The efficacy and safety of two commercial house dust mite extracts for allergic rhinitis: a head-to-head study.

Abstract

Several studies have demonstrated the efficacy of house dust mite (HDM) immunotherapy in allergic rhinitis (AR). We aimed to compare the efficacy and safety of 2 commercial HDM extracts in a Chinese AR population. This was an open-label study. HDM-associated AR patients were randomized into Dermatophagoides pteronyssinus (Dp) extracts (Alutard SQ; ALK, Hørsholm, Denmark) and Dp/Dermatophagoides farinae (Df) extracts (NovoHelisen Depot [NHD]; Allergopharma, Reinbek, Germany) groups. All patients received subcutaneous injections for 1 year, and were followed every 3 months during that 1-year period. Symptom score, medication score, and adverse reactions were recorded. The primary endpoint was the total combined symptom and medication score (CSMS) during the efficacy evaluation period. Blood samples were taken for specific immunoglobulin E (IgE), IgG4, and IgE-blocking factor tests at baseline and after the 1-year treatment. A total of 230 AR patients were randomized; 29 patients dropped out. Analysis of the primary endpoint demonstrated significant reductions in CSMS of 1.8 vs 3.1 (p < 0.001) in the Alutard group and 1.8 vs 3.3 (p < 0.001) in the NHD group compared with baseline. The 2 groups presented equal effectiveness with regard to CSMS, symptom score, and medication score (p > 0.05). The treatment was well tolerated in both groups; 17 (14.8%) patients experienced systemic reactions (SRs) in the Alutard group and 13 (11.3%) in the NHD group. The rates of SRs showed no difference in the 2 groups (p > 0.05), and no anaphylaxis occurred. IgG4 and IgE-blocking factor to Dp and Df were increased significantly in both groups after the 1-year treatment. Our study confirmed the equal efficacy and safety profile of both commercial extracts in HDM-associated AR patients.