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

Sublingual immunotherapy provides long-term relief in allergic rhinitis and reduces the risk of asthma: A retrospective, real-world database analysis

BACKGROUND

Allergy immunotherapy (AIT) is the only treatment for allergic rhinitis (AR) and/or allergic asthma (AA) with long-term efficacy. However, there are few real-life data on the progression of AR and/or AA in patients receiving AIT.

OBJECTIVES

To assess the real-world, long-term efficacy of grass pollen sublingual immunotherapy (SLIT) tablets in AR and their impact on asthma onset and progression.

METHODS

In a retrospective analysis of a German longitudinal prescription database, AR patients treated with grass pollen SLIT tablets were compared with a control group not having received AIT. Multiple regression analysis was used to compare changes over time in rescue symptomatic AR medication use after treatment cessation, asthma medication use, and the time to asthma onset in the two groups.

RESULTS

After applying all selection criteria, 2851 SLIT and 71 275 control patients were selected for the study. After treatment cessation, AR medication use was 18.8 percentage points lower (after adjustment for covariates, and relative to the pretreatment period) in SLIT tablet group than in the non-AIT group (P<.001). Asthma onset was less frequent in SLIT tablet group than in non-AIT group (odds ratio: 0.696, P=.002), and time to asthma was significantly longer (hazard ratio: 0.523; P=.003). After SLIT cessation, asthma medication use fell by an additional 16.7 percentage points (relative to the pretreatment period) in the SLIT tablet group vs the non-AIT group (P=.004).

CONCLUSIONS

Real-world treatment of AR patients with grass pollen SLIT tablets was associated with slower AR progression, less frequent asthma onset, and slower asthma progression.

Specific immunotherapy in allergic rhinitis

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

Molecular features of grass allergens and development of biotechnological approaches for allergy prevention

Allergic diseases are characterized by elevated allergen-specific IgE and excessive inflammatory cell responses. Among the reported plant allergens, grass pollen and grain allergens, derived from agriculturally important members of the Poaceae family such as rice, wheat and barley, are the most dominant and difficult to prevent. Although many allergen homologs have been predicted from species such as wheat and timothy grass, fundamental aspects such as the evolution and function of plant pollen allergens remain largely unclear. With the development of genetic engineering and genomics, more primary sequences, functions and structures of plant allergens have been uncovered, and molecular component-based allergen-specific immunotherapies are being developed. In this review, we aim to provide an update on (i) the distribution and importance of pollen and grain allergens of the Poaceae family, (ii) the origin and evolution, and functional aspects of plant pollen allergens, (iii) developments of allergen-specific immunotherapy for pollen allergy using biotechnology and (iv) development of less allergenic plants using gene engineering techniques. We also discuss future trends in revealing fundamental aspects of grass pollen allergens and possible biotechnological approaches to reduce the amount of pollen allergens in grasses.

New opportunities for allergen immunotherapy using synthetic peptide immuno-regulatory epitopes (SPIREs)

INTRODUCTION

Allergen immunotherapy (AIT) reduces allergic rhinoconjunctivitis (ARC) symptoms, but long-term efficacy requires treatment for 3-5 years. Synthetic peptide immuno-regulatory epitopes, a new class of AIT, are allergen peptides with a shorter, more convenient treatment regimen that could potentially have benefits on adherence and outcomes.

AREAS COVERED

Phase 2 trials of therapies derived from cat, house dust mite, grass, and ragweed allergen peptides demonstrated significant reduction in ARC symptoms after short-course treatment; improvement was sustained for 18-24 months posttreatment. We conducted a PubMed literature search for clinical publications using the search terms AIT; allergen peptides; ARC; cat, grass, house dust mite, and ragweed allergy; SCIT; SLIT; and synthetic peptides. Expert commentary: Long-term disease modification is a realistic goal of AIT. The inconvenience of conventional AIT regimens negatively impacts long-term persistence and, thus, efficacy. In comparison, SPIREs have a more convenient treatment regimen that could potentially have benefits on adherence and outcomes.

