Surabgene Lomparvovec Administered in the Suprachoroidal Space in Adult Participants With Diabetic Retinopathy Without Center-Involved Diabetic Macular Edema

Diabetic Retinopathy (DR) is a common eye condition caused by diabetes, where high blood sugar levels damage the blood vessels in the back part of the eye (called the retina). Over time, this damage can lead to vision problems and even blindness if not treated. This study will assess surabgene lomparvovec (sura-vec) as a potential one-time gene therapy administered in the suprachoroidal space (SCS) for the treatment of diabetic retinopathy (DR) and prevention of vision-threatening events (VTEs) in participants with non-proliferative DR (NPDR) without center-involved diabetic macular edema (CI-DME). This study will consist of 3 portions: a Phase 2b portion, a Phase 3 portion, and a bilateral treatment portion. Approximately 576 adult participants will be enrolled in the study across multiple sites in the United States and Puerto Rico. In the Phase 2b and Phase 3 portions, participants will be randomized to different groups to receive sura-vec and prophylactic steroids or sham and artificial tears in their study eye. If assigned to sham, participants will be given an opportunity to cross over and receive treatment with sura-vec. In the bilateral treatment portion, participants will be enrolled to receive sura-vec and prophylactic steroids in both eyes. In all 3 portions, follow-up in the study will continue through 5 years following administration of sura-vec in each eye. There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.