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FSGS – Retrophin, Inc.

Retrophin, Inc. is conducting a clinical study of primary and genetic focal segmental glomerulosclerosis (FSGS) in which you may be interested. To determine if you are eligible, please go to

This is a Phase 3, randomized, multicenter, double-blind, parallel, active-control study of oral sparsentan in patients with FSGS 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 FSGS.

Approximately 300 patients aged 8 to 75 years (inclusive) will be enrolled in the study. The study will be conducted in approximately 300 study centers, globally.

If applicable, patients who meet eligibility criteria will require washout from renin-angiotensin-aldosterone system (RAAS) blockers prior to their first dose of study drug. Patients will be randomly assigned in a 1:1 ratio to receive either sparsentan or active control (irbesartan).

For more study information, please click here or go to study identifier: NCT03493685.

Key Inclusion Criteria:

  • 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) or documentation of a genetic mutation in a podocyte protein associated with FSGS
  • Urine protein/creatinine (UP/C) ≥1.5 g/g at screening
  • eGFR ≥30 mL/min/1.73 m2 at screening.
  • Women of child-bearing potential must agree to contraception

Key Exclusion Criteria:

  • 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
  • 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 disease
  • Positive at screening for the human immunodeficiency virus (HIV) or markers indicating acute or chronic hepatitis B infection or hepatitis C infection
  • History of malignancy other than adequately treated basal cell or squamous cell skin cancer or cervical carcinoma within the past 2 years
  • Screening hematocrit value <27% or hemoglobin value <9 g/dL
  • Screening potassium value of >5.5 mEq/L
  • Extreme obesity (ie, ≥18 years of age with a body mass index (BMI) >40, or is <18 years of age with a BMI in the 99th percentile plus 5 units at screening, in whom there is a causal relationship between obesity and the development of
  • FSGS
  • History of alcohol or illicit drug use disorder
  • History of serious side effect or allergic response to any angiotensin II antagonist or endothelin receptor antagonist
  • Female patient is pregnant, plans to become pregnant during the course of the study, or is breastfeeding