A double-blind placebo-controlled evaluation of sublingual immunotherapy with a standardized ragweed extract in patients with seasonal rhinitis. Evidence for a dose-response relationship

The safety of sublingual immunotherapy, can the rare systemic reactions be prevented?

Introduction: The safety of subcutaneous immunotherapy (SCIT), and particularly the dramatic issue of fatal reactions, has been an obstacle that limited the implementation of a therapy with unique characteristics of action on the causes of allergy. The introduction of sublingual immunotherapy (SLIT) was aimed at solving safety problems while maintaining clinical efficacy.Areas covered: For more than 20 years, SLIT has been based on allergen extracts in drops at low average doses. As evidenced by meta-analyses, the typical adverse events (AE) have consisted of local reactions in the mouth and throat. Unlike the injection route, no correlation was observed between the administered dose and AEs. The development of SLIT products in tablets, based on higher doses than drops, has somewhat changed the concept of SLIT safety. Although large trials, performed to obtain regulatory agency approval, have shown overall high safety, rare anaphylactic reactions have been described.Expert opinion: SLIT is globally safe, and no fatal reactions have ever been reported, but with currently available high biological potency products it is necessary to follow prudential rules, such as the administration of the first dose under medical supervision and the thorough education of patients to avoid taking of higher doses than recommended.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. Fifty-two studies were identified and synthesised in the original Cochrane Review in 2015, but questions remained about the safety and efficacy of sublingual immunotherapy for people with asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

The original searches for trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov, WHO ICTRP, and reference lists of all primary studies and review articles found trials up to 25 March 2015. The most recent search for trials for the current update was conducted on 29 October 2019.

SELECTION CRITERIA

We included parallel randomised controlled trials, irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma. We selected outcomes to reflect recommended outcomes for asthma clinical trials and those most important to people with asthma. Primary outcomes were asthma exacerbations requiring a visit to the emergency department (ED) or admission to hospital, validated measures of quality of life, and all-cause serious adverse events (SAEs). Secondary outcomes were asthma symptom scores, exacerbations requiring systemic corticosteroids, response to provocation tests, and dose of inhaled corticosteroids (ICS).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data, and assessed risk of bias, all of which were cross-checked for accuracy. Any disagreements were resolved by discussion. We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We considered the strength of evidence for all primary and secondary outcomes using the GRADE approach.

MAIN RESULTS

Sixty-six studies met the inclusion criteria for this update, including 52 studies from the original review. Most studies were double-blind and placebo-controlled, varied in duration from one day to three years, and recruited participants with mild or intermittent asthma, often with comorbid allergic rhinitis. Twenty-three studies recruited adults and teenagers; 31 recruited only children; three recruited both; and nine did not specify. The pattern of reporting and results remained largely unchanged from the original review despite 14 further studies and a 50% increase in participants studied (5077 to 7944). Reporting of primary efficacy outcomes to measure the impact of SLIT on asthma exacerbations and quality of life was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence; 16 studies did not contribute any data, and a further six studies could only be included in a post hoc analysis of all adverse events. Allocation procedures were generally not well described; about a quarter of the studies were at high risk of performance or detection bias (or both); and participant attrition was high or unknown in around half of the studies. The primary outcome in most studies did not align with those of interest to the review (mostly asthma or rhinitis symptoms), and only two small studies reported our primary outcome of exacerbations requiring an ED or hospital visit; the pooled estimate from these studies suggests SLIT may reduce exacerbations compared with placebo or usual care, but the evidence is very uncertain (OR 0.35, 95% confidence interval (CI) 0.10 to 1.20; n = 108; very low-certainty evidence). Nine studies reporting quality of life could not be combined in a meta-analysis and, whilst the direction of effect mostly favoured SLIT, the effects were often uncertain and small. SLIT likely does not increase SAEs compared with placebo or usual care, and analysis by risk difference suggests no more than 1 in 100 people taking SLIT will have a serious adverse event (RD -0.0004, 95% CI -0.0072 to 0.0064; participants = 4810; studies = 29; moderate-certainty evidence). Regarding secondary outcomes, asthma symptom and medication scores were mostly measured with non-validated scales, which precluded meaningful meta-analysis or interpretation, but there was a general trend of SLIT benefit over placebo. Changes in ICS use (MD -17.13 µg/d, 95% CI -61.19 to 26.93; low-certainty evidence), exacerbations requiring oral steroids (studies = 2; no events), and bronchial provocation (SMD 0.99, 95% CI 0.17 to 1.82; low-certainty evidence) were not often reported. Results were imprecise and included the possibility of important benefit or little effect and, in some cases, potential harm from SLIT. More people taking SLIT had adverse events of any kind compared with control (OR 1.99, 95% CI 1.49 to 2.67; high-certainty evidence; participants = 4251; studies = 27), but events were usually reported to be transient and mild. Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Despite continued study in the field, the evidence for important outcomes such as exacerbations and quality of life remains too limited to draw clinically useful conclusions about the efficacy of SLIT for people with asthma. Trials mostly recruited mixed populations with mild and intermittent asthma and/or rhinitis and focused on non-validated symptom and medication scores. The review findings suggest that SLIT may be a safe option for people with well-controlled mild-to-moderate asthma and rhinitis who are likely to be at low risk of serious harm, but the role of SLIT for people with uncontrolled asthma requires further evaluation.

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.

Ragweed allergy immunotherapy tablet MK-3641 (Ragwitek®) for the treatment of allergic rhinitis

INTRODUCTION

Allergic rhinitis (AR) is among the most common chronic conditions affecting both children and adults. It is the cause of significant morbidity from the symptoms and interference with sleep. It results in major impairment of performance both at school and at work. In the U.S. and certain parts of Europe, ragweed pollen is a major cause of seasonal AR. In 2014, the U.S. Food and Drug Administration (FDA) approved a sublingual ragweed tablet (MK-3641) for use in adults with ragweed-induced AR. Areas covered: This paper will review the impact of ragweed-induced AR and available treatments including subcutaneous immunotherapy and studies with MK-3641. The principal search method was PubMed. Expert commentary: One dosing finding, two 28-day safety and two 52-week safety and efficacy studies have been conducted with MK-3641. The 12-U (12μg Amb a 1) tablet was the most effective. Local application site reactions were common but usually not serious. Only one, non-serious systemic reaction was reported in four safety studies. MK-3641 is a safe and effective treatment for ragweed-pollen-induced AR when treatment is initiated ≥ 12 weeks prior to the onset of the ragweed pollen season.

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.

