth, NJ/ALK-Abelló, Hørsholm, Denmark) has demonstrated beneficial effects on allergic rhinoconjunctivitis and asthma outcomes in European trials.

OBJECTIVE

This is the first trial to assess the efficacy/safety of HDM SLIT-tablets in North American subjects with HDM-induced allergic rhinitis with or without conjunctivitis (AR/C).

METHODS

In this double-blind, multicenter trial (NCT01700192) 1482 subjects (aged ≥12 years) with HDM-induced AR/C with or without asthma were randomized to a daily SQ HDM SLIT-tablet (12 SQ-HDM dose) or placebo for up to approximately 52 weeks. A rhinitis daily symptom score (DSS; 4 nasal symptoms, maximum score = 12) of 6 or greater, or 5 or greater with 1 symptom being severe, on 5 of 7 consecutive days before randomization was required. The primary end point was the average total combined rhinitis score, which was defined as the rhinitis DSS plus rhinitis daily medication score (DMS), during the last 8 treatment weeks.

RESULTS

Treatment with 12 SQ-HDM improved the total combined rhinitis score by 17% (95% CI, 10% to 25%) versus placebo. Improvements versus placebo in the secondary end points of average rhinitis DSS, rhinitis DMS, total combined rhinoconjunctivitis score, and visual analog scale-assessed AR/C symptoms were 16%, 18%, 17%, and 16%, respectively. All nominal P values were less than .001 versus placebo, except rhinitis DMS (P = 0.15). No treatment-related adverse events meeting the International Council on Harmonization definition of a serious adverse event were reported; 1 nonserious treatment-related systemic allergic reaction occurred (assessed as moderate intensity) at first administration under medical supervision and was treated with epinephrine.

CONCLUSIONS

In the first North American trial of use of a SLIT-tablet for HDM allergy, 12 SQ-HDM was well tolerated and improved HDM-induced rhinitis symptoms in adults and adolescents.

Treatment effect of sublingual immunotherapy tablets and pharmacotherapies for seasonal and perennial allergic rhinitis: Pooled analyses

BACKGROUND

Data comparing the treatment effect of allergy immunotherapy and pharmacotherapy are lacking.

OBJECTIVE

We sought to indirectly compare the treatment effect of sublingual immunotherapy (SLIT)-tablets with pharmacotherapy for seasonal allergic rhinitis (SAR) and perennial allergic rhinitis (PAR).

METHODS

Pooled data from randomized, double-blind, placebo-controlled trials for the clinical development programs of selected allergic rhinitis treatments were evaluated. Total nasal symptom scores (TNSSs) relative to placebo were compared. Subjects scored symptoms daily during entire pollen seasons in 6 timothy grass SLIT-tablet trials (n = 3094) and 2 ragweed SLIT-tablet trials (n = 658) and during the last 8 weeks of treatment in 2 house dust mite (HDM) SLIT-tablet trials (n = 1768). Subjects scored symptoms daily in 7 montelukast (10 mg, n = 6799), 9 desloratadine (5 mg, n = 4455), and 8 mometasone furoate nasal spray (MFNS; 200 μg daily, n = 2140) SAR or PAR trials. SLIT-tablet trials allowed rescue medication use, whereas most pharmacotherapy trials did not. A fixed-effect meta-analysis method estimated differences in on-treatment average TNSSs.

RESULTS

In grass and ragweed SLIT-tablet trials, overall improvement in TNSSs relative to placebo was 16.3% and 17.1%, respectively. In HDM SLIT-tablet trials, TNSS overall improvement relative to placebo was 16.1%. In the montelukast, desloratadine, and MFNS trials, TNSS overall improvement relative to placebo was 5.4%, 8.5%, and 22.2%, respectively, for SAR trials, and 3.7%, 4.8%, and 11.2%, respectively, for PAR trials.

CONCLUSIONS

Although comparisons were limited by study design heterogeneity and use of rescue medications in SLIT-tablet trials, effects on nasal symptoms with timothy grass and ragweed SLIT-tablets were nearly as great as with MFNS and numerically greater than with montelukast and desloratadine for SAR. HDM SLIT-tablet effects were numerically greater than all pharmacotherapies for PAR. SLIT-tablets offer the additional benefit of long-term efficacy.

