This study is examining how well a new medicine called tarcocimab works compared to a pretend treatment (called a sham) for people with diabetic retinopathy (DR), a condition where diabetes affects the eyes. People with either type 1 or type 2 diabetes can join if their recent HbA1c, a blood sugar test, is 12% or less. Participants must not have had certain eye treatments like injections or laser surgery in the last year. The study checks if participants' eye health improves after 48 weeks. During this time, participants will receive either tarcocimab or a sham treatment. This is a randomized, double-masked study, meaning neither the participants nor the researchers know who is getting the real treatment. This helps ensure the results are fair.

• The study lasts for 48 weeks.
• Participants must not have had recent certain eye treatments or surgeries.
• Pregnant women cannot participate.