Evidence in immunotherapy for paediatric respiratory allergy: Advances and recommendations

Allergic respiratory diseases are major health problems in paediatric population due their high level of prevalence and chronicity, and to their relevance in the costs and quality of life. One of the most important risk factors for the development of airway diseases in children and adolescents is atopy. The mainstays for the treatment of these diseases are avoiding allergens, controlling symptoms, and preventing them through sustained desensitization by allergen immunotherapy (AIT). AIT is a treatment option that consists in the administration of increasing amounts of allergens to modify the biological response to them, inducing long-term tolerance even after treatment has ended. This treatment approach has shown to decrease symptoms and improve quality of life, becoming cost effective for a large number of patients. In addition, it is considered the only treatment that can influence the natural course of the disease by targeting the cause of the allergic inflammatory response. The aim of this publication is to reflect the advances of AIT in the diagnosis and treatment of allergic respiratory diseases in children and adolescents reviewing articles published since 2000, establishing evidence categories to support the strength of the recommendations based on evidence. The first part of the article covers the prerequisite issues to understand how AIT is effective, such as the correct etiologic and clinical diagnosis of allergic respiratory diseases. Following this, the article outlines the advancements in understanding the mechanisms by which AIT achieve immune tolerance to allergens. Administration routes, treatment regimens, dose and duration, efficacy, safety, and factors associated with adherence are also reviewed. Finally, the article reviews future advances in the research of AIT.

Safety profile of sublingual immunotherapy

Sublingual immunotherapy (SLIT) was proposed for clinical practice about 20 years ago with the main aim of improving the safety and avoiding the adverse effects of traditional treatment for allergic airways disease. To date, 32 randomized controlled trials and 6 postmarketing surveys have been published that provide a robust documentation of the safety profile of the treatment.Looking at the randomized trials it emerges that the more frequent adverse event of SLIT is oral itching or swelling, followed by gastrointestinal complaints. These adverse events are invariably described as mild and easily managed by adjusting the dose. Relevant systemic adverse events (asthma, urticaria, angioedema) occur sporadically and, with the exception of oral/gastrointestinal adverse events, the incidence of adverse events seems not to differ between the placebo and active groups. The safety profile of SLIT does not differ between adults and children.The postmarketing surveys consistently show that the incidence of adverse events associated with SLIT is less than 10%, corresponding to less than 1 adverse event per 1000 doses, and is thus quite superior to the safety profile of subcutaneous immunotherapy. Of note, the most recent data show that the rate of adverse events with SLIT is not increased in children below the age of 5 years.

Sublingual immunotherapy for asthma

BACKGROUND

Asthma is a common long-term respiratory disease affecting approximately 300 million people worldwide. Approximately half of people with asthma have an important allergic component to their disease, which may provide an opportunity for targeted treatment. Sublingual immunotherapy (SLIT) aims to reduce asthma symptoms by delivering increasing doses of an allergen (e.g. house dust mite, pollen extract) under the tongue to induce immune tolerance. However, it is not clear whether the sublingual delivery route is safe and effective in asthma.

OBJECTIVES

To assess the efficacy and safety of sublingual immunotherapy compared with placebo or standard care for adults and children with asthma.

SEARCH METHODS

We identified trials from the Cochrane Airways Group Specialised Register (CAGR), ClinicalTrials.gov (www.ClinicalTrials.gov), the World Health Organization (WHO) trials portal (www.who.int/ictrp/en/) and reference lists of all primary studies and review articles. The search is up to date as of 25 March 2015.

SELECTION CRITERIA

We included parallel randomised controlled trials (RCTs), irrespective of blinding or duration, that evaluated sublingual immunotherapy versus placebo or as an add-on to standard asthma management. We included both adults and children with asthma of any severity and with any allergen-sensitisation pattern. We included studies that recruited participants with asthma, rhinitis, or both, providing at least 80% of trial participants had a diagnosis of asthma.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results for included trials, extracted numerical data and assessed risk of bias, all of which were cross-checked for accuracy. We resolved disagreements by discussion.We analysed dichotomous data as odds ratios (ORs) or risk differences (RDs) using study participants as the unit of analysis; we analysed continuous data as mean differences (MDs) or standardised mean differences (SMDs) using random-effects models. We rated all outcomes using GRADE (Grades of Recommendation, Assessment, Development and Evaluation) and presented results in the 'Summary of findings' table.

MAIN RESULTS

Fifty-two studies met our inclusion criteria, randomly assigning 5077 participants to comparisons of interest. Most studies were double-blind and placebo-controlled, but studies varied in duration from one day to three years. Most participants had mild or intermittent asthma, often with co-morbid allergic rhinitis. Eighteen studies recruited only adults, 25 recruited only children and several recruited both or did not specify (n = 9).With the exception of adverse events, reporting of outcomes of interest to this review was infrequent, and selective reporting may have had a serious effect on the completeness of the evidence. Allocation procedures generally were not well described, about a quarter of the studies were at high risk of bias for performance or detection bias or both and participant attrition was high or unknown in around half of the studies.One short study reported exacerbations requiring a hospital visit and observed no adverse events. Five studies reported quality of life, but the data were not suitable for meta-analysis. Serious adverse events were infrequent, and analysis using risk differences suggests that no more than 1 in 100 are likely to suffer a serious adverse event as a result of treatment with SLIT (RD 0.0012, 95% confidence interval (CI) -0.0077 to 0.0102; participants = 2560; studies = 22; moderate-quality evidence).Within secondary outcomes, wide but varied reporting of largely unvalidated asthma symptom and medication scores precluded meaningful meta-analysis; a general trend suggested SLIT benefit over placebo, but variation in scales meant that results were difficult to interpret.Changes in inhaled corticosteroid use in micrograms per day (MD 35.10 mcg/d, 95% CI -50.21 to 120.42; low-quality evidence), exacerbations requiring oral steroids (studies = 2; no events) and bronchial provocation (SMD 0.69, 95% CI -0.04 to 1.43; very low-quality evidence) were not often reported. This led to many imprecise estimates with wide confidence intervals that included the possibility of both benefit and harm from SLIT.More people taking SLIT had adverse events of any kind compared with control (OR 1.70, 95% CI 1.21 to 2.38; low-quality evidence; participants = 1755; studies = 19), but events were usually reported to be transient and mild.Lack of data prevented most of the planned subgroup and sensitivity analyses.

AUTHORS' CONCLUSIONS

Lack of data for important outcomes such as exacerbations and quality of life and use of different unvalidated symptom and medication scores have limited our ability to draw a clinically useful conclusion. Further research using validated scales and important outcomes for patients and decision makers is needed so that SLIT can be properly assessed as clinical treatment for asthma. Very few serious adverse events have been reported, but most studies have included patients with intermittent or mild asthma, so we cannot comment on the safety of SLIT for those with moderate or severe asthma. SLIT is associated with increased risk of all adverse events.

Dosing of sublingual immunotherapy for allergic rhinitis: evidence-based review with recommendations

BACKGROUND

Since the mid 1980s, the clinical use of sublingual immunotherapy (SLIT) has dramatically increased. However, 1 of the primary barriers to providing SLIT is lack of a published dosing recommendations. The purpose of this work is to provide a range of effective SLIT dosing based upon a rigorous review of the existing evidence base. An appendix with SLIT dosing recommendations is also included.