House Dust Mite-Specific Sublingual Immunotherapy Prevents the Development of Allergic Inflammation in a Mouse Model of Experimental Asthma

BACKGROUND

Evidence regarding sublingual immunotherapy (SLIT) efficacy and its good safety profile has been demonstrated with pollen and house dust mite (HDM) allergens in the treatment of airway allergies. In addition, the use of grass pollen presents a SLIT disease-modifying treatment for respiratory allergies.

OBJECTIVES

The aim of this study was to demonstrate the efficacy of HDM-based SLIT in mouse models of allergic airway inflammation and to gain insights into the involved local immunological mechanisms.

METHODS

Balb/c mice were sensitized/challenged with Dermatophagoides farinae (Der f) extract and underwent Der f-SLIT in prophylactic and therapeutic settings. The SLIT efficacy was assessed using lung function measurements, analysis of local inflammatory responses by bronchoalveolar lavage cell differentiation and lung histology. Humoral and cellular responses were monitored by ELISA, cytokine bead array and flow cytometry analyses.

RESULTS

In a prophylactic setting, Der f-SLIT with 12 development units per dose reduced the eosinophil-dominated inflammatory response in the lung paralleled by a marked reduction in airway hyperresponsiveness. Local Th2 responses were prevented as demonstrated by significantly lower levels of IL-5 and IL-13. Additionally, SLIT-treated mice revealed a lower proportion of CD4-CD8- x03B3;δ cells and a higher frequency of CD8+CD25+IFNx03B3;+ T cells in the lungs compared to sham-treated mice. In a therapeutic setting, Der f-SLIT also resulted in reduced inflammatory responses in the lung.

CONCLUSION

The efficacy of Der f-SLIT was demonstrated in prophylactic and therapeutic conditions using experimental mouse models of HDM-induced airway inflammation. A potential role of a so far underestimated lymphocyte subpopulation was also indicated.

Allergic Rhinitis: Mechanisms and Treatment

The prevalence of allergic rhinitis (AR) has been estimated at 10% to 40%, and its economic burden is substantial. AR patients develop specific immunoglobulin E (IgE) antibody responses to indoor and outdoor environmental allergens with exposure over time. These specific IgE antibodies bind to high-affinity IgE receptors on mast cells and basophils. Key outcome measures of therapeutic interventions include rhinitis symptom control, rescue medication requirements, and quality-of-life measures. A comprehensive multiple modality treatment plan customized to the individual patient can optimize outcomes.

Clinical considerations in the use of sublingual immunotherapy for allergic rhinitis

BACKGROUND

Allergen immunotherapy (AIT) has been in practice for more than 100 years. However, research in novel routes and delivery methods of immunotherapy to treat allergic rhinitis (AR) and conjunctivitis has only recently occurred in the United States, where the predominant form of AIT provided is largely via a subcutaneous immunotherapy (SCIT) route. AIT may prevent new sensitizations, improve symptoms, decrease medication usage, and prevent allergic asthma. Although AIT is the only potentially curative treatment for AR, access and adherence continue to be problematic. Only a fraction of eligible patients actually undergo treatment, and attrition rates are high. An obvious limitation of SCIT includes the requirement of regular injections to be provided in the physician's office due to the potential for anaphylaxis. Sublingual immunotherapy (SLIT) for home administration has been investigated as a potential alternative to address this limitation of SCIT.

METHODS

A literature review was performed including the current findings from randomized clinical trials and meta-analyses with a discussion of the most recent evidence for the efficacy, safety, and dosing of allergen SLIT.

RESULTS

The current data suggest that SLIT is effective for treatment of seasonal allergies, can potentially prevent asthma, and has a favorable safety profile. Head-to-head studies, however, are few, and comparative effectiveness still remains to be answered. Optimal treatment algorithms for SLIT have not yet been established, with wide variation in dosage selection and schedules. Similarly to SCIT, only a few allergens such as ragweed and grass pollen have been found to be effective in large clinical trials.

CONCLUSION

Recent data indicate that SLIT is an effective treatment modality for seasonal AR, improve quality of life, and can potentially prevent asthma but head-to head studies comparing SLIT to SCIT are needed.

