A Study of the Effect and Safety of Sparsentan in the Treatment of Patients With IgA Nephropathy

Key Inclusion Criteria for the Double-Blind Period: * Age 18 years or older at screening * Biopsy-proven primary IgAN * Proteinuria of ≥1 g/day at screening * eGFR ≥30 mL/min/1.73 m2 at screening * Currently on stable dose of ACEI and/or ARB therapy, for at least 12 weeks prior to screening (maximum tolerated dose and at least one-half of the maximum labeled dose) * Systolic BP ≤150 mmHg and diastolic BP ≤100 mmHg at screening * Willing to undergo change in ACEI and/or ARB and anti-hypertensive medications * Agree to contraception Key Exclusion Criteria for the Double-Blind Period: * IgAN secondary to another condition * Presence of cellular glomerular crescents in \>25% of glomeruli on renal biopsy (if biopsy available within 6 months of screening) * Chronic kidney disease (CKD) in addition to IgAN * History of organ transplantation, with exception of corneal transplants * Require any prohibited medications * Treatment of systemic immunosuppressive medications (including corticosteroids) for \>2 weeks within 3 months of screening * History of heart failure or previous hospitalization for heart failure or unexplained dyspnea, orthopnea, paroxysmal nocturnal dyspnea, ascites, and/or peripheral edema * Clinically significant cerebrovascular disease or coronary artery disease within 6 months of screening * Jaundice, hepatitis, or known hepatobiliary disease or elevations of transaminases (ALT/AST) \>2 times upper limit of normal at screening * History of malignancy other than…