Efficacy and safety of SQ house dust mite sublingual immunotherapy-tablet in Japanese children

SQ house dust mite sublingual immunotherapy for the treatment of adults with house dust mite-induced allergic rhinitis

Introduction: Allergic rhinitis (AR) is one of the most common chronic conditions affecting both children and adults. The house dust mites (HDM) account for a substantial part of the overall sources of allergens. In patients where allergen avoidance and symptom-relieving pharmacotherapy do not provide adequate disease control, specific allergen immunotherapy (AIT) is indicated. While subcutaneous injection (SCIT) is considered as a time-consuming and invasive treatment regimen, sublingual allergy immunotherapy (SLIT) appears as more convenient treatment strategy.Areas covered: This Drug Profile reviews the clinical data behind the development of the SQ HDM SLIT-tablet, including both the early studies and the pivotal studies, which formed the basis for regulatory approval in Europe, Japan, and the U.S.Expert opinion: The clinical trials behind the development of the SQ HDM-SLIT have demonstrated that the tablet provides a safe, well-tolerated and robust efficacy in the treatment of HDM-induced allergic rhinoconjunctivitis. Further, studies show that the SQ HDM SLIT-tablet is a cost-effective treatment option compared with SCIT.

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).

Efficacy and safety of sublingual dust mite drops in children with mono- or polysensitized allergic rhinitis

OBJECTIVE

To explore the efficacy and safety of sublingual house dust mite (HDM) drops in children with mono- or polysensitized allergic rhinitis.

METHODS

We conducted a retrospective cohort study of 65 children with monosensitized AR and 118 children with polysensitized AR who were scheduled for sublingual administration of HDM drops from January 2015 to June 2016. Interleukin (IL)-2, IL-4, and IL-17α, transforming growth factor-β1 (TGF-β1), specific immunoglobulin E (IgE), and specific IgG4 were detected by ELISA. The efficacies were assessed using symptoms score and medication score. All the outcomes were measured 1 month before the study and 1 month after the end of the 2-year treatment.

RESULTS

The total nasal symptoms score (TNSS) decreased significantly from 11.27 (9.81 ± 12.73) at baseline to 3.48(1.98 ± 4.98) at the end of sublingual treatment for the monosensitized AP group (t = 30.00, P < 0.01), and from 11.54(10.04 ± 13.04) to 3.56 (2.00 ± 5.16) for the polysensitized AR group (t = 40.05, P < 0.01), respectively. IL-2 and TGF-β1 increased significantly after treatment in contrast with before treatment in both the monosensitized group and the polysensitized group (both P < 0.01). In contrast, IL-4 and IL-17α decreased significantly after treatment compared with the baseline in both groups (both P < 0.01). Sublingual HDM drops were generally safe and well tolerant in both groups.

CONCLUSIONS

This study confirmed the efficacy and safety of sublingual AIT in both monosensitized and polysensitized AR patients (Chinese children).

[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.

Der p 1-specific regulatory T-cell response during house dust mite allergen immunotherapy

BACKGROUND

Allergen-specific immunotherapy (AIT) is the only available treatment for allergic diseases that can induce specific immune tolerance to allergens. The key mechanisms involved in this process include changes in allergen-specific regulatory T (Treg) cells.

METHODS

We studied 25 allergic rhinitis patients undergoing subcutaneous house dust mite-specific immunotherapy. Peripheral blood mononuclear cells were studied before and after 10, 30 weeks, and 3 years of AIT. Der p 1-specific T regulatory cell responses were investigated by characterization of Der p 1-MHC class II tetramer-positive cells and correlated with nasal symptom score.

RESULTS

Twelve of 25 AIT patients matched with their MHC class II expression to the Der p 1 peptide-MHC class II tetramers. A significant increase in the numbers of Der p 1-specific FOXP3⁺ Helios⁺ CD25⁺ CD127^- Treg cells after 30 weeks was observed, which slightly decreased after 3 years of AIT. In contrast, Der p 1-specific immunoglobulin-like transcript 3 (ILT3)⁺ CD25⁺ Treg cells decreased substantially from baseline after 3 years of AIT. ILT3⁺ Treg cells displayed compromised suppressive function and low FOXP3 expression. In addition, Der p 1-specific IL-10 and IL-22 responses have increased after 30 weeks, but only IL-10⁺ Der p 1-specific Treg cells remained present at high frequency after 3 years of AIT. Increased number of FOXP3⁺ Helios⁺ and IL-10⁺ and decreased ILT3⁺ Treg cell responses correlated with improved allergic symptoms.

CONCLUSION

The results indicate that AIT involves upregulation of the activated allergen-specific Treg cells and downregulation of dysfunctional allergen-specific Treg cell subset. Correction of dysregulated Treg cells responses during AIT is associated with improved clinical response.

Immunomodulation in Pediatric Asthma

Childhood asthma is actually defined as a heterogeneous disease, including different clinical variants and partially sharing similar immune mechanisms. Asthma management is mainly focused on maintaining the control of the disease and reducing the risk of adverse outcomes. Most children achieve good control with standard therapies, such as low doses of inhaled corticosteroids (ICS) and/or one or more controller. These medications are targeted to suppress bronchial inflammation and to restore airway responsiveness. However, they are not disease-modifying and do not specifically target inflammatory pathways of asthma; in addition, they are not significantly effective in patients with severe uncontrolled asthma. The aim of this review is to update knowledge on current and novel therapeutic options targeted to immunomodulate inflammatory pathways underlying pediatric asthma, with particular reference on biologic therapies.

Recent developments and highlights in allergen immunotherapy

Allergen immunotherapy (AIT) is the only disease-modifying treatment option for patients with IgE-mediated inhalant allergies. Though used in clinical practice for more than 100 years, most innovations in AIT efficacy and safety have been developed in the last two decades. This expert review aimed to highlight the recent progress in AIT for both application routes, the sublingual (SLIT) and subcutaneous (SCIT) forms. As such, it covers recent aspects regarding efficacy and safety in clinical trials and real-life data and outlines new concepts in consensus and position papers as well as in guidelines for AIT. Potential clinical and nonclinical biomarkers are discussed. This review also focuses on potential future perspectives in AIT, such as alternative application routes, immune-modulating adjuvants, and recombinant vaccines. In conclusion, this state of the art review provides a comprehensive overview of AIT and highlights unmet needs for the future.