A 300 IR sublingual tablet is an effective, safe treatment for house dust mite induced allergic rhinitis : an international, double-blind, placebo-controlled, randomized phase III clinical trial

Background: Allergic rhinitis induced by house dust mites (HDMs) is a highly prevalent but often underdiagnosed and undertreated/untreated chronic disease. It often has a negative impact on sleep, work, leisure activities, and health-related quality of life. Allergen immunotherapy is a proven, safe treatment for respiratory allergies. Objective: We sought to assess the efficacy and safety of a 300 index of reactivity (IR) sublingual tablet formulation of Dermatophagoides pteronyssinus:Dermatophagoides farinae 1:1 extract in adolescents (aged >_12) and adults with moderate to severe HDM-induced allergic rhinitis. Methods: In a phase III, international, double-blind, placebo controlled, randomized clinical trial, participants received approximately 12 months of treatment with placebo or the 300 IR tablet. The primary end point was the average total combined score during 4 weeks at the end of the treatment period. Results: A total of 1607 participants were randomized, and 1476 (including 555 [37.6%] with concomitant mild controlled asthma at inclusion) comprised the full analysis set. Over the primary evaluation period, the least squares mean average total combined score in the 300 IR group (3.62) was significantly lower (P <.0001) than in the placebo group (4.35), with a relative least squares mean difference of -16.9% (95% CI, -24.0% to -9.2%). All prespecified secondary end points were consistently improved in the 300 IR group, relative to placebo. The 300 IR tablet was generally well tolerated. Treatment related adverse events (mainly mild or moderate local reactions) were reported for 51.0% of the patients in the 300 IR group and 14.9% in the placebo group. Conclusions: The 300 IR sublingual HDM tablet is an effective, safe treatment for HDM-induced allergic rhinitis. (J Allergy Clin Immunol 2021;147:1020-30.