Supplementary Material for: The SQ House Dust Mite SLIT-Tablet Is Well Tolerated in Patients with House Dust Mite Respiratory Allergic Disease

<p><b><i>Background:</i></b> The SQ house dust mite (HDM) SLIT-tablet (ALK, Denmark) addresses the underlying cause of HDM respiratory allergic disease, and a clinical effect has been demonstrated for both HDM allergic rhinitis and allergic asthma. Here, we present pooled safety data from an adult population with HDM respiratory allergy, with particular focus on the impact of asthma on the SQ HDM SLIT-tablet tolerability profile. <b><i>Methods:</i></b> Safety data from 2 randomised double-blind, placebo-controlled clinical trials were included: MT-04: 834 adults with HDM allergic asthma not well controlled by inhaled corticosteroids and with HDM allergic rhinitis, and MT-06: 992 adults with moderate-to-severe HDM allergic rhinitis despite the use of allergy pharmacotherapy and with or without asthma. <b><i>Results:</i></b> The proportion of subjects experiencing adverse events (AEs) was greater in the active treatment group (12 SQ-HDM; 73% of subjects) compared to placebo (53%). The most common treatment-related AEs were local allergic reactions. No AEs were reported as systemic allergic reactions. Regardless of asthma status, most AEs were mild or moderate (>97% of AEs) and the frequency of serious AEs was low. Subgroup analysis revealed no statistically significant difference in the risk of experiencing moderate or severe treatment-related AEs for subjects with asthma compared to subjects without asthma (<i>p</i> = 0.88). In addition, subjects with partly controlled or uncontrolled asthma were no more likely to experience moderate or severe treatment-related AEs than subjects with controlled asthma (<i>p</i> = 0.42). <b><i>Conclusion:</i></b> The SQ HDM SLIT-tablet is well tolerated, and the safety profile was comparable for subjects with HDM respiratory allergic disease irrespective of asthma status.