Efficacy of fluticasone furoate nasal spray and levocetirizine in patients with Japanese cedar pollinosis subjected to an artificial exposure chamber

OBJECTIVE This study investigated the clinical efficacy of a combination therapy of levocetirizine (LCTZ) and fluticasone furoate nasal spray (FFNS), compared with LCTZ monotherapy, for the suppression of seasonal allergic rhinitis (SAR) symptoms induced in an artificial exposure chamber. METHODS This study was a single-center, placebo-controlled, randomized, 3-way cross-over comparative study performed in 42 Japanese cedar pollinosis patients. These subjects received (1) LCTZ plus FFNS (combination group), (2) LCTZ plus FFNS placebo (monotherapy group), or (3) LCTZ placebo plus FFNS placebo (placebo group) once on the night prior to exposure, with a 1-week washout period between exposures. Nasal (sneezing, rhinorrhea, nasal congestion, and itchy nose) and ocular (eye itching and tearing) symptoms were recorded every 15 min, and the number of sneezes, nose blowing events, and the amount of nasal secretions were measured during exposure. The primary end-point was the cumulative incidence of SAR symptoms during exposure and the 'ime to occurrence of symptoms'. The secondary end-points were the total nasal symptom score, the ocular symptom score, the amount of nasal discharge, and the number of sneezes and nose blowing events. RESULTS At all the measurement points, the lowest cumulative incidences for the nasal symptoms were observed in the combination group, followed by the monotherapy and placebo groups. All the subjects in the placebo group developed nasal symptoms within 2 h after pollen exposure, while three and eight subjects in the monotherapy and combination groups, respectively, did not develop any nasal symptoms during exposure. In addition, combination therapy delayed the onset of symptoms. CONCLUSIONS The results demonstrated that combination therapy with FFNS and LCTZ significantly suppressed the induced SAR symptoms and delayed the onset of symptoms compared with LCTZ monotherapy and placebo. Although the conditions of the allergen challenge study using an exposure chamber are different from those in real life, combination therapy with FF and LCTZ was confirmed to be an effective treatment for SAR.