Sublingual allergen immunotherapy with a liquid birch pollen product

Published online: November 30, 2018

Allergen immunotherapy (AIT) is the only disease-modifying treatment option available for patients with IgE-mediated allergic diseases such as allergic rhinoconjunctivitis (ARC) and can be administered by several routes. With sublingual administration the allergen is held underneath the tongue to allow the immune-modulating effect through the sublingual mucous membrane. In line with the regulatory guidance of the European Medicines Agency (EMA) products for AIT have to demonstrate their clinical efficacy in phase III trials subsequent to controlled clinical phase II trials of the investigational product for optimal dose determination.

In a research article recently published in The Journal of Allergy & Clinical Immunology (JACI), Pfaar and colleagues report on a randomized, double-blind, placebo-controlled (DBPC), phase III study with an open-label safety extension period in birch pollen allergic patients. In this study, a high-dose liquid birch pollen extract or placebo was used. The study was performed pre-seasonally over 3 to 6 months before the birch pollen season and continued co-seasonally during the pollen season, followed by an open-label safety extension period over 6 months. The trial included 406 adult patients with moderate to severe birch pollen induced ARC with or without mild to moderate, controlled asthma from 40 European clinical study centres. Clinical efficacy was analysed using the combined symptom and medication score (CSMS) which has been recently recommended by the European Academy of Allergy and Clinical Immunology (EAACI).

The authors found for this high-dose, liquid birch SLIT product substantial evidence for safety and clinically relevant efficacy. Results of primary endpoint analysis were consistently supported by results obtained for all secondary endpoints irrespective of analysis during the whole pollen season or the peak pollen season. The observed treatment effect size was found to be 32% and the decrease in CSMS in the active group was accompanied by a significantly improved quality of life as compared to placebo. Local and systemic adverse reactions were mainly of mild intensity and well controlled.

The data presented with the new EAACI-recommended CSMS scoring system verify its ease of use, its responsiveness over time and its fitness for the purpose of measuring disease influencing elements deemed associated with ARC. The CSMS score can therefore be recommended as a standard in future clinical trials with AIT products for the treatment of ARC.

The Journal of Allergy and Clinical Immunology (JACI) is the official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.

18-00644R3, Sublingual allergen immunotherapy with a liquid birch pollen product in seasonal allergic rhinoconjunctivitis with/without asthma

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