The primary aim of this trial is to evaluate the efficacy of the ALK house dust mite tablet given once daily compared to a placebo tablet in the treatment of house dut mite allergic rhinits.

Additionally the secondary objective of the trial is to evaluate the safety and tolarability of the ALK house dust mite tablet.

Immunotherapy has been shown to provide therapeutic benefits to subjects with house dust mite induced allergy. This trial is planned to investigate if clinically relevant improvements in rhinitis symptoms and with less use of symptomatic medication can be obtained in subjects with a history of poor didease control despite of use of symptomatic medications.

Inclusion Criteria:

• A history of house dust mite allergy
• Use of symptomatice medication for treatment of house dust mite allergy
• Positive skin prick test to mites
• Positive specific IgE

Exclusion Criteria:

• History of uncontrolled asthma
• Overlapping symptomatice allergies
• Previous treatment with immunotherapy