PURETHAL® Mites Dose Range Finding Study in Patients With Persistent Allergic Rhinitis/Rhinoconjunctivitis

Inclusion Criteria: * Signed informed consent * Patients (male or female) must be ≥ 18 and ≤ 60 years at screening * Patients with allergic rhinitis or rhinoconjunctivitis for at least 1 year; allergic symptoms related to HDM, with or without concomitant clinically stable controlled mild to moderate asthma (according to GINA classification) * Patients with a history of concomitant asthma should have a FEV1 \> 70% at inclusion. Patients without a history of asthma should have a FEV1 \> 70% or a PEF \> 80%. * Positive SPT to HDM D. pter and/or D. far * Serum specific IgE-test (ssIgE) level for HDM D. pter or D. far at screening * Positive nasal provocation test for HDM extract at screening Exclusion Criteria: * Current clinically relevant symptoms of seasonal rhinitis/rhinoconjunctivitis caused by other allergen(s) than HDM (with a demonstrated positive SPT for this allergen) at the time of inclusion * Patients sensitized to animals should not be included if they are symptomatic upon exposure and regularly exposed to animals * Completed allergen-specific immunotherapy (SCIT or SLIT) with HDM within the last 5 years * Completed unsuccessful allergen-specific immunotherapy (SCIT or SLIT) within the past 5 years * Allergen-specific immunotherapy (SCIT or SLIT) with other allergens than HDM during the study period * Any vaccination one week before start of therapy and during the up-dosing phase * Any anti-IgE therapy within the last 6 months prior to inclusion and during study * Severe immune disorders (including auto-immune diseases) and/or diseases requiring immunosuppressive drugs * Active malignancies or any malignant disease in the past 5 years * A chronic or acute disease that in the opinion of the investigator might place the patient at an additional risk, including but not limited to the following: cardiovascular insufficiency, any severe or unstable lung diseases, endocrine disorders, clinically significant renal or hepatic diseases, or haematological disorders * Moderate to severe nasal obstructive diseases such as polyps, septal deviations etc. * Clinically significant chronic sinusitis or ocular infection * Diseases with a contra-indication for the use of adrenaline (e.g. hyperthyroidism, glaucoma) * Use of systemic corticosteroids within 4 weeks of screening * Treatment with systemic or local b-blockers * Participation in a clinical study with a new investigational drug within the last 3 months or a biological within the last 6 months prior to the study or during the study * Pregnancy, lactation or inadequate contraceptive measures (contraceptive measures considered as adequate include appropriate use of oral contraception, i.m. contraception or a contraceptive device) * Alcohol, drug, or medication abuse within the past year and during study * Any abnormal laboratory parameter at screening that in the opinion of the investigator is considered clinically relevant * Lack of co-operation or compliance * Severe psychiatric, psychological, or neurological disorders * Patients who are employees of the department, 1st grade relatives, or partners of the investigator * Expected changes in HDM exposure during the study (avoidance measures, move, etc.)