Long-Term Efficacy and Dose-Finding Trial of Japanese Cedar Pollen Sublingual Immunotherapy Tablet

Focused allergic rhinitis practice parameter for Canada

Allergic rhinitis (AR) is a prevalent disease in Canada that affects both children and adults. Several guidelines for the management of AR have been published by professional allergy societies worldwide. However, there are regional differences in the clinical management of AR, and regulatory approval of some AR pharmacotherapies varies among countries. Thus, six research questions specific to the treatment of AR in Canada were identified for this focused practice parameter. Reviews of the literature published since 2016 were conducted to obtain evidence-based support for the responses of the Work Group to each research question. In response to research question 1 "In patients with symptoms indicative of AR, is serum-specific IgE sufficient to identify candidates for immunotherapy or is a skin prick test mandatory?" the Work Group concluded that either sIgE testing or skin prick test are acceptable for diagnosing AR and guiding immunotherapy. In response to research question 2 "When taking into account the preferences of the patient and the prescriber (stakeholder engagement) should second-generation oral antihistamine (OAH) or intranasal corticosteroid (INCS) be first line?" the Work Group concluded that existing guidelines generally agree on the use of INCS as a first-line therapy used for AR, however, patient and provider preferences and considerations can easily shift the first choice to a second-generation OAH. In response to research question 3 "Is a combination intranasal antihistamine (INAH)/INCS formulation superior to INCS plus OAH? Do they become equivalent after prolonged use?" the Work Group concluded that that the combination INAH/INCS is superior to an INCS plus OAH. However, there was insufficient evidence to answer the second question. In response to research question 4 "Do leukotriene receptor antagonists (LTRA) have a greater benefit than OAH in AR for some symptoms to justify a therapeutic trial in those who cannot tolerate INCS?" the Work Group concluded that LTRAs have inferior, or at best equivalent, daytime or overall symptom control compared with OAH, but LTRAs may improve nighttime symptom control and provide benefits in patients with AR and concomitant asthma. In response to research question 5 "Should sublingual immunotherapy (SLIT) tablets be considered first-line immunotherapeutic options over subcutaneous immunotherapy (SCIT) based on the evidence of efficacy?" the Work Group concluded that the choice of SLIT or SCIT cannot be made on efficacy alone, and differences in other factors outweigh any differences in efficacy. In response to research question 6 "Based on efficacy data, should ALL patients seen by an allergist be offered SLIT or SCIT as a treatment option?" the Work Group concluded that the efficacy data suggests that SLIT or SCIT should be used broadly in patients with AR, but other clinical concerns also need to be taken into consideration.

From the genesis to the present: The evolution of sublingual immunotherapy for cedar pollinosis

In 2004, we started the initial attempt to evaluate the efficacy of SLIT for Japanese cedar pollinosis (JCP) using Japanese cedar (JC) pollen extract solution through a multicenter, placebo-controlled, double-blind comparative study. Based on its success in demonstrating the substantial efficacy of SLIT, we next conducted a larger-scale study by administering JC pollen to all JCP patients recruited. It was because of aiming to ascertain the effectiveness and safety of SLIT and its underlying mechanisms by comparing high- and non-responder patients. Despite limitations posed by liquid medication, significant effectiveness and safety demonstrated by the 2-year treatment served as the foundation for launching the first SLIT medicine for JCP, in 2014. Furthermore, in addition to the clearer Th1/Th2-imbalanced property in the high-responders, the possible involvement of bitter taste receptors in CD4+ T cells, apoptosis pathways in CD4+ T cells and basophils, and inducing a mast cell degranulation inhibitory molecule in the effect of SLIT was demonstrated. To solve the limitations posed by liquid medication, clinical trials evaluating JC pollen sublingual tablets started in 2014. Due to the minimal side effects, ease of administration, and convenient storage, the sublingual tablet medicine was launched in 2018. Giving the ongoing rise in demand for SLIT and considering that more than 1% of JCP patients are currently undergoing SLIT, the practical use of this treatment for multiple allergens is becoming increasingly important.

SQ sublingual immunotherapy tablets for children with allergic rhinitis: A review of phase three trials

AIM

To provide paediatricians with a summary of efficacy and safety of SQ sublingual immunotherapy (SLIT) tablets from phase three, randomised, double-blind, placebo-controlled trials in children and adolescents with allergic rhinitis or rhinoconjunctivitis, with and without asthma.

METHODS

PubMed searches were conducted and unpublished data were included if necessary.

RESULTS

Of the 93 publications, 12 were identified reporting 10 trials. One trial was excluded as paediatric-specific efficacy data were unavailable. The nine eligible trials evaluated grass, house dust mite, ragweed and tree SLIT tablets. Consistent reductions in allergic rhinitis or rhinoconjunctivitis symptoms and medication use were observed with SQ SLIT tablets versus placebo. In a five-year trial, sustained reduction of allergic rhinoconjunctivitis symptoms, asthma symptoms and medication use were observed with SQ grass SLIT tablet versus placebo. The number-needed-to-treat to prevent asthma symptoms and medication use in one additional child during follow-up was lowest in younger children. SQ SLIT tablets were generally well tolerated across trials.

CONCLUSION

Evidence supports use of SQ SLIT tablets in children and adolescents with allergic rhinitis or rhinoconjunctivitis, with and without asthma. Long-term data demonstrate disease-modifying effects of SQ grass SLIT tablet and suggest the clinical relevance of initiating allergy immunotherapy earlier in the disease course.

Allergen Immunotherapy: The Evidence Supporting the Efficacy and Safety of Subcutaneous Immunotherapy and Sublingual Forms of Immunotherapy for Allergic Rhinitis/Conjunctivitis and Asthma

Allergen immunotherapy (AIT) is a recognized key therapeutic modality for the treatment of allergic respiratory disease. Definitive studies have provided evidence-based data to demonstrate its effectiveness in allergic rhinitis and asthma due to the inhalation of proteinaceous allergic substances from specific seasonal pollens, dust mites, animal allergens, and certain mold spores. Over the ensuing decades, laboratory investigations have provided objective evidence to demonstrate immunologic changes, including production of protective IgG antibody, suppression of IgE antibody, upregulation of regulatory T cells, and induction of a state of immune tolerance to the offending allergen(s). Tangential to this work were carefully designed clinical studies that defined allergen dose and duration of treatment, established the importance of preparing extracts with standardized allergens (or well-defined extracts) based on major protein moieties, and used allergen provocation models to demonstrate efficacy superior to placebo. In the United States, the use of subcutaneous immunotherapy extracts for AIT was grandfathered in by the Food and Drug Administration based on expert literature review. In contrast, sublingual tablet immunotherapy underwent formal clinical development programs (phase I-III clinical trials) that provided the necessary clinical evidence for safety and efficacy that led to regulatory agency approvals for the treatment of allergic rhinitis in properly characterized patients with allergy. The allergy specialist's treatment options currently include traditional subcutaneous AIT and specific sublingual tablets approved for grass, ragweed, house dust mites, trees belonging to the birch-homologous group, and Japanese cedar. Tangential to this are sublingual drops that are increasingly being used off-label (albeit not approved by the Food and Drug Administration) in the United States. This article will review the evidence-based literature supporting the use of these forms of AIT, as well as focus on several current controversies and gaps in our knowledge base that have relevance for the appropriate selection of patients for treatment with specific AIT.

