Objectives: To test the hypothesis that intranasal levocabastine (LEVO) may provide benefits as a oncedaily treatment in allergic rhinitis (AR), this non-inferiority study compared the effect at steady state of once- and twice-daily dosing with LEVO on allergen-induced nasal symptoms in AR patients.
Methods: This was a randomized, double-blind, three-way cross over study evaluating the effects of repeat doses of LEVO 200 µg once-daily, LEVO 200 µg twice-daily (total dose 400 µg) and placebo, all via intranasal spray, in 78 AR patients. The primary endpoint was weighted mean total nasal symptom score (TNSS) during a 4-hour allergen exposure in the Environmental Exposure Chamber measured at trough pharmacokinetic levels either 12 (LEVO twice-daily) or 24 (LEVO once-daily) hours post-dose.
Results: After 7 days dosing, the difference in weighted mean TNSS (0-4 hours) following LEVO once-daily versus twice-daily was 0.23 units (95% CI -0.36, 0.82), demonstrating noninferiority between the two LEVO dosing regimens by meeting the pre-specified criterion of an upper limit of 95% CI<1.0. Both dosing regimens of LEVO resulted in a statistically significant reduction in mean TNSS compared with placebo (adjusted mean difference from placebo: LEVO once-daily: -1.12 (95% CI -1.71, -0.53); LEVO twice-daily: -1.35 (-1.94, -0.76)), meeting the pre-specified criterion for superiority (upper limit of 95% CI<0). All treatments were well-tolerated.
Conclusions: The results of this study support the hypothesis that at steady state LEVO 200 µg taken once-daily provides similar benefit to LEVO 200 µg dosed twice-daily.
Trial registration: ClinicalTrials.gov NCT01949051.