Atacicept Phase 2/3 in Generalized Systemic Lupus Erythematosus (APRIL-SLE)

This study is to evaluate the efficacy and safety of atacicept compared to placebo in preventing new flares in subjects with systemic lupus erythematosus (SLE) and to confirm the optimal dose of atacicept for treatment of subjects with SLE and gain information on the effect of atacicept on markers specific to its mechanism of action (MoA) and their correlation to disease activity/progression. Study medication will be administered through subcutaneous (under the skin) injections, beginning with twice weekly injections for the first 4 weeks, followed by once weekly doses for 48 weeks. Following the last treatment, a safety follow-up period of 24 weeks will be conducted.