Safety of a SQ-standardised grass allergen tablet for sublingual immunotherapy: a randomized, placebo-controlled trial

Isolating the species element in grass pollen allergy: A review

Grass pollen is a leading cause of allergy in many countries, particularly Europe. Although many elements of grass pollen production and dispersal are quite well researched, gaps still remain around the grass species that are predominant in the air and which of those are most likely to trigger allergy. In this comprehensive review we isolate the species aspect in grass pollen allergy by exploring the interdisciplinary interdependencies between plant ecology, public health, aerobiology, reproductive phenology and molecular ecology. We further identify current research gaps and provide open ended questions and recommendations for future research in an effort to focus the research community to develop novel strategies to combat grass pollen allergy. We emphasise the role of separating temperate and subtropical grasses, identified through divergence in evolutionary history, climate adaptations and flowering times. However, allergen cross-reactivity and the degree of IgE connectivity in sufferers between the two groups remains an area of active research. The importance of future research to identify allergen homology through biomolecular similarity and the connection to species taxonomy and practical implications of this to allergenicity is further emphasised. We also discuss the relevance of eDNA and molecular ecological techniques (DNA metabarcoding, qPCR and ELISA) as important tools in quantifying the connection between the biosphere with the atmosphere. By gaining more understanding of the connection between species-specific atmospheric eDNA and flowering phenology we will further elucidate the importance of species in releasing grass pollen and allergens to the atmosphere and their individual role in grass pollen allergy.

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.

Use of Sublingual Immunotherapy for Aeroallergens in Children with Asthma

Asthma is a heterogeneous disease that in children is often allergen-driven with a type 2 inflammation. Sublingual immunotherapy represents an important progress in the use of personalized medicine in children with allergic asthma. It is a viable option for house dust mite-driven asthma and in subjects with the asthma associated with allergic rhinitis. The use and indications for isolated asthma caused by other allergens are still controversial owing to heterogeneity of commercially available products and methodological limitations of studies in children. Nevertheless, most studies and meta-analyses found the efficacy of sublingual immunotherapy. Sublingual immunotherapy is safe but cannot be recommended in children with uncontrolled asthma.

Cost-Effectiveness Of The SQ® Grass SLIT-Tablet In Children With Allergic Rhinitis: A German Payer Perspective

Background

The Grazax Asthma Prevention (GAP) trial has recently demonstrated significant reductions in the odds of asthma symptoms or medication use in patients treated with SQ^® grass SLIT-tablet relative to placebo, both in combination with allergy and asthma pharmacotherapy. The objective of the present analysis was to evaluate the cost-effectiveness of SQ grass SLIT-tablet relative to placebo in children with AR from the perspective of a German healthcare payer.

Methods

A cost-utility model was developed in Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) to evaluate the cost-utility of SQ grass SLIT-tablet in combination with pharmacotherapy versus pharmacotherapy alone in patients with AR. Transition probabilities were derived from the GAP trial, and costs were taken from a real-world insurance database analysis. Future costs and effects were discounted at 3% per annum, and extensive deterministic and probabilistic sensitivity analyses were performed.

Results

Over a 10-year time horizon, the base case analysis showed an increase in overall treatment costs of €897 per child being treated with SQ grass SLIT-tablet relative to pharmacotherapy alone. The increased treatment costs were accompanied by an improvement in patient quality of life of 0.10 quality-adjusted life years (QALYs) yielding an ICER of €8978 per QALY gained, falling well below a willingness-to-pay threshold of €17,800 per QALY gained. The base case results were insensitive to changes in all individual model parameters.

Discussion

Improvements in quality of life with the SQ grass SLIT-tablet would be accompanied by only a modest increase in costs over a 10-year time horizon, with the SQ grass SLIT-tablet therefore representing excellent value for money from the German healthcare payer perspective.

GRAZAX®: a sublingual immunotherapy vaccine for Hay fever treatment: from concept to commercialization

Allergen immunotherapy has been used for more than 100 y, but only recently underlying immunological mechanisms have started to be understood. New Allergy vaccines are now considered to be full pharmaceutical products, that should comply with general as well as specific pharmaceutical legal framework. GRAZAX® is the first global allergy vaccine developed in compliance with the new legal environment and is thus a reference for developing new allergy vaccines. Here, we provide a rationale description of GRAZAX®, providing a sequential description of its pharmaceutical and clinical development. With more than 25 clinical trials, involving more than 8000 patients, including as well three 5-y prospective clinical trials, GRAZAX® is a key product to understand the unique position of allergen-specific immunotherapy as a disease-modifying intervention.

Sublingual allergen immunotherapy for respiratory allergy: a systematic review

The objective of the systematic review is to provide complete and updated information on efficacy and safety of sublingual immunotherapy (SLIT) formulations for the treatment of allergic respiratory diseases (ARDs). The literature search was conducted on PubMed database, involving double-blind, randomized clinical trials published between January 1992 and 2018, written in English, and performed in humans. The number of articles finally selected for review was 112. Data from the majority of properly controlled clinical trials demonstrate that SLIT is effective not only with short-term use (first year) but also with long-term use (up to the third year of active therapy), for treating ARDs in children and adults. Both continuous and discontinuous schemes of administration showed significant reductions in symptom and medication scores. Moreover, a SLIT-induced disease-modifying effect has been documented mainly with grass pollen extracts, since improvement is maintained during at least 2 years of follow-up after a 3-year treatment period. Additionally, allergen immunotherapy should also be considered a preventive strategy, especially for decreasing bronchial asthma incidence in children and adolescents with allergic rhinitis treated with SLIT. This therapy is also safe, producing only a few mainly local and mild-to-moderate adverse events, and usually self-limited in time. The registration and authorization of allergen SLIT preparations (grasses and house-dust mite tablets) as drugs by regulatory agencies, such as the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA), has represented a landmark in allergy immunotherapy research. Further long-term studies, specially designed with allergens other than grass pollen or house-dust mites, not only in allergic rhinoconjunctivitis but also on asthmatic subjects, as well as studies comparing different administration schedules and/or routes, are required in order to continue the progress in the modern development of this particularly promising therapy.

