RATIONALE: Intranasal corticosteroids are considered the most effective treatment for the management of allergic rhinitis (AR) symptoms. The objective of this study was to evaluate the efficacy and safety of a new corticosteroid in development for the treatment of asthma and AR, ciclesonide (CIC), in patients with seasonal AR (SAR).METHODS: In this phase III, double-blind, placebo-controlled trial, patients with SAR (age ≥ 12 years) were randomized to receive intranasal CIC 200 μg (n = 164) or placebo (n = 163) once daily for 28 days. Patient-assessed total nasal symptom score (TNSS), physician-assessed overall nasal signs and symptoms severity (PANS), and Rhinoconjunctivitis Quality-of-Life Questionnaire (RQLQ) were evaluated. Adverse events (AEs) were monitored throughout the study.RESULTS: Ciclesonide significantly improved the average of am and pm reflective TNSS and instantaneous TNSS versus placebo from Days 1 through 14 (primary endpoint) and over the 28-day treatment period (p <0.001). Furthermore, CIC showed similar improvements in both am and pm placebo-adjusted reflective TNSS, suggesting a 24-hour effect. At Day 15, CIC improved RQLQ by -1.17 ± 0.10 compared with improvement of -0.72 ± 0.10 with placebo (p = 0.002). The frequency of treatment-related AEs was low and comparable between treatment groups, and the placebo-adjusted epistaxis rate for CIC was 1.8%.CONCLUSIONS: Ciclesonide administered intranasally was superior to placebo in relieving nasal symptoms in adult and adolescent patients with SAR. Ciclesonide was well tolerated, with a safety profile comparable with placebo and a low epistaxis rate. These data support the continued clinical development of CIC nasal spray. RATIONALE: Intranasal corticosteroids are considered the most effective treatment for the management of allergic rhinitis (AR) symptoms. The objective of this study was to evaluate the efficacy and safety of a new corticosteroid in development for the treatment of asthma and AR, ciclesonide (CIC), in patients with seasonal AR (SAR). METHODS: In this phase III, double-blind, placebo-controlled trial, patients with SAR (age ≥ 12 years) were randomized to receive intranasal CIC 200 μg (n = 164) or placebo (n = 163) once daily for 28 days. Patient-assessed total nasal symptom score (TNSS), physician-assessed overall nasal signs and symptoms severity (PANS), and Rhinoconjunctivitis Quality-of-Life Questionnaire (RQLQ) were evaluated. Adverse events (AEs) were monitored throughout the study. RESULTS: Ciclesonide significantly improved the average of am and pm reflective TNSS and instantaneous TNSS versus placebo from Days 1 through 14 (primary endpoint) and over the 28-day treatment period (p <0.001). Furthermore, CIC showed similar improvements in both am and pm placebo-adjusted reflective TNSS, suggesting a 24-hour effect. At Day 15, CIC improved RQLQ by -1.17 ± 0.10 compared with improvement of -0.72 ± 0.10 with placebo (p = 0.002). The frequency of treatment-related AEs was low and comparable between treatment groups, and the placebo-adjusted epistaxis rate for CIC was 1.8%. CONCLUSIONS: Ciclesonide administered intranasally was superior to placebo in relieving nasal symptoms in adult and adolescent patients with SAR. Ciclesonide was well tolerated, with a safety profile comparable with placebo and a low epistaxis rate. These data support the continued clinical development of CIC nasal spray.