METHODS

A comprehensive search of the past 25 years of the medical literature using PubMed was performed for specific antigens. Inclusion criteria for articles included: randomized, placebo-controlled studies of SLIT, studies with clinical allergic rhinitis outcomes, and dosing units available to determine the micrograms per month of major allergen administered. The extracted data was used to compile a range of effective SLIT dosing for individual antigens.

RESULTS

Seventy-five articles met the inclusion criteria, providing a range of effective dosing for some allergens. There was commonly a wide range in doses for particular antigens between the individual studies. For some antigens, there was significant overlap in dosage amount between studies showing efficacy and lack of efficacy. Clinical trials meeting inclusion criteria are not available for many allergens.

CONCLUSION

This study provided a comprehensive review of the published sublingual dosing ranges for specific antigens. The review provided a range of effective sublingual doses for some allergens, whereas for other allergens there was insufficient published data to determine specific doses. Recommendations for SLIT dosing were produced based on the data revealed in the review and expert opinion.

Ragweed-induced allergic rhinoconjunctivitis: current and emerging treatment options

Ragweed (Ambrosia spp.) is an annually flowering plant whose pollen bears high allergenic potential. Ragweed-induced allergic rhinoconjunctivitis has long been seen as a major immunologic condition in Northern America with high exposure and sensitization rates in the general population. The invasive occurrence of ragweed (A. artemisiifolia) poses an increasing challenge to public health in Europe and Asia as well. Possible explanations for its worldwide spread are climate change and urbanization, as well as pollen transport over long distances by globalized traffic and winds. Due to the increasing disease burden worldwide, and to the lack of a current and comprehensive overview, this study aims to review the current and emerging treatment options for ragweed-induced rhinoconjunctivitis. Sound clinical evidence is present for the symptomatic treatment of ragweed-induced allergic rhinoconjunctivitis with oral third-generation H1-antihistamines and leukotriene antagonists. The topical application of glucocorticoids has also been efficient in randomized controlled clinical trials. Combined approaches employing multiple agents are common. The mainstay of causal treatment to date, especially in Northern America, is subcutaneous immunotherapy with the focus on the major allergen, Amb a 1. Beyond this, growing evidence from several geographical regions documents the benefit of sublingual immunotherapy. Future treatment options promise more specific symptomatic treatment and fewer side effects during causal therapy. Novel antihistamines for symptomatic treatment are aimed at the histamine H3-receptor. New adjuvants with toll-like receptor 4 activity or the application of the monoclonal anti-immunoglobulin E antibody, omalizumab, are supposed to enhance conventional immunotherapy. An approach targeting toll-like receptor 9 by synthetic cytosine phosphate–guanosine oligodeoxynucleotides promises a new treatment paradigm that aims to modulate the immune response, but it has yet to be proven in clinical trials.

Clinical and cytokine responses to house dust mite sublingual immunotherapy

BACKGROUND

Cytokine responses accompanying sublingual immunotherapy (SLIT) responder phenotypes have not previously been reported.

OBJECTIVE

To investigate clinical and cytokine responses of house dust mite (HDM) sensitive patients with allergic rhinitis receiving HDM SLIT or placebo for 2 years.

METHODS

Sixty adults were randomized to receive SLIT or placebo. Clinical symptoms were measured using the Total 5 Symptom Score (TSS5) and Juniper Rhinitis Quality of Life Questionnaire. HDM specific IgE, IgG, skin prick tests, and HDM-stimulated release of interleukin (IL) 5 and interferon γ (IFN-γ) in peripheral blood mononuclear cells was studied at 0, 6, 12, and 24 months and IL-13, IL-4, and IL-10 at 0 and 24 months.

RESULTS

A total of 32 of 39 SLIT and 16 of 21 placebo patients completed the study. There was significant clinical improvement in both the SLIT and placebo groups. Median T5SS decreased from 14.75 to 5.25 in the SLIT group (P < .001) and 12.7 to 6.0 in the placebo group (P = .003). The median quality-of-life score also decreased in the SLIT group (P < .001) and the placebo group (P < .001). A subgroup analysis of patients found a 60% or greater improvement (on the T5SS and the Juniper Rhinitis Quality of Life Questionnaire) in the good responders group and a 30% to 59% improvement or no improvement in the intermediate responders group. This subgroup analysis also found more good responders in the SLIT group (47%) compared with the placebo group (25%; P = .07). Significant decreases in the IL-5/IFN-γ (P < .001), IL-13/IFN-γ (P < .001), and IL-4/IFN-γ (P = .03) ratios were found in the combined good clinical improvement group at 24 months.

CONCLUSION

A good clinical response (≥60% improvement in both TSS5 and quality of life) is associated with significant decreases in IL-5, IL-13, and IL-4 relative to IFN-γ during 2 years of SLIT therapy for HDMs.

The safety of self-administered allergen immunotherapy during the buildup and maintenance phases

BACKGROUND

Self-administered allergen immunotherapy is considered controversial. We believe the implementation of a self-administration protocol characterized by patient preselection and a slow buildup phase is safe.

METHODS

We analyzed 23,614 patient records and associated immunotherapy injections for systemic reactions (SR) during a 1-year period (2011 to 2012). SRs were graded in accordance with the World Allergy Organization (WAO) criteria.

RESULTS

Thirty-seven SRs were reported for 23,614 patients who self-administered 2,021,600 injections yielding an annual SR rate of 0.16% (per patient) or 0.002% (per injection). Only 9 of 4643 pediatric (0.19%) and 28 of 18,971 adult patients (0.15%) experienced 1 or more SRs. No deaths (grade V SR) occurred. From 2009 through early 2014, over 90,000 patients received more than 10 million injections in accordance with the United Allergy Services (UAS) protocol without fatalities.

CONCLUSION

We believe this safety profile is due to a preselection of patients to exclude those with a high risk for adverse reactions and a slow immunotherapy buildup phase. In contrast, previous studies documented office-based SRs ranging from approximately 3% to greater than 14%. Thus, the UAS home-immunotherapy SR rate is significantly lower than office-based immunotherapy SR rates (p < 0.0001). The enhanced safety of this protocol results in a decreased frequency and severity of SRs. This safety report, derived from analyses of one of the largest patient cohorts studied, corroborates and expands the observations of previous studies of self-administered subcutaneous immunotherapy in a low-risk patient population by assessing self-administered allergen immunotherapy during the buildup and maintenance phases.

Efficacy and safety of ragweed sublingual immunotherapy in Canadian patients with allergic rhinoconjunctivitis

Background

Currently accepted therapies for ragweed allergy in North America consist of pharmacotherapy and subcutaneous allergen immunotherapy injections to treat symptoms. Allergen immunotherapy not only reduces symptoms and the need for pharmacotherapy but has also been shown to have disease-modifying potential. Recently, ragweed immunotherapy administered via sublingual allergen tablet has been approved in North America for treatment of allergic rhinitis with and without conjunctivitis.

