The purpose of the trial is to assess the tolerability of the up-dosing phase of AVANZ Mite mix.

The frequency of patients with adverse reactions will be the primary endpoint.

Inclusion Criteria:

• Male and female patients 18-65 years of age.
• A clinical history of HDM induced allergic rhinoconjunctivitis with or without asthma at least one year prior to trial entry.
• Positive SPT to Dermatophagoides pteronyssinus (Der pte) or Dermatophagoides farinae (Der far) (wheal diameter ≥ 3 mm).
• A positive specific IgE against Der pte or Der far (≥Class 2; ≥0.70 KU/L) documenting in the last 5 years.

Exclusion Criteria:

• FEV1 < 70% of predicted value at screening after adequate pharmacologic treatment.
• Uncontrolled or severe asthma.
• A clinically relevant history of symptomatic perennial allergic rhinitis and/or conjunctivitis caused by an allergen, to which the subject is regularly exposed and sensitized.
• History of severe asthma exacerbation or emergency room visit or admission for asthma in the previous 12 months.
• At screening, current symptoms of, or treatment for, upper respiratory tract infection, acute sinusitis, acute otitis media or other relevant infection (serous otitis media is not an exclusion criterion).
• Treatment with parenteral corticosteroids, oral corticosteroids or anti-IgE in the previous 3 months or during the study (except for steroids if needed as rescue medication). Please, see Table 4.
• Currently treated with angiotensin converting enzyme (ACE) inhibitors, tricyclic antidepressants, β-blockers, mono amine oxidase inhibitors (MAOIs) and any other drug containing alum (e.g. antacids) taken on a daily basis.
• Previous treatment by other allergen concomitant IT or immunotherapy with HDM extracts within the previous 5 years (initiation of subcutaneous immunotherapy is acceptable if treatment has been discontinued before reaching maintenance dose; for SLIT 3 months in the last 5 years is accepted).
• History of anaphylactic shock due to e.g. food, insect venom, exercise or drug.
• History of severe and recurrent angioedema.
• Any contraindication according to the Investigator Brochure (IB).
• Use of an investigational drug within 30 days prior to screening.