The efficacy and safety of sublingual immunotherapy in house dust mite-induced asthma have yet to be firmly established. We report the results of a double-blind, placebo-controlled, randomized clinical trial performed in mainland China.

METHODS: After a three-month baseline period, 484 asthmatic adults were randomized 2 : 1 to 12 months of daily treatment with either an aqueous, standardized, 300 index of reactivity mixture of Dermatophagoides pteronyssinus and Dermatophagoides farinae extracts or a placebo. The primary efficacy criterion was well-controlled asthma for at least 16 of the last 20 weeks of treatment.

RESULTS: In the active (n = 308) and placebo (n = 157) groups, well-controlled asthma was achieved by 85.4% and 81.5% of the patients, respectively (P = 0.244). A subsequent post hoc analysis by asthma severity revealed significant clinical benefits in actively treated subjects with moderate, persistent asthma at baseline [401-800 μg budesonide/day (n = 175)], with greater achievement of well-controlled asthma (80.5% and 66.1% for the active treatment and placebo groups, respectively; P = 0.021) and totally controlled asthma (54.0% and 33.9%, respectively, P = 0.008), a higher percentage of patients with an asthma control questionnaire score < 0.75 (56.6% and 40.0%, respectively; P = 0.039) and a greater mean reduction in inhaled corticosteroid use (218.5 μg and 126.2 μg, respectively; P = 0.004). The active vs placebo differences in disease control and corticosteroid use were not significant for mild, persistent asthma. No treatment-related serious adverse events were reported.

CONCLUSIONS: Sublingual mite allergen immunotherapy was well tolerated in adult asthmatics and effectively controlled disease in patients with moderate (but not mild) persistent asthma (ClinicalTrials.gov: NCT00660452).