This study is testing a drug called anifrolumab for adults with a kidney problem called Active Proliferative Lupus Nephritis (LN). This is a serious disease where the body's own immune system attacks the kidneys. The study compares how well anifrolumab works against a placebo, which is a fake treatment with no medicine. The study uses a method where neither the patients nor the doctors know who is getting the real drug or placebo, to ensure fairness. The study will last about 116 weeks (over 2 years) and includes about 360 participants. To join, participants must have specific kidney test results and no history of other serious infections or certain types of cancer.

• Length and Visits: The study lasts about 116 weeks, so it's a long-term commitment.
• Treatment: Participants will receive either anifrolumab or a placebo.
• Risks: Participants with certain infections or other health issues are not eligible.