Study of Daxdilimab (HZN-7734) in Participants With Active Proliferative Lupus Nephritis (LN)

Inclusion Criteria: * Willing and able to understand and provide written informed consent * Adult men or women 18 to 80 years of age * Willing and able to comply with the prescribed treatment protocol and evaluations for the duration of the trial * Fulfill the 2019 European League Against Rheumatism/American College of Rheumatology Classification Criteria for Systemic Lupus Erythematosus (SLE) * Have at least one of the following at Screening per central lab: * Antinuclear antibodies (ANA) ≥ 1:80 * Anti-dsDNA antibodies elevated to above normal range as established by the central laboratory (ie, positive results) * Anti-Smith antibodies elevated to above normal (ie, positive results). * Diagnosis of proliferative LN based on a renal biopsy obtained within 6 months prior to signing the informed consent form (ICF) or during the Screening Period: * Class III (± class V) or class IV (± class V) LN according to the World Health Organization (WHO) or 2003 International Society of Nephrology (ISN)/Renal Pathology Society (RPS) classification (based on local evaluation of renal biopsy). * Urine protein to creatinine ratio ≥113.17 mg/mmol, obtained via a 24-hour urine collection at Screening. * Estimated glomerular filtration rate ≥35 mL/min/1.73 m2 * Negative serum beta-human chorionic gonadotropin test at Screening (females of childbearing potential only). Key Exclusion Criteria: * History of allergy, hypersensitivity reaction, or anaphylaxis to any component of the inv…