The aim of this phase III study is to asses if SUBLIVAC FIX Birch is safe and effective in reducing birch allergy induced symptoms and birch allergy medication usage.

Inclusion Criteria:

• Signed informed consent
• Age ≥ 18 and ≤65 years
• Moderate-to-severe birch pollen induced allergic rhinitis/rhinoconjunctivitis based on ARIA classification for at least 2 consecutive years
• FEV1 (forced expiratory volume at one second) > 70% (of predicted value) for patients with a history of asthma, FEV1 > 70% or PEF (peak expiratory flow) > 80% (of predicted value) for patients without a history of asthma
• Positive SPT (skin prick test) for birch pollen (mean wheal diameter ≥ 3mm compared to negative control; negative control should be negative; histamine control should be positive (mean wheal diameter ≥ 3mm)) assessed during screening.
• Serum specific anti-birch IgE (immunoglobulin E) concentration >0.7 U/ml
• Patients should be willing and capable to complete an e-diary daily during the birch pollen season (≥ 60% compliance in completion between Visit 1 and 2).
• A positive Nasal Provocation Test to birch pollen at Visit 2 (Lebel score ≥ 6) or a documented positive test within 1 year before start of treatment

Exclusion Criteria:

• Patients sensitized and symptomatic to pets should not be included if they are regularly exposed to pets
• Specific immunotherapy (SCIT or SLIT) with birch pollen or a cross-reacting allergen within the last 5 years
• SPT positive (mean wheal diameter ≥ 3mm compared to negative control; negative control should be negative; histamine control should be positive (mean wheal diameter ≥ 3mm)) patients to allergen(s) other than birch pollen, in the absence of a negative provocation test for this allergen(s) (within 1 year), who are expected to have clinically relevant symptoms during the birch pollen season
• Completed unsuccessful allergen-specific immunotherapy (SCIT or SLIT) within the last 5 years
• (Ongoing) allergen-specific immunotherapy (SCIT or SLIT) with any allergen(s) during the study period
• Vaccination one week before start of treatment and/or during the up-dosing phase
• Treatment with experimental products within the last 3 months or biologicals (including anti-IgE or TNF (tumor necrosis factor) - α treatment) within the last 6 months or during the study
• Uncontrolled asthma or other active respiratory diseases
• Clinically significant chronic sinusitis, ocular infection or severe inflammation of the oral mucosa
• Severe immune disorders (including auto-immune diseases) and/or diseases requiring immunosuppressive drugs
• Active malignancies or any malignant disease in the last 5 years
• Acute or chronic disease that in the opinion of the investigator is an additional risk for the patients, 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
• Diseases with a contra-indication for the use of adrenaline (e.g. hyperthyroidism, glaucoma)
• Use of systemic corticosteroids 4 weeks before the study
• Treatment with systemic or local β-blockers
• Known hypersensitivity to any of the excipients (Disodium phosphate dihydrate, Sodium dihydrogen phosphate dehydrate, aminocaproic acid, Peppermint oil, Caramel Colorant or Glycerol)
• A positive urine pregnancy test, lactation or inadequate contraceptive methods (adequate methods: oral contraceptives, IUD (intrauterine device), condom use and having no sexual relationship with a man)
• Alcohol-, drug or medication abuse
• Lack of co-operation or compliance
• Severe psychiatric, psychological, or neurological disorders
• Any physical or mental condition that precludes administration or allergen-specific immunotherapy, compliance or participation in a clinical trial
• Patients who are employees of the department, 1st grade relatives, or partners of the investigator
• Patients who have planned holidays outside the country for more than 7 continuous days during the defined pollen season (1st of March till 31st of May)