Efficacy and Safety of Twice-daily and Once-daily Olopatadine-Mometasone Combination Nasal Spray for Seasonal Allergic Rhinitis.

Background: GSP301 is an investigational fixed-dose combination nasal spray of olopatadine hydrochloride (antihistamine) and mometasone furoate (corticosteroid). Objective: To evaluate efficacy and safety of GSP301 in patients with seasonal AR (SAR). Methods: In this phase 2, double-blind, parallel-group study, patients (>= 12 years of age) with SAR were equally randomized to twice-daily GSP301 (olopatadine 665 mu g and mometasone 25 mu g), once-daily GSP301 (olopatadine 665 mu g and mometasone 50 mu g), twice-daily or once-daily olopatadine monotherapy (665 mu g), mometasone monotherapy (twice-daily 25 mu g or once-daily 50 mu g), or placebo for 14 days. The primary endpoint-mean change from baseline in morning and evening reflective Total Nasal Symptom Score (rTNSS)-was analyzed using analysis of covariance (ANCOVA; P < .05 = statistically significant). Average morning and evening 12-hour instantaneous TNSS (iTNSS), ocular symptoms, individual symptoms, onset of action, quality of life, and adverse events (AEs) were also assessed. Results: A total of 1111 patients were randomized. Twice-daily GSP301 provided statistically significant and clinically meaningful rTNSS improvements vs placebo (P < .001), twice-daily olopatadine (P = .049), and mometasone (P = .004). Similar significant improvements in iTNSS were observed with twice-daily GSP301 vs placebo (P < .001) and twice-daily mometasone (P = .007); improvements were not significant vs olopatadine (P = .058). Once-daily GSP301 provided significant rTNSS and iTNSS improvements vs placebo and once-daily olopatadine (P <.01, all) but improvements were not significant vs mometasone. Treatment-emergent AEs rates were 10.8%, 9.5%, and 8.2%, with twice-daily GSP301, once-daily GSP301, and placebo, respectively. Conclusion: Twice-daily GSP301 treatmentwas efficacious andwell tolerated, providing statistically significant and clinically meaningful improvements in rTNSS (primary endpoint) vs placebo and both monotherapies. (C) 2019 American College of Allergy, Asthma & Immunology.