Study of Sparsentan in Patients With Primary Focal Segmental Glomerulosclerosis (FSGS)

Key Inclusion Criteria for the Double-blind Period: * Sites within the US and UK: The patient is male or female aged 8 to 75 years, inclusive, weighing ≥20 kg at screening * Sites outside the US and UK: The patient is male or female aged 18 to 75 years, inclusive, weighing ≥20 kg at screening * Biopsy-proven focal segmental glomerulosclerosis (FSGS) lesion(s) or documentation of a genetic mutation in a podocyte protein associated with FSGS. * Urine protein/creatinine (UP/C) ≥1.5 g/g (170 mg/mmol) at screening * eGFR ≥30 mL/min/1.73 m2 at screening. * Women of childbearing potential must agree to the use of one highly reliable method of contraception from 7 days prior to the first dose of study medication until 90 days after the last dose of study medication, plus one additional barrier method during sexual activity Key Exclusion Criteria for the Double-blind Period: * FSGS secondary to another condition * Positive serological tests of another primary or secondary glomerular disease not consistent with a diagnosis of primary or genetic FSGS * History of type 1 diabetes mellitus, uncontrolled type 2 diabetes mellitus, or nonfasting blood glucose \>180 mg/dL (10.0 mmol/L) * Treated with rituximab, cyclophosphamide, or abatacept within ≤3 months prior to screening; if taking other chronic immunosuppressive medications, the dosage must be stable prior to screening * Documented history of heart failure, coronary artery disease, or cerebrovascular disease * Significant liver dise…