Methods

This was an analysis of pooled data for a prespecified subgroup of Canadian subjects from two multicentre, randomized, double-blind placebo-controlled trials of ragweed sublingual tablet (SLIT-T; 6 and 12 Amb a 1-U of Ambrosia artemisiifolia) in patients aged ≥18y, with ragweed-induced allergic rhinoconjunctivitis (AR/C) with or without asthma. Randomized subjects used once-daily ragweed SLIT-T or placebo for at least 12 weeks before the ragweed season and for up to 52 weeks post-randomization. The primary efficacy endpoint was the total combined score (TCS) based on the sum of AR/C daily symptom score (DSS) and daily medication score (DMS) averaged over the peak season. Treatment effects on TCS, DSS, and DMS in the entire season were also assessed. Adverse events (AEs) were monitored to assess safety.

Results

337 Canadian subjects were randomized in the two trials. During the peak season, ragweed SLIT-T 6 and 12 Amb a 1-U significantly reduced TCS by 26% (difference, -2.46 score point; p = .0009) and 40% (difference, -3.75 score point; p < .0001), respectively. In the overall population (N = 961), TCS reductions with 6 and 12 Amb a 1-U were 20% and 23%, respectively (both p < .001). Clinically meaningful reductions in entire-season TCS in Canadians were similar to those during peak ragweed season. Dose-dependent reduction of DSS and DMS was also observed for ragweed SLIT-T 6 and 12 Amb a 1-U during the peak season and the entire season. Ragweed SLIT-T was well tolerated in Canadian subjects and the overall population. Adverse events were generally mild to moderate and transient, occurring early in treatment; no systemic allergic reaction/anaphylaxis was noted.

Conclusion

Ragweed SLIT-T is an effective form of immunotherapy that provides symptomatic efficacy of AR/C with a favorable risk profile in Canadian and overall populations.

Trial registration

Clinicaltrials.gov identifiers NCT00783198 and NCT00770315.

Safety and tolerability of a short ragweed sublingual immunotherapy tablet

BACKGROUND

MK-3641 is a short ragweed sublingual tablet under investigation for immunotherapy of ragweed pollen-induced allergic rhinitis.

OBJECTIVE

To characterize the safety and tolerability of a ragweed sublingual tablet (Merck/ALK-Abelló) in ragweed-allergic adults with or without conjunctivitis.

METHODS

Data from 4 randomized, double-blinded, placebo-controlled trials of MK-3641 (2 28-day and 2 52-week trials) were evaluated. Pooled analyses examined short-term safety over 28 days from all 4 trials and long-term safety from the 52-week trials.

RESULTS

Across all studies, 757, 198, 454, and 1,058 subjects were randomized to placebo or 1.5, 6, or 12 Amb a 1-U of MK-3641, respectively. Treatment-related adverse events were more frequent in the 6- and 12-Amb a 1-U MK-3641 groups than in the placebo group and were primarily local application-site reactions occurring in the first few days of treatment. There was no treatment-associated loss of asthma control or worsening of asthma associated with treatment. No swellings led to airway obstruction or respiratory compromise. No treatment-related anaphylactic shock, life-threatening, or serious treatment-related adverse events were reported for any MK-3641 dose. Of the 1,707 MK-3641-treated subjects, 1 systemic (anaphylactic) reaction was reported (0.06%). The 52-week long-term assessment was generally similar to the safety profile based on the 28-day assessment.

CONCLUSION

MK-3641 doses up to and including 12 Amb a 1-U were well tolerated, with no unexpected safety findings. Sublingual immunotherapy risks such as worsening asthma or airway swellings that could cause airway obstruction were not observed. Systemic reactions and use of epinephrine were uncommon. In these studies, after the first dose was administered in a health care setting, self-administration was well tolerated.

TRIAL REGISTRATION

clinicaltrials.gov Identifiers: NCT01469182, NCT00783198, NCT00770315, and NCT00978029.

Dropouts in sublingual allergen immunotherapy trials - a systematic review

Participant dropouts can reduce the power of allergen immunotherapy clinical trials. Evaluation of the dropout rate and reasons for dropout are important not only in the planning of clinical studies but are also relevant for adherence to immunotherapy in daily clinical practice. A systematic review was carried out in order to establish the overall dropout rate among published double-blind, placebo-controlled randomized clinical trials of sublingual immunotherapy for respiratory allergic diseases. Dropouts were analysed in regards to allergen, formulation, treatment schedule, participant age, study size, number of centres and type of allergic disease. Relative dropout rates in placebo and active groups as well as reasons for dropout were also assessed. A total of 81 studies, comprising 9998 patients, were included. Dropout rates in sublingual immunotherapy controlled studies do not appear to be a major problem with a composite dropout percentage of 14% (95% CI:11.9-16). Furthermore, they are not different for active compared to placebo-treated participants. This lends support to the positive clinical outcomes seen in meta-analyses of these trials.

Randomized, double-blind, placebo-controlled trial of standardized ragweed sublingual-liquid immunotherapy for allergic rhinoconjunctivitis

BACKGROUND

Sublingual immunotherapy with liquid extracts provides an appealing alternative to subcutaneous immunotherapy for the treatment of allergic rhinoconjunctivitis (ARC), but a lack of robust evidence has deterred its use in North America.

OBJECTIVE

To determine the efficacy and tolerability of standardized glycerinated short ragweed sublingual allergen immunotherapy liquid (RW-SAIL) extract in subjects with ragweed-related ARC.

METHODS

This phase 3, randomized, placebo-controlled trial was conducted in North America. Subjects (age range, 18-55 years) with or without asthma were selected based on ARC symptom severity and erythema skin prick reaction to short ragweed. Subjects self-administered the maximum tolerated dose of RW-SAIL (n = 218) or placebo (n = 211) daily beginning approximately 8 to 16 weeks before and through the end of the ragweed pollen season. The primary end point was subject-assessed total combined daily rhinoconjunctivitis symptom and medication scores (TCS).

RESULTS

During the entire season, there was a 43% decrease in TCS in subjects treated with RW-SAIL compared with placebo. Similar decreases were observed in TCS between the 2 groups during peak season (42%) and in daily symptom scores during the entire (42%) and peak (41%) seasons. The occurrence of adverse events was similar between the treatment groups; most were mild in severity. Treatment-related oromucosal local application site reactions occurred early and were transient and self-limited. No anaphylaxis occurred.

CONCLUSIONS

This is the first successful North American confirmatory phase 3 clinical trial to demonstrate the safety and efficacy of a sublingual standardized ragweed allergen immunotherapy liquid extract for the treatment of ARC.

Randomized controlled trial of a ragweed allergy immunotherapy tablet in North American and European adults

BACKGROUND

In North America and Europe, millions of patients experience symptoms of allergic rhinitis with or without conjunctivitis (AR/C) on exposure to ragweed pollen. The disease burden can be significant, with most patients relying on symptomatic medications without disease-modifying potential. However, novel sublingual immunomodulatory treatment options may potentially play an important role if efficacy and side effect profiles allow the convenience of self-administration.

OBJECTIVES

This study evaluated an allergy immunotherapy tablet (AIT; SCH 39641/MK-3641) for treatment of ragweed-induced AR/C in the first large randomized, double-blind multinational trial of this therapeutic modality for ragweed allergy.