Sequential Treatment Initiation with Timothy Grass and Ragweed Sublingual Immunotherapy Tablets Followed by Simultaneous Treatment Is Well Tolerated

BACKGROUND

Dual treatment with grass and ragweed sublingual immunotherapy (SLIT) tablets has not been studied.

OBJECTIVE

To characterize the safety and tolerability of dual grass and ragweed SLIT-tablet administration.

METHODS

This open-label, multicenter trial (NCT02256553) enrolled North American adults (N = 102) allergic to grass and ragweed. The trial had 3 periods, each of 2 weeks duration. In period 1, subjects received once-daily timothy grass SLIT tablet (2800 bioequivalent allergen unit; Merck, Inc, Kenilworth, NJ/ALK, Hørsholm, Denmark). In period 2, subjects received a short ragweed SLIT tablet (12 Ambrosia artemisiifolia 1-U; Merck/ALK) every morning and a grass SLIT tablet every evening. In period 3, subjects received once-daily grass and ragweed SLIT tablets within 5 minutes (simultaneous intake). The primary end point was the proportion of subjects with 1 or more local swelling events in each period. Secondary end points were the proportion of subjects with 1 or more local adverse events (AEs), that discontinued the treatment because of AEs, and subjects with 1 or more local AEs requiring treatment.

RESULTS

No severe swellings, systemic allergic reactions, asthma attacks, or reactions requiring epinephrine were reported. Most (99%) AEs were graded mild to moderate. The proportions of subjects with 1 or more local swelling events were 14%, 22%, and 15% for periods 1, 2, and 3, respectively. For periods 1, 2, and 3, the proportions of subjects with 1 or more local AEs were 71%, 69%, and 56%, respectively; the proportions discontinuing the treatment because of treatment-related AEs were 5%, 1%, and 2%, and the proportions with 1 or more local AEs requiring treatment were 4%, 4%, and 1%.

CONCLUSIONS

In this trial, a 4-week sequential SLIT-tablet dosing schedule followed by simultaneous intake of timothy grass and ragweed tablets was well tolerated.

Allergen Immunotherapy: History and Future Developments

Allergen immunotherapy (AIT) was introduced in clinical practice more than 100 years ago. The clinical effectiveness in allergic rhinitis (and asthma) and in hymenoptera allergy was apparent early on but it was not until the mid-1900s that randomized placebo-controlled trials proved its efficacy. In the 1980s, sublingual immunotherapy (SLIT) was accepted in official guidelines. The availability of safer routes, such as SLIT, prompted increasing investigation of AIT for food allergy. The introduction of molecular-based diagnosis introduced the possibility of better targeted prescription of AIT. Other approaches are being explored, such as immunogenic peptides, recombinant allergens, and adjuvants.

Short ragweeds is highly cross-reactive with other ragweeds

BACKGROUND

The most widespread ragweed (Ambrosia) species in North America are short ragweed (Ambrosia artemisiifolia; Amb a), giant ragweed (Ambrosia trifida; Amb t), and western ragweed (Ambrosia psilostachya; Amb p). Varied geographic distributions of ragweed species raise questions regarding the need for ragweed species-specific allergen immunotherapy.

OBJECTIVE

To determine allergenic cross-reactivity among ragweed species by immunologic analyses of sera from subjects allergic to ragweed from North America and Europe.

METHODS

Sera were collected from 452 subjects allergic to ragweed who participated in Amb a sublingual immunotherapy tablet clinical trials. All subjects had positive skin prick test and serum IgE against Amb a. Ragweed-specific IgE (pre treatment) and IgG4 (post treatment) were measured by ImmunoCAP. IgE inhibition studies among Amb a, Amb t, and Amb p were conducted. Using pooled sera from another ragweed-allergic population, IgE inhibition studies of 7 less widespread Ambrosia species also were conducted.

RESULTS

A strong correlation between Amb a vs Amb p and Amb t serum IgE levels was observed. In the vast majority of pretreatment sera, Amb a inhibited Amb a, Amb p, and Amb t IgE reactivity by more than 90%. Strong correlations were observed between Amb a vs Amb p and Amb t post-treatment IgG4 levels. In pooled sera, Amb a extract inhibited the binding of serum IgE to all 10 ragweed species by 98%-100%.

