A Study to Evaluate the Efficacy and Safety of IBI302 inSubjects With Diabetic Macular Edema（DME）

Inclusion criteria： * Informed Consent Form (ICF) must be signed before participating in the study, compliance is good, and willing to complete the visit as planned; * Subjects aged 18-80 years (inclusive) at the time of screening, and diagnosed with type I or type II diabetes; * DME involved the macular fovea at screening; * CST≥320 μm as confirmed by OCT in the study eye at screening. * At baseline, visual acuity loss in the study eye due to DME with BCVA ranging from 19 to 78 ETDRS letters (inclusive); * Currently use of insulin, or other injectable drugs, or oral hypoglycemic agents to treat diabetes, HbA1c ≤10% at screening; Exclusion criteria： Eye disease * High-risk PDR in the study eye; * Dense hard exudation that destroyed the fovea structure of the macula in the study eye; * Iris neovascularization in the study eye; * Other systemic/ocular disease associated with the study eye may cause subjects fail to respond to study treatment or confuse the interpretation of study findings; * Uncontrolled glaucoma in the study eye; Eye treatment * Any previous treatment with IBI302 in the study eye before baseline; * Intravitreal injection of anti-VEGF or anti-complement agents in the study eye within 90 days prior to baseline; * Panretinal photocoagulation or macular laser (focal, grid or micropulse) in the study eye within 90 days prior to baseline; * Cataract surgery was performed in the study eye within 90 days prior to baseline; * YAG laser capsulotomy or YAG laser peripheral iridotomy were performed in the study eye within 90 days prior to baseline. * Any other intraocular surgery (eg, corneal transplantation, glaucoma filtration, pars plana vitrectomy, or radiotherapy) Systemic diseases/treatments * Currently untreated diabetes mellitus or previously untreated patients who initiated oral or injectable antidiabetic medication \<90 days prior to administration. * Uncontrolled hypertension. * Systemic use of anti-VEGF or anti-complement agents within 90 days prior to baseline * The presence of any other pre-existing disease, metabolic disorder, abnormal results on a physical examination or clinical laboratory examination that may reasonably be suspected of causing contraindications with the investigational drug, or affecting the interpretation of study results, or placing subjects at high risk of treatment complications (e.g., coagulation dysfunction, history of acute cardiovascular and cerebrovascular disease, history of treated or untreated malignancies within the past 5 years, etc.); * Systemic treatment for suspected or active systemic infection (e.g., tuberculosis, hepatitis B, hepatitis C, etc.); * Pregnant or lactating women.