Besifloxacin ophthalmic suspension 0.6% in patients with bacterial conjunctivitis: A multicenter, prospective, randomized, double-masked, vehicle-controlled, 5-day efficacy and safety study.

Background: Besifloxacin ophthalmic suspension 0.6% is a new topical fluoroquinolone for the treatment of bacterial conjunctivitis. Besifloxacin has potent in vitro activity against a broad spectrum of ocular pathogens, including drug-resistant strains.

Objective: The primary objective of this study was to compare the clinical and microbiologic efficacy of besifloxacin ophthalmic suspension 0.6% with that of vehicle (the formulation without besifloxacin) in the treatment of bacterial conjunctivitis.

Methods: This was a multicenter, prospective, randomized, double-masked, vehicle-controlled, parallel-group study in patients with acute bacterial conjunctivitis. Patients received either topical besifloxacin ophthalmic suspension or vehicle administered 3 times daily for 5 days. At study entry and on days 4 and 8 (visits 2 and 3), a clinical assessment of ocular signs and symptoms was performed in both eyes, as well as pinhole visual acuity testing, biomicroscopy, and culture of the infected eye(s). An ophthalmoscopic examination was performed at study entry and on day 8. The primary efficacy outcome measures were clinical resolution and eradication of the baseline bacterial infection on day 8 in culture-confirmed patients. The safety evaluation included adverse events, changes in visual acuity, and biomicroscopy and ophthalmoscopy findings in all patients who received at least 1 dose of active treatment or vehicle.

Results: The safety population consisted of 269 patients (mean [SD] age, 34.2 [22.3] years; 60.2% female; 82.5% white) with acute bacterial conjunctivitis. The culture-confirmed intent-to-treat population consisted of 118 patients (60 besifloxacin ophthalmic suspension, 58 vehicle). Significantly more patients receiving besifloxacin ophthalmic suspension than vehicle had clinical resolution of the baseline infection at visit 3 (44/60 [73.3%] vs 25/58 [43.1%], respectively; P < 0.001). Rates of bacterial eradication also were significantly greater with besifloxacin ophthalmic suspension compared with vehicle at visit 3 (53/60 [88.3%] vs35/58 [60.3%]; P < 0.001). The cumulative frequency of adverse events did not differ significantly between the 2 groups (69/137 [50.4%] and 70/132 [53.0%]). The most common ocular adverse events were eye pain (20/190 treated eyes [10.5%] and 13/188 [6.9%]), blurred vision (20/190 [10.5%] and 22/188 [11.7%]), and eye irritation (14/190 [7.4%] and 23/188 [12.2%]); these events were of mild or moderate severity. Changes in visual acuity and treatment-emergent events observed on biomicroscopy and direct ophthalmoscopy also were comparable between treatment groups.

Conclusion: Besifloxacin ophthalmic suspension 0.6% given 3 times daily for 5 days was both efficacious and well tolerated compared with vehicle in the treatment of these patients with bacterial conjunctivitis. ClinicalTrials.gov Identifier: NCT00622908.