Primary membranous nephropathy (PMN) is an autoimmune process in which podocyte antigens, most commonly the phospholipase A2 receptor (PLA2R), are targeted by circulating autoantibodies that cause complement-mediated injury and failure of the glomerular filtration barrier. While spontaneous remission can occur in one-third of patients, risk factors such as sustained high-level proteinuria, declining kidney function, or thrombotic complications often lead to consideration of immunosuppression. Therapeutic regimens have evolved over the decades, beginning with corticosteroid monotherapy (now known to be ineffective) and followed by the successful combination of alkylating agents alternating with corticosteroids over a 6-month course (the Ponticelli regimen).