Intra-Seasonal Initiation of the SQ-Standardised Grass Allergy Immunotherapy Tablet Routinely Applied by Allergy Specialists and General Practitioners with Experience in Treatment of Allergy: A Non-Interventional Observational Study

INTRODUCTION

Intra-seasonal start of treatment with the SQ® grass sublingual immunotherapy (SLIT) tablet (GRAZAX®, ALK, Denmark) has been previously demonstrated to be well-tolerated. The objective of our study was to investigate the tolerability of intra-seasonal start of treatment comparing patients treated by allergists and general practitioners experienced in treatment of allergy (GPs).

METHODS

In a non-interventional, open-label, observational study, data on intra-seasonal start with the SQ® grass SLIT tablet were recorded in patients treated by allergists and GPs in Germany. Adverse events (AEs) were recorded by the physicians at first administration and during the 1-3-month observation period. The tablets taken and any AEs were recorded by the patients in diaries for the first 14 days.

RESULTS

Treatment with the SQ® grass SLIT tablet was started in 198 patients, and in 179 intra-seasonal (allergists: 140, GPs: 39) and 19 post-seasonal; average treatment period was 47 days. AEs related to intra-seasonal start were reported in 43.6% of patients; no relevant differences between allergists and GPs were observed. In the subgroup of GPs, patients were younger (p = 0.0191), had more frequently asthma (p = 0.0043), more patients used symptomatic medication in the previous pollen season (p = 0.0198) and were more frequently treated for other diseases (p = 0.0467). In the allergists subgroup, more diagnostic allergy tests were applied (p < 0.0001) with less anti-allergic premedication at first administration (p = 0.0026).

CONCLUSION

The intra-seasonal start of treatment with the SQ® grass SLIT tablet in patients routinely treated by allergists or GPs with experience in treatment of allergy was well-tolerated, although patient characteristics were different with respect to age, frequency of asthma and concomitant allergies, use of symptomatic medication in the previous grass pollen season and concomitant treatment of other diseases. The safety profile from a previous placebo-controlled clinical trial and data from a previous real-life study on intra-seasonal start performed by allergists were confirmed.

Low-Dose Allergen-Specific Immunotherapy Induces Tolerance in a Murine Model of Shrimp Allergy

BACKGROUND

The efficacy and safety of allergen-specific immunotherapy (AIT) are highly dose-dependent.

METHODS

We investigated the dosage effects of AIT and the underlying mechanisms in a murine model of shrimp hypersensitivity. BALB/c mice were sensitized with recombinant shrimp allergen rMet e 1 and challenged orally with a high dose of rMet e 1 to elicit an allergic response. These sensitized mice were then treated with a low (0.01 mg), medium (0.05 mg), or high dosage (0.1 mg) of rMet e 1 intraperitoneally before receiving a second oral challenge. The allergic responses and immunological changes in the gut were compared between animals receiving different dosages.

RESULTS

We found that all sensitized mice that received rMet e 1 immunotherapy were desensitized, regardless of the dosage, and protected at the second oral challenge. Nevertheless, the mice in the high-dosage group experienced severe systemic reactions during the treatment phase. In contrast, regulatory T (Treg) cell-associated genes were upregulated only in the low- and medium-dosage groups, and Foxp3+ cells were more abundant in the gut lymphoid tissues than in the high-dosage group.

CONCLUSIONS

Our results demonstrate that low-dosage immunotherapy favors the induction of local Foxp3+ Treg cells and the upregulation of regulatory cytokines. The safety advantages and long-term efficacy of low-dosage immunotherapy should be taken into consideration when developing immunotherapy dose schedules.

Clinical management, expectations, and satisfaction of patients with moderate to severe allergic rhinoconjunctivitis treated with SQ-standardized grass-allergen tablet under routine clinical practice conditions in Spain

BACKGROUND

Sublingual immunotherapy has been proven as a well-tolerated and effective treatment for allergic rhinitis. Within this type of treatment, GRAZAX® is the most documented product in terms of safety and efficacy. The objective of this study was to identify the patients' expectations and level of treatment satisfaction, as well as the clinical management of patients with moderate/severe allergic rhinoconjunctivitis treated with GRAZAX®.

METHODS

This was a non-interventional, observational, multi-centre, open-label study involving a total of 131 adult patients aged 18-66 years with confirmed diagnosis of grass-allergy and initiated treatment with GRAZAX® between June 2010 and April 2011.

RESULTS

In the pollen season after starting treatment, 56.6% of patients stated that their symptoms were much less/less intense, 86% needed less symptomatic medication for control of their symptoms, and 74.4% manifested to have improved (quite/a lot) as regards their allergic disease since treatment was initiated as compared with previous grass pollen season. The patient satisfaction with GRAZAX® was measured using a visual analogue scale (VAS) between 0 (minimum satisfaction) and 100 (maximum satisfaction) comprising five different items: effectiveness, tolerability, cost, convenience and overall satisfaction. The results obtained for each item were [mean (SD)]: 74.7 (18.1), 70.3 (36.1), 39.3 (25.8), 86.2 (12.6), 78.4 (15.8) respectively. The patient's level of satisfaction is highly influenced, especially in terms of assessment of effectiveness, tolerability and convenience, by the information provided by the specialist.

CONCLUSIONS

In summary, it can be concluded that improved communication leads to increased patient knowledge, greater patient compliance, and increased patient satisfaction.

Therapeutic interventions in severe asthma

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

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.

Adverse reactions and tolerability of high-dose sublingual allergen immunotherapy

BACKGROUND

Sublingual allergen immunotherapy is an effective treatment against allergic respiratory disease. Many studies have shown the safety of this type of therapy, although the factors that might affect the tolerability of high-dose sublingual immunotherapy have not been well established. The aim of this study was to determine the factors that affect the tolerability of sublingual allergen immunotherapy.

PATIENTS AND METHODS

A total of 183 subjects aged ≥5 years, diagnosed with allergic rhinitis with/without mild to moderate asthma due to sensitization to grass, olive pollen, or mites, were included in this open, retrospective, multicentric, noninterventional study. Sublingual immunotherapy was administered for at least 3 months.

