This trial is an open, national, multi-centre trial. The trial will be initiated in December 2013 and subjects will receive treatment for 6 weeks.

Safety monitoring will be performed in an ongoing basis through a Clinical Safety Group with immediate access to Adverse Events registered in the clinical database. The composition, procedures and deliverables of the Clinical Safety Group will be detailed in a Safety Agreement prior to trial start.

Inclusion Criteria:

• A clinical history of Salsola kali pollen induced allergic rhinoconjunctivitis with or without asthma at least one year prior to trial entry.
• Positive Skin Prick Test to Salsola kali pollen (wheal diameter ≥ 3 mm).
• Documenting in the last 5 years a positive specific Immunoglobulin E against Salsola kali pollen (≥ Class 2; ≥0.70 KU/L).

Exclusion Criteria:

• Forced expiratory volume at one second 1 < 70% of predicted value at screening after adequate pharmacologic treatment.
• Uncontrolled or severe asthma.
• 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).
• 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.
• Immunotherapy with Cupressus arizonica or Salsola kali pollen 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) or concomitant immunotherapy with any other allergen.
• History of anaphylactic shock due to e.g. food, insect venom, exercise or drug.
• History of severe and recurrent angioedema.