Comparative analysis of the efficacy of intranasal MP29-02 (a novel formulation of azelastine and FP) has already been conducted in patients with moderate-to-severe seasonal AR. The combination formulation appeared to be superior in these patients with better symptomatic relief. However, objective analysis of the effect of this treatment on nasal mediators and/or nasal hyperreactivity has not yet been performed and would help in understanding the additional benefit of the combination treatment over monotherapy with nasal corticosteroids.