This study is testing a medicine called obinutuzumab for kids and teens with a kidney problem caused by lupus, called lupus nephritis (LN). Lupus is a disease where the immune system, which usually fights germs, attacks the body instead. This study is in Phase II, which means it’s checking how well the medicine works and how safe it is. Obinutuzumab is given to kids aged 12-18 in a way where neither they nor the doctors know if they're getting the real medicine or a placebo (a harmless pill). For younger kids aged 5-12, they will all get the real medicine, and the study will see how it affects them. To join, kids need to have had a kidney biopsy (a small piece of kidney taken to check for disease) showing active LN and must have taken certain medicines before. They cannot join if they have other serious health problems or infections. If you think your child might be eligible, talk to your doctor to see if this study could be a good fit.

• The study is double-blind for teens, meaning neither they nor the doctors know who gets the real medicine.
• Open label for younger children, meaning they all receive the actual medicine.
• Participants will be observed for safety and effectiveness of the treatment.