RESULTS

The most frequent adverse reaction was oral pruritus (13.7% of the patients). Most of the reactions were local (84.7%) and immediate (93.5%) and occurred during the initiation phase (60.6%). All reactions were mild to moderate in severity. No serious adverse reactions were registered. When comparing factors with potential influence on the occurrence of adverse reactions, the results between the groups of subjects with and without adverse reactions showed no statistically significant differences in sex (P=0.6417), age (P=0.1801), years since the disease was first diagnosed (P=0.3800), treatment composition (P=0.6946), polysensitization (P=0.1730), or clinical diagnosis (P=0.3354). However, it was found that treatment duration had a statistically significant influence (3 months, >3 months: P=0.0442) and the presence of asthma was close to statistical significance (P=0.0847).

CONCLUSION

In our study, treatment duration is significantly associated with the occurrence of adverse reactions after the administration of high doses of sublingual allergen immunotherapy.

Health-Related Quality of Life During Routine Treatment with the SQ-Standardised Grass Allergy Immunotherapy Tablet: A Non-Interventional Observational Study

BACKGROUND AND OBJECTIVE

Allergy immunotherapy (AIT) with the SQ(®) grass sublingual immunotherapy (SLIT)-tablet has been shown to be efficacious, well-tolerated and to improve disease-specific health-related quality of life (HRQoL) in controlled clinical trials. The aim of our study was to investigate HRQoL in patients with allergic rhinoconjunctivitis routinely treated with the SLIT-tablet and taking symptomatic medication as needed compared with patients treated only with symptomatic medication.

METHODS

In a non-interventional, open-label study, patients treated with the SLIT-tablet were observed for about 12 months compared with patients only symptomatically treated. Patients assessed their HRQoL with the 12-Item Short Form Health Survey (SF-12) and the Rhinitis Quality of Life Questionnaire (RQLQ) in the grass pollen seasons (GPS) at baseline (GPS1, HRQoL1), after GPS1 (HRQoL2) and in the following GPS (GPS2, HRQoL3). Tolerability, compliance, symptoms and medication use were assessed in the SLIT-tablet group by the physician.

RESULTS

Overall, data were analysed in 576 patients. Mean differences (±SD) in overall scores for HRQoL3 versus HRQoL1 (186 patients) of SF-12 were +11.4 ± 16.8 (SLIT-tablet) and -3.4 ± 15.7 (symptomatic medication), (p < 0.0001), and of RQLQ -1.31 ± 1.07 and +0.10 ± 0.74 (p < 0.001), and for HRQoL3 versus HRQoL2 (238 patients) of SF-12 -1.6 ± 15.3 and -10.0 ± 14.1 (p = 0.0003), and of RQLQ +0.22 ± 1.29 and +1.24 ± 1.30 (p < 0.0001). Tolerability and adherence for the SLIT-tablet were comparable with data of other non-interventional studies.

CONCLUSIONS

Routine treatment with the SQ(®) grass SLIT-tablet resulted in clear improvements in disease-specific and general quality of life, while no improvements were observed in patients treated only symptomatically.

Tolerability of the SQ-standardised grass sublingual immunotherapy tablet in patients treated with concomitant allergy immunotherapy: a non-interventional observational study

Background

The majority of allergic patients are poly-sensitized. For causal treatment by allergy immunotherapy (AIT) a single or few allergen products containing the clinically most relevant allergens are applied, but few data on tolerability of multiple application of AIT is available. The aim of our study was to investigate safety and tolerability in patients who started treatment by sublingual immunotherapy (SLIT) with the standardised SQ^® grass SLIT-tablet and were treated with concomitant AIT products.

Methods

In a non-interventional, open-label, observational study in Germany treatment of patients with the SQ^® grass SLIT-tablet and concomitant AIT (SCIT or SLIT) was documented between January 2012 and January 2014. Patients were followed at visits at first administration of the SQ^® grass SLIT-tablet and after 1–3 months of treatment. Tolerability of the treatment with the SQ^® grass SLIT-tablet and concomitant AIT were assessed by the physician and administration of AIT and adverse events (AEs) were recorded by the patients in diaries. AEs and adverse drug reactions (ADRs) were coded by using the Medical Dictionary for Regulatory Activities.

Results

In total, 181 patients were documented by 48 allergists and 160 patients treated with a concomitant AIT (SCIT 130, SLIT 30). AEs were reported in 58 (36.3 %) patients with concomitant AIT, and AEs considered related with the SQ^® grass SLIT-tablet in 49 (30.6 %) and with concomitant AIT in 18 (11.3 %) patients. Treatment was discontinued due to ADRs in 12 (7.5 %) patients and severity of ADRs was assessed mild or moderate in 29 (18.1 %), and severe in 20 (12.5 %) patients. Most common reactions were localised at the application site of the SQ^® grass SLIT-tablet as oral pruritus, throat irritation, oedema mouth and paraesthesia oral; no serious ADRs were reported. Overall tolerability of the SQ^® grass SLIT-tablet if given with concomitant AIT was assessed as “good” or “very good” by 91.0 % of patients and 91.6 % of physicians.

Conclusions

In comparison to data from previous studies no increase in frequency of AEs or change in the tolerability profile was observed when SLIT with the SQ^® grass SLIT-tablet was administered with concomitant SCIT or SLIT.

Critical appraisal of Timothy grass pollen extract GRAZAX in the management of allergic rhinitis

Allergic rhinitis is one of the most common diseases of adult and pediatric age, associated with grass pollen (GP) allergy in >50% cases, with a consistent impact on quality of life of affected patients. A grass allergen tablet, containing standardized extract derived from Timothy grass (Phleum pratense) pollen and ~15 μg major allergen P. pratense (rPhl p 5), may be the future of allergen-specific immunotherapy (IT) for GP allergy. The aim of this review was to critically evaluate the role of Timothy GP extract IT for the management of allergic rhinitis. For this purpose, we have tried to analyze potential mechanisms of action at the basis of Timothy GP extract, we have reviewed efficacy studies to establish potential benefits and clinical response, and we have also evaluated safety and tolerability profiles and patient focus perspective, such as quality of life, satisfaction and acceptability, and compliance to this IT.

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.

Allergen immunotherapy in asthma; what is new?

