['allergic rhinoconjunctivitis']
['sq tree slit-tablet', 'placebo']

        Inclusion Criteria:

          -  Written informed consent obtained before any trial related procedures are performed

          -  Male or female aged 18 to 65 years

          -  Female subjects of child-bearing potential must have a negative urine pregnancy test
             and be willing to practise contraceptive methods

          -  History of moderate-to-severe rhinoconjunctivitis induced by pollens from the birch
             group with or without asthma despite having received treatment with symptom relieving
             medication during the previous 2 tree pollen seasons

          -  Positive SPT response (wheal diameter ≥ 3 mm) to Betula verrucosa

          -  Positive specific IgE against Bet v1 (≥ IgE Class 2; ≥0.70 kU/L)

          -  Willing and able to comply with the trial protocol

          -  Minimum level of rhinoconjunctivitis symptoms, defined as a TSS of at least 7 (of 18),
             at one timepoint during birch baseline EEC session.

        Exclusion Criteria:

          -  Symptoms induced by interfering allergens that are expected to be present during the
             periods where the subject attends the EEC sessions

          -  Rhinoconjunctivitis caused by animal hair and dander to which the subject is regularly
             exposed.

          -  Allergic symptoms induced by perennial allergens such as house dust mites, and moulds

          -  A clinical history of uncontrolled asthma within 3 months prior to screening

          -  Reduced lung function FEV1 (< 70% of predicted value after adequate pharmacological
             treatment)

          -  Asthma requiring treatment with inhaled corticosteroid within the past 3 months prior
             to screening

          -  Previous treatment with any allergy immunotherapy product with tree pollen allergens
             or a cross-reacting allergen within the past 5 years

          -  Ongoing treatment with any allergy immunotherapy product

          -  Immunosuppressive treatment within 3 months prior to the screening visit

          -  Treatment with tricyclic antidepressants, catecholamine-O-methyltransferase
             inhibitors, mono amine oxidase inhibitors and beta-blockers

          -  Treatment with antidepressant medication with antihistaminic effect

          -  Treatment with antipsychotic medications with antihistaminic effect

          -  Treatment with anti-IgE drugs within 130 days/5 half-lives of the drug (which ever
             longest)

          -  Treatment with an investigational drug within 30 days/5 half-lives of the drug (which
             ever longest) prior to screening

          -  Severe oral inflammation or oral wounds at randomisation

          -  Symptoms of or treatment for upper respiratory tract infection, acute sinusitis, acute
             otitis media or other relevant infections that have not resolved 1-week prior to the
             baseline birch and oak Environmental Exposure Chamber sessions and at the
             randomisation visit

          -  Clinically relevant nasal polyps

          -  A history of paranasal sinus surgery

          -  A history of surgery of nasal turbinates

          -  A history of anaphylaxis with cardiorespiratory symptoms

          -  A history of recurrent (defined as two or more episodes) generalised urticaria during
             the last 2 years

          -  A history of drug-induced (incl. Allergy Immunotherapy) facial angioedema or a family
             (parents and siblings) history of hereditary angioedema

          -  Any clinically relevant chronic disease (≥3 months duration) that in the opinion of
             the investigator would interfere with the trial assessments or the safety of the
             subject

          -  An uncontrolled systemic disease affecting the immune system (e.g. insulin-dependent
             diabetes, autoimmune disease, immune complex disease, or immune deficiency disease
             whether acquired or not)

          -  A history of allergy, hypersensitivity or intolerance to the investigational medicinal
             product (except Betula verrucosa) or any of the symptomatic medications provided in
             this trial

          -  Being immediate family of the investigator or trial staff, defined as the
             investigator's/staff's spouse, parent, child, grandparent or grandchild.
      