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

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.

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.

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.

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.

Clinicaltrials.gov identifier: NCT03654976; EudraCT number: 2016-004363-39.