Investigating Experimental Treatments for Rhinitis: A State-of-the-Art Systematic Review

Background: Rhinitis is a common inflammatory condition that affects the nasal passages, significantly impacting quality of life and placing a considerable burden on healthcare systems. While traditional treatments offer limited relief, there is a growing interest in novel therapies. This systematic review aims to analyze investigational new treatments for rhinitis. Methods: A search was conducted in ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and the European Union Clinical Trials Register, as well as PubMed, Web of Science, and the Cochrane Library. Both ongoing and completed clinical trials exploring innovative therapies for rhinitis, including immunotherapy, probiotics, and stem cell therapy, were included. Results: This systematic review compiled information from 74 clinical trials-51 completed and 23 ongoing-focused on new treatments for rhinitis. A significant portion of the completed studies (44) focused on various forms of immunotherapy, which showed potential for long-term effectiveness and had a high safety profile. Another seven completed trials investigated probiotics as a treatment method, yielding mixed results, though they did show promise in managing symptoms, particularly when combined with other treatments. The ongoing trials are primarily investigating immunotherapy, with a smaller number looking at probiotics and stem cell therapy. This shows a continued exploration of innovative and diverse therapies for managing rhinitis. Conclusion: This study highlights the potential of emerging rhinitis therapies to improve patient outcomes and enhance quality of life. Continued research is recommended for developing more effective, personalized, and targeted therapeutic strategies for rhinitis.

Allergen immunotherapy in China

Allergen immunotherapy (AIT) is an etiological treatment strategy that involves administering escalating doses of clinically relevant allergens to desensitize the immune system. It has shown encouraging results in reducing allergy symptoms and enhancing patients' quality of life. In this review, we offer a thorough overview of AIT in China, examining its efficacy, safety, current practices, and prospects. We further underscore the progress made in AIT research and clinical applications, as well as the distinct challenges and opportunities that China faces in this area.

Effectiveness of sublingual immunotherapy in pediatric cedar pollinosis: A real-world database study

BACKGROUND

Pediatric allergic rhinitis (AR), including cedar pollinosis (CP), is increasing in Japan. We investigated the effects of sublingual immunotherapy (SLIT), which has limited studies of its effectiveness in real-world settings, on children with CP.

METHODS

This retrospective cohort study used a claim database in 2018-2021. Children aged ≤15 years with CP records in 2019 were eligible and were followed up through 2021. We included 2962 CP children undergoing SLIT and 547 who were not. The medication score was used to evaluate SLIT effectiveness in the cedar pollen dispersal season each year. Adverse events and the occurrence of allergic diseases were also evaluated.

RESULTS

Medication score was higher in the SLIT group during the index period but lower in 2021 compared to the non-SLIT group (mean ± standard deviation: 5.17 ± 2.39 and 4.74 ± 2.38 in 2019, 3.13 ± 2.30 and 3.55 ± 2.48 in 2021, respectively). The adjusted mean difference between groups from 2019 to 2021 was -0.62 (95% confidence interval: -0.86 to -0.39, p < .0001), and the medication score was reduced in the SLIT group (risk ratio: 1.2: 1.1 to 1.3). The occurrence of adverse events involving abdominal disorders (adjusted odds ratio [aOR]: 0.64: 0.51 to 0.81), asthma exacerbation (aOR: 0.37: 0.24 to 0.57), and allergic diseases involving hay fever unrelated to CP (aOR: 0.60: 0.45 to 0.80) or asthma (aOR: 0.71: 0.58 to 0.86) was lower in the SLIT group.

CONCLUSION

In children with CP, SLIT is effective, well tolerated, and could decrease the occurrence of other allergic diseases.

Efficacy and safety of Artemisia annua sublingual immunotherapy in patients with seasonal allergic rhinoconjunctivitis over two pollen seasons

OBJECTIVE

This study investigates the efficacy and safety of sublingual immunotherapy (SLIT) with A. annua allergens in patients with seasonal allergic rhinoconjunctivitis over two pollen seasons.

METHODS

Seventy patients with moderate-severe seasonal allergic rhinoconjunctivitis were divided evenly into the SLIT and control groups. The SLIT last from 3 months before the summer-autumn pollen season in 2021 till the end of the summer-autumn pollen season in 2022. The daily individual symptom score, total rhinoconjunctivitis symptom score (dTRSS), total medication score (dTMS), combined score of medication and rhinoconjunctivitis symptom (dCSMRS), visual analog scale (VAS) score, and adverse events (AEs) were evaluated.

RESULTS

The average pollen concentration in 2022 was twice that previous two-year during the pollen season. Fifty-six patients completed treatments (SLIT group: 29, control group: 27). Compared with baseline, the individual symptoms, dTRSS, dTMS, dCSMRS, and VAS scores of SLIT group declined in 2021. After 16 months of SLIT, all efficacy indexes in 2022 were still lower than baseline and equivalent to those in 2021. In control group, the efficacy indexes in 2022 were higher than that in 2020 and 2021. The efficacy indexes of SLIT group were lower than those of control group in 2021 and 2022. SLIT is effective for both mono- and poly-sensitized patients. AEs incidence in SLIT group was 82.7% without severe AEs.

CONCLUSIONS

The A. annua-SLIT can obtain efficacy and safety over two pollen seasons for patients with moderate-severe seasonal allergic rhinoconjunctivitis.

Efficacy of Japanese cedar pollen sublingual immunotherapy tablets for Japanese cypress pollinosis

Background

We previously demonstrated the efficacy of Japanese cedar (JC) pollen sublingual immunotherapy (SLIT) tablets for treating seasonal allergic rhinitis in a clinical trial (trial no. 206-2-1) that covered 5 pollen dispersal seasons from 2015 to 2019.

Objective

Our aim was to perform post hoc analysis of the 206-2-1 trial data to evaluate the efficacy of JC pollen SLIT tablets for patients with rhinitis induced by pollen from Japanese cypress (JCY), a related Cupressaceae species that has a pollen dispersal season overlapping with that of JC.

Methods

Data were analyzed for 240 patients who received placebo during the first pollen dispersal season in 2015, were then rerandomized to receive JC SLIT tablets (the PA group) or placebo (the PP group) for 18 months (the 2016 and 2017 dispersal seasons), and were observed untreated for 2 years (the 2018 and 2019 dispersal seasons). The PA and PP groups were assigned to "high" and "low" subgroups if their rhinitis symptoms were exacerbated/did not change or decreased, respectively, during the peak JCY pollen dispersal period in 2015. The mean total nasal symptom and medication scores and other outcomes were compared for the high-PP, high-PA, low-PP, and low-PA groups during the 2016 to 2019 peak JCY pollen dispersal periods.

Results

The mean total nasal symptom and medication scores were significantly lower for the high-PA and low-PA groups than for the corresponding PP groups over the 4 years of treatment and observation. JCY pollen-specific IgE levels increased in both PA groups.

Conclusion

JC pollen SLIT tablets effectively suppressed JCY pollinosis symptoms, supporting the clinical relevance of immunologic cross-reactivity between JC and JCY allergens.

Cell-penetrating albumin enhances the sublingual delivery of antigens through macropinocytosis

Innovations in oral immunotherapy have greatly advanced the therapeutic control of allergies. However, these therapeutic effects suffer from the fact that the amount of antigen delivered to antigen-presenting cells is limited given the formulations that are currently available. We recently designed a cell-penetrating albumin and found that this modified albumin enters cells via the induction of macropinocytosis. Herein, we report on a novel system for delivering antigens based on cell-penetrating albumin-inducible macropinocytosis that allows larger amounts of antigens to be delivered to antigen-presenting cells. A treatment with cell-penetrating albumin significantly increased the permeability of ovalbumin (45 kDa) or dextran (2000 kDa) on monolayers derived from human oral squamous carcinoma cells. Flow cytometric analyses showed that the cell-penetrating albumin treatment resulted in a significant elevation in the amount of dextran that was delivered to two types of antigen-presenting cells. Finally, mice that had been sensitized by Japanese cedar pollen extract (JCPE) and cell-penetrating albumin showed a decline in the frequency of nose-rubbing against a subsequent intranasal administration of JCPE. These findings suggest that the sublingual administration of cell-penetrating albumin efficiently delivers antigens to antigen-presenting cells via the induction of macropinocytosis, resulting in an enhancement in the therapeutic effect of sublingual immunotherapy.

