Efficacy of Once-Daily Ophthalmic Bilastine for the Treatment of Allergic Conjunctivitis: A Dose-Finding Study

Bilastine is a nonsedating second-generation antihistamine for the symptomatic treatment of allergic rhinoconjunctivitis and urticaria. Our study aimed to evaluate the optimal dose, efficacy, and safety of a newly developed once-daily preservative-free ophthalmic formulation of bilastine for allergic conjunctivitis.

Our phase 2, single-center, double-masked, randomized trial compared the efficacy of 3 doses of a bilastine ophthalmic formulation (0.2%, 0.4%, and 0.6%) with that of vehicle for the treatment of allergic conjunctivitis. The primary efficacy endpoint was the reduction in ocular itching. The Ora-CAC Conjunctival Allergen Challenge model was used to assess ocular and nasal symptoms at the onset of action (15 minutes) and at 8- and 16-hours after treatment. Tolerance and safety were also evaluated.

A total of 121 adults with seasonal and/or perennial ocular allergy were randomized. Bilastine ophthalmic formulations 0.2%, 0.4%, and 0.6% were significantly superior (P>.001) to vehicle for the treatment of ocular itching at 3, 5, and 7 minutes after challenge at onset of action (15 minutes) and at 8 hours after treatment. Bilastine 0.6% was also effective at 16 hours after treatment. Treatment differences for bilastine 0.6% were statistically significant (P<.001) compared to vehicle at all timepoints for tearing, eyelid swelling, and nasal symptoms. No relevant adverse events were observed.

All the tested ophthalmic bilastine doses were efficacious for rapid reduction of ocular itching. The 0.6% formulation was effective up to 16 hours after treatment, making it suitable for once-daily administration. The new formulation was safe and well tolerated.