Recruitment was stopped before start of the pollen season

Birch pollen allergic patients are currently treated by subcutaneous injections of pollen extracts either by standard allergen specific immunotherapy (SIT) or ultra-rush immunotherapy. Such treatment is prone to side effects and has to be performed in a hospital environment due to the risk of potential anaphylactic reactions. The aim of this study is to test the new product AllerT expected to show widely reduced side effects. AllerT will be injected via two different routes, subcutaneous versus intradermal. The primary endpoint of the study is the local and systemic safety of repeated injections of the product. Since AllerT should provide patients with a pre-seasonal treatment to decrease seasonal allergic symptoms, we will also evaluate the potential efficacy of the approach using a nasal provocation test (NPT) with birch pollen

In addition to the initial protocol, post hoc evaluations were conducted, after new ethics committee reviews, to assess quality of life during the birch pollen season following the trial (April 2009) and to obtain blood samples for evaluation of immunology markers IgG4 and IgE after the season 2010 (July 2010) and after the season 2012 (July 2012),

Inclusion Criteria:

• Allergic rhinitis symptoms during the pollen season preceding the study, confirmed by SPT (prick tests) and/or a positive specific IgE CAP test for birch pollen (class I minimum)
• Positive SPT to Bet v 1 (prick tests), negative SPT to AllerT

Exclusion Criteria:

• received immunotherapy against any allergen within 3 years before the start of the study.
• symptomatic to perennial allergens or active seasonal allergy during the trial.
• non controlled asthma (peak flow lower than 30% of predicted value).
• history of any severe medical condition able to influence the course of the study
• Any confirmed or suspected immunodeficiency condition, including human immunodeficiency virus (HIV) infection and asplenia.
• Subjects under immunosuppressive medication.
• Pregnant or lactating women or women willing or intending to become pregnant during the study.
• Any other significant finding which, in the opinion of the investigator, would increase the risk of having an adverse outcome from participating in this protocol or of dropping out of the study