Onset of Action of Azelastine 0.15% Versus Olopatadine/Mometasone for Allergen-Induced Rhinitis: An EEU Crossover Study

Bousquet J, Klimek L, Kuhl HC et al.  Clin Transl Allergy. 2026 Nov;16(11):e70213. doi: 10.1002/clt2.70213. 

ABSTRACT

Background

The aim of this study was to compare the onset of action (primary), and overall efficacy (secondary) of azelastine nasal spray 0.15% (AZE 0.15%) with mometasone/olopatadine combination therapy (OloMom) in subjects with allergen-induced rhinitis under controlled allergen exposure conditions in an Environmental Exposure Unit (EEU).

Method

This was a randomized, double-blind, placebo-controlled, three-period Williams cross-over study. Participants were randomized to receive AZE 0.15%, OloMom, or placebo. Efficacy was assessed during two pollen challenge sections in an EEC, after a single dose and after 3.5 days of treatment.

Following a minimum 14-day washout period, subjects received alternate treatment and repeated study procedures until all three interventions were evaluated. The primary endpoint was time to onset of action based on change from baseline in Total Nasal Symptom Score (TNSS). Secondary assessments included total and individual nasal and ocular symptoms and overall efficacy after 3.5 days of treatment.

Results

Mean change from baseline in TNSS (0–12) by treatment
for 4 h post-dose (ITT population).

Eighty-four subjects completed the study (mean age 41.5 years; balanced sex distribution), all with confirmed ragweed sensitivity. All treatments reduced TNSS post-dose, with most effective and fastest relief from AZE 0.15%, onset at 15 minutes, sensitivity analyses supported onset at 10 minutes, and greater early nasal, ocular, and total symptom relief compared to OloMom and placebo.

Conclusion

AZE 0.15% delivered rapid and clinically significant relief of AR, demonstrating greater early symptoms improvement compared with OloMom. Overall efficacy was comparable between treatments, supporting AZE 0.15% as an effective, steroid-free alternative for rapid symptom control in patients with pollen allergies.

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