Single-cell immunoprofiling after immunotherapy for allergic rhinitis reveals functional suppression of pathogenic Th2 cells and clonal conversion

BACKGROUND

Allergic rhinitis is a growing problem worldwide. Currently, the only treatment that can modify the disease is antigen-specific immunotherapy; however, its mechanism(s) of action is not fully understood.

OBJECTIVE

To comprehensively investigate the role and changes of antigen-specific T cells before and after sublingual immunotherapy (SLIT) for Japanese cedar pollinosis (JCP).

METHODS

We cultured PBMCs obtained both before and at 1 year after initiating SLIT and used a combination of single-cell RNA sequence and repertoire sequencing. To investigate biomarkers, we used PBMCs from patients participating a phase II/III trial of SLIT tablets for JCP and PBMCs from good and poor responders in outpatients.

RESULTS

Antigen-stimulated culturing after SLIT led to clonal expansion of Th2 and Treg cells, and most of these CD4⁺ T cells retained their CDR3 regions before and after treatment, indicating antigen-specific clonal responses and differentiation secondary to SLIT. However, SLIT reduced the number of clonal functional Th2 cells but increased the Trans-type Th2 cell population that expresses musculin (MSC), TGF-β, and IL-2. Trajectory analysis suggested that SLIT induced clonal differentiation of the Trans-type Th2 cells differentiated into Treg cells. Using real-time PCR, we found that the MSC levels increased in the active SLIT group and good responders after 1 year of treatment.

CONCLUSION

The combination of single-cell RNA sequencing and repertoire analysis helped reveal a part of the underlying mechanism-that SLIT promotes the expression of MSC on pathogenic Th2 cells and suppresses their function; MSC may be a potential biomarker of SLIT for allergic rhinitis.

Delivery options for sublingual immunotherapy for allergic rhinoconjunctivitis: clinical considerations for North America

Background: Sublingual immunotherapy (SLIT) can be delivered via tablets (SLIT-T) or aqueous drops (SLIT-D). SLIT-D dosing recommendations using North American extracts were published in 2015. We review the 2015 recommendations in the context of recent research, and compare and contrast dosing, efficacy, safety, adherence, and cost of SLIT-T and SLIT-D for allergic rhinoconjunctivitis (ARC) in North America. Methods: Randomized controlled trials (RCT) of SLIT-D and SLIT-T trials were identified by a systematic PubMed search through March 1, 2022. Results: Dose-finding studies have been conducted for all approved SLIT-T; efficacy in North American populations was demonstrated in 11 RCTs. Approved SLIT-T are uniform internationally. Few dose-finding studies for SLIT-D have been conducted using North American extracts; efficacy was demonstrated in 2 RCTs. Extrapolation of dosing from SLIT-D studies conducted with extracts from other geographic regions is unreliable. Since the 2015 SLIT-D dosing recommendations, no new RCTs of SLIT-D have been conducted with North American extracts, whereas 6 SLIT-T RCTs have since been conducted in North America. Local allergic reactions are the most common adverse events with SLIT-T and SLIT-D, but both can induce systemic allergic reactions. Adherence to SLIT-D and SLIT-T remains a challenge. Patients must pay for SLIT-D directly, whereas SLIT-T is usually covered by insurance. Conclusion: As part of shared decision-making, patients should be informed about the scientific evidence supporting the use of SLIT-T and SLIT-D for ARC.

CD44 is critical for the enhancing effect of hyaluronan in allergen-specific sublingual immunotherapy in a murine model of chronic asthma

Allergen-specific sublingual immunotherapy (SLIT) is a potentially effective disease-modification treatment for patients with allergic asthma. Because CD44 signaling enhances regulatory T (Treg) cell-induction, administering CD44 ligands such as hyaluronan (HA) with allergen-specific SLIT may enhance the therapeutic effects. We evaluated the role of CD44 in Treg cell-induction in T helper type 2 (Th2)-mediated chronic airway inflammation using CD44-/- mice and the efficacy of HA on SLIT in a Dermatophagoides farinae (Df)-induced murine model of chronic asthma. Th2 responses and Treg cell induction were evaluated in CD44-/- mice. We devised a new SLIT model of Df-induced chronic asthma utilizing HA as an adjuvant. The effects of HA added to the new SLIT model were evaluated by the early asthmatic response (EAR) and airway hyperresponsiveness (AHR), eosinophilic airway inflammation, and serum Df-specific IgE levels. Th2-mediated chronic eosinophilic airway inflammation was worse in CD44-/- mice compared with Df-sensitized wild-type (WT) mice. HA enhanced the effect of Df-induced Treg cells in a CD44-dependent manner. Sublingual Df treatment in combination with HA, but not alone, normalized EAR and AHR, and significantly reduced the serum IgE levels and the bronchoalveolar lavage fluid (BALF) eosinophil number. HA also induced Treg cells in a Df-sensitized spleen cell culture in a CD44-dependent manner. The treatment-enhancing effects of HA in this SLIT model were diminished in CD44-/- mice. CD44 is a key contributor to Treg cell induction and critical for the enhancing effects of HA in a Df-induced murine model of chronic asthma.

Effects of sublingual immunotherapy with tablets or drops containing Japanese cedar pollen antigens on nasal symptoms and sleep disturbance in patients with Japanese cedar pollinosis

OBJECTIVE

We examined the effects of SLIT with tablets containing JCP antigens on nasal symptoms and sleep disturbance in patients with Japanese cedar pollinosis during pollen dispersal season.

METHODS

A total of 128 patients with Japanese cedar pollinosis were categorized into four groups:19 one-year SLIT with tablets group, 16 two-year SLIT with drops group, 19 antihistamine group, and 74 untreated group. The scores of nasal symptoms and sleep disturbance were evaluated based on the Japanese guidelines for allergic rhinitis and the Athens Insomnia Scale.

RESULTS

The scores of nasal symptoms and sleep disturbance at the peak cedar pollen period in the two-year SLIT with drop group and the one-year SLIT with tablets group were significantly lower than those in untreated group. Additionally, these scores were significantly lower in the one-year SLIT with tablets group than those in the antihistamine group.

CONCLUSION

It is suggested that SLIT with JCP tablets improved both nasal symptoms and sleep disturbances at peak pollen period in patients with Japanese cedar pollinosis. SLIT with JCP tablets for one year was more effective than SLIT with JCP drops for two years and prophylactic treatment with antihistamines. J. Med. Invest. 69 : 97-100, February, 2022.

Efficacy of dual sublingual immunotherapy with Japanese cedar pollen and house dust mite allergens in patients with allergic rhinitis sensitized to multiple allergens

OBJECTIVE

In the present study, we examined the effects of dual sublingual immunotherapy (SLIT) with Japanese cedar pollen (JCP) and house dust mite (HDM) allergens on nasal symptoms during the peak pollen period (PPP) and in late fall (LF) in patients with allergic rhinitis (AR) sensitized to both JCP and HDM. We then compared the efficacy of dual-SLIT with JCP and HDM to that of mono-SLIT with JCP at PPP.

METHODS

Twenty-five bisensitized patients with AR who showed positive serum specific immunoglobulin E (IgE) against both JCP and HDM were enrolled. In dual-SLIT, 16 patients received JCP drops/tablets and HDM tablets concurrently. In mono-SLIT with JCP, nine patients received JCP drops/tablets. Nasal symptoms were scored on a 0-4 point scale.

RESULTS

The nasal scores at PPP and in LF in the bisensitized patients with AR who received dual-SLIT with JCP and HDM in 2019 were significantly lower than those in the same patients who received antihistamines only in 2018. The decrease in scores of nasal obstruction at PPP from 2018 to 2019 in patients who received dual-SLIT was significantly greater than those in patients who received mono-SLIT with JCP. Dual-SLIT was well tolerated and only had mild adverse effects.

CONCLUSION

These findings suggest that dual-SLIT suppressed both JCP-induced seasonal and HDM-induced perennial nasal symptoms in bisensitized patients with AR. Dual-SLIT was more effective in suppressing nasal obstruction at PPP than mono-SLIT with JCP with limitation of baseline characteristics not to be controlled between the two groups, suggesting that dual-SLIT suppressed HDM-induced priming effects, thus resulting in further suppression of nasal obstruction at PPP.

