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

The purpose of this study is to evaluate the effectiveness, safety and tolerability of Afimetoran in participants with active Systemic Lupus Erythematosus (SLE). The extension period will provide additional long-term safety and efficacy data and enable those participants initially randomized to placebo to receive treatment with Afimetoran.

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