Efficacy and tolerability of ophthalmic epinastine: A randomized, double-masked, parallel-group, active- and vehicle-controlled environmental trial in patients with seasonal allergic conjunctivitis

Abstract Background: Epinastine hydrochloride is an antihistamine with mast cell-stabilizing and anti-inflammatory activity. Objective: The aim of this study was to assess the efficacy and tolerability of ophthalmic epinastine in patients with seasonal allergic conjunctivitis (SAC) exposed to environmental allergens. Methods: This randomized (age-stratified), double-masked, parallel-group, active- and vehicle-controlled, environmental, Phase III clinical trial was conducted at 6 ophthalmology clinics in the United States. Patients aged ≥9years diagnosed with SAC and who had a positive reaction in a conjunctival allergen challenge were enrolled. Patients were randomly assigned in a 2:2:1 ratio to receive 1 drop/eye BID of epinastine hydrochloride 0.05% ophthalmic solution, levocabastine hydrochloride 0.05% ophthalmic suspension, or vehicle of epinastine, respectively, for 8 weeks. The primary end point was ocular itching, and secondary end points included ocular hyperemia, chemosis, ocular mucous discharge (all assessed on a 5-point scale), eyelid swelling (assessed on a 4-point scale), and tearing (present or absent). Efficacy analyses used assessments from the two 1-week periods with the highest pollen counts. For tolerability assessment slit-lamp biomicroscopy and visual acuity examinations were conducted at each study visit (weeks 0, 2, 4, 6, and 8). Results: Two-hundred ninety-eight patients (159 females, 139 males; mean [SD] age, 32.7 [14.6] years [range, 9–71 years]) entered the study; 118 received epinastine, 118 received levocabastine, and 62 received vehicle. Epinastine-treated patients reported significantly less ocular itching than those receiving vehicle ( P = 0.045); scores for hyperemia were similar between these 2 groups. Ocular itching and hyperemia scores were similar between the epinastine and levocabastine groups. No clinically or statistically significant between-group differences were seen in slit-lamp biomicroscopy findings, changes in visual acuity from baseline, or the incidence of treatment-related adverse effects. Conclusions: In this study of patients with SAC, ophthalmic epinastine instilled twice daily was more effective than vehicle for the control of ocular itching and was similar in efficacy to levocabastine for control of ocular itching and hyperemia. Epinastine was well tolerated.