The use and role of allergen immunotherapy (AIT) in asthma is still a matter of debate, and no definite recommendation about this is made in guidelines, both for the subcutaneous and sublingual routes. This is essentially due to the fact that most controlled randomised trials were not specifically designed for asthma, and that objective measures of pulmonary function were only occasionally considered. Nonetheless, in many trials, favourable results in asthma (symptoms, medication usage, bronchial reactivity) were consistently reported. There are also several meta analyses in favour of AIT, although their validity is limited by a relevant methodological heterogeneity. In addition to the crude clinical effect, a disease modifying action of AIT (prevention of asthma onset and long-lasting effects) have been reported. The safety is an important aspect to consider in asthma. Fatalities were rare: in Europe no fatality was reported in the last three decades, as in the United States in the last 4 years. Based on previous surveys, and common sense, uncontrolled asthma is still recognized as the most important risk factor for severe adverse events. On the contrary, there is no evidence that AIT can worsen or induce asthma. According to the available evidence, AIT can be safely used as add-on treatment when asthma is associated with rhinitis (a frequent condition), provided that asthma is adequately controlled by pharmacotherapy. AIT cannot be recommended or suggested as single therapy. When asthma is the unique manifestation of respiratory allergy, its use should be evaluated case by case.

Selection of patients for sublingual versus subcutaneous immunotherapy

Allergen immunotherapy is the sole treatment for IgE-mediated allergic diseases directed at the underlying mechanism. The two widely accepted administration routes are sublingual (SLIT) and subcutaneous (SCIT). We reviewed how patients should best be selected for immunotherapy and how the optimal administration route can be defined. Before deciding SCIT or SLIT, appropriate selection of patients for allergen immunotherapy (AIT) is mandatory. To be eligible for AIT, subjects must have a clear medical history of allergic disease, with exacerbation of symptoms on exposure to one or more allergens and a corresponding positive skin or in vitro test. Then the route of administration should be based on: published evidence of clinical and immunologic efficacy (which varies per allergic disease and per allergen); mono- or multi-allergen immunotherapy, for SLIT multi-allergen immunotherapy was not effective; safety: adverse events with SLIT are more frequent, but less severe; and, costs and patient preferences, closely related to adherence issues. All these are discussed in the article.

Oral/sublingual Phleum pretense grass tablet (Grazax/Grastek) to treat allergic rhinitis in the USA

With the approval of two grass tablets and one ragweed tablet for sublingual immunotherapy (SLIT) by the US FDA in April 2014, the practice of allergy immunotherapy (AIT) in the USA has dramatically changed. Until this time, there were no approved allergen extracts for sublingual administration and physicians who prescribed SLIT for their patients did so without full knowledge of proper dosing or assurance of its safety. Now sublingual allergen tablets are available that have proven safe and effective doses. This article describes, in detail, the studies that have been conducted with a timothy grass SLIT tablet and draws some comparisons to the alternative 5-grass SLIT tablet. It also attempts to predict what will be the impact of the introduction of these tablets on the practice of AIT in the USA over the next few years.

A Phase I clinical trial with subcutaneous immunotherapy vaccine of Timothy grass pollen extract according to EMA guidelines

Aim: A double-blind placebo-controlled study was conducted according to EMA guidelines, to evaluate safety, tolerability and short-term treatment effects of three up-dosing regimens of Phleum pratense subcutaneous immunotherapy. Materials & methods: Forty-two patients were randomized to groups: A (6 weekly doses), B (8 weekly doses) or C (eight doses, two clustered increasing doses over 3 weeks). Results: The most frequent adverse events were local reactions. No serious adverse events were found. Higher number and more severe systemic reactions were reported in group C. A decrease in cutaneous responses and an increase of specific antibodies was shown in all active groups even at very short-term. Conclusion: Phleum pratense subcutaneous immunotherapy in depot presentation exhibited good safety and tolerability. Group A seemed to show the best profile.

The efficacy and safety of the Timothy grass allergy sublingual immunotherapy tablet in Canadian adults and children

BACKGROUND

The effect of sublingual Timothy grass immunotherapy tablet 2800 BAU (grass SLIT-T) has been evaluated in three North American trials in adults and children who have allergic rhinitis with or without conjunctivitis (AR/C). This paper examines the effects of grass SLIT-T in Canadians.

METHODS

Data for grass-allergic Canadians in three randomized, placebo-controlled, double-blind trials were analyzed post hoc: 1) adults ≥18 y, grass-pollen season [GPS] 2009; 2) children 5- <18 y, 2009; and 3) adults 18-65 y and children 5- <18 y, GPS 2012. Data from the GPS 2009 trials were pooled to provide a more precise estimate of treatment effects than the individual studies would provide. In every trial, participants received once-daily grass SLIT-T or placebo approximately 12 weeks before and continuing throughout the GPS. Participants used daily electronic diaries to record AR/C symptoms and medication use for treatment of symptoms. The therapeutic effect of grass SLIT-T was measured as a total combined score (TCS = daily symptom score + daily medication score) averaged over the entire GPS. Safety was assessed by monitoring adverse events (AEs).

RESULTS

In the three trials, 386 Canadian participants were randomized; the overall population had 2284 participants. Canadian participants treated with grass SLIT-T in the pooled adult-pediatric 2009 trials showed a 38% mean TCS reduction relative to placebo (-2.06 difference [95% CI: -3.72, -0.39]; 3.32 vs. 5.37). Participants treated with grass SLIT-T in the adult-pediatric 2012 trial showed a 37% median TCS reduction relative to placebo (-1.53 difference [95% CI: -2.1, -0.3]; 2.58 vs. 4.11). Similar efficacy findings were observed over the peak GPS. Approximately 90% of treatment-related AEs were mild or moderate in severity. Two Canadian participants had moderate systemic allergic reactions (skin, respiratory, abdominal symptoms) to grass SLIT-T; symptoms resolved within 1 hour without medical intervention or treatment. No serious or life-threatening treatment-related AEs occurred.

CONCLUSION

The 2800 BAU Timothy grass SLIT-T significantly improved AR/C induced by Timothy grass pollen in adults and children ≥5 y in Canadians, which was consistent with the robust efficacy observed in the overall trial population. The treatment was generally well tolerated.

TRIAL REGISTRATION

Clinicaltrials.gov identifiers NCT00562159, NCT00550550, NCT01385371.