METHODS

Adults (n = 784) with short ragweed-induced AR/C were randomly assigned to approximately 52 weeks of daily self-administered ragweed AIT of 1.5, 6, or 12 units of Ambrosia artemisiifolia major allergen 1 (Amb a 1-U) or placebo. Subjects could use as-needed allergy rescue medication. Symptoms and medications were recorded daily. The primary efficacy end point was total combined daily symptom/medication score (TCS) during peak ragweed season. Safety was monitored through adverse event diaries maintained through study duration.

RESULTS

During peak ragweed season, ragweed AIT of 1.5, 6, and 12 Amb a 1-U reduced TCS by 9% (-0.76; P = .22), 19% (-1.58; P = .01), and 24% (-2.04; P = .002) compared with placebo. During the entire season, ragweed AIT of 1.5, 6, and 12 Amb a 1-U reduced TCS by 12% (-0.88; P = .09), 18% (-1.28; P = .01), and 27% (-1.92; P < .001) compared with placebo. Treatment was well tolerated; no systemic allergic reactions occurred.

CONCLUSIONS

In this trial, ragweed AIT of 12 Amb a 1-U was effective and tolerable with a safety profile that permitted daily self-administration of ragweed allergen immunotherapy.

Fast onset of action of sublingual immunotherapy in house dust mite-induced allergic rhinitis: a multicenter, randomized, double-blind, placebo-controlled trial

OBJECTIVES/HYPOTHESIS

To investigate how quickly an allergic rhinitis (AR) patients' symptoms will improve with sublingual immunotherapy (SLIT).

STUDY DESIGN

Double-blind placebo study.

METHODS

This is a multicenter, randomized, double-blind, placebo-controlled study of SLIT used to treat house dust mite-induced AR. A total of 120 AR patients, aged 4 to 60 years, were treated for 6 months and randomized into two groups: 1) SLIT with Dermatophagoides pteronyssinus (D.p.) and Dermatophagoides farina (D.f.) extract (n = 60) ; and 2) matched placebo controls (n = 60). Symptom, medications received, and a visual analog scale score were recorded during the whole study. Serum-specific IgE and IgG4 to D. p. and D. f. were assessed before and after the treatment.

RESULTS

Eighty-five patients (70.8%) completed the study. Twelve patients (20%) chose to withdraw from the SLIT group, but none because of serious adverse effects. The total symptom and visual analog scores VAS in the SLIT group decreased significantly when compared to the placebo controls (P <0.05) after week 14, as well as for the significant (P <0.05) improvement of all individual AR symptoms in the SLIT group (e.g., sneezing, nasal discharge, itching, and nasal obstruction) after week 22. There was a significant (P <0.05) increase of IgG4 to both D.f. and D.p. in the SLIT, but not in the placebo group after treatment.

CONCLUSION

SLIT with a mixture of D.f. and D.p. extract is an effective and safe treatment for patients with house dust mite-induced AR. Its onset of action can be observed as early as 14 weeks after treatment.

Clinical improvement after escalation for sublingual immunotherapy (SLIT)

Sublingual immunotherapy (SLIT) permits rapid antigen escalation with an improved safety profile over that of subcutaneous immunotherapy. Outcomes for SLIT in terms of the timing of clinical improvement were investigated in a retrospective review of patients undergoing SLIT who completed quality of life (QOL) and medication-use questionnaires at baseline and immediately after antigen escalation was performed. A subset of patients (n = 24) also completed maintenance-phase questionnaires. Paired post-escalation data (mean 5.5 weeks; N = 38) demonstrated improvement (p< 0.05) in overall QOL scores and in 6 of 14 symptom domains. Maintenance phase data (n = 24) revealed significant improvements in total QOL scores and in 5 symptom domains. A significant reduction in nasal steroid use was also demonstrated during the maintenance phase of treatment (p < 0.05). Significant improvement is seen immediately post-escalation in SLIT patients. This improved QOL appears to be maintained, and perhaps even increases, during the maintenance phase, with decreased nasal steroid use.

Mechanisms of immunotherapy to aeroallergens

Allergen immunotherapy is allergen-specific, allergen dose- and time-dependent and is associated with long-term clinical and immunological tolerance that persists for years after discontinuation. Successful immunotherapy is accompanied by the suppression of numbers of T-helper 2 (Th2) effector cells, eosinophils, basophils, c-kit+mast cells and neutrophils infiltration in target organs, induction of IL-10 and/or TGF-β+Treg cells and increases in 'protective' non-inflammatory blocking antibodies, particularly IgG4 and IgA2 subclasses with inhibitory activity. These events are accompanied by a reduction and/or a redirection of underlying antigen-specific Th2-type T cell-driven hypersensitivity to the allergen(s) used for therapy. This suppression occurs within weeks or months as a consequence of the appearance of a population of regulatory T cells that exert their effects by mechanisms involving cell-cell contact, but also by the release of cytokines such as IL-10 (increases IgG4) and TGF-β (increases specific IgA). The more delayed-in-time appearance of antigen-specific T-helper 1 responses and alternative mechanisms such as Th2 cell anergy and/or apoptosis may also be involved. The mechanisms of sublingual immunotherapy are similar to those following a subcutaneous administration of allergen, whereas it is likely that additional events following antigen presentation in the sublingual mucosa and regional lymph nodes are involved. These insights have resulted in novel approaches and portend future biomarkers that may be surrogate or predictive of the clinical response to treatment.

Sublingual immunotherapy for treating allergic conjunctivitis

BACKGROUND

Allergic ocular symptoms, although frequently trivialised, are common and represent an important comorbidity of allergic rhinitis. Sublingual Immunotherapy (SLIT) is an effective and well-tolerated treatment for allergic rhinitis, but its effects on symptoms of ocular allergy have not been well established.

OBJECTIVES

To evaluate the efficacy of SLIT compared with placebo for reductions in ocular symptoms, topical ocular medication requirements and conjunctival immediate allergen sensitivity.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 1), MEDLINE (January 1950 to January 2011), EMBASE (January 1980 to January 2011), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to January 2011), Web of Science (January 1970 to January 2011), Biosis Previews, (January 1979 to January 2011), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) (January 2011), ClinicalTrials.gov (www.clinicaltrials.gov) (January 2011), the Australian New Zealand Clinical Trials Registry (ANZCTR) (www.actr.org.au) (July 2010), SCOPUS (November 2008) and the UK Clinical Trials Gateway (January 2010). There were no language or date restrictions in the search for trials. All electronic databases except for SCOPUS, the UK Clinical Trials Gateway and ANZCTR were last searched on 19 January 2011.

SELECTION CRITERIA

Randomised controlled trials (RCTs), double-masked and placebo controlled, which evaluated the efficacy of SLIT in patients with symptoms of allergic rhinoconjunctivitis (ARC) or allergic conjunctivitis (AC).