CONCLUSION

In a population of subjects allergic to Amb a, substantial allergenic cross-reactivity among Amb a, Amb p, and Amb t was demonstrated. These in vitro data suggest that an Amb a-based single-species ragweed allergen immunotherapy may be therapeutically active in patients exposed to diverse ragweed pollens.

TRIAL REGISTRY

Clinicaltrials.gov, NCT00770315, NCT00783198, and NCT00330083.

New developments in allergen immunotherapy

PURPOSE OF REVIEW

Allergic rhinitis, conjunctivitis, and asthma impact quality of life and cost billions of dollars in lost wages, productivity, and medical expenditures. Allergen immunotherapy is the only therapy that alters the allergen immune response, resulting in fewer symptoms upon natural exposure. This review summarizes recent immunotherapy developments.

RECENT FINDINGS

Subcutaneous immunotherapy (SCIT) remains a disease modifying treatment for allergic rhinoconjunctivitis and asthma with rare complications of therapy. Recent evidence suggests that SCIT may be effective in select cases of atopic dermatitis, particularly for patients with dust mite sensitivity. Sublingual immunotherapy (SLIT) tablets are now commercially available for grass and ragweed allergy and appear to have a superior safety profile to SCIT with similar long-term effectiveness, because as with SCIT, symptom improvement persists after the SLIT course is completed. SLIT tablets are administered daily at home (after initial supervised dosing) and may be used shortly before and during the target pollen seasons in a precoseasonal fashion (instead of perennial dosing). Research continues into experimental approaches using oral food allergen immunotherapy (OIT) to modify the natural history of food allergies. Although a proportion of patients in OIT trials experience sustained unresponsiveness, many do not and current recommendations limit the use of OIT to research protocols.

SUMMARY

Patients have new well tolerated and effective options for more convenient treatment of asthma and allergic rhinoconjunctivitis associated with grass and ragweed allergy. SCIT remains effective for polysensitized patients and may be an option for some patients with atopic dermatitis. Research continues into novel food allergy treatments.

Allergen immunotherapy on the way to product-based evaluation-a WAO statement

Allergen immunotherapy (AIT) is widely used in clinical practice for patients with moderate to severe allergic rhinitis due to inhalant allergens and may be delivered via subcutaneous (SCIT) and sublingual routes (SLIT). However, the quality of evidence for individual AIT products is very heterogeneous, and extensions of overall conclusions ("class effects") on the efficacy and disease-modifying effects to all AIT products are unjustified. In contrast, each product needs to be evaluated individually, based on available study results, to justify efficacy and specific claims on sustained and disease modifying effects per allergen and targeted patient group (children vs. adults, allergic rhinitis vs. asthma). WAO intends to support the current development to evidence-based AIT, which ultimately will lead to a more efficacious treatment of allergic patients and the appropriate recognition of AIT.

Allergy immunotherapy: the future of allergy treatment

Allergic respiratory disease represents a significant and expanding health problem worldwide. Allergic symptoms, such as asthma and hay fever, cause sleep impairment and reduce school and work performance. The cost to society is substantial. Allergen avoidance and pharmacotherapy cannot control the disease. Only allergy immunotherapy has disease-modifying potential and should be included in optimal treatment strategies. Allergy immunotherapy was first administered as subcutaneous injections and has been practiced for the past 100 years or so. Recently, tablet-based sublingual allergy immunotherapy (SLIT) was introduced with comprehensive clinical documentation. SLIT tablets represent a more patient-friendly concept because they can be used for self-treatment at home.

Effective treatment of house dust mite-induced allergic rhinitis with 2 doses of the SQ HDM SLIT-tablet: Results from a randomized, double-blind, placebo-controlled phase III trial

BACKGROUND

The SQ HDM SLIT-tablet (ALK) has been developed for treatment of house dust mite (HDM)-induced respiratory allergic disease.

OBJECTIVE

This trial investigated the efficacy and safety of the SQ HDM SLIT-tablet in adults with moderate-to-severe HDM-induced allergic rhinitis (AR).

