A Study to Evaluate the Continuous Safety and Efficacy of Litifilimab (BIIB059) in Adults With Active Systemic Lupus Erythematosus

The primary objective of this study is to evaluate the long-term safety and tolerability of litifilimab in participants with active systemic lupus erythematosus (SLE). The secondary objectives of this study are to evaluate the long-term effect of litifilimab on disease activity in participants with SLE, to evaluate the long-term effect of litifilimab in participants with SLE in maintaining low disease activity, to evaluate the effect of litifilimab in participants with active SLE in preventing irreversible organ damage, to assess long-term use of oral corticosteroid (OCS) with participants receiving litifilimab treatment, to assess the impact of litifilimab on participant-reported Health-Related Quality-of-Life Questionnaire (HRQoL), symptoms, and impacts of SLE, to evaluate long-term effect of litifilimab on laboratory parameters, and to evaluate immunogenicity of litifilimab.