DATA COLLECTION AND ANALYSIS

The primary outcome was the total ocular symptom scores. Secondary endpoints included individual ocular symptom scores (such as itchy eyes, red eyes, watery eyes, swollen eyes), ocular medication scores (eye drops) and conjunctival immediate allergen sensitivity (CIAS). Data were analysed and reported as standardised mean differences (SMDs) using Review Manager software.

MAIN RESULTS

Forty-two trials (n = 3958 total participants; n= 2011 SLIT and n = 1947 placebo) had available data to evaluate the efficacy of SLIT on AC and were included in the meta-analyses. Heterogeneity among studies (I(2) statistic) was around 50% or below for all endpoints. Sublingual immunotherapy induced a significant reduction in both total ocular symptom scores (SMD -0.41; 95% confidence interval (CI) -0.53 to -0.28; P < 0.00001; I(2) = 59%) and individual ocular symptom scores for red eyes (SMD -0.33; 95% CI -0.45 to -0.22; P < 0.00001; I(2) = 27%), itchy eyes (SMD -0.31; 95% CI -0.42 to -0.20; P < 0.00001; I(2) = 46%) and watery eyes (SMD -0.23; 95% CI -0.34 to -0.11; P < 0.0001; I(2) = 42%) compared to placebo. Those participants having active treatment showed an increase in the threshold dose for the conjunctival allergen provocation test (SMD 0.35; 95% CI 0.00 to 0.69; P = 0.05; I(2) = 43%). No significant reduction was observed in ocular eye drops use (SMD -0.10; 95% CI -0.22 to 0.03; P = 0.13; I(2) = 34%).

AUTHORS' CONCLUSIONS

Overall, SLIT is moderately effective in reducing total and individual ocular symptom scores in participants with ARC and AC. There were however some concerns about the overall quality of the evidence-base, this relating to inadequate descriptions of allocation concealment in some studies, statistical heterogeneity and the possibility of publication bias. There is a need for further large rigorously designed studies that study long-term effectiveness after discontinuation of treatment and establish the cost-effectiveness of SLIT.

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.

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.

Immunological effects of sublingual immunotherapy: clinical efficacy is associated with modulation of programmed cell death ligand 1, IL-10, and IgG4

Sublingual immunotherapy (SLIT) is an alternate route of administration of allergen-specific immunotherapy with an improved safety profile; to clarify the immune mechanisms elicited by this therapy, we analyzed the clinical and immunologic effects of SLIT in patients with a clinical history of ragweed sensitization. To analyze possible difference among immunotherapeutic protocols, we also compared patients receiving preseasonal, seasonal, or prolonged sublingual therapy (≥ 3 y); patients receiving symptomatic therapy alone were enrolled as well in the study. Clinical and immunological parameters were measured twice in and out of the pollination period. Clinical benefits, as measured by the visual analog scale for symptoms and for use of drugs, were evident in all three groups of individuals receiving immunotherapy, but were significantly better in patients undergoing prolonged SLIT. Immunologically, SLIT resulted in increased IL-10 production, programmed cell death ligand 1 expression, and concentration of allergen-specific IgG4, as well as in the reduction of CD80 and CD86 expression and IL-4 production. SLIT, thus, is associated with modulation of programmed cell death ligand 1 expression and IL-10 synthesis and favors the production of allergen-specific IgG4. These effects are evident from the first pollen season, independently from therapeutic regimen (preseasonal or seasonal) even if a prolonged treatment is necessary to obtain full clinical efficacy. A more detailed understanding of the interaction of allergen and APCs within the oral mucosa will allow improved targeting of allergy vaccine.

Allergen immunotherapy: immunomodulatory treatment for allergic diseases

Allergen immunotherapy is currently the only immune-modifying treatment for allergic disease. At the present time it is indicated for the treatment of allergic rhinitis, asthma and venom hypersensitivity. Efficacy appears to be dose dependent, and the immunological mechanisms responsible for the clinical efficacy of immunotherapy are still being elucidated. Immunological changes associated with immunotherapy include induction of T regulatory cells, increase in allergen-specific immunoglobulin G4, increase in interleukin-10 production and downregulation of the T helper 2 response. The disadvantages of allergen immunotherapy include risk of adverse events and patient time and inconvenience. Risks of immunotherapy range from large local reactions to mild systemic reactions, such as rhinitis. Fatalities from immunotherapy injections have been reported at a rate of approximately one fatality per 2.5 million injections. Conventional subcutaneous immunotherapy build-up schedules involve administration of a single-dose increase each visit and it may take several months before a patient achieves the therapeutic maintenance dose. Accelerated schedules, such as rush and cluster, will allow the patient to achieve the maintenance dose sooner but there may be a greater risk of a systemic reaction. The current focus of immunotherapy research is to develop safer and more effective vaccines. Another approach to enhancing immunotherapy safety is through an alternative delivery method. Sublingual immunotherapy is clearly safer than subcutaneous immunotherapy, but further investigation is needed to determine optimal dose and appropriate patient selection.

Italian real-life experience of omalizumab

Omalizumab is a humanized murine monoclonal antibody directed toward a portion of the IgE indicated in Europe for the treatment of severe persistent allergic asthma, inadequately controlled despite high-dose of ICS (mean BDP equivalent dose of inhaled corticosteroid 2224.68microg/die) in association with long-acting beta(2) agonists. Our aim was to describe the experience, efficacy and safety in a cohort of Italian patients treated with omalizumab in a real-life clinical setting. One hundred and forty two patients from 13 Italian Centers were observed and analysed. The dosage of omalizumab was established according to the labelling indication, with a median dose of IgE of 297.38IU/ml or kU/l. During the previous year, all patients experienced frequent exacerbations (mean=4.87), emergency visits (mean=4.45) and hospitalisation (mean=1.53). Following treatment with omalizumab, the annual rate of exacerbations, emergency visits and hospitalisation decreased by 79%, 88% and 95%, respectively. The proportion of patients without exacerbation, not needing emergency visits and hospitalization increased by 610%, 154% and 28%, respectively. The response to omalizumab measured with the GETE (global evaluation of treatment effectiveness) scale rated as good to excellent in 77% of patients. Overall, 9.6% (n=9) of the patients experienced one single adverse effect. Only one patient reported a serious adverse event (local reaction at the site of injection) leading to interruption of treatment. The observed reduction of asthma-related events in particularly poorly controlled patients in this Italian real-life setting is consistent with the results of other observational studies.

Development of an allergen extract for sublingual immunotherapy--evaluation of Staloral

BACKGROUND

Specific immunotherapy (IT) is an effective treatment for rhinitis and asthma caused by aeroallergens sensitization. Sublingual IT (SLIT) was introduced to solve the problem of systemic reactions to subcutaneous IT (SCIT) and developed to represent an actual treatment option. It is now generally accepted that allergen doses much higher than those administered by SCIT must be used to achieve clinical efficacy on allergic symptoms.

OBJECTIVE

To evaluate the characteristics of Staloral, an allergen extract produced by Stallergenes (Antony, France) in terms of practical administration, efficacy, safety and mechanism of action.

