A Study of Felzartamab in Participants With Lupus Nephritis

Inclusion Criteria:

• Diagnosis of Systemic Lupus Erythematosus (SLE) according to the 2019 EuropeanLeague Against Rheumatism (EULAR)/ American College of Rheumatology (ACR) criteria

• Diagnosis of International Society of Nephrology/ Renal Pathology Society (ISN/RPS) 2003 Class III or IV LN as evidenced by renal biopsy performed within 1 year priorto or during screening, either with or without the presence of Class V LN

• Proteinuria (urine protein to creatinine ratio) > 1.0 gram per gram (g/g), based on 24-hour urine collection during screening

• eGFR ≥ 45 milliliter/minute/1.73 square meters (mL/min/1.73 m^2) (as calculated bythe Chronic Kidney Disease Epidemiology Collaboration formula)

• History of inadequate response, for lack of efficacy or intolerance, to at least athree-month course of one standard of care treatment for lupus nephritis, asdetermined by the treating physician

Exclusion Criteria:

• Presence of rapidly progressive glomerulonephritis, as defined by at least one ofthe following: crescent formation in > 50% of glomeruli on renal biopsy, sustaineddoubling of serum creatinine within 12 weeks of screening, or the investigator'sopinion that the participant has rapidly progressive glomerulonephritis

• Greater than 50% of glomeruli with sclerosis on renal biopsy

• Currently requiring hemodialysis or peritoneal dialysis or expected to requiredialysis during the study treatment period

• A previous kidney transplant or other organ transplant, or planned transplant withinstudy treatment period

Other protocol-defined inclusion/exclusion criteria may apply