LEVEL OF EVIDENCE

3b, a case-controlled study.

New Frontiers: Precise Editing of Allergen Genes Using CRISPR

Genome engineering with clustered regularly interspaced short palindromic repeats (CRISPR) technology offers the unique potential for unequivocally deleting allergen genes at the source. Compared to prior gene editing approaches, CRISPR boasts substantial improvements in editing efficiency, throughput, and precision. CRISPR has demonstrated success in several clinical applications such as sickle cell disease and β-thalassemia, and preliminary knockout studies of allergenic proteins using CRISPR editing show promise. Given the advantages of CRISPR, as well as specific DNA targets in the allergen genes, CRISPR gene editing is a viable approach for tackling allergy, which may lead to significant disease improvement. This review will highlight recent applications of CRISPR editing of allergens, particularly cat allergen Fel d 1, and will discuss the advantages and limitations of this approach compared to existing treatment options.

Allergen Release Profiles of Fast-Dissolving Freeze-Dried Orodispersible Sublingual Allergy Immunotherapy Tablets

Background

Sublingual allergy immunotherapy tablets (SLIT-tablets) provide a well-tolerated and clinically efficacious treatment for allergic disease such as allergic rhinitis and allergic asthma. In SLIT, uptake of allergen by immune-competent cells in the oral mucosa activates the immune system and leads to tolerance toward the sensitizing allergen. The ability to deliver the full allergen content into solution within the recommended sublingual holding time is therefore an essential quality of SLIT-tablets that must be supported by the tablet formulation for all relevant allergen sources. SLIT-tablets based on a fast-dissolving orodispersible freeze-dried formulation (Zydis) are currently available for 5 of the most prevalent allergens: tree (birch and related species from the birch-homologous group), grass, ragweed, Japanese cedar, and house dust mite.

Objectives

The purpose of this study was to examine the allergen release properties of three freeze-dried SLIT-tablets containing tree, ragweed, and Japanese cedar extracts, respectively. The correlation between SLIT-tablet allergen release and the level of allergen-specific T-cell activation was examined for the tree SLIT-tablet.

Methods

Allergen release kinetics and tablet disintegration times for the 3 freeze-dried SLIT-tablets were examined. For all 3 tablets, the magnitude of solubilized major allergen relative to time in solution was compared to external controls to achieve a measure of the total allergen release. Additional assessments of allergen release occurring after the initial timepoint (15 or 30 seconds in solution) were done independently of external controls by linear regression analyses. For the tree SLIT-tablet, the immunological potency of the released major allergen was assessed at each experimental timepoint by a Bet v-specific T-cell activation assay.

Results

All 3 SLIT-tablets disintegrated within 1 second after contact with assay buffer without any detectible residue. Complete release of major allergens (Bet v 1, Amb a 1, and Cry j 1, respectively) was seen at the earliest experimental time points (15 or 30 seconds). For the tree SLIT-tablet, full T-cell activation was achieved at 30 seconds (earliest experimental time point).

Conclusions

The freeze-dried SLIT-tablet formulation consistently provides rapid and complete release of allergen from a wide range of species in a standardized in vitro assay. Full release of the SLIT-tablet allergen content within the sublingual holding time is a prerequisite for maximal exposure of allergens to the sublingual mucosa immune system. The freeze-dried SLIT-tablet formulation examined here supports short sublingual holding times and furthermore offers a convenient administration form of allergy immunotherapy.

Molecular allergology and its impact in specific allergy diagnosis and therapy

Progressive knowledge of allergenic structures resulted in a broad availability of allergenic molecules for diagnosis. Component-resolved diagnosis allowed a better understanding of patient sensitization patterns, facilitating allergen immunotherapy decisions. In parallel to the discovery of allergenic molecules, there was a progressive development of a regulation framework that affected both in vitro diagnostics and Allergen Immunotherapy products. With a progressive understanding of underlying mechanisms associated to Allergen immunotherapy and an increasing experience of application of molecular diagnosis in daily life, we focus in analyzing the evidences of the value provided by molecular allergology in daily clinical practice, with a focus on Allergen Immunotherapy decisions.

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.

Disease-Modifying Effect of Japanese Cedar Pollen Sublingual Immunotherapy Tablets

BACKGROUND

Japanese cedar (JC) pollinosis is a common allergic rhinitis in Japan. JC pollen sublingual immunotherapy (SLIT) tablets are licensed for the treatment of JC pollinosis.

OBJECTIVE

To assess the disease-modifying effects of JC pollen SLIT tablets over 5 years (2014-2019), comprising a 3-year treatment period and 2-year follow-up.

METHODS

A total of 1042 patients with JC pollinosis (aged 5-64 years) were included in the study. An optimal dose-finding study was performed in the first 15 months, after which 240 patients in the placebo (P) group and 236 patients in the optimal active dose (A) group (5000 Japanese allergy units) were re-randomized to receive P or A for an additional 18 months (designated AA, AP, PA, and PP groups). Clinical efficacy was evaluated by the total nasal symptom and medication score (TNSMS) during the peak symptom period of each JC pollen season over 3 years of treatment and 2 years of observation after treatment cessation.

RESULTS

The AA, AP, and PA groups exhibited significantly reduced TNSMS; however, the largest relative reduction was seen in the AA group both during the treatment period (third season, 46.3% vs PP, P < .001) and during the 2-year follow-up period (fourth and fifth seasons, 45.3% and 34.0% vs PP, respectively; P < .001). The most common adverse drug reactions were mild reactions at the administration site.

CONCLUSIONS

JC pollen SLIT tablets show sustained clinical efficacy during 3 years of treatment and sustained disease-modifying effects for at least 2 years after treatment cessation.

Next-Generation Allergen-Specific Immunotherapy for Japanese Cedar Pollinosis Using Molecular Approaches

Japanese cedar (JC) pollinosis is the most major IgE-mediated type I allergic disease in Japan. Allergen-specific immunotherapy is the only curative treatment for allergic diseases. Subcutaneous immunotherapy and sublingual immunotherapy have been introduced in Japan for JC pollinosis, but do not avoid some adverse side effects, because the natural allergens used as tolerogens cross-link with specific IgE types on mast cells and basophils. To make immunotherapy for JC pollinosis safer, more effective and convenient, rice-based oral allergy vaccines using hybrid peptides composed of multiple T-cell epitopes or recombinant deconstructed hypoallergenic derivatives derived from major allergens — Cry j 1 and Cry j 2 — have been developed and their efficacy and safety evaluated by oral administration of transgenic rice seeds. Furthermore, recombinant modified JC allergens conjugated with various immunomodulatory molecules and DNA-based vaccines have been created and their efficacy assessed.

Long-term oral administration of transgenic rice containing cedar pollen T-cell epitopes potentially improves medication- and allergy-related quality-of-life scores

Background: We previously developed a transgenic rice that contains seven linked human predominant T-cell epitopes (7Crp) derived from Japanese cedar (JC) pollen allergens Cry j 1 and Cry j 2. Oral administration of 80 g of transgenic rice for 20 weeks suppressed allergen-specific T-cell proliferation in participants with JC pollinosis, but their clinical symptoms did not improve. Objective: We examined the clinical efficacy of low-dose (5 g and 20 g) intake of the transgenic rice administered for two successive seasons. Methods: In this randomized, double-blind, placebo controlled study, transgenic rice seeds (5 g or 20 g) were orally administered to the participants for 24 weeks in each of two successive JC pollen seasons. We analyzed T-cell proliferation and cytokine expression, and monitored symptom and medication scores during the pollen season. Quality of life (QOL) was evaluated by using the Japanese Allergic Rhinitis Quality of Life Standard Questionnaire (JRQLQ). Results: Specific T-cell proliferation after stimulation with 7Crp, Cry j 1, and Cry j 2 was significantly suppressed in the second JC pollen season. No significant differences were found among the three groups (5 g, 20 g, and placebo) with regard to clinical symptoms or medication scores in the first season. However, the medication scores and face scale for overall condition of JRQLQ improved in the 5-g transgenic rice group in the second season, although careful re-examination with a large sample size is necessary to confirm the results. Conclusion: Low-dose oral administration of transgenic rice that contains 7Crp significantly reduced allergen-specific T-cell responses and improved medication scores during the second season of administration. Thus, oral intake of the transgenic rice has the potential to induce immune tolerance to JC pollen allergens when administered for at least two successive seasons.

