Background: Bilastine is a second-generation antihistamine approved for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. The present trial evaluated the efficacy and safety of a new bilastine 0.6% preservative-free eye drop formulation for the symptomatic treatment of allergic conjunctivitis.
Methods: This phase 3, multicenter, double-masked, randomized study compared the efficacy, safety, and tolerability profile of bilastine 0.6% ophthalmic solution with that of ketotifen 0.025% and vehicle. The primary efficacy endpoint was reduction in ocular itching. The Ora-CAC® Allergen Challenge Model was used to assess ocular and nasal symptoms at 15 minutes (onset of action) and 16 hours after treatment.
Results: Patients (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 after treatment (P<.001). Symptoms improved with ketotifen compared to vehicle 15 minutes after treatment (P<.001). Bilastine demonstrated statistical noninferiority to ketotifen for all 3 post-CAC timepoints at 15 minutes after instillation, based on an inferiority margin of 0.4. Compared with vehicle, bilastine improved in conjunctival redness, ciliary redness, episcleral redness, chemosis, eyelid swelling, tearing, rhinorrhea, ear and palate pruritus, and nasal congestion at 15 minutes after treatment (P<.05). Ophthalmic bilastine was safe and well tolerated. Mean drop comfort scores were significantly better for bilastine than for ketotifen immediately upon instillation (P<.05) and similar to those of vehicle.
Conclusions: Ophthalmic bilastine effectively reduced ocular itching for 16 hours after administration, 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