From IgE to clinical trials of allergic rhinitis

The current scientific research is continuously aiming at identifying new therapeutic targets with the purpose of modifying the immune response to allergens. The evolution in immunological methods has led to the identification of immunoglobulin E (IgE) as both a diagnostic biomarker and potential therapeutic target in allergic diseases, such as allergic rhinitis. Allergen immunotherapy has been used for more than 100 years to treat allergic diseases and it is today considered the only disease-modifying treatment capable of inducing a long-lasting immunological and clinical tolerance toward the causal allergen. During the past 20 years, major advances have been made in understanding the molecular and cellular mechanisms of allergen tolerance in humans. Moreover, there has been considerable progress in allergen extract modifications and additions to standard extracts. The recognition that IgE plays a pivotal role in basic regulatory mechanisms of allergic inflammation has recently stimulated research into the therapeutic potential of directly targeting this antibody. Omalizumab, the most advanced humanized anti-IgE monoclonal antibody, is currently approved for the treatment of uncontrolled allergic asthma and chronic spontaneous urticaria. Interesting results also arise from studies in which omalizumab was administered in patients with allergic rhinitis. The aim of this review is to provide an update on current findings on immunological and clinical effects of allergen immunotherapy and anti-IgE therapy, which have been shown to have synergistic modes of action for the treatment of allergic rhinitis.

"The value of pre- and co-seasonal sublingual immunotherapy in pollen-induced allergic rhinoconjunctivitis"

Allergen immunotherapy (AIT) is a guidelines-approved, disease-modifying treatment option for respiratory allergies, including allergic rhinitis (AR) induced by pollen. The various AIT regimens employed to date in pollen-induced AR can be classified as continuous (i.e. year-round) or discontinuous (i.e. pre-seasonal alone, co-seasonal alone or pre- and co-seasonal). Pre-and co-seasonal regimens are typically used for sublingual allergen immunotherapy (SLIT) and have economic and compliance advantages over perennial (year-round) regimens. However, these advantages must not come at the expensive of poor efficacy or safety. The results of recent double-blind, placebo-controlled, randomized clinical trials show that pre- and co-seasonal SLIT is safe and effective in patients with AR induced by grass pollen (treated with a tablet formulation) or by birch pollen (treated with a liquid formulation). Progress in SLIT has been made in defining the optimal dose of major allergen, the administration frequency (daily), the duration of pre-seasonal treatment (four months) and the number of treatment seasons (at least three). Post-marketing, "real-life" trials of pre- and co-seasonal birch or grass pollen SLIT regimens have confirmed the efficacy and safety observed in the clinical trials. In the treatment of pollen-induced AR, pre- and co-seasonal SLIT regimens appear to be at least as effective and safe as perennial SLIT regimens, and are associated with lower costs and good compliance. Good compliance may mean that pre- and co-seasonal SLIT regimens are inherently more effective and safer than perennial SLIT regimens. When considering the pre- and co-seasonal discontinuous regimen in particular, a 300 IR five-grass-pollen formulation is the only SLIT tablet with a clinical development programme having provided evidence of short-term, sustained and post-treatment efficacy.

Oral transmucosal drug delivery for pediatric use

The formulation of medicines for children remains a challenge. An ideal pediatric formulation must allow accurate dose administration and be in a dosage form that can be handled by the target age group. It is also important to consider the choices and the amount of excipients used in the formulation for this vulnerable age group. Although oral formulations are generally acceptable to most pediatric patients, they are not suitable for drugs with poor oral bioavailability or when a rapid clinical effect is required. In recent years, oral transmucosal delivery has emerged as an attractive route of administration for pediatric patients. With this route of administration, a drug is absorbed through the oral mucosa, therefore bypassing hepatic first pass metabolism and thus avoiding drug degradation or metabolism in the gastrointestinal tract. The high blood flow and relatively high permeability of the oral mucosa allow a quick onset of action to be achieved. It is a simple and non-invasive route of drug administration. However, there are several barriers that need to be overcome in the development of oral transmucosal products. This article aims to provide a comprehensive review of the current development of oral transmucosal delivery specifically for the pediatric population in order to achieve systemic drug delivery. The anatomical and physiological properties of the oral mucosa of infants and young children are carefully examined. The different dosage forms and formulation strategies that are suitable for young patients are discussed.

