SQ House Dust Mite Sublingual Immunotherapy Tablet in Children With Allergic Asthma: A Randomised Phase III Trial

Abstract

Background: In children, house dust mite (HDM) sensitisation is a contributing factor for developing allergic asthma. HDM allergen immunotherapy has demonstrated efficacy and safety in adults with allergic asthma; however, evidence for its use in children is limited. MT-11 evaluated the efficacy and safety of the SQ HDM sublingual immunotherapy (SLIT) tablet in children (5–17 years) with HDM allergic asthma. Methods: This phase III, randomised, double-blind, placebo-controlled trial randomised 533 children with a recent history of asthma exacerbations, despite treatment with inhaled corticosteroids and/or long-acting beta-agonists, to daily treatment with SQ HDM SLIT-tablet or placebo for 24–30 months. The primary endpoint was the annualised rate of clinically relevant asthma exacerbations. Adverse events (AEs) were reported throughout the trial. Results: The rate ratio for the annualised rate of clinically relevant asthma exacerbations was 0.89 (95% CI: 0.60, 1.31), in favour of the SQ HDM-SLIT tablet; superiority over placebo was not established. Most treatment-related AEs (TRAEs) were of mild or moderate severity, and few subjects discontinued due to TRAEs (< 2%). The most common TRAEs were local application site reactions (oral pruritus, throat irritation, ear pruritus, and upper abdominal pain). There was no increased incidence of asthma-related events, and no anaphylaxis or adrenaline use in the SQ HDM SLIT-tablet group. Conclusion: As a result of the coronavirus disease 2019 pandemic, asthma exacerbation rates were much lower than expected, contributing to the primary endpoint not being met. The SQ HDM SLIT-tablet was well tolerated in a paediatric population with inadequately controlled HDM allergic asthma. Trial Registration: Clinicaltrials.gov identifier: NCT03654976; EudraCT number: 2016-004363-39.