A Study of Guselkumab in Participants With Active Lupus Nephritis

The purpose of this study is to evaluate the efficacy of guselkumab in participants with active lupus nephritis (LN).

Guselkumab is a monoclonal antibody (mAb) that binds to human interleukin (IL)-23 with high affinity and blocks binding of extracellular IL-23 to cell surface IL-23 receptor, inhibiting IL 23 specific intracellular signaling and subsequent activation and cytokine production. It is used in treatment of plaque psoriasis, psoriatic arthritis, generalized pustular psoriasis, erythrodermic psoriasis. Lupus is a heterogeneous autoimmune disease with lesions confined to skin (cutaneous lupus erythematosus \[CLE\]) to others that involve 1 or more vital internal organs (systemic lupus erythematosus \[SLE\]). Renal involvement due to SLE is termed lupus nephritis (LN). There is a high unmet need for new treatment options in LN that are safe and effective, especially new therapies that can provide improved long-term efficacy over currently available therapies. This study will evaluate safety and efficacy of guselkumab added to standard-of-care compared to placebo added to standard-of-care. Total duration of study is up to 68 weeks: a less than or equal to 8 week screening period, a 48 week double-blind treatment period, a 12 week safety follow-up period after last dose. Participants who complete the assessments at Week 52 and have achieved complete renal response (CRR) may have the option to participate in the long-term extension (LTE) of study through Week 152 and the 12-week safety follow-up visit. Hypothesis of this study is that guselkumab plus standard-of-care is superior to placebo plus standard-of-care in participants with active LN as measured by the proportion of participants inducing at least a 50 percentage reduction of proteinuria with protocol specified steroid tapering regimen at Week 24. Safety assessments include Adverse events (AEs), clinical laboratory tests (hematology and chemistry), systolic and diastolic blood pressures over time, monitoring for hypersensitivity reactions, AEs temporally associated with infusion, injection-site reactions, suicidality assessment, and early detection of active tuberculosis (TB).

Eligibility Criteria:
Inclusion Criteria:

* At screening and randomization, must be receiving oral glucocorticoids at minimum prednisone equivalent dose of 10 milligrams per day (mg/day) and maximum 1 mg/kg/day or less than or equal to (\<=) 60 mg/day, whichever is lower. Treated for greater than or equal to (\>=) 6 weeks with stable dosing \>=2 weeks before randomization
* If receiving angiotensin-converting enzyme (ACE) inhibitor/angiotensin II receptor blockers (ARB), a stable dose for at least 2 weeks prior to randomization
* Positive antinuclear antibody (ANA; \>= 1:80 titer by central laboratory test) or anti-double-stranded deoxyribonucleic acid (dsDNA) antibodies (\>=30 international units per milliliter (\[U/mL\] by central laboratory test) detected at screening
* Kidney biopsy documentation of active International Society of Nephrology (ISN)/Renal Pathology Society (RPS) proliferative nephritis: Class III-IV (with or without class V membranous nephritis) within the last 6 months prior to screening or performed during screening
* Urine Protein to Creatinine Ratio (UPCR) \>= 1.0 milligram/milligram (mg/mg) assessed on 2 first morning urine void specimens during screening. These 2 specimens do not need to be on consecutive days, however, 2 samples must be tested with UPCR \>= 1.0 mg/mg in a row. The UPCR requirement must be met after at least 8 weeks of mycophenolate mofetil (MMF)/mycophenolic acid (MPA) treatment, and after stable glucocorticoid dosing is achieved at the dose intended at time of randomization

Exclusion Criteria:

* Comorbidities (other than lupus nephritis \[LN\], example, asthma, chronic obstructive pulmonary disease) which have required 3 or more courses of systemic glucocorticoids within the previous 12 months
* Has other inflammatory diseases that might confound the evaluations of efficacy, including but not limited to rheumatoid arthritis (RA), psoriatic arthritis (PsA), RA/lupus overlap, psoriasis, Crohn's disease, or active Lyme disease
* Received PO (orally) or intravenously (IV) cyclophosphamide within 3 months prior to randomization
* History of latent or active granulomatous infection, including histoplasmosis or coccidioidomycosis, before screening
* History of being human immunodeficiency virus (HIV) antibody-positive, or tests positive for HIV at screening