METHODS

Data were obtained from 20 double-blind, placebo-controlled studies using Staloral in patients sensitized to pollens and house-dust mites, and also from open studies concerning practical administration and the mechanism of action.

RESULTS/CONCLUSION

Efficacy and safety of Staloral, as demonstrated by the revision of the studies, which used doses up to 1125 times those administered with SCIT, are very satisfactory and confer to this allergen extract optimal characteristics for treating patients with seasonal allergies due to pollens or with perennial symptoms induced by dust mites. The main mechanism of action is the interaction with dendritic cells of the oral mucosa and the subsequent tolerance induced in T cells.

Quality of life outcomes with sublingual immunotherapy

PURPOSE

Immunotherapy is the titrated exposure of allergens to induce immunologic tolerance and offers long-term immune modification. Traditional subcutaneous immunotherapy (SCIT) has resulted in several deaths and raised safety concerns. Sublingual immunotherapy (SLIT) is an alternative administration route for allergen-specific immunotherapy. Compared to SCIT, SLIT has a shorter escalation phase, equal or greater efficacy for rhinitis, and an improved safety profile. The purpose of this study was to evaluate quality of life measures in a preliminary patient sample initiating SLIT at our institution.

MATERIALS AND METHODS

Patients with appropriate allergen reactivity were given the option to pursue immunotherapy by traditional SCIT or by SLIT techniques. Patients choosing SLIT completed the mini-Rhinoconjunctivitis Quality of Life Questionnaire (m-RQLQ), a 14-item Likert-type questionnaire, at baseline and during maintenance therapy. Patients typically reached maintenance dosing in less than 5 weeks.

RESULTS

Paired m-RQLQ data were available for 15 patients after antigen titration. Initial m-RQLQ results indicate statistically significant (P < .05) improvement on 12 of 14 domains, including impact on regular and recreational activities, sleep, nose rubbing and nose blowing, stuffy nose and runny nose, itchy eyes, sore eyes, watery eyes, thirst, and tiredness. In addition, total m-RQLQ score showed statistically significant improvement (P = .001). No serious adverse events occurred with the initiation of SLIT.

CONCLUSION

These results indicate that SLIT is effective in controlling allergic symptoms and is safe in an introductory patient sample. Double-blind placebo-controlled trials are needed to confirm our preliminary results.

Mechanisms of sublingual immunotherapy

Allergen-specific sublingual immunotherapy is now recognized to be an efficacious and well-tolerated treatment for allergic rhinitis. Emerging treatment strategies are also aimed at the primary treatment of allergic asthma, particularly allergy to house dust mites. Knowledge of the exact mechanisms of action of sublingual immunotherapy is at a basic level, although there appear to be similarities to the immunological changes seen in subcutaneous immunotherapy. An improved understanding should allow the development of more effective treatment programs and widen the potential use of this form of immunotherapy. This review discusses the possible mechanism of action of sublingual immunotherapy, including data from animal and clinical studies, while comparing this with the current understanding of subcutaneous immunotherapy.

Administration regimens for sublingual immunotherapy to pollen allergens: what do we know?

The modalities of administration of sublingual immunotherapy (SLIT), including dosing, build-up phase, duration of the treatment, and frequency of the maintenance dose are largely variable. In the case of pollen (SLIT), the complexity increases, since preseasonal, coseasonal and pre-coseasonal regimens can be used. The administration regimens are of relevance from a practical point of view, but can also have economic implications. We review herein the available literature (randomized double blind controlled studies) on pollen SLIT, in order to derive experimentally-supported suggestions about the regimens of administration that should be preferred.

Sublingual immunotherapy and allergic rhinitis

This paper reviews the safety and efficacy of sublingual immunotherapy (SLIT) in the treatment of allergic rhinitis. The literature from 1986 through 2007 shows approximately a 6000-fold range in doses found to be effective with SLIT. However, recent studies in large patient populations have demonstrated a clear dose response with an effective dose range that appears to be equivalent to one to two times the monthly subcutaneous immunotherapy dose administered daily or weekly (ie, 15 to 30 microg of major allergen). Further study is needed to establish the optimal dose and dosing schedule for each formulation. Local reactions (eg, oral itchiness) are common, and serious adverse reactions, although rare, have been reported. Cost-effective analysis cannot be made until the effective dose is established. SLIT appears to be a promising treatment for allergic rhinitis, but it is currently considered investigational in the United States until a formulation approved by the US Food and Drug Administration is available.

Efficacy and safety of specific immunotherapy with a high-dose sublingual grass pollen preparation: a double-blind, placebo-controlled trial

BACKGROUND

Sublingual immunotherapy (SLIT) is increasingly being used for the treatment of allergic rhinitis, but there are conflicting study results demonstrating clinically relevant efficacy.

OBJECTIVE

To show clinical efficacy and safety of a new high-dose grass pollen preparation for SLIT.

METHODS

In a 2-year, double-blind, placebo-controlled trial, 185 subjects with rhinitis or rhinoconjunctivitis, with or without asthma, were treated with a recently developed, high-dose, 6-grass pollen mixture for SLIT once daily.

RESULTS

The primary end point, a combined symptom-medication score, showed almost no change in the placebo group during a 42-day evaluation period in the grass pollen season from 2003 to 2005, whereas active treatment was associated with a significant and clinically relevant improvement (full analysis set, P = .01; main data set, P = .002). The effect was irrespective of asthma diagnosis. Allergen-specific IgE showed no difference in both groups, and specific IgG4 and IgG1 increased with active treatment in the first and second study years compared with placebo, clearly indicating the immunogenic effect of the active treatment. The SLIT was well tolerated. No serious adverse drug reactions occurred.

CONCLUSIONS

High-dose, sublingual, specific immunotherapy with an extract of a 6-grass pollen mixture showed a significant and clinically relevant improvement in subjects with grass pollen-associated rhinitis or rhinoconjunctivitis, with or without asthma. The treatment with the sublingual solution was well tolerated.

Optimal dose, efficacy, and safety of once-daily sublingual immunotherapy with a 5-grass pollen tablet for seasonal allergic rhinitis

BACKGROUND

Sublingual immunotherapy is well tolerated and data suggest its effectiveness for the treatment of allergic rhinitis in adults, but it lacks optimum dose definition.

OBJECTIVE

To assess the efficacy, safety, and optimal dose of grass pollen tablets for immunotherapy of patients with allergic rhinoconjunctivitis.

METHODS

In this multinational, randomized, double-blind, placebo-controlled study, 628 adults with grass pollen rhinoconjunctivitis (confirmed by positive skin prick test and serum-specific IgE) received 1 of 3 doses of a standardized 5-grass pollen extract, or placebo, administered sublingually using a once-daily tablet formulation. The treatment was initiated 4 months before the estimated pollen season and continued throughout the season. The primary outcome was Rhinoconjunctivitis Total Symptom Score; secondary outcomes included 6 individual symptom scores, rescue medication use, quality of life, and safety assessments.

