This study is testing the safety and effects of a new drug called ALN-ANG3 for adults with diabetic kidney disease. Diabetic kidney disease is when the kidneys are damaged due to diabetes. The study aims to find out how safe the new drug is and how well it works. Researchers are interested in any side effects and how much of the drug is in the blood at different times.

Eligibility: To join, you should have type 2 diabetes and use medicine or lifestyle changes to control it. Your Hemoglobin A1C (HbA1c) should be between 6.5 to 10%, which measures blood sugar over three months. Your kidneys should filter a certain amount of blood (eGFR 30 to 90 mL/min/1.73 m²), and you should have a specific level of protein in your urine (UACR 500 to 5000 mg/g). You cannot join if you have other kidney diseases not caused by diabetes or need treatments like dialysis.

• The study drug is experimental, meaning it's still in testing.
• Participants must meet certain health criteria to join.
• There might be risks, and side effects will be monitored.