An adverse event (AE) is defined as any untoward medical occurrence in a patient or clinical investigation participant administered a pharmaceutical product and which does not necessarily have a causal relationship with this treatment. A serious adverse event (SAE) is an event that results in death, is life-threatening, requires or prolongs hospitalization, results in a congenital anomaly, persistent or significant disability/incapacity or is an important medical event that, based on medical judgment, may jeopardize the participant and may require medical or surgical intervention to prevent any of the outcomes listed above. Treatment-emergent events (TEAEs) are defined as an adverse event with an onset date that is on or after the first dose of study drug from Study M20-186, and no more than 30 days after the last dose of study drug from Study M20-186. For more details on adverse events please see the Adverse Event section.

SLE Responder Index (SRI)-4 is defined as follows with all criteria compared to Baseline: * ≥ 4-point reduction in Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) score * No worsening of the overall condition (\< 0.3 point increase in Physician's Global Assessment \[PhGA\]) * No new British Isles Lupus Assessment Group (BILAG) A or more than 1 new BILAG B disease activity scores (i.e., no organ system changes from baseline B/C/D/E to A and no more than 1 organ system changes from baseline C/D/E to B). A letter score is assigned to each organ system with following indications: A = severe, B = moderate, C = mild, D = inactive with prior history, and E = inactive with no history.