PURPOSE: The safety of KPI-121 0.25%, an ophthalmic nanoparticle suspension of loteprednol etabonate, was evaluated in subjects with dry eye disease (DED) in one phase 2 and three phase 3 randomized trials of similar design. METHODS: Adults with DED received KPI-121 0.25% or vehicle drops 4 times daily (QID) for ≥2 weeks; 1430 subjects received KPI-121 0.25% and 1438 subjects received vehicle drops. Main safety assessments were adverse events (AEs) and intraocular pressure (IOP). As a common side effect associated with the use of ocular corticosteroids is elevated IOP, subjects with a history of or current diagnosis of glaucoma were excluded. RESULTS: Instillation site pain was the most common AE, reported by 5.2% of subjects in the KPI-121 0.25% group and 4.4% of subjects in the vehicle group; other AEs were reported by ≤0.8% of subjects in the KPI-121 group. IOP elevations, a side effect associated with the use of ophthalmic corticosteroids, were observed with low incidence: 0.6% and 0.2% of subjects in the KPI-121 and vehicle groups, respectively. An IOP elevation was defined as an increase from baseline of >5 mm Hg that resulted in an IOP of ≥21 mm Hg in either eye during use of the study product. CONCLUSIONS: KPI-121 ophthalmic suspension 0.25% seemed to be safe and well tolerated when dosed QID for 2 to 4 weeks in those DED subjects included in the 4 trials.