A Study to Evaluate THR-317 and Ranibizumab Combination Treatment for Diabetic Macular Oedema (DME)

Inclusion Criteria: * Male or female aged 18 years or older * Type 1 or type 2 Diabetes Mellitus * CI-DME with central subfield thickness of ≥ 320μm on Spectralis® SD-OCT or ≥ 305μm on non Spectralis SD-OCT, in the study eye * Anti-vascular endothelial growth factor (anti-VEGF) treatment naïve study eye, or poor or no response to prior treatment with ranibizumab in the study eye * Reduced vision primarily due to DME, with BCVA ≤ 72 and ≥ 23 ETDRS letter score (≤ 20/40 and ≥ 20/320 Snellen equivalent) in the study eye * Non-proliferative diabetic retinopathy of any stage in the study eye * Written informed consent obtained from the subject prior to screening procedures Exclusion Criteria: * Concurrent disease in the study eye, other than CI-DME, that could compromise BCVA, require medical or surgical intervention during the study period or could confound interpretation of the results * Previous confounding treatments / procedures, or their planned / expected use during the study period for up to 30 days after the last administration of study treatment * Any active ocular / intraocular infection or inflammation in either eye * Aphakic study eye * Poorly controlled Diabetes Mellitus * Uncontrolled hypertension * Pregnant or lactating female, or female of child-bearing potential not utilising an adequate form of contraception, or male of reproductive potential not utilising contraception