Acthar for Treatment-Resistant or Treatment-Intolerant Proteinuria

Inclusion Criteria Potential participants must meet the following summary criteria for inclusion in the study: * Is male or non-pregnant, non-lactating female * Has primary FSGS, is nephrotic and did not achieve at least partial proteinuria response with prior therapy * Has been treated with an angiotensin converting enzyme inhibitor or receptor blocker (or have documented intolerance), for at least 4 weeks before screening * Has blood pressure no higher than 150/90 mmHg * Meets all other inclusion criteria detailed in the protocol Exclusion Criteria Potential participants will not be eligible for the the study if they meet the following summary criteria: * Has hepatitis B or C, tuberculosis, or other contraindication listed on the United States (US) Prescribing Information for Acthar * Has Type 1 or Type 2 diabetes mellitus or any clinically significant infection * Has received specific treatments at exclusionary time points per protocol * Has been involved in a therapeutic drug/device trial (other than for FSGS) within 4 weeks before screening * Meets any other exclusion criteria detailed in the protocol * Has any other condition that might, per protocol or in the opinion of the investigator, compromise: 1. the safety and well-being of the participant or their offspring 2. the safety of study staff 3. analysis of results