Inclusion Criteria:

• Urine protein to creatinine ratio of ≥ 3.0 g/g (as measured from a 24 hour urine collection).
• Active anti-PLA2R antibody positive MN in need for immunosuppressive therapy (IST) according to investigator judgement and diagnosed on the basis of a biopsy, archival biopsy acquired within 5 years prior to screening is acceptable.
• Estimated glomerular filtration rate ≥ 50 ml/min/1.73m² or >30 and < 50 ml/min/1.73m², and interstitial fibrosis and tubular atrophy score of less than 25% on a renal biopsy obtained within the last 6 months prior to start of screening.
• on supportive treatment with an Angiotensin Converting Enzyme Inhibitor or an Angiotensin II Receptor Blocker for at least 4 weeks prior to Screening, having reached a stable dose.
• Systolic BP ≤ 150 mmHg and diastolic BP ≤ 100 mmHg -Vaccinated against Pneumococcus within the last 3 years prior to date of signing informed consent (subjects may be vaccinated during screening to meet this criterion; interval to first dose of MOR202 must be at least 14 days).
• Cohort 1a (newly diagnosed patients):
  • Serum anti-PLA2R antibodies ≥ 150.0 Response Units(RU)/mL determined at screening by Euroimmun ELISA.
• Cohort 1b, relapse subjects:
  • Must have had complete immunological and/or clinical remission according to judgement of the investigator and serum anti-PLA2R antibodies ≥ 50.0 RU/mL determined at screening by Euroimmun ELISA.
• Cohort 2:
  • Failure of previous therapy; i.e., subject never achieved a complete immunological and/or clinical remission according to judgement of the investigator. during or after completion of a recognized IST containing cyclosporine A, tacrolimus, mycophenolate-mofetil, ACTH or alkylating agents (e.g., cyclophosphamide), or rituximab. Serum anti-PLA2R antibodies ≥ 20.0 RU/mL determined at screening by the Euroimmun ELISA.

Exclusion Criteria:

• Hemoglobin < 90 g/L.
• Thrombocytopenia: Platelets < 100.0x10^9/L.
• Neutropenia: Neutrophils < 1.5x10^9/L.
• Leukopenia: Leukocytes < 3.0x10^9/L.
• Hypogammaglobulinemia: Serum immunoglobulins ≤ 5.0 g/L.
• Secondary cause of MN (e.g., Systemic lupus erythematosus, medications, malignancies). 
• Concomitant renal disease other than MN (e.g., diabetic renal disease, lupus nephritis, IgA nephropathy).