Japanese cedar and cypress pollinosis updated: New allergens, cross-reactivity, and treatment

Pollen from many tree species in the Cupressaceae family is a well-known cause of seasonal allergic diseases worldwide. Japanese cedar pollinosis and Japanese cypress pollinosis, which are caused by pollen from Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa), respectively, are the most prevalent seasonal allergic diseases in Japan. Recently, the novel major Japanese cypress allergen Cha o 3 and the homologous Japanese cedar allergen Cry j cellulase were identified, and it was shown, for the first time, that cellulase in plants is allergenic. Although the allergenic components of pollen from both species exhibit high amino acid sequence identity, their pollinosis responded differently to allergen-specific immunotherapy (ASIT) using a standardized extract of Japanese cedar pollen. Pharmacotherapy and ASIT for Japanese cedar and cypress pollinosis have advanced considerably in recent years. In particular, Japanese cedar ASIT has entered a new phase, primarily in response to the generation of updated efficacy data and the development of new formulations. In this review, we focus on both Japanese cypress and cedar pollinosis, and discuss the latest findings, newly identified causative allergens, and new treatments. To manage pollinosis symptoms during spring effectively, ASIT for both Japanese cedar and Japanese cypress pollen is considered necessary.

Recent development on the use of sublingual immunotherapy tablets for allergic rhinitis

OBJECTIVE

Allergic rhinitis (AR) is an immunoglobulin (Ig) E-mediated inflammatory condition that causes sneezing, nasal congestion, rhinorrhea, and nasal itch. Although subcutaneous immunotherapy for the treatment of AR has been in use and well established as a treatment modality, sublingual immunotherapy (SLIT) is increasingly considered to be the safer and more convenient alternative. Thus, the objective of this review is to describe recent findings pertaining to the use of SLIT tablets (SLIT-T) for AR.

DATA SOURCES

A database search (PubMed.gov) for articles published between January 1, 2017, and February 9, 2021, was conducted using the following key words: "allergic rhinitis," AND-ed "sublingual immunotherapy." Included were randomized placebo-controlled trials. Other experimental design studies were excluded.

STUDY SELECTIONS

A total of 11 randomized placebo-controlled trials were selected for full-text review and included in the analysis. All studies investigated the use of SLIT on patients with seasonal AR (4 tree pollen, 1 grass pollen, and 1 Japanese cedar) or perennial AR (3 house dust mite).

RESULTS

Our review of 7 recently published randomized placebo-controlled trials with 2348 subjects receiving SLIT reported increased efficacy, safety, supportive immunologic parameters (IgE and IgG4 pre- and posttreatment levels), and improved quality of life. All studies excluded subjects with overlapping seasonal or perennial allergens, a history of moderate-to-severe uncontrolled asthma, or reduced lung function.

CONCLUSION

Our review highlights that SLIT is a safe and effective treatment that considerably reduces symptoms and medication requirements in AR and improves quality of life.

Increased Thrombin-Activatable Fibrinolysis Inhibitor in Response to Sublingual Immunotherapy for Allergic Rhinitis

OBJECTIVES/HYPOTHESIS

The objective of this study was to determine the role of thrombin-activatable fibrinolysis inhibitor (TAFI) as a candidate biomarker for therapeutic efficacy of sublingual immunotherapy (SLIT) and to identify the role of TAFI in the pathogenesis of allergic rhinitis (AR).

STUDY DESIGN

Retrospective cohort study and laboratory study.

METHODS

Serum was collected from patients with allergies to Japanese cedar pollen before, during, and after treatment with SLIT. We measured the levels of immunoreactive TAFI, C3a, and C5a in serum by enzyme-linked immunosorbent assay (ELISA) and assessed their relative impact on a combined symptom-medication score. We also examined the impact of TAFI on mast cells and fibroblasts in experiments performed in vitro.

RESULTS

Serum levels of TAFI increased significantly in response to SLIT. By contrast, serum C3a levels decreased significantly over time; we observed a significant negative correlation between serum levels of TAFI versus C3a and symptom-medication score. Mast cell degranulation was inhibited in response to TAFI, as it was the expression of both CCL11 and CCL5 in cultured fibroblasts.

CONCLUSIONS

High serum levels of TAFI may be induced by SLIT. TAFI may play a critical protective role in pathogenesis of AR by inactivating C3a and by inhibiting mast cell degranulation and chemokines expression in fibroblasts.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Intranasal levels of lead as an exacerbation factor for allergic rhinitis in humans and mice

BACKGROUND

Air pollutants are suspected to affect pathological conditions of allergic rhinitis (AR).

OBJECTIVES

After detecting Pb (375 μg/kg) in Japanese cedar pollen, the effects of intranasal exposure to Pb on symptoms of AR were investigated.

METHODS

Pollen counts, subjective symptoms, and Pb levels in nasal epithelial lining fluid (ELF) were investigated in 44 patients with Japanese cedar pollinosis and 57 controls from preseason to season. Effects of intranasal exposure to Pb on symptoms were confirmed by using a mouse model of AR.

RESULTS

Pb levels in ELF from patients were >40% higher than those in ELF from control subjects during the pollen season but not before the pollen season. Pb level in ELF was positively associated with pollen counts for the latest 4 days before visiting a hospital as well as scores of subjective symptoms. Intranasal exposure to Pb exacerbated symptoms in allergic mice, suggesting Pb as an exacerbation factor. Pb levels in ELF and nasal mucosa in Pb-exposed allergic mice were higher than those in Pb-exposed nonallergic mice, despite intranasally challenging the same amount of Pb. Because the increased Pb level in the nasal mucosa of Pb-exposed allergic mice was decreased after washing the nasal cavity, Pb on the surface of but not inside the nasal mucosa may have been a source of increased Pb level in ELF of allergic mice.

CONCLUSIONS

Increased nasal Pb level partially derived from pollen could exacerbate subjective symptoms of AR, indicating Pb as a novel hazardous air pollutant for AR.

Sublingual Immunotherapy: How Sublingual Allergen Administration Heals Allergic Diseases; Current Perspective about the Mode of Action

Owing to the successful application of sublingual immunotherapy (SLIT), allergen immunotherapy (AIT) has become one of the leading treatments for allergic diseases. Similar to the case with other AITs, such as subcutaneous and oral immunotherapies, not only the alleviation of allergic symptoms, but also the curing of the diseases can be expected in patients undergoing SLIT. However, how and why such strong efficacy is obtained by SLIT, in which allergens are simply administered under the tongue, is not clearly known. Various potential mechanisms, including the induction of blocking antibodies, T cell tolerance, regulatory B and T cells, CD103^-CD11b⁺ classical dendritic cells, and CD206⁺ macrophages, and the reduction of innate lymphoid cells, mast cells, and basophils, have been suggested. Recently, through a comparative analysis between high- and non-responder patients of SLIT, we have successfully proposed several novel mechanisms. Here, we introduce our recent findings and summarize the current understanding of the mechanisms underlying the strong efficacy of SLIT.

Long-term treatment of Japanese cedar pollinosis with Japanese cedar pollen SLIT drops and persistence of treatment effect: A post-marketing clinical trial

BACKGROUND

There have been no reports of treatment effect persistence after long-term sublingual immunotherapy (SLIT) in patients with Japanese cedar (JC) pollinosis. Therefore, we conducted a post-marketing clinical trial to investigate the efficacy, safety, and effect persistence of JC pollen SLIT drops after approximately 3 years of treatment.

