Efficacy and Safety of Grass Pollen Sublingual Immunotherapy

Inclusion Criteria: * male or female aged 18-50 * patients with grass pollen related allergic rhinoconjunctivitis for at least 2 pollen seasons * Positive skin prick test and IgE value of at least Class 2+ * RTSS of greater or equal to 14 during pollen season prior tot the start of the study * Patients must be in general good health * Patients with normal spirometry * Informed consent given and willing to comply with the protocol * Female patients are eligible if they use an accepted contraceptive method * Negative urine pregnancy test if female Exclusion Criteria: * Pregnancy, breast feeding * Asthma requiring treatment other than beta-2 inhaled agonists * patients who have taken oral steroids within 12 weeks before screening visit * patients who have received desensitisation treatment for grass pollen * treatment by immunotherapy with any other allergen within the previous 5 years * patients who have suffered a lower respiratory tract infection within 4 weeks or an upper respiratory tract infection within 2 weeks of the screening visit * patients at risk of non-compliance * participation in any other clinical study within the previous 3 months * patients with a past or current disease, which may affect participation in or outcome of this study. * patients treated with beta-blockers or under continuous corticotherapy * allergic sensitivity to epithelial allergens the patients is exposed to * positive skin prick test for environmental allergens and suffering from serious allergic symptoms due to exposure to these allergens during study period * intention to subject the patient to surgery of the nasal cavity during current study * Usual contraindications of immunotherapy * a clinical history of symptomatic seasonal allergic rhinitis and/or asthma due to tree pollen or weed pollen adjacent to the start of, and potentially overlapping the grass pollen season