Sublingual immunotherapy: recent advances

The practice of administering sublingual immunotherapy for respiratory allergy is gaining more and more diffusion worldwide as a consequence of the robust demonstration of clinical efficacy and safety provided by recent high-powered and well-designed studies, confirming for individual seasonal allergens the results of previous metanalyses in adult and pediatric populations. Preliminary evidence derives from recent rigorous trials on perennial allergens, like house dust mites, and specifically designed studies addressed the benefits on asthma. Emerging research suggests that SLIT may have a future role in other allergic conditions such as atopic dermatitis, food, latex and venom allergy. Efforts to develop a safer and more effective SLIT for inhalant allergens have led to the development of allergoids, recombinant allergens and formulations with adjuvants and substances targeting antigens to dendritic cells that possess a crucial role in initiating immune responses. The high degree of variation in the evaluation of clinical effects and immunological changes requires further studies to identify the candidate patients to SLIT and biomarkers of short and long term efficacy. Appropriate management strategies are urgently needed to overcome the barriers to SLIT compliance.

Safety and tolerability of an intra-seasonal initiation of the SQ-standardised grass allergy immunotherapy tablet: a non-interventional observational study investigating the feasibility during routine administration

Background and Objective

For specific immunotherapy to pollen allergy, a pre-seasonal start of treatment is recommended by international guidelines. In a placebo-controlled clinical trial with adults, an intra-seasonal start of therapy with the SQ-standardised grass allergy immunotherapy tablet (AIT) was well-tolerated. The objective of our study was to investigate the feasibility of an intra-seasonal start of grass AIT administered during routine treatment by practising allergists.

Methods

In a multicentre, prospective, open-label, uncontrolled, non-interventional observational study, data on routine treatment with grass AIT were recorded in patients who started administration of tablets within the 2010 grass pollen season in Germany. Adverse events (AEs) were recorded by the physician at visits for the first administration in the clinic and at the end of the 1- to 3-month observation period. AEs and daily administration of the tablet were recorded by the patients in diaries for the first 14 days. Treatment satisfaction, global tolerability and perceived effect of treatment were assessed by the patient and physician at the end of the study.

Results

A total of 662 patients were treated with 1 tablet daily by 286 physicians. Grass AIT was started intra-seasonally in 620 patients and post-season in 42. The average treatment period was 51.6 days. AEs were recorded in 52.1 % of all patients and in 35.6 % at first administration, with throat irritation (21.3 %), paraesthesia oral (19.9 %), oral pruritus (14.0 %) and ear pruritus (10.3 %) being the most frequent AEs related to grass AIT. The intensity of the AEs was assessed as mild or moderate in 42.1 % of patients and severe in 8.0 %; AEs related to grass AIT were classified as serious in two patients. Grass AIT was discontinued due to AEs in 7.7 % of patients. Diaries were evaluable for 77.0 % of patients; the average rate of patients with AEs decreased continuously from 44.7 % (day 1) to 26.9 % (day 14) and the average daily rate of patients who forgot to take their tablet was about 5 %. Overall tolerability was assessed by 87.2 % of patients and 91.4 % physicians as “very good” or “good” and effectiveness of treatment was assessed as “very good” or “good” in 81.4 % of patients and 85.8 % of physicians. More than 90 % of patients and physicians were satisfied with the treatment.

Conclusion

The tolerability data for an intra-seasonal start of grass AIT during routine treatment confirm the safety profile from the previous controlled trial. Tolerability was assessed as good in combination with high satisfaction with the treatment and compliance.

Sublingual immunotherapy: World Allergy Organization position paper 2013 update

We have prepared this document, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2013 Update", according to the evidence-based criteria, revising and updating chapters of the originally published paper, "Sublingual Immunotherapy: World Allergy Organization Position Paper 2009", available at http://www.waojournal.org. Namely, these comprise: "Mechanisms of sublingual immunotherapy;" "Clinical efficacy of sublingual immunotherapy" - reporting all the data of all controlled trials published after 2009; "Safety of sublingual immunotherapy" - with the recently published Grading System for adverse reactions; "Impact of sublingual immunotherapy on the natural history of respiratory allergy" - with the relevant evidences published since 2009; "Efficacy of SLIT in children" - with detailed analysis of all the studies; "Definition of SLIT patient selection" - reporting the criteria for eligibility to sublingual immunotherapy; "The future of immunotherapy in the community care setting"; "Methodology of clinical trials according to the current scientific and regulatory standards"; and "Guideline development: from evidence-based medicine to patients' views" - including the evolution of the methods to make clinical recommendations.Additionally, we have added new chapters to cover a few emerging crucial topics: "Practical aspects of schedules and dosages and counseling for adherence" - which is crucial in clinical practice for all treatments; "Perspectives and new approaches" - including recombinant allergens, adjuvants, modified allergens, and the concept of validity of the single products. Furthermore, "Raising public awareness about sublingual immunotherapy", as a need for our patients, and strategies to increase awareness of allergen immunotherapy (AIT) among patients, the medical community, all healthcare stakeholders, and public opinion, are also reported in detail.

Specific immunotherapy in asthma: a comprehensive review

BACKGROUND

The prescription of allergen immunotherapy (SIT) in asthma remains a matter of debate and official guidelines often do not provide clear recommendations in this regard.

METHODS

An extensive review of the literature was untaken.

RESULTS

There are many robust studies with SCIT and SLIT showing positive results related to improving asthma symptoms, in particular when asthma was associated with rhinitis. In addition, there are several favourable meta-analyses, although their validity is limited by the heterogeneity of the trials included. The disease modifying effect of SIT (prevention of asthma onset and long-lasting effects) should be considered when prescribing this treatment. Regarding safety, fatalities seem to be rare: in Europe no fatality has been reported over the last two decades, and the same has been observed in USA in the last 4 years. Uncontrolled asthma is universally recognized as the most important risk factor for severe adverse events, but there is no clear demonstration that SIT can worsen or induce asthma. In contrast, of the few studies specifically designed to evaluate asthma, none had a formal sample size calculation, and pulmonary function was assessed as primary outcome only sporadically.

CONCLUSIONS

According to the presently available evidence, SLIT and SCIT can be used in asthma associated with rhinitis (the most common condition), provided that asthma is adequately controlled by pharmacotherapy. In such cases, a measurable clinical benefit on asthma symptoms can be expected. SIT cannot be presently recommended as single therapy when asthma is the unique manifestation of respiratory allergy.

