Study to Investigate Effects of CAL-263 in Subjects With Allergic Rhinitis Exposed to Allergen in an Environmental Chamber

Inclusion Criteria: 1. Age \>18 and \<55 years 2. Has a history of seasonal allergic rhinitis for at least 2 years 3. Has sensitivity to grass pollen demonstrated by a positive response to skin prick testing 4. Has a positive Radio Allergen Sorbent Test (class 2 or greater) for grass pollen during the previous 12 months or at screening 5. Is otherwise healthy 6. Is able to provide written informed consent Exclusion Criteria: 1. Is a female of childbearing 2. History of chronic nasal or upper respiratory tract symptoms or disorders other than allergic rhinitis 3. History of nonallergic rhinitis, chronic sinusitis or severe asthma 4. Has a nasal condition likely to affect the outcome of the study 5. Is currently taking regular medication, whether prescribed or not, including corticosteroids, vitamins, macrolides, anti-fungal agents and herbal remedies 6. Has taken a prohibited medication within the specified interval prior to Visit 1