METHODS

The trial was a randomized, double-blind, placebo-controlled phase III trial conducted in 12 European countries including 992 adults with moderate-to-severe HDM-induced AR despite treatment with pharmacotherapy. Subjects were randomized 1:1:1 to 1 year of daily treatment with placebo, 6 SQ-HDM, or 12 SQ-HDM. The primary end point was the total combined rhinitis score (ie, the sum of rhinitis symptom and medication scores) during the efficacy assessment period (approximately the last 8 weeks of the treatment period). Key secondary end points were rhinitis symptoms, medication scores, quality of life, and the combined rhinoconjunctivitis score.

RESULTS

Analysis of the primary end point (observed data) demonstrated absolute reductions in total combined rhinitis score of 1.18 (P = .002) and 1.22 (P = .001) compared with placebo for 6 SQ-HDM and 12 SQ-HDM, respectively. The statistically significant treatment effect was evident from 14 weeks of treatment onward. For all key secondary end points, efficacy was confirmed for 12 SQ-HDM, with statistically significant reductions of rhinitis symptoms and medication scores, improved quality of life, and a reduced combined rhinoconjunctivitis score in the efficacy assessment period compared with placebo. The treatment was well tolerated.

CONCLUSION

The trial confirmed the efficacy and favorable safety profile of both 6 SQ-HDM and 12 SQ-HDM in adults with HDM-induced AR. The treatment effect was present from 14 weeks of treatment onward.

Long-term adherence to sublingual therapy: literature review and suggestions for management strategies based on patients' needs and preferences

Sublingual immunotherapy (SLIT) is an at-home, self-administered, long-term therapy. As with other chronic diseases, patient adherence is a prerequisite for the success of SLIT. Its ease of intake and convenience should ensure adequate patient compliance; however, a recent post-marketing manufacturers' survey has shown a very high rate of discontinuation. The available literature on patient adherence to SLIT is reviewed in the present article. Great differences exist between controlled studies, which show a satisfactory adherence rate, and long-term real-life studies, which show poor compliance with SLIT. Remarkable divergence in the weight placed on different reasons for SLIT discontinuation is reported in the various studies. The main reasons for withdrawal are analysed and discussed. Data from placebo-controlled studies demonstrate that adherence depends less on the patient's perception of the inefficacy of therapy or other causes than on the patient's motivation, that is the patient's decision to participate in the trial and to meet the researcher's expectations. The enrolment of patients who agree to enter a blind, placebo-controlled trial is conceptually similar to a concordance process. Concordance is a consultation process that aims to establish a therapeutic alliance between the physician and patient and to bring about agreement on a therapeutic programme. Concordance is based on the patient's beliefs and needs and implies actions that support the patient's adherence. Suggestions are given for a SLIT management strategy based on the concordance process and designed to integrate the patient's viewpoints into treatment-related decisions and to meet patients' preferences and their health-system-related needs.

Mechanisms of allergen-specific immunotherapy and immune tolerance to allergens

Substantial progress in understanding mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumors, organ transplantation and chronic infections has led to a variety of targeted therapeutic approaches. Allergen-specific immunotherapy (AIT) has been used for 100 years as a desensitizing therapy for allergic diseases and represents the potentially curative and specific way of treatment. The mechanisms by which allergen-AIT has its mechanisms of action include the very early desensitization effects, modulation of T- and B-cell responses and related antibody isotypes as well as inhibition of migration of eosinophils, basophils and mast cells to tissues and release of their mediators. Regulatory T cells (Treg) have been identified as key regulators of immunological processes in peripheral tolerance to allergens. Skewing of allergen-specific effector T cells to a regulatory phenotype appears as a key event in the development of healthy immune response to allergens and successful outcome in AIT. Naturally occurring FoxP3⁺ CD4⁺CD25⁺ Treg cells and inducible type 1 Treg (Tr1) cells contribute to the control of allergen-specific immune responses in several major ways, which can be summarized as suppression of dendritic cells that support the generation of effector T cells; suppression of effector Th1, Th2 and Th17 cells; suppression of allergen-specific IgE, and induction of IgG4; suppression of mast cells, basophils and eosinophils and suppression of effector T cell migration to tissues. New strategies for immune intervention will likely include targeting of the molecular mechanisms of allergen tolerance and reciprocal regulation of effector and regulatory T cell subsets.

