A Study of Belimumab in Idiopathic Membranous Glomerulonephropathy

Inclusion Criteria

• Age & Gender: Male or female between 18 and 75 years of age inclusive, at the time of signing the informed consent.
• Histological diagnosis: Have clinical diagnosis of IMGN, as verified by biopsy (either by light microscope with immuno-fluorescence, or by electron microscope) in the last 7 years with non-active disease >3 years (non-active defined as subject not on immunosuppressants and proteinuria 15% decrease in eGFR in 3 months before screening, unless due to medication change).
• Blood Pressure: Uncontrolled hypertension defined as blood pressure (BP) greater than 150/90 millimeters of mercury (mm Hg) (treatment target greater than and equal to 140/80) as assessed by either : Blood pressures measured 3 times on each of at least 2 clinic visits during screening, after the patient has sat quietly for at least 5 minutes, with greater than 50% of measurements being greater than 150/90 or average daytime blood pressure on a 24 hour ambulatory blood pressure monitor.
• Prior Therapy: Have received treatment with the following therapies at the times specified prior to Day 0: Therapy - B-cell targeted therapy except rituximab (e.g., other anti- CD20 agents, anti-CD22 [epratuzumab], anti-CD52 [alemtuzumab], B lymphocyte stimulator-receptor fusion protein [BR3], transmembrane activator and calcium modulator and cyclophylin ligand interactor Fc, or belimumab), Time period: anytime; Therapy: Rituximab (Subjects with rituximab treatment between 1 and 2 years prior to Day 0 are eligible if there is documented evidence of B-cell repopulation to >50% of pre-treatment levels.), Period: 2 years; Therapy: Abatacept and any other biologic investigational agent other than B cell targeted therapy (i.e. not approved for sale in the country in which it is being used), Time Period: 364 days; Therapy: Cyclophosphamide or chlorambucil 3 or more courses of systemic corticosteroids for concomitant conditions (e.g., asthma, atopic dermatitis). (Topical or inhaled steroids are permitted.), Time Period: 180 days; Therapy: Anti-tumour necrosis factor (TNF) or anti-IL-6 therapy (e.g. adalimumab, etanercept, infliximab, tocilizumab). Interleukin-1 receptor antagonists (e.g. anakinra). Other immunosuppressive/immunomodulatory agents (e.g azathioprine, 6-mercaptopurine, mycophenolate mofetil (PO)/ mycophenolate mofetil hydrochloride (IV), mycophenolate sodium (PO), methotrexate, tacrolimus, sirolimus, thalidomide, leflunomide, mizoribine, ciclosporin). Intravenous immunoglobulin (IVIG). Plasmapheresis, leukapheresis, Time Period: 90 days; Therapy: A non-biologic investigational agent (i.e. not approved for sale in the country in which it is being used). Intravenous corticosteroid, Adrenocorticotropic hormone (ACTH). Adenocorticotropic hormone (ACTH), aliskiren A change in dose of >50% for angiotensin pathway antihypertensive (e.g., ACE inhibitor, angiotensin receptor blocker), Time Period: 60 days; Therapy: A live vaccine. Greater than 30 milligrams per day (mg/day) corticosteroid, Time Period: 30 days; Therapy: Greater than 10mg/day corticosteroid. A change in dose of a corticosteroid. Note: Changes to inhaled steroids and new topical immunosuppressive agents (e.g., eye drops, topical creams) are allowed, Time Period: 14 days;
• Transplantation: Have a history of a major organ transplant (e.g., heart, lung, kidney, liver) or hematopoietic stem cell/marrow transplant.
• Cancer: Have a history of malignant neoplasm within the last 5 years, except for adequately treated cancers of the skin (basal or squamous cell) or carcinoma in situ of the uterine cervix.
• Acute or chronic infection: Have required management of acute or chronic infections, as follows: Currently on any suppressive therapy for a chronic infection (such as tuberculosis, pneumocystis, cytomegalovirus, herpes simplex virus, herpes zoster and atypical mycobacteria); Hospitalisation for treatment of infection within 60 days prior to Day 0; Use of parenteral (IV or intramusc