METHODS

This was an open-label trial of 233 patients with JC pollinosis who were treated with JC pollen SLIT drops for approximately 3 years (2015-2017) and followed-up for an additional 2 years (2018-2019). Efficacy and effect persistence were evaluated using nasal and ocular symptom scores, daily use of rescue medication, and Japanese Rhinoconjunctivitis Quality of Life Questionnaire scores recorded during the JC pollen dispersal season of each year. Safety was evaluated by monitoring adverse events and adverse drug reactions.

RESULTS

The mean combined total nasal symptom and medication score (range 0-18) during the peak symptom periods of 2015 through 2019 were 5.47 ± 3.38, 4.52 ± 3.13, 3.58 ± 2.63, 5.28 ± 4.01, and 6.83 ± 4.65, respectively. The percentage of patients who used no rescue medications during the same periods was 64.8%, 75.2%, 80.3%, 63.7%, and 50.3%, respectively. A total of 138 adverse drug reaction incidents were recorded in 73 of the 233 patients (31.3%), of which 134 incidents (97.1%) were mild in severity.

CONCLUSIONS

JC pollen SLIT drops demonstrated treatment duration-dependent efficacy with effects that persisted for 2 years after cessation of treatment. The drug had a favorable safety profile over the 5-year study period.

Simplified AIT for allergy to several tree pollens-Arguments from the immune outcome analyses following treatment with SQ tree SLIT-tablet

BACKGROUND

The SQ tree SLIT-tablet (containing birch extract) proved clinically significant effects during the pollen season for birch as well as alder/hazel. Immune outcomes of this treatment for allergens from multiple birch homologous trees need further investigation. We hypothesize that birch pollen extract AIT modulates a highly cross-reactive immune response and that this may be the basis for the observed clinical cross-protection.

METHODS

Blood samples were collected from 397 birch allergic patients during SQ tree SLIT-tablet or placebo treatment (1:1) for up to 40 weeks. Serum IgE and IgG₄ specific to birch, and birch homologous tree pollens from alder, hazel, hornbeam, beech and chestnut were measured by ImmunoCAP. IgE-Blocking Factor (IgE-BF) for alder, birch and hazel during treatment was measured by Advia Centaur and blocking effects for birch and all these birch homologous tree pollens were further investigated by basophil activation (BAT). Antibody readouts were investigated in patient subsets. T-cell responses (proliferation) to allergen extracts and peptide pools (group 1 allergens) were investigated in T-cell lines from 29 untreated birch pollen-allergic individuals.

RESULTS

Significant Pearson correlations between serum IgE towards birch, alder, hazel, hornbeam and beech were observed (r-values > .86). T-cell reactivity was observed throughout the birch homologous group. Almost identical kinetics for changes in IgE towards birch, alder and hazel were observed during treatment and similar species-specific changes were seen for serum-IgG₄ . IgG₄ reactivity towards birch and alder, hazel, hornbeam and beech correlated significantly at end-of-treatment (r-values > .72). Treatment resulted in similar IgE-BF kinetics for alder, birch, and hazel and blocking of BAT for multiple trees in most actively treated patients investigated.

CONCLUSIONS

Systematic analyses of T-cell and antibody cross-reactivities before and during birch pollen extract AIT provide the immunological basis for the observed clinical effect of SQ tree SLIT-tablet treatment of tree pollen allergy induced by multiple trees in the birch homologous group.

Allergic rhinitis

Allergic rhinitis (AR) is caused by immunoglobulin E (IgE)-mediated reactions to inhaled allergens and is one of the most common chronic conditions globally. AR often co-occurs with asthma and conjunctivitis and is a global health problem causing major burden and disability worldwide. Risk factors include inhalant and occupational allergens, as well as genetic factors. AR impairs quality of life, affects social life, school and work, and is associated with substantial economic costs. The Allergic Rhinitis and its Impact on Asthma (ARIA) initiative classified AR into intermittent or persistent and mild or moderate/severe. The diagnosis is based on the clinical history and, if needed in patients with uncontrolled rhinitis despite medications or with long-lasting symptoms, on skin tests or the presence of serum-specific IgE antibodies to allergens. The most frequently used pharmacological treatments include oral, intranasal or ocular H₁-antihistamines, intranasal corticosteroids or a fixed combination of intranasal H₁-antihistamines and corticosteroids. Allergen immunotherapy prescribed by a specialist using high-quality extracts in stratified patients is effective in patients with persistent symptoms. Real-world data obtained by mobile technology offer new insights into AR phenotypes and management. The outlook for AR includes a better understanding of novel multimorbid phenotypes, health technology assessment and patient-centred shared decision-making.

State of the Art: Development of a Sublingual Allergy Immunotherapy Tablet for Allergic Rhinitis in Japan

Allergic rhinitis (AR) caused by house dust mite (HDM) and Japanese cedar pollen (JCP) represents a significant, expanding health problem in Japan. Allergic symptoms often have a severe impact on the QOL such as sleep disturbance and reduced school and work performance. In addition to the classical symptoms, AR is known to be a risk factor for the development of allergic asthma, a potentially life-threatening condition. Allergy immunotherapy (AIT) is a well-documented, safe, effective treatment option for respiratory allergic disease. It has been demonstrated that AIT can provide relief from clinical symptoms and that AIT has the potential to provide long-term post-treatment effect. Although the mechanism of AIT is not fully understood, it can actively modulate protective allergen-reactive pathways of the immune system and alter the natural course of disease. Unlike pharmacotherapy, AIT addresses the basic immunological mechanisms that are responsible for the development and persistence of allergic conditions. Currently two main routes of AIT administration are commonly available, subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT). Both SCIT and SLIT are clinically effective, and SLIT is particularly well tolerated, with a lower risk of systemic allergic reactions compared with SCIT. To date, SLIT tablets have been developed for a range of different allergies including HDM and JCP and are the best-documented AIT treatment form. Here we introduce the current status of development of a SLIT tablet in Japan for AR, examine the clinical aspects and mechanism of action of AIT, and discuss the future directions of SLIT.

Artemisia Annua sublingual immunotherapy for seasonal allergic rhinitis: A multicenter, randomized trial

Background

Artemisia annua is the most common outdoor aeroallergen throughout Northern China; however, no multicenter study has investigated sublingual immunotherapy (SLIT) as a treatment option for Artemisia annua-induced allergic rhinitis (AR). The aim of this study was to evaluate the efficacy and safety of an innovative SLIT for Artemisia annua-related AR.

Methods

This was a randomized, double-blind, placebo-controlled, multicenter, phase 3 clinical trial conducted in China (NCT XXX). A total of 702 Artemisia annua-sensitized eligible patients were randomized in a ratio of 2:1 to receive Artemisia annua-SLIT or placebo. The treatment lasted 32 weeks; including 5-weeks up-dosing phase and 27-weeks maintenance phase. The primary endpoint was the daily combined score of medication and rhinoconjunctivitis symptom (CSMRS), and secondary endpoints were daily total nasal symptom score (dTNSS) and daily rescue medication score (dRMS) during peak pollen period. Safety of treatment was evaluated according to adverse events (AEs) experienced.

Results

Mean daily CSMRS was significantly improved during the peak pollen period in the SLIT group compared with the placebo group (1.46 ± 0.47 vs 1.88 ± 0.42, P < 0.0001 in full analysis set [FAS]; 1.49 ± 0.52 vs 1.95 ± 0.46, P < 0.0001 in per protocol set [PPS]); representing a 22.3% and 23.6% reduction, respectively, relative to placebo. In specifically Artemisia annua monosensitized patients, mean daily CSMRS reductions were demonstrated as 24.1% and 27.0% in the FAS and PPS populations, respectively, when comparing the active treatment to placebo treatment. Similarly, SLIT decreased dTNSS in peak pollen period by 19.0% in FAS and 22.3% in PPS, respectively, relative to placebo. In coincidence, dRMS in peak pollen period was reduced by 22.0% in FAS and 26.0% in PPS. 65.8% patients in SLIT group experienced treatment-related AEs, none of which was serious.