Balancing efficacy against safety in sublingual immunotherapy with inhalant allergens: what is the best approach?

Over the last 20 years, studies and clinical trials have demonstrated efficacy, safety and cost-effectiveness of sublingual immunotherapy (SLIT) for respiratory allergic diseases. Nevertheless, it seems to be mostly used as a second-line therapeutic option, and adherence to treatment is not always optimal. Selective literature research was done in Medline and PubMed, including guidelines, position papers and Cochrane meta-analyses concerning SLIT in adult patients. The most recent reviews confirm SLIT as viable and efficacious treatment especially for allergic rhinitis, even if the optimal dosage, duration, schedule are not clearly established for most of the products. Despite an optimal safety profile, tolerability and patient-reported outcomes concerning SLIT have received poor attention until now. Recently, new tools have been specifically developed in order to investigate these aspects. Regular assessment of tolerability profile and SLIT-related patient-reported outcomes will allow balancing efficacy with tolerability and all the other patient-related variables that may affect treatment effectiveness beyond its efficacy.

Grading local side effects of sublingual immunotherapy for respiratory allergy: speaking the same language

Sublingual immunotherapy (SLIT) is increasingly used worldwide. Despite its safety being well ascertained, there is no universally accepted system to grade and classify its adverse events (AEs). According to the literature, it seems reasonable to classify and grade systemic side effects by using the previously published World Allergy Organization recommendations. On the other hand, local side effects are the most frequent with SLIT, sometimes leading to its discontinuation. Therefore grading of the severity of local side effects was perceived as necessary for the purpose of uniform reporting, classification, and quantification of this aspect. A World Allergy Organization Taskforce, after examining the available literature and the postmarketing surveillance data, proposed a clinically based grading of the severity of local AEs caused by SLIT. The use of the Medical Dictionary for Regulatory Activities nomenclature for AEs was also included in this context. The proposed grading system for SLIT-induced local reactions is expected to improve and harmonize surveillance and reporting of the safety of SLIT.

Sublingual immunotherapy for allergic rhinitis and conjunctivitis

Sublingual immunotherapy (SLIT) for allergic respiratory diseases was first described in 1986 and immediately appeared as a viable alternative to the traditional subcutaneous route. Since then, more than 60 randomized controlled trials have been published, almost all with very favorable results. The average improvement over placebo in symptom score and medication use was always greater than 20%. The results of the clinical trials were pooled in several meta-analyses, which consistently confirmed the efficacy of the treatment. SLIT is characterized by a satisfactory safety profile, its side effects being mainly limited to oral discomfort. Only six anaphylaxes and no fatalities have been so far reported. Due to the good risk:benefit ratio, SLIT is currently being investigated in diseases other than respiratory allergy, such as food allergy and atopic dermatitis.

Efficacy of sublingual immunotherapy versus subcutaneous injection immunotherapy in allergic patients

While it is generally accepted that Subcutaneous Injection Immunotherapy (SCIT) and Sublingual Immunotherapy (SLIT) are both efficacious, there is not yet a significant amount of information regarding their comparative efficacy. In this paper, we performed a retrospective chart review and compared treatment results in two groups of patients (both with nasal allergies with or without asthma) that were treated either with SCIT or SLIT. Both treatment modalities were found to be of similar efficacy.

Sublingual immunotherapy in allergic rhinitis

Current treatment options for allergic rhinitis (AR) include allergen avoidance and environmental control, pharmacotherapy, nasal surgery and immunotherapy. Among these, immunotherapy is the only therapeutic option that modifies fundamental immunologic mechanism by inducing desensitization. Specific allergen immunotherapy has been used for 1 century since 1911 and subcutaneous immunotherapy (SCIT) has been demonstrated to be effective in asthma and AR. However, SCIT has several disadvantages such as inconvenience, invasiveness and potentially severe systemic reactions. Thus, sublingual immunotherapy (SLIT) has recently received much attention around the world as a treatment for AR and is now widely used to replace the subcutaneous route. SLIT has recently been introduced in Korea and is now available for AR treatment in the Asia-Pacific region. This review offers better understanding of SLIT for AR by summarizing published articles and our previous works regarding proposed mechanisms, indication and efficacy, safety and adverse events, and compliance.

European Academy of Allergy and Clinical Immunology task force report on 'dose-response relationship in allergen-specific immunotherapy'

BACKGROUND

For a century, allergen-specific immunotherapy (SIT) has proven to be an effective treatment for allergic rhinitis, asthma, and insect sting allergy. However, as allergen doses are frequently adapted to the individual patient, there are few data on dose-response relationship in SIT. Allergen products for SIT are being increasingly required to conform to regulatory requirements for human medicines, which include the need to demonstrate dose-dependent effects.

METHODS

This report, produced by a Task Force of the EAACI Immunotherapy Interest Group, evaluates the currently available data on dose-response relationships in SIT and aims to provide recommendations for the design of future studies.

RESULTS

Fifteen dose-ranging studies fulfilled the inclusion criteria and twelve reported a dose-response relationship for clinical efficacy. Several studies also reported a dose-response relationship for immunological and safety endpoints. Due to the use of different reference materials and methodologies for the determination of allergen content, variations in study design, and choice of endpoints, no comparisons could be made between studies and, as a consequence, no general dosing recommendations can be made.

CONCLUSION

Despite recently introduced guidelines on the standardization of allergen preparations and study design, the Task Force identified a need for universally accepted standards for the measurement of allergen content in SIT preparations, dosing protocols, and selection of clinical endpoints to enable dose-response effects to be compared across studies.

Maintenance dosing for sublingual immunotherapy by prominent European allergen manufacturers expressed in bioequivalent allergy units

BACKGROUND

Sublingual immunotherapy (SLIT) has become established in Europe, and its efficacy is being evaluated in the United States. The doses used for SLIT in Europe today are difficult to evaluate, because each manufacturer expresses the potency of its extracts differently.

OBJECTIVES

To compare in vitro European SLIT maintenance solutions against US licensed standardized allergenic extract concentrates and to determine the monthly SLIT doses delivered expressed in bioequivalent allergy units ([B]AU).

