The purpose of this Phase 1b study is to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of AKB-9778 ophthalmic solution (eye drops) administered for 7 days in adults. The study is a double-masked, multiple- ascending dose trial and will enroll four cohorts of up to 12 subjects. Dose cohorts will receive increasing doses of AKB-9778 ophthalmic solution or vehicle-matched placebo daily for 7 days. Cohort 5 will enroll subjects with open angle glaucoma or ocular hypertension who will continue current prostaglandin therapy during the study. Cohort 5 subjects will receive the maximum tolerated dose from the previous cohorts.

Key Inclusion Criteria:

• Aged > 18 years to 70 years inclusive in Cohort 1; aged ≥ 45 to 70 years inclusive in Cohorts 2-4, aged 18 to 80 years inclusive in Cohort 5.
• For subjects in Cohort 1, IOP between 12 and 23 mm Hg (inclusive). For subjects in Cohorts 2-4, IOP between 16 and 23mm Hg (inclusive). For subjects in Cohort 5, IOP between 17 and 27 mm Hg (inclusive).
• Central corneal thickness of 480 to 600 μm, inclusive
• For subjects in Cohort 5, diagnosis of OAG or OHT
• For subjects in Cohort 5, currently receiving prostaglandin therapy for IOP lowering

Key Exclusion Criteria:

• Diagnosis of any form of glaucoma in Cohorts 1-4
• Clinically significant eye trauma within 6 months of screening
• Any intraocular ophthalmic procedure within 6 months of screening
• Any ocular inflammation within 90 days of screening or a history of recurrent uveitis in either eye
• Subjects with any known chronic ocular disease (other than incipient cataract or refractive error)
• Any condition preventing valid applanation tonometry measurement, e.g., clinically significant corneal disease, refractive surgery
• Visual acuity (VA) worse than 20/30 in either eye, For Cohort 5 VA worse than 20/100 in either eye