Safety and Effect of Intravitreal Injection of a Derivative of Nucleoside Reverse Transcriptase Inhibitor in Subjects with Diabetic Macular Edema

Inclusion Criteria: * 18 years or older * BCVA of ≥ 24 and ≤ 73 letters (20/40 or worse but at least 20/320) by an ETDRS chart. BCVA of the non-study eye must be no worse than 20/400) * Diagnosis of diabetes mellitus, type 1 or 2 with non-proliferative or non-high risk proliferative diabetic retinopathy. * DME based on investigator's clinical evaluation and demonstrated on fundus photographs, fluorescein angiograms, and spectral domain-optical coherence tomography (SD-OCT) * Mean foveal thickness of at least 300 µm by SD-OCT * Ability and willingness to comply with the treatment and follow-up procedures * Ability to understand and sign the informed consent form * Intraocular pressure of ≤ 21 on 2 or less IOP lowering medications Exclusion Criteria: * Pregnant patients, currently lactating patients, or females of childbearing potential (unless using reliable contraception such as double barrier, surgical sterilization, oral contraceptives, intrauterine device (IUD), etc.) * Allergy or hypersensitivity (known or suspected) to fluorescein or any component of the investigational product or delivery system * Any ocular surgery in the study eye within 12 weeks of screening * Any history of vitrectomy in the study eye * Aphakia in the study eye * Presence of severe foveal ischemia, defined as foveal avascular zone (FAZ) of \>1.5 mm2 on OCT-Angiography * Prior intraocular or periocular treatment for DME * Macular laser for the treatment of diabetic macular edema within 12 weeks of screening * Any change in systemic steroidal therapy within 3 months of screening * Retinal or choroidal neovascularization due to ocular conditions other than diabetic retinopathy * History or presence of viral disease of the cornea or conjunctiva * History or presence of any disease or condition that in the investigator's opinion would preclude study treatment or follow-up or that in the opinion of the investigator would render them as unlikely to benefit from study treatment. * Any lens or corneal opacity which impairs visualization of the posterior pole * Participation in another clinical trial within 12 weeks before the screening visit or during the study * Expectation that subject will be moving away from the area of the clinical treatment center without the ability to return for visits within the study period