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IgAN – Retrophin, Inc.

Retrophin, Inc. is conducting a clinical study of Immunoglobulin A Nephropathy (IgAN) in which you may be interested. To determine if you are eligible, please go to

This is a randomized, multicenter, double-blind, parallel-group, active-control study of oral sparsentan in patients with IgAN compared to active control, irbesartan. The investigational drug (sparsentan) is a dual-acting endothelin receptor antagonist and angiotensin receptor blocker.

The purpose of the study is to evaluate the potential benefit of sparsentan on kidney function by analyzing change in proteinuria (protein in urine) and estimated glomerular filtration rate (eGFR) as compared to current standard-of-care treatment. Our investigational approach is to lower proteinuria levels with sparsentan and slow the decline of kidney function in patients with IgAN.

Approximately 280 patients aged ≥18 years will be enrolled in the study globally.

Patients enrolled in the PROTECT study (Protocol 021IGAN17001) will be those at high risk of progressing to renal failure. They will be randomly assigned a 1:1 ratio to either sparsentan or irbesartan, as the active control (current standard treatment) at the Day 1 (Randomization) visit. Study medication (sparsentan and irbesartan) will be administered as a single oral morning dose.

The primary endpoint is change in proteinuria (urine protein/creatinine ratio) from baseline to Week 36 in sparsentan-treated patients as compared to irbesartan-treated patients.

For more study information, please click here or go to study identifier: NCT03762850.

Key Inclusion Criteria:

  •  Age 18 years or older at screening
  • Biopsy-proven 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
  • Women of child-bearing potential must agree to contraception

Key Exclusion Criteria:

  • 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)
  • The patient has 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 adequately treated basal cell or squamous cell skin cancer or cervical carcinoma within the past 2 years
  • Hematocrit value <27% or hemoglobin value <9 g/dL at Screening
  • Potassium >5.5 mEq/L at Screening
  • History of alcohol of illicit drug use disorder
  • History of serious side effect or allergic response to any angiotensin II antagonist or endothelin receptor antagonist, including sparsentan or irbesartan, or has a hypersensitivity to any of the excipients in the study medications
  • For female: Pregnancy, or planning to become pregnant during the course of the study, or breastfeeding
  • Participation in a study of another investigational product within 28 days of screening