Efficacy and Safety of LNP023 Compared With Rituximab in Subjects With Idiopathic Membranous Nephropathy

Inclusion Criteria: * Female or male adult (≥18 years) subjects at screening visit with a diagnosis of idiopathic (primary) MN confirmed by renal biopsy within 36 months prior to screening. A renal biopsy may be taken at any time during the run-in period to confirm the diagnosis of MN and facilitate subject eligibility, if the most recent biopsy was performed greater than 36 months prior to the screening visit. * Anti-PLA2R antibody titer of ≥ 60 RU/mL at screening visit. If sites opt to use a local laboratory, with prior agreement with sponsor, an anti-PLA2R titer performed within 4 weeks prior to screening visit can be used. * Urine protein ≥ 3.5 g/24h at screening and baseline visits * ≤50% reduction in both anti-PLA2R level and 24h urine protein between screening and baseline * Estimated GFR (using the CKD-EPI formula) ≥ 30 mL/min per 1.73 m2 at screening * Receiving stable dose at the maximum recommended dose according to local guidelines or maximum tolerated dose of ACEi and/or ARB and/or statins and/or diuretics for at least 8 weeks prior to Day 1 * Vaccination against Neisseria meningitidis, Streptococcus pneumoniae and Haemophilus influenzae (in accordance with local guidelines) at least 28 days prior to Day 1 and no longer than 5 years prior to Day 1. Exclusion Criteria: * Secondary causes of MN, e.g. systemic autoimmune diseases, solid or haematological malignancies, infections or chronic intake of drugs (e.g. gold salts, NSAIDs, penicillamines) * Diagnostic renal biopsy showing evidence of crescent formation in glomeruli, suggestive of an alternative or additional diagnosis to primary idiopathic MN. * Previous treatment with B-cell depleting or B-cell modifying agents such as, but not limited to rituximab, belimumab, daratumomab or bortezomib. * Previous treatment with immunosuppressive agents such as cyclophosphamide, chlorambucil, mycophenolate mofetil (or equivalent), cyclosporine, tacrolimus or azathioprine within 90 days prior to Day 1. Low dose systemic corticosteroid therapy is permitted, though the subject should have been on stable dose equivalent to ≤10 mg prednisolone for at least 90 days prior to Day 1. * Previous treatment with gemfibrozil or strong CYP2C8 inhibitors such as clopidogrel within 7 days prior to Day 1 * Presence or suspicion (based on judgment of the investigator) of active infection within 30 days prior to Day 1, or history of severe recurrent bacterial infections * Known contra-indications for the use of rituximab, including hypersensitivity to the active substance or to murine proteins, or to any of the excipients (sodium citrate, polysorbate 80, sodium chloride, sodium hydroxide, hydrochloric acid, water for injections). Other contra-indications for the use of rituximab, including active, severe infection, patients in a severely immunocompromised state, severe heart failure (NYHA Class IV) or severe, uncontrolled cardiac disease.