RESULTS

Both the 300-index of reactivity (IR) and 500-IR doses significantly reduced mean Rhinoconjunctivitis Total Symptom Score (3.58 +/- 3.0, P = .0001; and 3.74 +/- 3.1, P = .0006, respectively) compared with placebo (4.93 +/- 3.2) in the intent-to-treat and per-protocol analyses. The 100-IR group (4.70 +/- 3.1) score was not significantly different from placebo. Analysis of all secondary efficacy variables (sneezing, runny nose, itchy nose, nasal congestion, watery eyes, itchy eyes, rescue medication usage, and quality of life) confirmed the efficacy of the 300-IR and 500-IR doses. No serious side effects were reported.

CONCLUSION

In the first pollen season, the efficacy and safety of sublingual immunotherapy with grass tablets was confirmed. The 300-IR and 500-IR doses both demonstrated significant efficacy compared with placebo.

CLINICAL IMPLICATIONS

The risk-benefit ratio favors the use of 300-IR tablets for clinical practice.

Allergic rhinitis and its impact on asthma update: allergen immunotherapy

The Allergic Rhinitis and its Impact on Asthma document was first published in 2001. Since then, new data on specific immunotherapy have appeared. This review is intended as an update to the original document. MedLine (2001 to June 2006) was searched with appropriate key words, and panelists were asked to identify further relevant articles. Randomized controlled trials were considered for the evaluation of efficacy. For the evaluation of safety and additional effects, studies with lower grades of evidence were included. The clinical efficacy of injection immunotherapy in rhinitis and asthma was confirmed, as well as the safety, provided that recommendations are followed. Studies have demonstrated the long-term efficacy and the preventive effect of immunotherapy in reducing the onset of new sensitizations. One randomized open trial demonstrated that in children with allergic rhinitis, injection immunotherapy may reduce the risk of developing asthma. There is strong evidence that sublingual immunotherapy is effective in allergic rhinitis in adults. Recent meta-analyses demonstrated its efficacy in allergic rhinitis in children and in asthma, although more definitive trials are required. Current data indicate that sublingual immunotherapy is safe and the rate of adverse reactions is not greater below 5 years of age. One randomized open trial showed that in children with allergic rhinitis, sublingual immunotherapy reduced the onset of asthma. Further studies are needed to identify the optimal maintenance dose and to elucidate the mechanism of action. Novel approaches for immunotherapy are currently under evaluation, including the use of adjuvants, peptides, and DNA-conjugated and recombinant allergens.

Assessment of sublingual immunotherapy efficacy in children with house dust mite-induced allergic asthma optimally controlled by pharmacologic treatment and mite-avoidance measures

Although several studies have demonstrated the efficacy of subcutaneous immunotherapy in allergic asthma, few have shown the same benefit using sublingual immunotherapy (SLIT) in asthmatic patients. This study was conducted to assess the efficacy of house dust mite (HDM) SLIT in addition to allergen avoidance and standard pharmacologic treatment. A double-blind, placebo-controlled trial was performed in 111 children (aged 5-15 yr) with HDM-induced mild-to-moderate asthma. After a 4-week baseline phase, patients were randomly assigned to receive SLIT with tablets of HDM extract (n = 55) or placebo (n = 56) for 18 months. Pharmacologic treatment was adjusted every 3 months following a step-down approach. Asthma symptom scores, reduction in use of inhaled corticosteroids and inhaled beta(2)-agonists, rhinitis symptoms, lung function tests, skin sensitivity to HDM, dust mite-specific immunoglobulin (Ig) E and IgG(4), and quality of life (QoL) were assessed during the study. After 18 months of treatment, diurnal and nocturnal asthma symptoms scores did not show significant differences between SLIT and placebo groups. Inhaled corticosteroids and inhaled beta(2)-agonists use was reduced in both groups without significant differences between groups. There were no significant differences in lung function (forced expiratory volume in 1 s and peak flow rate variations) between groups. Rhinitis symptom score decreased in both groups, with no difference between the two groups. The severity dimension of QoL was significantly improved in the SLIT group (age 6-12 yr). SLIT induced a significant reduction of skin sensitivity to HDM (p < 0.01) and a significant increase in HDM-specific IgE and IgG(4) antibodies (p < 0.001) in the SLIT group compared with the placebo group. SLIT was well tolerated with mild/moderate local adverse events. No severe systemic reactions were reported. This study indicates that, when mild-moderate asthmatic children are optimally controlled by pharmacologic treatment and HDM avoidance, SLIT does not provide additional benefit, despite a significant reduction in allergic response to HDM. Under such conditions, only a complete, but ethically unfeasible, discontinuation of inhaled corticosteroid would have demonstrated a possible benefit of SLIT.

New insights in sublingual immunotherapy

Sublingual immunotherapy (SLIT) is accepted in the official documents and is currently used in many European countries. In recent years, new clinical data on efficacy and safety have been published, including meta-analyses in adults and children and surveys of safety in children younger than age 5 years. Moreover, it has been shown that, similar to the injection route, SLIT can prevent the onset of new sensitizations and the onset of asthma. Additionally, the mechanisms of action are beginning to be systematically studied. Some points need further investigation, such as the effect in asthma, the mechanisms of action, and the optimal dose to be administered.

Long-lasting effects of sublingual immunotherapy for house dust mites in allergic rhinitis with bronchial hyperreactivity: A long-term (13-year) retrospective study in real life

BACKGROUND

Subcutaneous immunotherapy for respiratory allergy has shown a long lasting efficacy after its discontinuation, whereas evidence in the case of sublingual immunotherapy (SLIT) is weak. This retrospective study evaluates whether SLIT exerts a long-lasting effect and whether it relates to its duration.

METHODS

Sixty-five patients allergic to mite and positive to methacholine challenge 13 years ago were studied. Twelve (control group, SLIT 0) were treated for 4 years only with standard pharmacological therapy (SPT), while 53 received SLIT and SPT. Among these, four groups were identified according to SLIT duration. Fifteen patients were treated for 1 year (SLIT 1), 10 for 2 (SLIT 2), 14 for 3 (SLIT 3) and 14 for 4 years (SLIT 4). Clinical parameters (symptom monthly score, SMS), bronchial reactivity and FEV1 were evaluated in 1992 (run-in), 1993 (baseline) and every 2 years from 1997 to 2005.

RESULTS

Two to 3 years after the treatment ended, a positive effect on SMS, but not methacholine challenge and FEV1, was seen in the SLIT groups versus SLIT 0. At this time interval an effect on methacholine challenge was also seen in SLIT 3. After 7-8 years a significant difference was seen for SMS, i.e., it was significantly better in SLIT 4 than in the other groups, while bronchial reactivity was still improved in SLIT 1, 3 and 4 only after 5-6 years.

CONCLUSIONS

The effects of a 4-year SLIT on clinical parameters but not bronchial reactivity and FEV1 last 7-8 years after its discontinuation. SLIT shorter than 4 years yields proportionally less impressive results.