Background and objective: Allergic conjunctivitis is the most common type of ocular allergy. The objective of this study was to evaluate the efficacy of a new once-daily, preservative-free, bilastine 0.6% eye drop formulation for the treatment of allergic conjunctivitis.
Methods: Two double-masked, vehicle controlled, clinical studies (a Phase 2 Dose Ranging Study and a Phase 3 Efficacy Study) were conducted to assess the efficacy of bilastine ophthalmic solution for the treatment of signs and symptoms of allergic conjunctivitis. Both studies used the Ora-CAC® Conjunctival Allergen Challenge (CAC) Model to allow observations of allergic responses under controlled conditions. Each study was analyzed separately and then combined to create an integrated dataset.
Results: Efficacy was achieved for the primary efficacy endpoint of ocular itching for three bilastine concentrations (0.2%, 0.4%, and 0.6%) at 15 minutes and 8 hours post-instillation and bilastine 0.6% ophthalmic solution was also efficacious at 16 hours post-instillation. Bilastine 0.6% ophthalmic solution demonstrated non-inferiority to ketotifen 0.025% at the onset of action. From the integrated data set, differences between vehicle and bilastine 0.6% were significant at all time points both at onset (15 minutes) and at a prolonged duration (16 hours) after instillation.
Conclusion: This multi-trial assessment suggests that bilastine 0.6% ophthalmic solution is efficacious for the treatment of the signs and symptoms of allergic conjunctivitis, with a rapid and prolonged duration of action, and has a favorable safety profile. The added convenience of a once-a-day dosing regimen may contribute to patient adherence and improve their quality of life.

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