Inclusion Criteria: - Participants must have signed and dated an Institutional Review Board/ Independent Ethics Committee (IRB/IEC)-approved written informed consent form (ICF) in accordance with regulatory, local, and institutional guidelines - Participants must be ≥16 years of age at the time of signing the ICF - Meet the European League Against Rheumatism (EULAR) / American College of Rheumatology (ACR) 2019 classification criteria for systemic lupus erythematosus (SLE) - Have an inadequate response to glucocorticoids and ≥ 2 immunosuppressant therapies, one of which is a biologic therapy consistent with treatment guidelines, used for at least 3 months each. Eligibility is regardless of prior hydroxychloroquine or any anti-malarial treatment. Inadequate response is defined as a lack of response, insufficient response, or lack of sustained response after at least 3-month treatment with appropriate doses of a standard of care agent. Intolerance or contraindication may be considered as inadequate response provided it is documented and confirmed acceptable by the Adjudication Committee - Have active disease at study entry when signing ICF, defined as: - ≥ 1 British Isles Lupus Assessment Group Index (BILAG) A OR ≥ 1 BILAG B with history of SLE manifestations that would qualify for a BILAG A within the last 24 months, AND - Positive autoantibodies (at least one) to confirm diagnosis of SLE: Antinuclear antibody ≥1:160, anti-dsDNA, anti-Sm, anti-Ro (SSA), anti-La (SSB), or low complement proteins (C3 or C4) - Participants with lupus nephritis (LN) meeting the study eligibility criteria must have had a renal biopsy per standard of care within 6 months (± 30 days) prior to signing the ICF, indicating the presence of active Class III or IV LN (alone or in combination with Class V) according to the 2018 Revised International Society of Nephrology/Renal Pathology Society (ISN/RPS), with < 60% interstitial fibrosis and tubular atrophy < 60% global glomerulosclerosis Exclusion Criteria: - Pregnant women - Participants enrolled in concurrent interventional clinical trials involving investigational therapies or any other clinical trial - Participant is unwilling or unable to comply with routine clinical follow-up necessary for collection of study data