SQ house dust mite sublingually administered immunotherapy tablet (ALK) improves allergic rhinitis in patients with house dust mite allergic asthma and rhinitis symptoms

BACKGROUND

House dust mite (HDM) allergy is associated with persistent allergic rhinitis (AR) and allergic asthma.

OBJECTIVE

To investigate the efficacy and safety of a SQ HDM sublingually administered immunotherapy tablet (ALK, Hørsholm, Denmark) in adults and adolescents with HDM respiratory allergic disease and report the AR results.

METHODS

Six hundred four subjects at least 14 years old with HDM AR and mild to moderate HDM allergic asthma were randomized 1:1:1:1 to double-blinded daily treatment with 1, 3, 6 SQ-HDM or placebo. End-of-treatment rhinoconjunctivitis symptoms and medication score were predefined extrapulmonary end points. A subgroup analysis was conducted post hoc in subjects with a total combined rhinitis score (TCRS) > 0 (ie, with AR symptoms and/or AR medication use during the 4-week baseline period). The subgroup was comprised of 498 subjects (82%).

RESULTS

In the subgroup, the absolute difference in end-of-treatment TCRS between 6 SQ-HDM and placebo was -0.78 (95% confidence interval -1.47 to -0.07, relative difference 28.8%, P = .0357). Furthermore, a significant difference was found for the total score of the Rhinitis Quality of Life Questionnaire with Standardized Activities RQLQ(S) and for the individual domains: activities, sleep, non-nose and non-eye symptoms, and nasal symptoms. For the TCRS and Rhinitis Quality of Life Questionnaire score, a dose response was seen, with numerically lower, nonsignificant differences for 1 and 3 SQ-HDM. The predefined analysis for the entire trial population showed no statistically significant difference between the placebo and actively treated groups. No safety concerns were observed.

CONCLUSION

Efficacy in mild to severe AR of 6 SQ-HDM compared with placebo was demonstrated by statistically significant improvements in TCRS and Rhinitis Quality of Life Questionnaire score in subjects with AR present at baseline. The treatment was well tolerated.

TRIAL REGISTRATION

EudraCT, no 2006-001795-20; ClinicalTrials.gov, identifier NCT00389363.

Identification of the cysteine protease Amb a 11 as a novel major allergen from short ragweed

BACKGROUND

Allergy to pollen from short ragweed (Ambrosia artemisiifolia) is a serious and expanding health problem in the United States and in Europe.

OBJECTIVE

We sought to investigate the presence of undescribed allergens in ragweed pollen.

METHODS

Ragweed pollen proteins were submitted to high-resolution gel electrophoresis and tested for IgE reactivity by using sera from 92 American or European donors with ragweed allergy. Pollen transcriptome sequencing, mass spectrometry (MS), and recombinant DNA technologies were applied to characterize new IgE-binding proteins.

RESULTS

High-resolution IgE immunoblotting experiments revealed that 50 (54%) of 92 patients with ragweed allergy were sensitized to a 37-kDa allergen distinct from Amb a 1. The full-length cDNA sequence for this molecule was obtained by means of PCR cloning after MS sequencing of the protein combined with ragweed pollen RNA sequencing. The purified allergen, termed Amb a 11, was fully characterized by MS and confirmed to react with IgEs from 66% of patients. This molecule is a 262-amino-acid thiol protease of the papain family expressed as a combination of isoforms and glycoforms after proteolytic removal of N- and C-terminal propeptides from a proform. Three-dimensional modeling revealed a high structural homology with known cysteine proteases, including the mite Der p 1 allergen. The protease activity of Amb a 11, as well as its capacity to activate basophils from patients with ragweed allergy, were confirmed. The production of a nonglycosylated recombinant form of Amb a 11 in Escherichia coli established that glycosylation is not required for IgE binding.

CONCLUSION

We identified the cysteine protease Amb a 11 as a new major allergen from ragweed pollen. Given the similar physicochemical properties shared by the 2 major allergens, we hypothesize that part of the allergenic activity previously ascribed to Amb a 1 is rather borne by Amb a 11.