Background: Bilastine is a second-generation antihistamine approved for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. This trial evaluated the efficacy and safety of a new bilastine 0.6% preservative-free eye-drops formulation for the symptomatic treatment of allergic conjunctivitis.
Methods: This phase 3, multicenter, double-masked, randomized study evaluated the efficacy, safety and tolerability of bilastine 0.6% ophthalmic solution compared to ketotifen 0.025% and vehicle. The primary efficacy endpoint was ocular itching reduction. The Ora-CAC® Allergen Challenge Model was used to assess ocular and nasal symptoms at 15 minutes (onset of action) and 16 hours post-treatment.
Results: Subjects (N=228) were 59.6% male, and the mean (SD) age was 44.1 (13.4) years. Bilastine demonstrated efficacy in reducing ocular itching compared to vehicle at both onset of action and 16 hours post-treatment (P <0.001). Ketotifen showed improvement compared to vehicle 15 minutes post-treatment (P <0.001). Bilastine demonstrated statistical non-inferiority to ketotifen for all 3 post-CAC timepoints at 15 minutes post-instillation, based on an inferiority margin of 0.4. Bilastine demonstrated improvement over vehicle (P <0.05) for conjunctival redness, ciliary redness, episcleral redness, chemosis, eyelid swelling, tearing, rhinorrhea, ear and palate pruritus and nasal congestion at 15 minutes post-treatment. Ophthalmic bilastine was safe and well tolerated. Mean drop comfort scores were significantly better (P <0.05) for bilastine compared with ketotifen immediately upon instillation, and similar compared with vehicle.
Conclusions: Ophthalmic bilastine effectively reduced ocular itching for 16 hours post-treatment, suggesting that it could be used as a once-daily treatment for the signs and symptoms of allergic conjunctivitis. ClinicalTrials.gov identifier: NCT03479307.

Key words: Allergic conjunctivitis, Antihistamine, Bilastine, Preservative-free, Once-daily