Phase 2 Placebo-Controlled Study to Assess the Safety and Efficacy of ESK-001 in Active Systemic Lupus Erythematosus

Inclusion Criteria: Patients with 6 or more months of SLE according to the 2019 EULAR/ACR criteria, have positive autoantibodies or low complement at screening, and have active SLE as measured by SLEDAI-2K of 6 or more, or 4 or more if joint involvement is present. Patients need to be on treatment which can be: * A stable dose of oral corticosteroid (≤40 mg/day prednisone or equivalent) for a minimum of 2 weeks prior to signing of the informed consent form (ICF) at the Screening Visit. The dose of oral corticosteroid the patient is taking should not increase between screening and Week 0 (Day 1). * And/or antimalarial treatment (e.g., hydroxychloroquine, chloroquine, quinacrine), * And/or no more than 1 of the following conventional DMARDS: * Azathioprine ≤200 mg/day * Mycophenolate mofetil ≤2 g/day or mycophenolic acid ≤1.44 g/day * Oral, subcutaneous, or intramuscular (IM) methotrexate ≤20 mg/week. Exclusion Criteria: * Drug-induced SLE or other autoimmune diseases that, in the opinion of the Investigator, are likely to confound efficacy assessments * Active, proliferative lupus nephritis that in the Investigator's opinion may require treatment not allowed by the protocol * Current disease other than SLE that, in the opinion of the Investigator, is likely to interfere with SLE disease activity assessments. Examples include severe fibromyalgia, severe osteoarthritis and severe cardiorespiratory diseases. * Active severe or unstable neuropsychiatric SLE including, …