Conclusion

This study indicates that SLIT with Artemisia annua drops is an effective and safe treatment option in Chinese patients with Artemisia Annua-induced AR.

β-Blockers and angiotensin-converting enzyme inhibitors with sublingual immunotherapy: are risks related to individual product safety profile?

PURPOSE OF REVIEW

The objective of this article is to review the available literature regarding the risks associated with sublingual immunotherapy and angiotensin-converting enzyme (ACE) inhibitors or β-blocker use. It also evaluates for any differences in these risks among the available sublingual immunotherapy (SLIT) tablets.

RECENT FINDINGS

A literature search was conducted in PubMed to identify peer-reviewed articles using the following keywords: anaphylaxis, ACE inhibitor, β-blocker, and sublingual immunotherapy. Minimal data exist regarding their safety of SLIT in patients concomitantly taking ACE inhibitors or β-blockers. The adverse reaction rates seem similar between SLIT products.

SUMMARY

A risk-versus-benefit discussion should be communicated with the patient taking a β-blocker before beginning SLIT but automatic denial of SLIT to these patients is not warranted.

Artemisia annua-sublingual immunotherapy for seasonal allergic rhinitis: A randomized controlled trial

BACKGROUND

Artemisia annua is an important autumnal pollen allergen for seasonal allergic rhinitis (SAR) in northern China. To date, no study has investigated allergen immunotherapy with A annua. We aimed to investigate the efficacy and mechanisms underlying A annua-sublingual immunotherapy (SLIT).

METHODS

This was a randomized, double-blind, placebo-controlled phase III clinical trial involving 71 SAR patients, randomized to SLIT with A annua extract (n = 47) or placebo (n = 24) for 32 weeks. Total nasal symptom score (TNSS; primary clinical end point) was evaluated at baseline (peak pollen phase (PPP) in the previous year), initiation of A annua-SLIT, 1st PPP during SLIT, end of SLIT and 2nd PPP during follow-up. Blood samples and nasal secretions were collected at beginning and after SLIT for assessment of T cells and inflammatory mediators. Safety was assessed according to adverse events (AEs) reported.

RESULTS

Artemisia annua-SLIT significantly reduced TNSS to a greater level from baseline (from 9.45 ± 1.68 to 6.16 ± 2.27) than placebo (from 9.29 ± 2.09 to 9.05 ± 2.40) at the 1st PPP (P < .001) and sustained the improvement in symptoms throughout to the 2nd PPP. Preseasonal A annua-SLIT for 16 weeks significantly decreased Th2 cells, increased nTreg and Tr1 cells in blood; and increased cystatin 1 (CST1) in nasal secretion after 16 and 32 weeks compared with pretreatment. Overall, 17/47 patients experienced mild local AEs and 2 patients mild systemic AEs, after A annua-SLIT.

CONCLUSION

Artemisia annua-SLIT is an efficacious and safe treatment in patients with A annua SAR.

Decreased numbers of metachromatic cells in nasal swabs in Japanese cedar pollinosis following sublingual immunotherapy

Background and Objective

Nasal symptoms were reduced following allergen‐specific sublingual immunotherapy (SLIT) for allergic rhinitis. The mechanisms underlying the effectiveness of SLIT for Japanese cedar pollinosis are poorly understood. We studied changes in the numbers of metachromatic cells, eosinophils, and neutrophils following SLIT for Japanese cedar pollinosis.

Methods

Nasal swabs were taken in the preseason (n = 32) and in pollinosis season (n = 49) from subjects given sublingual drop immunotherapy for an average duration of 1.5 years. The numbers of metachromatic cells (mast cells and basophils), eosinophils and neutrophils were determined and compared with those from untreated subjects in preseason (n = 65) and in season (n = 54).

Results

SLIT subjects had a significantly reduced frequency of moderate to most severe symptoms in comparison to untreated subjects in preseason (P < .001, the Mann‐Whitney U test), and (P < .00001) in season. Metachromatic cell counts in nasal swabs of SLIT subjects in preseason and in season were lower than those of untreated subjects (P = .014, the Mann‐Whitney U test) and (P = .00001) respectively. Eosinophil numbers in SLIT subjects were not significantly different than in untreated subjects in both preseason (P = .29) and in season (P = .09). However, when SLIT subjects in season were divided into those with greater than or equal to 1.5 years, or <1.5 years of SLIT duration, the degree of eosinophilia in those with SLIT greater than or equal to 1.5 years was significantly lower (P = .011) than in untreated patients, but not in those with SLIT less than 1.5 years (P = .9). There were no significant differences in neutrophil numbers in nasal swabs between untreated and SLIT subjects in preseason and in season.

Conclusion

One of mechanisms underlying the effectiveness of sublingual drop immunotherapy for Japanese cedar pollinosis is a reduction of the number of metachromatic cells in preseason and in season. Eosinophilia was also reduced in season in those given SLIT for greater than or equal to 1.5 years.

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

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

The Journal of Allergy and Clinical Immunology: In Practice 2019 Highlights

This article provides highlights of the clinically impactful original studies and reviews published in The Journal of Allergy and Clinical Immunology: In Practice in 2019 on the subjects of anaphylaxis, asthma, dermatitis, drug allergy, food allergy, immunodeficiency, immunotherapy, rhinitis/sinusitis, and urticaria/angioedema/mast cell disorders. Within each topic, practical aspects of diagnosis and management are emphasized. Treatments discussed include lifestyle modifications, allergen avoidance therapy, positive and negative effects of pharmacologic therapy, and various forms of immunologic and desensitization management. We designed this review to help readers consolidate and use this extensive and practical knowledge for the benefit of their patients.

Clinical aspects of sublingual immunotherapy tablets and drops

BACKGROUND

Sublingual immunotherapy (SLIT) is administered via tablets (SLIT-T) or liquid drops (SLIT-D). In North America, currently 4 SLIT-T formulations are approved by the US Food and Drug Administration for allergy immunotherapy, and SLIT-D is an off-label use of subcutaneous immunotherapy (SCIT) extracts.

OBJECTIVE

To compare and contrast aspects of SLIT-T and SLIT-D, including physical characteristics, mechanism of action, dosing, efficacy, safety, adherence, and cost.

DATA SOURCES

PubMed literature review (no limits), product prescribing information, and manufacturer websites.

STUDY SELECTIONS

Publications related to physical characteristics, mechanism of action, dosing, efficacy, safety, and adherence.

RESULTS

Published evidence indicates that tablet and drop formulations differ in regard to physical characteristics, dosing, and strength of evidence for efficacy. Whether there are any differences in absorption and mechanism of action between the 2 formulations is currently unknown. Optimal dosing, efficacy, and safety have been established for SLIT-T. In contrast, in North America there is little support for efficacy of SLIT-D from randomized double-blind, placebo-controlled trials, and dose ranges have not been appropriately evaluated. SLIT-T treats a single allergen, whereas in the United States SLIT-D often contains multiple allergens to treat polysensitization. The safety profiles of SLIT-T and SLIT-D appear similar, and both formulations are considered safer than SCIT.

CONCLUSION

Professional guidelines should make a clear distinction between SLIT-T and SLIT-D in their recommendations to minimize confusion with the umbrella term SLIT.

Safety profile and immunological response of dual sublingual immunotherapy with house dust mite tablet and Japanese cedar pollen tablet

BACKGROUND

There have been no studies of dual administration of sublingual immunotherapy (SLIT) tablets for perennial and seasonal allergic rhinitis. This trial (JapicCTI-184014) was conducted to investigate the safety profile and immunological response during dual therapy with SQ house dust mite (HDM) and Japanese cedar pollen (JCP) SLIT tablets.

