A Study to Evaluate the Safety and Effectiveness of a Nasal Spray to Treat Seasonal Allergies

This will be a Phase III, randomized, double-blind, placebo-controlled, parallel-group study in subjects with moderate-to-severe seasonal allergic rhinitis (SAR). The study will begin with a 7-day, single-blind, placebo lead-in period (Day -7 to Day 1). Subjects will be instructed to take placebo lead-in medication twice daily (1 spray per nostril), approximately every 12 hours. On Day 1, subjects who satisfy the symptom severity requirements and continue to meet all of the study inclusion/exclusion criteria will be randomized in a 1:1:1:1 ratio to receive 1 spray per nostril twice daily of MP29-02, azelastine hydrochloride, fluticasone propionate, or placebo nasal spray. Efficacy will be assessed by the change from baseline in the subject-reported 12-hour reflective Total Nasal Symptom Score (TNSS). On Days 1 through 14, subjects will rate the instantaneous and reflective TNSS symptoms of sneezing, nasal congestion, runny nose, and nasal itching; the instantaneous and reflective total ocular symptom score (TOSS) symptoms of itchy eyes, watery eyes and eye redness; and the symptom of postnasal drip, twice daily (AM and PM) in a diary prior to the dose of study medication. Symptoms will be scored on a 0 to 3 scale (0 = no symptoms, 1 = mild symptoms, 2 = moderate symptoms, 3 = severe symptoms), such that the maximum daily symptom severity score will be 24 for the TNSS and 18 for the TOSS. Additional secondary efficacy variables will include reflective individual nasal and ocular symptom scores, as well as change from Baseline to Day 14 in the Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ). Subjects ≥ 18 years of age will complete the RQLQ on Day 1 (prior to dosing) and Day 14. Subjects will return to the clinic on Day 7 for an interim evaluation. After completing the 2-week double-blind treatment period, subjects will return to the clinic on Day 14 (or at time of early termination) for an end-of-study evaluation. Safety and tolerability assessments will be made on Days 7 and 14. Tolerability will be evaluated by subject-reported adverse events (AEs), nasal examinations, and vital signs assessments.