Comparison of Different Up-dosing Schedules With Osiris Phleum Pratense

Inclusion Criteria: * Written informed consent obtained before entering the trial * Male or female \>/= 18 years at visit 1 * A clinically relevant history of grass pollen induced allergic rhinoconjunctivitis (moderate to severe) and having received symptomatic treatment during grass pollen season 2010 and 2011 * Positive skin prick test response (wheal diameter \>/= 3mm) to Phleum pratense * Positive specific IgE against Phleum pratense (\>/= 0,70KUL / class 2) * Female subjects of childbearing potential must have a negative pregnancy test and be willing to practice appropriate contraceptive methods until Visit 4 * Subjects willing and able to comply with trial protocol regimen Exclusion Criteria: * Subjects included in another protocol (treatment intervention and/or investigational medicine product) or having participated in another clinical trial within 30 days prior to visit 1 * A clinically relevant history of symptomatic seasonal allergic rhinoconjunctivitis caused by an allergen (e.g. hazel, alder, birch, ash) to which the subject will be exposed during the 30-day treatment period. * A clinically relevant medical history of symptomatic perennial allergy to allergen(s) to which the subject is regularly exposed (e.g. cat, house dust mites). * Known sensitization (history of positive SPT) to food allergens with oral allergy syndrome * Uncontrolled asthma (in accordance with GINA guidelines) within the last 12 months * FEV \< 60% of predicted within the last 12 months *…