A Study of Onset of Action of Loratadine and Fexofenadine in Participants With Seasonal Allergic Rhinitis (P08712)

A Double-Blind, Parallel, Randomized, Placebo Controlled Trial to Evaluate Onset of Action of Loratadine and Fexofenadine in Subjects With Seasonal Allergic Rhinitis in a Pollen Challenge Chamber

The purpose of this study is to determine the onset of action of two commercially available over-the-counter antihistamines (Loratadine and

Fexofenadine) in a model of seasonal allergic rhinitis (SAR). Participants undergo sensitization exposures to Mountain Cedar (juniperus ashei) pollen in a Biogenics Research Chamber; those who demonstrate an adequate allergic response determined by the Major Symptom Complex (MSC) score will then receive drug.

Inclusion Criteria:

• Female participants of child bearing potential must demonstrate a negative

urine pregnancy test at Screening (Visit 1) and Visit 4 (prior to randomization) and agree to use (and/or have their partner use) 2 acceptable methods of birth control beginning at the Screening visit and throughout the study.

• Willing to stop use of current decongestant and allergy medications at the start of the washout period (Visit 1) and during the trial.
• Documented history or participant-reported history of seasonal allergic rhinitis caused by mountain cedar pollen within the last 2 years and documented or participant-reported symptoms over at least the last 2 mountain cedar allergy seasons.
• Documented skin testing (prick with wheal ≥ 4 mm larger than the diluent) within the last 1 year to mountain cedar pollen present.
• Capable of reading English.
• Body mass index (BMI) <35.

Exclusion Criteria:

• Any significant medical condition which, in the judgment of the investigator, is a contraindication to the use of loratadine, fexofenadine or might interfere with the trial. These may include thyroid disease (e.g., hyperthyroidism, hypothyroidism), uncontrolled diabetes mellitus, coronary heart disease, ischemic heart disease, elevated intraocular pressure, prostatic hypertrophy.
• Have started allergen immunotherapy within 1 month preceding enrollment or participants starting allergen immunotherapy or anticipating immunotherapy dose change during the trial. Xolair (omalizumab) may not be used within 4 years prior to trial participation.
• Known allergy or intolerance to loratadine, desloratadine, or fexofenadine.
• History of rhinitis medicamentosa.
• Use of systemic (oral, rectal, injectable), topical (up to 1% topical hydrocortisone is permitted), or nasal corticosteroids in the last 30 days or current or expected use of disallowed medications as listed in the protocol.
• Asthma, with the exception of mild intermittent asthma.