A Study of Felzartamab in Participants With Lupus Nephritis

Inclusion Criteria:

   - Diagnosis of Systemic Lupus Erythematosus (SLE) according to the 2019 European League
   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 prior to
   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 by the
   Chronic Kidney Disease Epidemiology Collaboration formula)

   - History of inadequate response, for lack of efficacy or intolerance, to at least a
   three-month course of one standard of care treatment for lupus nephritis, as
   determined by the treating physician

Exclusion Criteria:

   - Presence of rapidly progressive glomerulonephritis, as defined by at least one of the
   following: crescent formation in > 50% of glomeruli on renal biopsy, sustained
   doubling of serum creatinine within 12 weeks of screening, or the investigator's
   opinion 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 require
   dialysis during the study treatment period

   - A previous kidney transplant or other organ transplant, or planned transplant within
   study treatment period

Other protocol-defined inclusion/exclusion criteria may apply