Efficacy and safety of sublingual tablets of house dust mite allergen extracts in adults with allergic rhinitis

Preliminary studies have suggested the efficacy of sublingual tablets of house dust mite (HDM) extracts in adults with allergic rhinitis. We sought to assess the efficacy and safety of 2 doses of HDM sublingual tablets over 1 treatment year and the subsequent immunotherapy-free year. Adults with HDM-associated allergic rhinitis were randomized in a double-blind, placebo-controlled study to receive 500 index of reactivity (IR) tablets, 300IR tablets, or placebo administered once daily for 1 year and were followed for the subsequent year. The primary efficacy variable was the Average Adjusted Symptom Score over the year 1 primary period (ie, October 1 to December 31). Symptoms and rescue medication scores, onset of action, patient-reported outcomes, and safety were secondary variables. The same end points were evaluated during the immunotherapy-free year. The primary efficacy end point was analyzed by using analysis of covariance. Five hundred nine participants were randomized, and 427 continued in the immunotherapy-free year. Both the 500IR and 300IR HDM sublingual tablets significantly reduced mean Average Adjusted Symptom Scores compared with placebo by -20.2% (P = .0066) and -17.9% (P = .0150), respectively. Efficacy of both doses was maintained during the treatment-free follow-up phase. The onset of action was at 4 months. Participants' global evaluation of treatment success was significantly higher in the 500IR and 300IR groups compared with the placebo group (P = .0206 and P = .0001, respectively). Adverse events were generally application-site reactions. There were no reports of anaphylaxis. Twelve months of treatment with 500IR and 300IR sublingual tablets of HDM allergen extracts was efficacious and well tolerated. Efficacy was maintained during the treatment-free follow-up year