This study investigates the safety of two up-dosing regimen. The safety of PURETHAL Grasses will be evaluated in a rush regimen (maximum dose reached in 3 injections during 2 weeks) compared to the conventional regimen (maximum dose reached in 6 injections during 5 weeks).

The primary parameter will be the proportion of patients who experience systemic reactions > grade I within 24 hours after injection or who need more than 2 additional injections during the up-dosing phase until the maintenance dose has been reached.

It is expected that up-dosing PURETHAL Grasses according to the rush regimen is as safe as using the conventional regimen.

Inclusion Criteria

• Patients with rhinitis or rhinoconjunctivitis, with or without mild asthma (FEV1 > 70%) for at least 2 years related to grass pollen, eligible for SCIT.

• Confirmation of IgE-mediated allergy by means of:

  • Positive SPT to grass pollen (mean wheal diameter ≥ 3 mm and negative control truly negative (no reaction), or
  • Specific serum IgE-test (ssIgE >0.7 U/ml) for grass pollen, or
  • Positive provocation test for grass pollen.

• Age ≥ 18 years.

• Patients have given a written informed consent

Exclusion Criteria:

• Chronic asthma or emphysema, particularly with a FEV1 ≤ 70% of predicted value.
• Serious immuno-pathological diseases or malignancies (including auto-immune diseases, tuberculosis, HIV).
• Active inflammation/infection of the target organs (nose, eyes, lungs).
• Severe atopic dermatitis in need for systemic immunosuppressive medication.
• Symptomatic coronary heart diseases (e.g heart failure, recent myocardial infarction, unstable angina, serious arrhythmias) or severe (even under treatment) arterial hypertension.
• Severe kidney disease.
• Diseases with a contra-indication for the use of adrenaline.
• Treatment with systemic or local beta-blockers or immunosuppressive drugs.
• History of life threatening anaphylactic events, including anaphylactic food allergy, insect venom anaphylaxis, exercise or drug induced anaphylaxis.
• Any specific immunotherapy (including sublingual) during the study period or during the previous 3 years for a period longer than three months.
• Participation in a clinical study with a new investigational drug within the last three months.
• Pregnancy, lactation or inadequate contraceptive measures (adequate measures: oral contraceptives, IUD, condom use if used together with a spermicide and having no sexual relationship with a man).
• Alcohol or drug abuse.
• Lack of co-operation or severe psychological disorders.
• Completed or ongoing long-term treatment with tranquilizer or psycho active drugs.
• Low compliance or inability to understand instructions/study documents.
• Completed or ongoing treatment with anti-IgE-antibody.
• Patients being in relationship or dependence with the sponsor or investigator.
• Allergy to any of the excipients.
• Severe illness or any other condition, which makes the patient, in the opinion of the investigator, unsuitable for the study.