Safety and Tolerability of Besifloxacin Ophthalmic Suspension 0.6% in the Treatment of Bacterial Conjunctivitis Data from Six Clinical and Phase I Safety Studies

Background: Besifloxacin is a novel fluoroquinolone, specifically a chloro-fluoroquinolone, with potent broad-spectrum bactericidal activity for the topical treatment of bacterial conjunctivitis. Objective: The objective of this report was to provide a comprehensive assessment of the safety and tolerability of besifloxacin ophthalmic suspension 0.6% across clinical and phase I safety studies. Methods: Data were drawn from two phase I safety studies in healthy adults, an open-label, phase II pharmacokinetic study of patients with bacterial conjunctivitis and from integrated data from three randomized, double-masked, parallel-group, safety and efficacy studies of patients with bacterial conjunctivitis (two were vehicle controlled and one was active controlled with moxifloxacin ophthalmic solution 0.5%, as base). Safety assessments included changes in visual acuity, ocular assessments with ophthalmoscopy and biomicroscopy, and assessment of adverse events (AEs). Results: Safety data for besifloxacin ophthalmic suspension 0.6% were available for 1350 patients, including 1192 patients (1810 eyes) in the integrated analysis. Systemic exposure following topical administration of besifloxacin ophthalmic suspension 0.6% was negligible. No changes were seen in corneal endothelial cell density. In the integrated safety analysis of the three safety and efficacy studies, the most commonly reported ocular AEs in study eyes receiving besifloxacin ophthalmic suspension 0.6% were blurred vision (2.1%), eye pain (1.8%), eye irritation (1.4%), nonspecific conjunctivitis (1.2%) and eye pruritus (1.1%). Blurred vision, eye irritation and nonspecific conjunctivitis occurred in significantly fewer besifloxacin-treated patients than in vehicle-treated patients (p <= 0.05). Headache (1.8%) was the most frequently reported non-ocular AE. Most AEs were mild in severity and there were no treatment-related serious AEs. Besifloxacin ophthalmic suspension 0.6% did not significantly affect visual acuity, biomicroscopy or ophthalmoscopy compared with vehicle or moxifloxacin. Conclusion: The results from this comprehensive data set of 1350 patients demonstrate that besifloxacin ophthalmic suspension 0.6% has a favourable safety profile and is well tolerated.