FDA Approves Sparsentan, First Medicine for Patients With FSGS

The FDA approved sparsentan (Filspari; Travere Therapeutics) for reduce proteinuria in adult and pediatric patients aged 8 years and older with focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome. With this action, sparsentan has become the first and only medicine approved by the FDA for FSGS, according to the manufacturer’s news release.¹

“Today marks a historic milestone for people living with FSGS, who for the first time have an FDA-approved medicine for this rare and devastating condition,” Eric Dube, PhD, president and CEO of Travere Therapeutics, said in the news release. “This approval reflects years of perseverance and our belief that those living with FSGS deserve better…expanding [sparsentan]’s potential reach to more than 100,000 people in the US with FSGS and [immunoglobulin A nephropathy] IgAN who need better treatment options.”¹

FSGS is a rare proteinuric kidney disorder in both children and adults defined by progressive scarring of the kidney and often leads to kidney failure. It is characterized by proteinuria, where protein leaks into the urine due to a breakdown of the normal filtration mechanism in the kidney. Once it is in the urine, protein is considered to be toxic to other parts of the kidney and is believed to contribute to further disease progression. Prior to this indication, sparsentan was FDA-approved to slow kidney function decline in adults with primary IgAN who are at risk for disease progression.¹

The approval is supported by the phase 3 DUPLEX (NCT03493685)² clinical trial, a global, randomized, multicenter, double-blind, parallel-arm, active-controlled study that assessed the efficacy and safety of sparsentan in 371 patients aged 8 to 75 years with biopsy-proven or genetic FSGS. After a 2-week washout period, patients were randomly assigned to receive either sparsentan (n = 184) or irbesartan (n = 187; Avapro; Sanofi). These were subsequently dose-titrated to the maximum dose of 800 mg or 300 mg, respectively, as patients could tolerate.²

The primary trial’s efficacy end point at the final analysis was the rate of change in estimated glomerular filtration rate (eGFR) from baseline to week 108, and those who completed the double-blind portion of the study were eligible to participate in the open-label extension of the trial.^1,2 These 2-year data were published in the New England Journal of Medicine.³

At the 36-week point, approximately 42.0% in the sparsentan group and 26.0% in the irbesartan group had partial remission of proteinuria (P = .009), which was sustained through 108 weeks. At the time of the final analysis at week 108, there were no significant between-group differences in the eGFR slope. The between-group difference in total slope (day 1 to week 108) was about 0.3 ml/min/1.73 m² of body-surface area per year (95% CI, −1.7 to 2.4), and the between-group difference in the slope from week 6 to week 108 was 0.9 ml/minute/1.73 m²/year (95% CI, −1.3 to 3.0). Further, the mean change in eGFR from baseline to week 112 was −10.4 ml/minute/1.73 m² with sparsentan compared with −12.1 ml/minute/1.73 m² with irbesartan (difference: 1.8 ml/minute/1.73 m² [95% CI, −1.4 to 4.9]).³

“Today’s approval of [sparsentan] provides nephrologists with a new FDA-approved option for patients living with FSGS,” Kirk Campbell, MD, president of the National Kidney Foundation and the C. Mahlon Kline Professor and chief of the Division of Renal-Electrolyte and Hypertension in the Perelman School of Medicine at the University of Pennsylvania, said in the news release. “For decades, treatment options have been limited, often relying on off-label therapies such as long-term steroids that can carry a significant burden for patients.”¹

In the trial, both sparsentan and irbesartan had similar safety profiles, and the frequency of adverse events (AEs) was similar in the 2 groups.³ The most common AEs reported among those treated with sparsentan are peripheral edema, hypotension (including orthostatic hypotension), hyperkalemia, dizziness, and anemia.¹

“In the DUPLEX study, [sparsentan] delivered rapid and sustained reductions in proteinuria compared to irbesartan, with particularly meaningful effects in patients without nephrotic syndrome… For patients without active nephrotic syndrome, where optimizing foundational therapy is critical, [sparsentan] represents an important new option,” concluded Campbell.¹

REFERENCES

1. Travere Therapeutics Announces Full FDA Approval of FILSPARI® (sparsentan), the First and Only Approved Medicine for FSGS. News release. Travere Therapeutics. News release. April 13, 2026. Accessed April 15, 2026. https://ir.travere.com/press-releases/news-details/2026/Travere-Therapeutics-Announces-Full-FDA-Approval-of-FILSPARI-sparsentan-the-First-and-Only-Approved-Medicine-for-FSGS/default.aspx

2. Study of Sparsentan in Patients With Primary Focal Segmental Glomerulosclerosis (FSGS) (DUPLEX). ClinicalTrials.gov identifier: NCT03493685. Updated June 12, 2025. Accessed April 15, 2026. https://clinicaltrials.gov/study/NCT03493685

3. Rheault MN, Alpers CE, Barratt J, et al. Sparsentan versus Irbesartan in Focal Segmental Glomerulosclerosis. N Engl J Med. 2023;389(26):2436-2445. doi:10.1056/NEJMoa2308550