Evaluation of alcaftadine 0.25% ophthalmic solution in acute allergic conjunctivitis at 15 minutes and 16 hours after instillation versus placebo and olopatadine 0.1%

PURPOSE: To evaluate the effectiveness of alcaftadine 0.05%, 0.1%, and 0.25% ophthalmic solutions in treating the signs and symptoms of allergic conjunctivitis when compared with olopatadine hydrochloride 0.1% and placebo using the conjunctival allergen challenge (CAC) model. METHODS: One hundred and seventy subjects were randomized and 164 subjects completed all visits. CAC was performed to determine and confirm subjects’ eligibility at visits 1 and 2, respectively. The CAC was repeated at visit 3 (day 0 ± 3), 16 hours after study medication instillation, and at visit 4 (day 14 ± 3), 15 minutes after instillation. Ocular itching and conjunctival redness were evaluated after an allergen challenge, along with several secondary endpoints. RESULTS: Alcaftadine 0.25% and olopatadine 0.1% treatments exhibited significantly lower mean scores compared with placebo for ocular itching and conjunctival redness at visits 3 and 4. Most adverse events were self-limiting and mild in severity. No serious treatment-related adverse events occurred. CONCLUSION: Treatment with alcaftadine 0.25% ophthalmic solution resulted in mean differences of >1 unit (ocular itching) and approximately >1 unit (conjunctival redness), which was significant (P < 0.001) compared with placebo treatment. All doses of alcaftadine were safe and well tolerated in the population studied.