The primary objective of this study is to evaluate the efficacy of the combination of mometasone furoate nasal spray (MFNS) and oxymetazoline nasal spray (OXY) given together once a day in treating subjects with seasonal allergic rhinitis (SAR) in relieving symptoms including nasal congestion. The secondary objectives of this study are to evaluate the potential of the combination to produce tachyphylaxis and/or rebound congestion, and to evaluate the safety of the combination.

Inclusion Criteria:

• Must be 12 years of age or older, of either sex, and of any race.
• Must have at least a 2-year documented history of SAR which exacerbates during the time period over which the subject will be participating.
• Must have a documented (within the past 12 months) positive skin-prick test response to an appropriate seasonal allergen appropriate to the geographical vicinity in which the study is being carried out and over the period of time the subject is participating.
• Must be clinically symptomatic at the Screening and Baseline Visits.
• Must be in general good health as confirmed by routine clinical and laboratory testing and electrocardiogram results.
• Must be free of any clinically significant disease, other than SAR, which would interfere with the study evaluations.
• Must be willing to give written informed consent and must be able to adhere to dosing and visit schedules and study requirements.
• Female subjects of child-bearing potential must have a negative serum pregnancy test at screening. Nonsterile and premenopausal female subjects must be using a medically acceptable method of birth control prior to screening and during the entire study.
• Must have the ability to transmit electronic diary data on a regular basis.

Exclusion Criteria:

• A subject with a history of anaphylaxis and/or other severe local reaction(s) to skin testing.
• A subject with asthma who requires chronic use of inhaled or systemic corticosteroids.
• A subject with current or history of frequent, clinically significant sinusitis or chronic purulent postnasal drip.
• A subject with rhinitis medicamentosa.
• A subject with glaucoma and/or increased intraocular pressure.
• A subject who has nasal structural abnormalities, including large nasal polyps and marked septal deviations, which significantly interfere with nasal air flow.
• A subject who, in the opinion of the investigator, is dependent on nasal, oral, or ocular decongestants, nasal topical antihistamines, or nasal steroids.
• A pregnant or nursing female.
• A subject with current evidence of clinically significant hematopoietic, cardiovascular, hepatic, renal, neurologic, psychiatric, pulmonary, autoimmune disease, or other disease that precludes the subject's participation in the study. Particular attention should be given to exclude subjects with conditions that would currently interfere with the absorption, distribution, metabolism, or excretion of the study drug or interfere with the subject's ability to complete or reliably complete the diaries.