Different Doses of Tyrosine Adsorbed Grass Pollen Allergoid With Monophosphoryl Lipid A (MPL) in Patients Sensitized to Grass Pollen

Inclusion Criteria: * positive skin prick test for grass and rye allergen * Specific IgE for grass and rye as documented by radioallergosorbent or equivalent test with class \>= 2 * History of at least 1 season of moderate to severe seasonal rhinoconjunctivitis due to an IgE - mediated allergy to pollen from grass and rye * Males or non-pregnant, non-lactating females who are post-menopausal or naturally or surgically sterile. Females of childbearing potential have a confirmed absence of pregnancy according to a negative urine pregnancy test and must be using an acceptable birth control method. * Spirometry at Screening demonstrates FEV1 \>= 80% predicted and FEV1/FVC \>= 70% Exclusion Criteria: * Acute or subacute atopic dermatitis and/or urticaria factitia and/or urticaria due to physical or chemical influence and/or chronic dermatitis * Patient has moderate to severe asthma * Visual inspection of the forearms indicates potential problems with the conduct or interpretation of the skin prick test; both forearms must be available for testing * History or presence of diabetes, cancer or any clinically significant cardiac, metabolic renal, hematologic diseases or disorders * Recent clinically significant history (within 2 years) of hepatic gastrointestinal, dermatologic, venereal, neurologic or psychiatric diseases or disorders * Any clinically significant (as determined by the investigator) abnormal laboratory value * Perennial allergens: clinically relevant sensitivity against house dust mites, molds, and epithelia * Patient has clinically relevant sensitivity against the following summer/autumn season flowering plants: plantain, orache, nettle, mugwort, Bermuda grass, or ragweed. * Secondary alteration at the affected organ * History of autoimmune diseases and/or rheumatoid diseases * Patient is taking b-blockers * Patient who is not allowed to receive adrenalin * Patients in whom tyrosine metabolism is disturbed * Presence of a disease with a pathogenesis interfering with the immune response and patient has received medication which could influence the results of this study * Documented evidence of acute or significant chronic infection * History of anaphylaxis * Documented history of angioedema * Hypersensitivity to excipients in the study medications * Previous or current immunotherapy with comparable grass/rye allergen extracts * Currently using anti-allergy medication and other drugs with antihistaminic activity * Patients currently participating in a clinical trial or who have been exposed to study medication within the last 30 days * Patient is pregnant or planning pregnancy and/or lactating * Patient has received treatment with preparation containing MPL® during the past 12 months * Any systemic disorder that could interfere with the evaluation of the study medication(s) * Clinical history of drug or alcohol abuse that would interfere with the patient's participation in the study