Obinutuzumab Induced Decreases of PLA2Rab in MN: a Pilot Study
Objective: To assess the disappearance rate (half-life) of anti-PLA2R antibodies in high-risk primary membranous nephropathy (pMN) patients treated with obinutuzumab (OBI), and to evaluate immunological and clinical remission, adverse events, and quality of life.
Design: Open-label, single-center, prospective pilot intervention study conducted at Radboud University Medical Center. Population: 20 adult patients with high-risk PMN, defined by proteinuria ≥3.5 g/24h despite 6 months of supportive treatment with ACE inhibitors or ARBs. Intervention: OBI 1000 mg on days 1 and 15, with two additional infusions after 6 months if anti-PLA2R antibody levels remain positive and proteinuria exceeds 2 g/24h. Follow-up: Patients were monitored at baseline, and at weeks 1, 2, 4, 8, 12, 24, 37, and 52.
• Age ≥ 18 years.
• Diagnosis of PMN, confirmed by:
‣ Kidney biopsy or
⁃ Positive serum PLA2Rab test either by IFT and/or ELISA)
• Serum PLA2Rab titer \> 80 RU/ml
• Proteinuria ≥ 3.5 g/24h despite supportive treatment for at least 6 months with a maximally tolerated and stable dose of ACE-i or ARB.
• Serum albumin \< 30 g/l measured by BCP assay.
• eGFR ≥ 30 ml/min/1.73m2.
• Treatment with immunosuppression is warranted, as determined by the treating physician.