ACTHAR GEL in Patients With Membranous (Class V) Lupus Nephritis

Inclusion Criteria: * Patients ≥ 18 years of age who have pure Class V LN or Class V+II LN diagnosed by a kidney biopsy within 4 months of screening. If a patient has segmental glomerular scarring indicative of previous Class III or IV lesions, but no evidence of current Class III or IV activity, and only the Class V component is active, they can be enrolled, despite having a mandatory ISN/RPA classification of Class V + III or IV * Proteinuria ≥ 3 g/d despite adequate blood pressure control defined as systolic blood pressure ≤ 130 mm Hg 75% of the time, per the clinical judgment of the site investigator. * Serum creatinine \< 2 mg/dl or eGFR \> 30 ml/minute Exclusion Criteria: * Patients \< 18 years of age * Pregnancy or planning to become pregnant anytime throughout their participation in the trial, up until 30 days after last dose of study drug. * Kidney biopsy with active Class III or IV LN * More than 50% interstitial fibrosis and/or glomerulosclerosis on kidney biopsy * Patients with hepatitis B, C, HIV, TB or other active and chronic infections at the time of screening * Patients with liver disease and transaminases greater than 2.5 times the upper limit of normal of the laboratory, patients with diabetes mellitus type I or II, patients with refractory hypokalemia, patients with Cushing's Disease or Syndrome * Patients who have been treated with cyclophosphamide, cyclosporine A, tacrolimus, B-cell depleting therapies, or experimental therapies including biologics within 6 months of screening * Patients with active neuropsychiatric lupus, lupus pneumonitis, lupus vasculitis at screening * Patients with high or very high extra-renal lupus activity defined as an xSLEDAI score greater than 10 at the time of screening * Patients who have received high-dose intravenous methylprednisolone (1 g cumulative) within 3 months of screening * Patients currently receiving, or who have received MMF or AZA in the 3 months preceding enrollment for extra-renal SLE. * Patients who have received methotrexate or who are receiving methotrexate and it can be discontinued will be eligible; if methotrexate cannot be stopped safely, the patient will not be eligible. * Patients currently receiving more than 20 mg/d prednisone that cannot be safely reduced to 20mg/d or less beginning at least one month before enrollment on day 0 * Patients who are not on a stable dose of Anti-Malarials and/or Anti-hypertensives at least one month preceding baseline visit and during the study. (Refer to allowed medication section)