Different Immunosuppressive Treatment in iMN

Inclusion Criteria: * idiopathic membranous nephropathy * Female, must be post-menopausal, sterile or have effective contraception * must be off steroid or mycophenolate mofetil for \>1 month and alkylating agents for or RTX\> 6 months * Angiotensin-converting-enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) for ≥ 3 months with controlled blood pressure prior to beginning of immunosuppressive therapy or if patients are intolerant to ACEI/ARB. * proteinuria ≥4g/24h and decreased ≤ 50% from baseline Exclusion Criteria: * presence of active infection or a secondary cause of membranous nephropathy * proteinuria associated with diabetic nephropathy * pregnancy or breast feeding * history of resistance to rituximab or alkylating agents or corticosteroid * Patients who previously achieved remission after treatment of rituximab or alkylating agents but relapsed off rituximab or alkylating agents after 6 months are eligible.