To investigate the safety and efficacy of DE-112 in lowering intraocular pressure in subjects with primary open-angle glaucoma or ocular hypertension.

This study will be conducted in two stages. Stage One is an open-label, adaptive dose-selection, safety and efficacy trial of up to four concentrations of DE-112 ophthalmic solution enrolling a total of 24 subjects.

Stage Two of the study is a randomized, double-masked, placebo- and active-controlled, parallel-group, multi-center trial comparing the efficacy and safety of two concentrations of DE-112 ophthalmic solution with placebo and timolol enrolling a total of 120 subjects.

Inclusion Criteria:

• Provide signed, written informed consent
• 18 yeas of age and older
• Diagnosed with primary open-angle glaucoma or ocular hypertension
• Female subject of childbearing potential must utilize reliable contraceptive throughout the study and have a negative urine pregnancy test prior to enrollment into this study
• Meet specific Visit 2, Day 0 (Baseline)criteria at baseline

Exclusion Criteria:

• Females who are pregnant, nursing or planning a pregnancy
• Presence of any abnormality or significant illness that could be expected to interfere with the study.