Systemic Lupus Erythematosus (SLE) is an autoimmune disease where the body attacks its own cells. This study checks if a medicine called ianalumab is safe to use for a long time in people who have moderate to severe SLE. Participants need to have finished one of the earlier SLE studies to join. The study lasts up to 7 years and is divided into three parts:

• First, a 3-year period where participants will receive either the medicine or a placebo (a harmless pill) without knowing which one it is.
• Second, a 2-year period where the safety of stopping the medicine is checked. If needed, participants can take ianalumab openly.
• Finally, up to 2 years of monitoring to ensure safety.

To join, participants must have completed one of the earlier studies and be expected to benefit from the treatment. They shouldn't use certain therapies, have active infections, or receive live vaccines during the study. Pregnant or nursing women cannot participate. It's important for participants to agree and sign forms before starting.