Evaluation of the Efficacy of Allergen-specific Immunotherapy Using Assessment in an Allergen Exposure chamber-a Randomized Placebo-controlled Double-blind Study

The main objective of the study is to measure and correlate clinical parameters suitable for the assessment of allergen immunotherapy (AIT) with an aluminum hydroxide-adsorbed preparation of house dust mite (Dermatophagoides pteronyssinus/ Dermatophagoides farinae) allergens in adults with moderate to severe allergic rhinitis/rhinoconjunctivitis with or without controlled allergic bronchial asthma caused by house dust mite (HDM) allergens. The assessment of clinical responses will be evaluated following an allergen challenge in allergen exposure chamber (AEC) before and during the course of AIT. Patients' response to therapy will be evaluated as well as in the AEC and by patient's personal environment (Diary).