Safety and Tolerability Study of Ragweed SLIT Tablets

Inclusion Criteria:

- written consent

- male or female subjects from 18 yo 60 years old and in general good health

- for women of child bearing potential: negative urine pregnancy test and use of medically effective contraceptive method

- symptoms of ragweed pollen induced allergic rhinitis for at least the last 2 years

- sensitization to ragweed pollen as demonstrated with positive skin prick test to ragweed pollen and specific IgE level (ragweed pollen) > 0.70 kU/l at screening

- FEV1 at least of 80% of predicted value at screening

Exclusion Criteria:

- past or current disease which, as judged by the investigator, may affect the outcome of this study

- history of life-threatening asthma

- asthma requiring daily treatment (whatever the pharmaceutical class)

- pregnant or lactating women

- subjects who previously received desensitisation treatment to ragweed pollen and/or other Asteraceae or who plan to start desensitisation treatment during this study

- symptoms during the treatment phase due to a sensitivity to a second allergen

- subjects treated with ongoing immunotherapy with another allergen