A Study Evaluating the Efficacy and Safety of Afimetoran Compared With Placebo in Participants With Active Systemic Lupus Erythematosus (SLE)

Inclusion Criteria: * Diagnosed ≥ 12 weeks before the screening visit and qualify as having SLE according to the SLE International Collaborating Clinics (SLICC) Classification Criteria at the screening visit * Test positive, as determined by the central laboratory, for at least one of the following lupus related autoantibodies at the time of screening: antinuclear antibody ≥ 1:80, anti-double-stranded deoxyribonucleic acid (dsDNA) antibody, or anti-Smith antibody. * Have a total Hybrid Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) score ≥ 6 points and clinical Hybrid SLEDAI score ≥ 4 points with joint involvement and/or rash Exclusion Criteria: * Active severe lupus nephritis (LN) as assessed by the investigator * Active or unstable neuropsychiatric lupus manifestations defined by the Hybrid SLEDAI * Diagnosis of Mixed Connective Tissue Disease for which the predominant diagnosis is not SLE * Antiphospholipid Syndrome Other protocol-defined inclusion/exclusion criteria apply