Dose Finding for the Treatment of Rhinitis/Rhinoconjunctivitis Against Grass Pollen Allergy

Inclusion Criteria: * Written informed consent * Positive suggestive clinical history of intermittent or persistent moderate to severe rhinitis /rhinoconjunctivitis, with or without moderate asthma, due to grass pollen allergy * Subjects with a positive skin prick-test (wheal sixe \>6 mm diameter) Specific immunoglobulin E (IgE, CAP \>3) to grass pollen * Age between 14 and 65 years * Both genders * Subjects capable of giving informed consent * Subjects capable of complying with the dosing regimen * Subjects that have not received immunotherapy in the last 5 years * Subjects presenting sensitization to another aeroallergens and or mites, cats or dogs, but that is considered clinically not relevant or no clinical interference with the nasal provocation test. Exclusion Criteria: * Subjects outside of the age range. * Subjects who have previously received immunotherapy for the treatment of the allergic rhinitis/rhinoconjunctivitis due to grass pollen and other allergens in the last 5 years. * Subjects that immunotherapy may be an absolute contraindication according to the criteria of the immunotherapy Committee of the Spanish society of Allergy and Clinical Immunology, and of the European Allergy and Clinical Immunology Immunotherapy Subcommittee may also include. * Subjects with important symptoms of rhinoconjunctivitis /bronchial asthma in which the suspension of the systemic antihistamine treatment is contraindicated. * Subjects with persistent severe or not controlled ast…