METHODS

We studied Dermatophagoides pteronyssinus, timothy grass pollen, cat (hair) and short ragweed pollen allergen extracts. The SLIT maintenance solutions of 4 leading European manufacturers and standardized concentrate extracts of 3 US manufacturers were analyzed with the following assays: protein content, relative potency (immunoglobulin E [IgE]-binding enzyme-linked immunosorbent assay [ELISA] inhibition) and major allergen content. The relative monthly allergen dose in (B)AU was calculated for each recommended SLIT schedule.

RESULTS

Relative potency was approximately 10 times higher for US concentrate standardized extracts-which are meant to be diluted-than for European SLIT maintenance solutions of D pteronyssinus and timothy grass pollen. For cat (hair) and short ragweed pollen, the difference was less. Measurements of relative potency and major allergen content correlated well. In our assays, European mite extracts contain a very low quantity of Der p 2 compared with US mites.

CONCLUSION

Recommended SLIT doses in Europe vary widely among the manufacturers, but are consistently lower (Eur1) or higher (Eur4) over all four allergens tested. SLIT efficacy probably depends on additional factors apart from the exact dose. SLIT dose finding studies should be done for each product.

Sublingual immunotherapy for allergic respiratory diseases: efficacy and safety

Subcutaneous immunotherapy (SCIT) is effective and safe when properly prescribed and administered. However, a certain risk of severe side effects exists, even when the reaction is managed correctly. These potential adverse effects stimulated the search for new administration routes (nasal, bronchial, oral, sublingual), which were expected to be safer. Not all of these alternative routes provided an improved benefit-safety profile compared with SCIT. The sublingual route (SLIT) seemed to be a good candidate for the clinical practice because of its satisfactory safety profile and is now considered an acceptable alternative to SCIT in adults and children.

Immunologic effects and tolerability profile of in-season initiation of a standardized-quality grass allergy immunotherapy tablet: a phase III, multicenter, randomized, double-blind, placebo-controlled trial in adults with grass pollen-induced rhinoconjunctivitis

BACKGROUND

The summary of product characteristics of the grass allergy immunotherapy tablet (AIT) (Phleum pratense grass pollen allergen extract) states that clinical effect may be observed in the first pollen season of treatment, if treatment is initiated ≥2 months (8 weeks) before the start of the grass pollen season. However, because patients with grass allergy may first present to physicians during the season, immediate treatment initiation (ie, in-season initiation) may increase treatment compliance and reduce the risk for disease progression compared with asking patients to return before the next pollen season to initiate treatment. This "in-season approach" may offer more patients the potentially beneficial treatment option of specific immunotherapy. However, to date, the immunomodulatory effects and tolerability of in-season treatment initiation is unknown.

OBJECTIVE

The aim of this study was to assess the immunologic effects and tolerability of in-season initiation of treatment with the grass AIT.

METHODS

This multicenter, randomized, double-blind, placebo-controlled trial was carried out in Germany and Austria. Adults with grass pollen allergy (positive skin-prick test and specific grass-pollen immunoglobulin [Ig] E) and grass pollen-induced moderate to severe persistent rhinoconjunctivitis were enrolled. Patients were randomly assigned to receive once-daily grass AIT or placebo, starting during the 2008 grass pollen season and continuing for 8 to 10 weeks. The primary end point was change from baseline in IgE-blocking factor (serum components competing with IgE for allergen binding). Secondary end points included changes from baseline in specific IgE and IgG(4) and measures of tolerability (assessed mainly by adverse events [AEs]). Blood samples for immunologic assessment were obtained by the investigators at baseline and after treatment. All AEs observed by the investigator and/or reported by the patient were recorded throughout the trial and follow-up.

RESULTS

A total of 276 patients were enrolled and formed the full analysis set (mean age, 35 years; 55% men, 45% women; 99% white; mean weight, 76 kg; history of asthma, 41%; mean duration of grass allergy, 15.1 years). No major differences in medical history were found between the grass AIT group (n = 219) and the placebo group (n = 57). The change from baseline in mean concentration of IgE-blocking factor was significantly greater with grass AIT compared with placebo (+0.14 vs +0.05; P < 0.0001). The changes from baseline in specific IgE and specific IgG(4) concentrations were significantly greater with AIT compared with placebo (IgE, +0.59 vs +0.21 log kU/L; IgG(4), +0.18 vs +0.04 log relative units; both, P < 0.0001). At least 1 AE was reported in 58% of patients in the AIT group and in 40% of patients in the placebo group. Most AEs considered related to AIT were mild or moderate events in the mouth, throat, and/or ears (eg, oral pruritus). Four serious AEs were reported in the AIT group (sinusitis, road traffic accident, salmonellosis, meniscus lesion), but all were considered unlikely to be related to treatment. Three percent of the grass AIT group and 2% of the placebo group were withdrawn from the trial due to an AE.

CONCLUSIONS

In-season initiation of grass AIT was associated with an immunomodulatory response in terms of induction of IgE-blocking factor, specific IgE, and specific IgG(4). In-season initiation of grass AIT was generally well tolerated in this group of adults with moderate to severe grass pollen-induced rhinoconjunctivitis. These findings are consistent with those related to the preseasonal initiation of AIT therapy.

Systematic reviews of sublingual immunotherapy (SLIT)

Allergic rhinitis is common worldwide, with significant morbidity and impact on quality of life. In patients who don't respond adequately to anti-allergic drugs. Subcutaneous allergen immunotherapy is effective although requires specialist administration. Sublingual immunotherapy may represent an effective and safer alternative. This Cochrane systematic review is an update of one published in 2003. We searched Cochrane ENT Group Trials Register, Central, PubMed, EMBASE, CINAHL, Web of Science, Biosis Previews, Cambridge Scientific Abstarcts, mRCT and additional sources. We included randomised, double-blind, placebo- controlled trials of sublingual immunotherapy in adults and children. Two authors selected studies and assessed them for quality. Data were put into RevMan 5.0 for a statistical analysis. We used standardised mean difference (SMD), with a random effect model to combine data. Sixty studies were included, with 49 suitable for meta-analysis. We found significant reductions in symptoms (SMD -0.49; 95%CI (-0.64 to -0.34, P < 0.00001)) and medication requirements (SMD -0.32; 95%CI (-0.43 to -0.21, P < 0.00001)) compared with placebo. None of the trials reported severe systemic reactions, anaphylaxis or use of Adrenaline. This updated review reinforces the conclusion of the original 2003 Cochrane Review that sublingual immunotherapy is effective for allergic rhinitis and appears a safe route of administration.

