A Study Investigating the Immunologic Effects and Safety of 60-day Treatment of the ALK HDM Tablets in Adult Subjects With HDM-Induced Allergic Rhinitis and/or Atopic Asthma

Inclusion Criteria:

• Written informed consent obtained before entering the study

• Patients 18-65 years of age, with a clinical history consistent with HDM-inducedallergic rhinitis or allergic rhinoconjunctivitis with or without HDM-induced allergicatopic asthma for more than 1 year

• Use of symptomatic treatment of HDM-induced allergic rhinitis and/or HDM-inducedatopic asthma, i.e. antihistamines, nasal decongestants, nasal and/or inhaledcorticosteroid for more than 1 year

• if HDM-induced atopic asthma is present, it should be of mild to moderate severity,controlled on treatment corresponding to steps 1-3 of The Global initiative for asthma (GINA)

• Positive skin prick test response (wheal diameter ≥3 mm) to D pteronyssinus and/orD.farinae

• Moderate or higher level of D.pteronyssinus and/or D.farinae specific IgE (defined as ≥IgE Class 2; or ≥0.70 kilo unit (kU)/L)

• Patient one of the following:

1. Male

2. Female, infertile

3. Female, with a negative pregnancy test and willingness to practice appropriatecontraceptive methods until treatment with study drug has been discontinued.

• Patient willing and able to comply with study protocol

Exclusion Criteria:

• Previous treatment with HDM immunotherapy for more than 1 month within the last 5years

• Ongoing treatment with any allergen-specific immunotherapy product

• Reduced lung function (defined as Forced expiratory volume in 1 second (FEV1) < 70% ofpredicted value after adequate pharmacologic treatment) measured at Visit 1 and Visit 2

• Clinical history of uncontrolled asthma within 3 months prior to the screening visit

• Having experienced a severe asthma exacerbation within 3 months prior to screeningvisit

• Symptoms of or treatment for upper respiratory tract infection, acute sinusitis, acuteotitis media or other relevant infectious process at randomization

• Inflammatory conditions in the oral cavity with severe symptoms such as oral lichenplanus with ulcerations or severe oral mycosis at randomization

• History of anaphylaxis with cardiorespiratory symptoms (immunotherapy,exercise-induced, food allergy, drugs or an idiopathic reaction)

• History of recurrent generalized urticaria (defined as two or more episodes) duringthe last 2 years

• A history of drug induced (incl. immunotherapy) facial angioedema or a family (parentsand siblings) history of hereditary angioedema

• Any chronic disease (e.g. cystic fibrosis, malignancy, malabsorption or malnutrition,renal or hepatic abnormality or any other diseases that in the opinion of theinvestigator would interfere with the study evaluations or the safety of the subject)

• Systemic disease affecting the immune system (e.g. autoimmune disease, immune complexdisease, or immune deficiency disease whether acquired or not)

• Immunosuppressive treatment (ATC code L04 or L01) within 3 months prior to thescreening visit

• Currently treated with tricyclic antidepressants; catecholamine-O-methyltransferase (COMT) inhibitors and mono amine oxidase inhibitors (MAOIs) and beta-blockersincluding topical administration

• Use of medication at the screening visit which at the time of skin prick test (SPT)can interfere with the result (i.e. antihistamines)

• Use of an investigational drug within 30 days/5 half-lives of the drug (which everlongest) prior to the screening visit

• History of allergy, hypersensitivity or intolerance to a excipient in theinvestigational medicinal product (except D.Pteronyssinus and D.farinae)

• Being immediate family of the investigator or study staff, defined as theinvestigator's/staff's spouse, parent, child, grandparent or grandchild

• Severe mental disorders that in the opinion of the investigator would interfere withthe study evaluations or the safety of the subject

• Cardiovascular conditions in which complications are possible when using adrenaline

• Women who are pregnant or breastfeeding