B-Cell Depletion With Obinutuzumab & Standard Therapy in Lupus Nephritis
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Reviewed by Dat Tien Nguyen, B.A, ScM.
Translated by Nhi Phuong Quynh Le, B.A |
Posted on May 12th, 2025
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Lupus nephritis is a severe autoimmune condition in which the immune system produces antibodies that mistakenly target kidney cells, impairing their filtration function. Although new therapies such as belimumab and voclosporin have recently been approved by regulatory agencies in the United States and Europe, these treatments have shown limitations in clinical outcomes. Consequently, there remains an urgent need for alternative therapeutic options. With funding from Roche, a study was conducted to evaluate the efficacy and safety of obinutuzumab in the treatment of lupus nephritis.
This phase 3 randomized controlled trial enrolled 271 participants, with a mean age of 33 years, who had been diagnosed with active class III or IV lupus nephritis secondary to systemic lupus erythematosus, as defined by the American College of Rheumatology classification criteria. Baseline renal function assessments revealed a median serum creatinine level of approximately 0.75 mg/dL and a median estimated glomerular filtration rate (eGFR) of 108 mL/min/1.73 m². Participants were randomly assigned to receive intravenous infusions of either 1000 mg of obinutuzumab or a placebo. The antibody was administered at baseline, and again at weeks 2, 24, 26, and 52. Obinutuzumab is a monoclonal antibody that targets the CD20 antigen on B cells, disrupting the production of pathogenic autoantibodies. All participants also received standard background therapy with mycophenolate mofetil and prednisone.
By 24 weeks following the completion of treatment, researchers observed that obinutuzumab was associated with greater improvement in renal function compared to placebo. Additionally, obinutuzumab significantly reduced levels of complement proteins C3 and C4, thereby lowering the potential for immune complex formation and subsequent kidney damage. The treatment also consistently decreased levels of anti–double-stranded DNA autoantibodies, whereas patients in the placebo group exhibited a net increase—an outcome correlated with poorer prognosis. However, B-cell depletion by obinutuzumab was associated with a higher incidence of infections, particularly respiratory tract infections and COVID-19, leading to treatment discontinuation in 7.4% of patients in the obinutuzumab group.
This phase 3 randomized controlled trial enrolled 271 participants, with a mean age of 33 years, who had been diagnosed with active class III or IV lupus nephritis secondary to systemic lupus erythematosus, as defined by the American College of Rheumatology classification criteria. Baseline renal function assessments revealed a median serum creatinine level of approximately 0.75 mg/dL and a median estimated glomerular filtration rate (eGFR) of 108 mL/min/1.73 m². Participants were randomly assigned to receive intravenous infusions of either 1000 mg of obinutuzumab or a placebo. The antibody was administered at baseline, and again at weeks 2, 24, 26, and 52. Obinutuzumab is a monoclonal antibody that targets the CD20 antigen on B cells, disrupting the production of pathogenic autoantibodies. All participants also received standard background therapy with mycophenolate mofetil and prednisone.
By 24 weeks following the completion of treatment, researchers observed that obinutuzumab was associated with greater improvement in renal function compared to placebo. Additionally, obinutuzumab significantly reduced levels of complement proteins C3 and C4, thereby lowering the potential for immune complex formation and subsequent kidney damage. The treatment also consistently decreased levels of anti–double-stranded DNA autoantibodies, whereas patients in the placebo group exhibited a net increase—an outcome correlated with poorer prognosis. However, B-cell depletion by obinutuzumab was associated with a higher incidence of infections, particularly respiratory tract infections and COVID-19, leading to treatment discontinuation in 7.4% of patients in the obinutuzumab group.