Effects of Olopatadine Hydrochloride Nasal Spray 0.6% in the Treatment of Seasonal Allergic Rhinitis: A Phase III, Multicenter, Randomized, Double-Blind, Active- and Placebo-Controlled Study in Adolescents and Adults

Background: Seasonal allergic rhinitis (SAR) is an allergen-induced inflammatory reaction that occurs during periods of high pollen count. Current treatments for SAR include allergen avoidance, systemic antihistamines, and steroidal and nonsteroidal intranasal sprays. Olopatadine is a selective antihistamine and an inhibitor of proinflammatory mediators from human mast cells. An intranasal formulation of olopatadine has been developed for the treatment of SAR. Objective: The aim of this study was to compare the efficacy and tolerability of olopatadine hydrochloride nasal spray 0.6% (OLO) relative to azelastine hydrochloride nasal spray 0.1% (AZE) and an inactive vehicle in the treatment of SAR. Methods: This Phase III, multicenter, randomized, double-blind, active- and placebo-controlled, parallel-group study was conducted at 21 centers across the United States. Eligible patients were aged >= 12 years and had a history of SAR and verified allergy to a prevalent local allergen. After a run-In period during which inactive vehicle was administered, patients were randomly assigned to OLO, AZE (active control), or inactive vehicle (identical to OLO; placebo control), 2 sprays in each nostril BID for 16 days. The timing of enrollment was correlated with the start of the allergy season at each site. Symptoms were recorded twice daily in an electronic diary. Efficacy assessments included changes in mean daily reflective total nasal symptom scores (TNSS). Tolerability was evaluated based on adverse events (AEs) and nasal, physical, and cardiovascular parameters. Results: A total of 544 patients were randomized. The mean age was 36 years (range, 12-77 years); men and boys represented 32.2% of the population; and the patients were predominantly white (75.4%). The mean reductions from baseline in reflective TNSS were 26.8%, 29.9%, and 18.4% with OLO, AZE, and inactive vehicle, respectively (P = 0.003 OLO vs inactive vehicle; 95% CI, -2.5% to 8.7% OLO vs AZE [non-Inferiority]). The most commonly reported treatment-related AE in the OLO and AZE groups was bitter taste (1.2.2% [22/180] and 19.7% [37/1.88], respectively). The prevalence and intensity of bitter taste were significantly lower with OLO than with AZE (P = 0.05 and P = 0.005, respectively). In the group that received inactive vehicle, the prevalence of bitter taste was 1.7% (3/176). The prevalences of other treatment-related AEs, including epistaxis and nasal discomfort, were >= 3.7% in each group and did not differ significantly between groups. Conclusions: In this small study in patients aged :12 years with SAR, the percentage reduction from baseline in TNSS was significantly greater with OLO (2 sprays in each nostril BID) compared with vehicle and not significantly different from that with AZE. OLO and AZE were similarly well tolerated, with the exception of prevalence and intensity of bitter taste, which were significantly lower with OLO. (Clin Ther. 2009;31:99-107) (C) 2009 Excerpta Medica Inc.