A phase III study comparing preservative-free latanoprost eye drop emulsion with preserved latanoprost in open-angle glaucoma or ocular hypertension

Background/Objectives: To evaluate the efficacy and safety of preservative-free latanoprost eye drop emulsion in reducing intraocular pressure (IOP) versus preserved latanoprost in open-angle glaucoma (OAG) or ocular hypertension (OHT). Methods: A Phase III non-inferiority study randomised patients with OAG/OHT 1:1 to receive preservative-free latanoprost eye drop emulsion or preserved latanoprost. The primary efficacy endpoint was change from baseline in peak (9:00 A.M. ± 1 h) and trough (4:00 P.M. ± 1 h) IOP at Week 12 (non-inferiority margin: 95% confidence interval for treatment difference of ≤1.5 mmHg). Key secondary endpoints were change from baseline in corneal fluorescein staining (CFS) score and in ocular surface disease (OSD) average symptom score at Week 12 (in patients with baseline CFS ≥ 1 or OSD score > 0, respectively). Results: Non-inferiority criteria for IOP-lowering were met. Least square (LS) mean (standard error [SE]) IOP change from baseline with preservative-free latanoprost eye drop emulsion (N = 193) versus preserved latanoprost (N = 193) at Week 12 was −8.8 (0.3) mmHg versus −8.2 (0.3) mmHg at peak (difference: −0.6 mmHg; nominal p = 0.023); −8.6 (0.2) mmHg versus −8.1 (0.3) mmHg at trough (difference: −0.5 mmHg; p = 0.080). LS mean change in CFS (SE) was −0.7 (0.07) with preservative-free latanoprost eye drop emulsion and −0.4 (0.08) with preserved latanoprost (nominal p < 0.001). LS mean change in OSD symptom score was −0.3 (0.1) with preservative-free latanoprost eye drop emulsion and −0.2 (0.1) with preserved latanoprost (nominal p = 0.090). Conclusions: Preservative-free latanoprost eye drop emulsion demonstrated non-inferior IOP-lowering efficacy compared with preserved latanoprost, and improved signs and symptoms of OSD.