METHODS

This was a multicenter, open-label, randomized trial of 109 Japanese patients with coexisting HDM and JCP allergic rhinitis who had positive tests for HDM- and JCP specific IgE (≥0.7 kU/L). Patients were allocated to receive HDM (N = 54) or JCP (N = 55) SLIT tablets alone for 4 weeks followed by 8 weeks of dual therapy with both SLIT tablets administered within 5 min of each other. Adverse events (AEs), adverse drug reactions (ADRs), and serum IgE and IgG4 specific for HDM (Dermatophagoides farinae, Dermatophagoides pteronyssinus) and JCP were recorded.

RESULTS

The percentage of subjects with AEs and ADRs was similar between the two groups and between the two periods of monotherapy and dual therapy. Most AEs and ADRs were mild in severity, and no serious events were observed. The most common ADRs were local events in the oral cavity. Levels of IgE and IgG4 specific for HDM (D. farinae, D. pteronyssinus) and JCP were increased after treatment with HDM and JCP SLIT tablets, respectively.

CONCLUSIONS

Dual therapy with both SLIT tablets administered within 5 min after 4 weeks of monotherapy with HDM or JCP tablet was well tolerated and induced the expected immunological responses.

Highlights of Novel Vaccination Strategies in Allergen Immunotherapy

Increasing safety while maintaining or even augmenting efficiency are the main goals of research for novel vaccine development and improvement of treatment schemes in allergen immunotherapy (AIT). To increase the efficacy of AIT, allergens have been coupled to innate immunostimulatory substances and new adjuvants have been introduced. Allergens have been modified to increase their uptake and presentation. Hypoallergenic molecules have been developed to improve the safety profile of the vaccines. Administration of recombinant IgG4 antibodies is a new, quick, passive immunization strategy with remarkable efficiency. Results of some current investigations aiming at further improvement of AIT vaccines have been summarized.

Treatment duration-dependent efficacy of Japanese cedar pollen sublingual immunotherapy: Evaluation of a phase II/III trial over three pollen dispersal seasons

BACKGROUND

We conducted a randomized, placebo-controlled, double-blind clinical trial to investigate the optimal dose and long-term efficacy and safety of Japanese cedar (JC) pollen tablets for SLIT (JapicCTI-142579). Here, we report details of the effects of the JC pollen SLIT tablet on rhinitis and conjunctivitis symptoms over three pollen dispersal seasons.

METHODS

A total of 1042 JC pollinosis patients (aged 5-64 years) were randomized to receive tablets containing placebo (P), 2000, 5000, or 10,000 Japanese allergy units (JAU) of JC pollen for 15 months to identify an optimal dose. Patients receiving P (n = 240) and the optimal dose (5000 JAU; A, n = 236) were then randomized to receive P or A for an additional 18 months (AA, AP, PA, and PP groups, allocation ratio 2:1:1:2). Nasal and ocular symptoms, rescue medication use, and quality of life (QOL) were assessed on quantitative scales.

RESULTS

In the second and third seasons, the AA, AP, and PA groups exhibited significantly better improvements in nasal, ocular, and medication scores compared with the PP group in the order AA > AP > PA > PP during the second season and AA > PA > AP > PP during the third season. Rescue medication use and QOL scores were also significantly better in the AA, AP, and PA groups compared with the PP group.

CONCLUSIONS

The JC pollen SLIT tablet relieved nasal and ocular symptoms and medication use and improved QOL in a treatment duration-dependent manner. Continuous dosing regimens appear to enhance the efficacy of the drug.

Efficacy and Safety of HDM SLIT Tablet in Japanese Adults with Allergic Asthma

BACKGROUND

The standardized quality (SQ) house dust mite (HDM) sublingual immunotherapy (SLIT) tablet has demonstrated efficacy and safety for allergic asthma (AA) in European trials.

OBJECTIVE

To evaluate the efficacy and safety of SQ HDM SLIT tablet treatment for up to 19 months in Japanese adults with AA.

METHODS

In this randomized, double-blind, placebo-controlled trial, patients aged 18 to 64 years with AA were randomly assigned (1:1:1) to SQ HDM SLIT doses of 10,000 or 20,000 Japanese Allergy Unit or placebo. Subjects had Asthma Control Questionnaire score of 1.0 to 1.5 and daily inhaled corticosteroid use of 200 to 400 μg of fluticasone propionate at randomization. The primary end point was the time from randomization to the first asthma exacerbation as the inhaled corticosteroid dose was being reduced.

RESULTS

Of the 826 randomized subjects, 693 (84%) completed the trial. No statistically significant differences between the active groups and the placebo group were observed for the primary or any other efficacy end points. However, post hoc analysis indicated a significant difference between the 20,000 Japanese Allergy Unit and placebo groups among subjects who used a short-acting β₂-agonist during the baseline period (hazard ratio, 0.70; 95% CI, 0.48-1.00; P = .04997). No deaths or anaphylactic reactions were reported. Most adverse events were mild to moderate in severity.

CONCLUSIONS

The trial demonstrated a favorable safety profile of the SQ HDM SLIT tablet in Japanese adult patients with AA. The treatment appeared to be efficacious in patients requiring rescue medication (ie, short-acting β₂-agonist) at baseline in the efficacy assessment using asthma exacerbation during inhaled corticosteroid reduction (JapicCTI number 121847).

[Developmental history of sublingual immunotherapy]

Allergen immunotherapy is the only curative treatment for IgE-mediated allergic diseases in contrast to symptomatic treatment such as anti-histamine agents. Subcutaneous immunotherapy (SCIT) has been introduced in Japan for treatment of allergic rhinitis and/or asthma caused by pollens and/or house dust mites (HDM) in early 1960s, and the clinical efficacy has been well-known. However, the major drawbacks of SCIT are necessity of repeated painful injections as well as the risk of severe systemic adverse reactions. Sublingual immunotherapy (SLIT) was developed to resolve these issues. In Japan, Japanese cedar (JC) pollen SLIT-drop was developed initially for treatment of JC pollinosis, and approved for patients of 12 years of age and older in 2014. For adolescent and adult patients with HDM-allergic rhinitis, HDM SLIT-tablet was launched in 2015 and subsequently approved to be also available for pediatric patients (<12 years of age) in 2018. Moreover, JC pollen SLIT-tablet for JC pollinosis was approved in 2018 for all patients with no age limit. Here, we also describe that the formulation technologies of SLIT tablets and distribution of allergens after sublingual administration as well as the development of SLIT drop/tablets.

Establishment of enzyme-linked immunosorbent facilitated antigen binding as a biomarker assay for Japanese cedar pollen allergy immunotherapy

BACKGROUND

Clinical efficacy of allergen-specific Immunotherapy (AIT) towards Japanese cedar (JC) pollen allergy is firmly established but JC pollen-specific biomarker assays are lacking. Treatment-related increase of allergen-specific antibodies is a robust biomarker of successful AIT. Allergen-specific non-IgE antibodies are believed to reduce the effects of allergen exposure by competing with IgE for allergen binding, and in-vitro assays quantifying the effects of AIT-induced IgE-blocking antibodies are advantageous. A cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay of JC pollen was established.

METHODS

Serum IgE-allergen complexes were captured by immobilized recombinant CD23, and allergen-IgE-CD23 complexes were detected by a biotin-conjugated anti-human IgE antibody. Sera from JC pollen-allergic subjects without or with subcutaneous immunotherapy (SCIT) with JC pollen extract were used (n = 11/group).

RESULTS

Optimal assay conditions were established at 20 μg/mL CD23 and 0.3 μg/mL JC pollen extract, and the dependency on CD23 and IgE was verified. The data show that the JC pollen ELIFAB assay is fit for purpose and demonstrates that the IgE-blocking activity is significantly increased in the JC pollen SCIT group compared with the non-treated group.

CONCLUSION

The JC pollen ELIFAB assay represents a simple, cell-free biomarker assay for monitoring the development of IgE-blocking antibody activity during JC pollen AIT.