[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.

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

BACKGROUND: The SQ house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet (TO-203, Torii, Japan/ALK, Denmark) treatment has been effective against respiratory allergic diseases in patients aged ≥12 years during European, Japanese, and North American trials. This trial was conducted to investigate the efficacy and safety of this treatment in Japanese children (5-17 years) with moderate-to-severe HDM allergic rhinitis (AR). METHODS: In this randomized, double-blind, placebo-controlled trial, 458 Japanese children were randomly assigned to a daily SQ HDM SLIT-tablet [10 000 Japanese Allergy Unit (JAU), equivalent to 6 SQ-HDM in Europe and the US] or placebo (1:1) treatment for 1 year. Inclusion required an AR symptom score of ≥7 on at least 7 days during a 14-day run-in period while symptomatic treatment was withdrawn. The primary endpoint was the total combined rhinitis score (TCRS) comprising AR symptom and medication scores during the last 8 weeks of the treatment period. RESULTS: The analysis of primary endpoint demonstrated statistically significant absolute reduction in TCRS of 1.22 with a relative difference of 23% (95% confidence interval, 14% to 31%) in the 10 000 JAU compared with placebo. Predefined stratified analyses revealed the same degree of efficacy of 1.11 (P = 0.002), 21% (8% to 32%) and 1.36 (P = 0.001), 26% (11% to 38%), respectively, in pediatric (5-11 years) and adolescent subjects (12-17 years). The treatment was well tolerated by both pediatric and adolescent subjects. CONCLUSION: This trial, for the first time, demonstrated the efficacy and safety of the HDM SLIT-tablet in pediatric patients with moderate-to-severe HDM AR (JapicCTI-152953).

Long-term safety of subcutaneous immunotherapy with TO-204 in Japanese patients with house dust mite-induced allergic rhinitis and allergic bronchial asthma: Multicenter, open label clinical trial.

BACKGROUND: To evaluate the long-term safety of subcutaneous immunotherapy with TO-204, a standardized house dust mite (HDM) allergen extracts, we conducted a multicenter, open label clinical trial. METHODS: Japanese patients aged 5-65 years were eligible for the study, if they had HDM-induced allergic rhinitis (AR), allergic bronchial asthma (BA), or both. TO-204 was administered in a dose titration scheme, and the maintenance dose was determined according to the predefined criteria. The treatment period was 52 weeks, and patients who were willing to continue the treatment received TO-204 beyond 52 weeks. This clinical trial is registered at the Japan Pharmaceutical Information Center (Japic CTI-121900). RESULTS: Between July 2012 and May 2015, 44 patients (28 with AR and 16 with allergic BA) were enrolled into the study. All patients were included in the analysis. The duration of treatment ranged from 23 to 142 weeks and the median maintenance dose was 200 Japanese allergy units (JAU). Adverse events occurred in 22 patients (50%). The most common adverse event was local reactions related to the injection sites. Four patients experienced anaphylactic reactions when they were treated with the dose of 500 JAU. Two patients experienced anaphylactic shock with the doses of 1000 JAU at onset. These 6 patients could continue the study with dose reduction. CONCLUSIONS: Safety profile of TO-204 was acceptable in Japanese patients with HDM-induced AR or allergic BA. Higher doses should be administered carefully, because the risk of anaphylaxis increased at doses of 500 or 1000 JAU.