Efficacy and Safety of Sublingual Tablets of Grass Pollen Allergen Extract

A Randomised, Double-blind, in Parallel Groups Placebo-controlled, Mono-centre, Phase I Study to Assess After Allergen Challenge in an Allergen Exposition Chamber the Effect and Its Time Course of Sublingual Immunotherapy (SLIT) Administered as 300IR Allergen-based Tablets Once Daily to Adults Suffering From Grass Pollen Rhinoconjunctivitis

The objective of this study is to assess the effect of grass pollen extract SLIT tablets on the Rhinoconjunctivitis Total Symptom Score (RTSS) of the six rhinoconjunctivitis symptoms in response to grass pollen challenge after one week, one, two and four months of treatment in patients suffering from Seasonal Allergic Rhinoconjunctivitis (SAR) due to grass pollen.

The purpose of this study is to determine whether SLIT tablets are effective on symptoms of allergic rhinitis compared to placebo in patients suffering from allergic rhinitis to grass pollen when exposed in an allergen chamber and also to determine the onset of action of SLIT tablets on allergic rhinitis symptoms.

Inclusion Criteria:

• Male or female outpatients 18-50 years old
• grass pollen rhinoconjunctivitis of at least 2 years.
• positive specific skin prick test and a specific IgE dosage level of at least 0.70 kU/L at screening.
• written consent
• a positive response to the baseline challenge test (RTSS reaches 7 at one time-point at least during baseline challenge)

Exclusion Criteria:

• Allergic rhino-conjunctivitis due to a co-sensitisation, likely to significantly change the symptoms of the subject throughout the study
• Asthma requiring treatment other than short-acting beta-2 inhaled agonists.
• Desensitisation treatment for grass pollen in the previous five years and current immunotherapy with another allergen.