This study is about testing a new medicine called litifilimab for people with Systemic Lupus Erythematosus (SLE). SLE is a disease where the immune system, which usually protects the body, attacks it instead. The researchers want to see if litifilimab can help reduce the symptoms of SLE. Participants in the study will continue to take their usual medications like antimalarials (drugs to prevent malaria), steroids (drugs that reduce inflammation), and immunosuppressants (drugs that lower the immune system response).

The study involves getting injections under the skin every 4 weeks for 52 weeks. Some people will get the real medicine, and others will get a placebo, which is a fake medicine that looks real. Neither the participants nor the researchers will know who is getting litifilimab. After the treatment, there will be a 24-week period to check safety. The study lasts up to 80 weeks with 22 visits in total.

• The study lasts up to 80 weeks with 22 visits.
• Participants will get injections every 4 weeks.
• Participants stay on their regular SLE medications.