Efficacy and Safety Study of BLX-028914 in Subjects With Allergic Rhinitis

Inclusion Criteria: * 18 to 50 years of age (inclusive), male or female * Body Mass Index (BMI) between 18 and 28 kg/m2 (inclusive) * History of pollen-induced seasonal allergic rhinitis but otherwise healthy * Positive skin prick test for timothy and/or birch allergen * Sufficient reaction to nasally administered allergen at screening * Signed informed consent obtained Exclusion Criteria: * Expected symptoms of seasonal allergic rhinitis during the study period * Asthma * Nasal anatomical deviations, ongoing nasal symptoms, ongoing upper respiratory tract infection * Anti-allergy immunotherapy in the previous two years * Extensive use of nasal sprays * Any medication except for contraceptives, during their last five half- lives prior to the first treatment period except for occasional OTC analgesics * Ingestion of grapefruit or grapefruit juice or herbal remedies (e.g. St John's-wort) that may effect the enzyme CYP3A4 * Smoking within 3 months of first treatment period * Clinically significant laboratory findings * Pregnant or breast feeding woman or woman of childbearing potential not using adequate birth control * Known hypersensitivity to any constituent of the study medication or placebo * Participation in any other investigational study in the last three months * Subject anticipated not being able to adhere to study plan according to investigator judgement