Allergy immunotherapy tablet: Grazax® for the treatment of grass pollen allergy

Immunotherapy is the only treatment for allergy that alters the natural course of this disease. Sublingual immunotherapy has been developed to make immunotherapy more suitable for allergic patients. In the largest clinical program ever conducted with grass allergen-specific immunotherapy, over 2000 adults and more than 500 children have been exposed to Grazax(®) (ALK-Abello A/S, Hoersholm, Denmark). Grazax is an oral lyophilisate tablet (allergy immunotherapy tablet [AIT]) for sublingual administration, containing 75,000 standardized quality tablet units of allergen extract of grass pollen (Phleum pratense). Grazax is indicated for treatment of grass pollen-induced rhinitis and conjunctivitis in adult and pediatric patients. Results from the GT-08 trial (first, second and third treatment years) showed a reduction of 31, 36 and 29%, respectively, in symptom scores and a reduction of 38, 45 and 40% of medication scores, respectively, compared with placebo. Subjects treated with Grazax also had an increased number of well days and a relevant improvement in quality of life. More subjects experienced excellent and complete rhinoconjunctivitis control in comparison with patients treated with symptomatic medications only. Grazax treatment is also associated with a sustained and relevant increase of specific IgG4. This increase is also observed after stopping AIT treatment. The most common adverse events related to Grazax treatment are local reactions, such as oral itch, edema of the mouth, ear pruritus, throat irritation and sneezing. Clinical efficacy of Grazax is observed also after 1 and 2 years of follow-up after stopping the AIT treatment. Grazax is efficacious and safe for treatment of grass-pollen rhinoconjunctivitis in both adults and children. Grazax is the first AIT showing a disease-modifying effect on grass pollen-induced allergic rhinoconjuctivitis.

The current role of sublingual immunotherapy in the treatment of allergic rhinitis in adults and children

Allergic rhinitis is a very common disease affecting about 20% of people. It may be treated by allergen avoidance when possible, by antiallergic drugs such as antihistamines and topical corticosteroids, and by allergen-specific immunotherapy. The latter is the only treatment able to act on the causes and not only on the symptoms of respiratory allergy and is able to maintain its efficacy even after stopping, provided an adequate duration of treatment of 3-5 years is ensured. Sublingual immunotherapy (SLIT) was introduced in the 1990s as a possible solution to the problem of adverse systemic reactions to subcutaneous immunotherapy and has been demonstrated by more than 50 trials and globally evaluated thus far by five meta-analyses as an effective and safe treatment for allergic rhinitis. Life-threatening reactions are extremely rare. However, it is important to note that clinical efficacy occurs only if SLIT meets its needs, ie, sufficiently high doses are regularly administered for at least 3 consecutive years. This is often overlooked in the current practice and may prevent the same success reported by trials from being achieved.

Sublingual immunotherapy for allergic rhinitis

BACKGROUND

This is an update of a Cochrane Review first published in The Cochrane Library in Issue 2, 2003.Allergic rhinitis is a common condition which can significantly impair quality of life. Immunotherapy by injection can significantly reduce symptoms and medication use but its use is limited by the possibility of severe systemic adverse reactions. Immunotherapy by the sublingual route is therefore of considerable interest.

OBJECTIVES

To evaluate the efficacy and safety of sublingual immunotherapy for allergic rhinitis in adults and children.

SEARCH STRATEGY

We searched the Cochrane ENT Group Trials Register; CENTRAL (2010, Issue 3); PubMed; EMBASE; CINAHL; Web of Science; BIOSIS Previews; Cambridge Scientific Abstracts; mRCT and additional sources for published and unpublished trials. The date of the most recent search was 14 August 2009.

SELECTION CRITERIA

Randomised, double-blind, placebo-controlled trials of sublingual immunotherapy in adults or children. Primary outcome measures were symptom and medication scores. We also collected adverse event data.

DATA COLLECTION AND ANALYSIS

Two independent authors selected studies and assessed risk of bias. One author extracted data which was rechecked by two other authors. We used the standardised mean difference (SMD) with a random-effects model to combine data.

MAIN RESULTS

We included a total of 60 randomised controlled trials in the review. Forty-nine were suitable for pooling in meta-analyses (2333 SLIT, 2256 placebo participants). Overall, we found a significant reduction in symptoms (SMD -0.49; 95% confidence interval (CI) -0.64 to -0.34, P < 0.00001) and medication requirements (SMD -0.32; 95% CI -0.43 to -0.21, P < 0.00001) in participants receiving sublingual immunotherapy compared to placebo. None of the trials included in this review reported severe systemic reactions or anaphylaxis, and none of the systemic reactions reported required the use of adrenaline.

AUTHORS' CONCLUSIONS

This updated review reinforces the conclusion of the original 2003 Cochrane Review that sublingual immunotherapy is effective for allergic rhinitis and has been proven to be a safe route of administration.

Emerging sublingual immunotherapy drugs

IMPORTANCE OF THE FIELD

There is epidemiological evidence that respiratory allergy has reached epidemic proportions; owing to the related socio-economic impact, this topic deserves particular attention. An integrated approach involving pharmacotherapy and the immunomodulatory effect of immunotherapy is expected to optimize the management of respiratory allergy, reducing its clinical and economic burdens. Sublingual immunotherapy (SLIT) has gained increasing interest for its efficacy comparable to traditional subcutaneous immunotherapy and its good safety profile.

AREAS COVERED IN THIS REVIEW

A review of the up-to-date state of the art concerning the key aspects of SLIT is provided; the critical issues are discussed in the light of the comprehensive revision of the recent World Allergy Organization position paper and the subsequent literature, paying particular attention to efficacy, safety, additional effects, adherence and clinical developments.

WHAT THE READER WILL GAIN

The overview of current certainties and concerns, related to the use of SLIT, allows the reader's insight into the future directions of research and clinical applications of SLIT, aimed at covering current unmet needs.

TAKE HOME MESSAGE

A large amount of experimental evidence sustains the use of SLIT, though some aspects still need to be clarified to provide clear, evidence-based recommendations. Unmet needs represent the basis for future research, while clinical hypotheses would open the search for new indications and modalities.