A Study of PER-001 in Participants With Diabetic Retinopathy

Inclusion Criteria: * Must be ≥ 18 years of age at the time of signing the informed consent * A negative pregnancy test for females of childbearing potential at Screening (serum) and Day 1 (urine). * Best-corrected visual acuity (BCVA) of ≥ 60 Early Treatment Diabetic Retinopathy Study (ETDRS) letters (Snellen equivalent of 20/63 or better) at Screening in potentially eligible eye(s) and prior to randomization at Day 1 in the study eye * Moderately severe to severe non-proliferative diabetic retinopathy (NPDR) (diabetic retinopathy severity scale \[DRSS\] of 47 to 53) within the standard 7-field ETDRS. Exclusion Criteria: * Hemoglobin A1c \>12%, or if HbA1c ≤12%, diabetes mellitus is uncontrolled in the opinion of the investigator * Any condition which, in the opinion of the investigator, would preclude the participant's ability to comply with study requirements including completion of the study (including but not limited to diagnosis of dementia, Alzheimer's, and/or other neurological disease or physical incapacity) * Females who are pregnant, nursing, or planning a pregnancy during the study * Active cancer within past 12 months except for appropriately treated carcinoma in situ of the cervix, non-melanoma skin carcinoma or prostate cancer * Uncontrolled blood pressure (defined as systolic \>180 or diastolic \>110 mmHg while the participant is sitting). * Currently untreated diabetes mellitus or previously untreated participants who initiated oral anti-diabetic medication or insulin within 3 months prior to Day 1 * History of cerebrovascular accident or myocardial infarction within 6 months prior to Day 1 * Uncontrolled atrial fibrillation * Systemic anti-VEGF treatment within 4 months prior to Day 1 * Any significant media opacity which precludes clinical evaluation and imaging of the retina * Presence of centrally involved DME (within 500 μm of the foveal center) at Screening and Day 1 * Tractional retinal detachment, pre-retinal fibrosis, vitreomacular traction, or epiretinal membrane involving the fovea or disrupting the macular architecture * Active rubeosis * History of vitrectomy surgery or retinal detachment or macular hole (Stage 3 or 4) * Uncomplicated cataract surgery within 3 months of Screening or yttrium-aluminum- garnet capsulotomy (YAG) within 4 weeks of Screening * Aphakia or absence of posterior capsule * Evidence of uncontrolled glaucoma (intraocular pressure must be \< 25 mmHg) at Screening * History of recurrent infectious or inflammatory ocular disease * Active infectious conjunctivitis, keratitis, scleritis, or endophthalmitis (Note: mild blepharitis is permitted if stable) * Any active uveitis and/or vitritis or history of idiopathic or autoimmune-associated uveitis * History of herpetic ocular diseases