Immunotherapy - risk/benefit in food allergy

Food allergy is a growing health concern in the westernized world with approx. 6% of children suffering from it. A lack of approved treatment has led to strict avoidance of the culprit food proteins being the only standard of care. Nowadays in-depth research is conducted to evaluate the possible use of allergen-specific immunotherapy (SIT) as an active therapeutic option for food allergy. Various routes of administration for the immunotherapy are investigated, including subcutaneous, oral, sublingual, and epicutaneous, and some appear to be successful in inducing a temporary tolerant state. Most research has been conducted with oral immunotherapy due to its efficacious and relatively safe profile. Increasing interest is dedicated to safer and more convenient approaches, such as sublingual and epicutaneous SIT; however, doubts exist about their possible capacity to induce temporary tolerant state and permanent oral tolerance. The high frequency of allergic adverse reactions of the various approaches and the inability to achieve permanent oral tolerance have highlighted the need of refinements in the strategies. A promising strategy for preventing IgE cross-linking and thus enhancing safety of SIT, while still activating T cells, is the use of tolerogenic peptides. The implementation of such an immunotherapy approach has the potential of not only increasing the chance of achieving a permanent state of tolerance, but also improving the safety and tolerability of the therapy. Immunotherapy for food allergy is still not ready for the clinic, but current and upcoming studies are dedicated to collect enough evidence for the possible implementation of allergen-SIT as a standard treatment for food allergy.

Allergen immunotherapy: how to balance the different views from pulmonologists and allergists?

Allergen immunotherapy (AIT) is the treatment characterizing the allergological approach to respiratory allergy. Unfortunately, most available data from the literature and current practice indicate that pulmonologists do no consider AIT when choosing the treatment strategy in patients with asthma. Indeed AIT, from its introduction in 1911 to nowadays, was unceasingly improved and has accumulated clear evidence on its effectiveness. Moreover, AIT has a characteristic not shared by drugs in the capacity to modify the natural history of asthma, due to its immunologic mechanisms of actions, and thus also works after the treatment withdrawal. This also makes AIT a clearly cost-effective treatment over time. It is surprising that pulmonologists, for whom asthma is a major disease to manage, do not consider AIT when choosing the optimal treatment in single patients. The insufficient information on AIT and the availability of allergen extracts with less than good quality are likely to be the most important factors influencing such an attitude. The current development of standardized, pharmaceutical-grade products for AIT seems capable of making allergen extracts comparable to drugs and to stimulate a rethinking of AIT's role in the treatment of asthma in pulmonologists. A reappraisal of the significance of the allergen-specific bronchial challenge could represent a further factor suggesting AIT as a reliable option.

Oral administration of allergen extracts from mugwort pollen desensitizes specific allergen-induced allergy in mice

Clinically, sublingual immunotherapy (SLIT) using allergen extracts effectively alleviates the symptoms of allergic rhinitis and asthma. We hypothesized that oral administration of a high-dose of allergen extracts imitates SLIT, which may prevent IgE-related responses in allergic diseases. In the present study, we investigated the effects of oral administration of allergen extracts from mugwort pollen (MP) on allergen-induced inflammation and airway hyperresponsiveness (AHR) in an allergic mouse model. After administration of MPdrop containing Art v 1 and Art v 4 extracts derived from MP specifically in MP-sensitized mice, the effects of MPdrop on AHR, inflammatory cell accumulation, cytokine production in the bronchoalveolar lavage fluid and lung tissue, and serum IgE and IgG levels were investigated. The results indicated that MPdrop not only prevented the AHR in response to methacholine in a dose-dependent manner but also significantly reduced the total serum and allergen-specific IgE levels. All of the maximal effects were achieved at a dose of 100μg/(kgd) and were comparable to the effects of dexamethasone at a dose of 0.5mg/(kgd). Furthermore, oral administration of MPdrop dose-dependently elevated allergen-specific serum IgG2a levels, reduced total and allergen-specific IgE levels and normalized the imbalance between the Th1 cytokine IL-12 and Th2 cytokines IL-4 and IL-5. Finally, oral administration of MPdrop significantly reduced goblet cell hyperplasia and eosinophilia in the MP-sensitized allergic mouse model. These data suggest that MPdrop effectively improves specific allergen-induced inflammation and AHR in MP-sensitized and -challenged mice and provides the rationale for clinical use of MPdrop in the specific allergen-induced asthma.