FDA Approves Sparsentan for Focal Segmental Glomerulosclerosis

The FDA has approved sparsentan (Filspari; Travere Therapeutics) to reduce proteinuria in patients 8 years and older with focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome, a rare kidney disorder that can often lead to kidney failure.¹

Sparsentan is a first-in-class therapeutic, classified as both an angiotensin II receptor blocker and an endothelin-1 receptor antagonist.² It received an accelerated approval from the FDA in February 2023 to reduce proteinuria in immunoglobulin A (IgA) nephropathy (IgAN)³ and traditional full approval in September 2024 to slow kidney decline in patients with IgAN⁴—both times keeping its place as the only nonimmunosuppressive treatment for these indications.

This most recent approval follows the FDA’s January decision to extend the Prescription Drug User Fee Act target action date for Travere’s supplemental new drug application to April 13, 2026. The agency’s reasoning was so it could “further characterize the clinical benefit of [sparsentan]”; safety and manufacturing of the novel treatment were not questioned.⁵

“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,” said Eric Dube, PhD, president and CEO of Travere Therapeutics.¹ “This approval reflects years of perseverance and our belief that those living with FSGS deserve better. It also builds on our leadership and progress in rare kidney diseases, expanding [sparsentan]’s potential reach to more than 100,000 people in the US with FSGS and IgAN who need better treatment options. [Sparsentan] will be available for nephrologists to immediately prescribe to individuals with FSGS. We are profoundly grateful to the patients, caregivers, investigators, healthcare providers, regulators, and advocates who made this moment possible.”

The approval means that sparsentan is now the only medication approved by the FDA to treat FSGS, which is its second indication overall for a rare kidney disease, with IgAN being the other.¹

Data from the phase 3 DUPLEX trial (NCT03493685) were used to support the new indication.¹ In the randomized, multicenter, double-blind, parallel, active-control trial, 375 patients aged 8 to 75 years were enrolled and randomly assigned 1:1 to either sparsentan or irbesartan, the active control.⁶ To be included, all patients had to weigh at least 20 kg, have biopsy-proven FSGS or documentation of a genetic mutation in a podocyte protein associated with FSGS, have a urine protein/creatinine ratio of at least 1.5 g/g (170 mg/mmol) at screening, and have an estimated glomerular filtration rate (eGFR) of at least 30 mL/min/1.73 m² at screening. Women considering pregnancy also had to agree to use highly reliable contraception from 7 days before their first study dose to 90 days after their final study dose. The initial daily sparsentan dose was 400 mg, which was titrated up to the target of 800 mg daily, and the initial daily irbesartan dose was 150 mg, which was titrated up to the target of 300 mg daily.

By week 108 overall, patients treated with sparsentan had superior results in proteinuric reduction compared with the patients who received the maximum dose of irbesartan, at 46% vs 30% (P = .0299). Results trended similarly for patients who did not have nephrotic syndrome, at a 48% proteinuria reduction vs 27% (P = .0075) for those in the control group, as well as for eGFR. The mean change from baseline to week 108 in eGFR was –11.3 mL/min/1.73 m² compared with –12.4 mL/min/1.73 m².

References

1. Travere Therapeutics announces full FDA approval of Filspari (sparsentan), the first and only approved medicine for FSGS. News release. Travere Therapeutics. April 13, 2026. Accessed April 14, 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. Sparsentan. Drugbank. Accessed April 13, 2026. https://go.drugbank.com/drugs/DB12548
3. Travere Therapeutics announces FDA accelerated approval of Filspari (sparsentan), the first and only non-immunosuppressive therapy for the reduction of proteinuria in IgA nephropathy. News release. Travere Therapeutics. February 17, 2023. Accessed April 13, 2026. https://ir.travere.com/press-releases/news-details/2023/Travere-Therapeutics-Announces-FDA-Accelerated-Approval-of-FILSPARI-sparsentan-the-First-and-Only-Non-immunosuppressive-Therapy-for-the-Reduction-of-Proteinuria-in-IgA-Nephropathy-02-17-2023/default.aspx
4. Travere Therapeutics announces full FDA approval of Filspari (sparsentan), the only non-immunosuppressive treatment that significantly slows kidney function decline in IgA nephropathy. News release. Travere Therapeutics. September 5, 2024. Accessed April 13, 2026. https://ir.travere.com/press-releases/news-details/2024/Travere-Therapeutics-Announces-Full-FDA-Approval-of-FILSPARI-sparsentan-the-Only-Non-Immunosuppressive-Treatment-that-Significantly-Slows-Kidney-Function-Decline-in-IgA-Nephropathy-09-05-2024/default.aspx
5. Travere Therapeutics announces FDA extends review of sNDA for Filspari (sparsentan) in FSGS. News release. Travere Therapeutics. January 13, 2026. Accessed April 13, 2026. https://ir.travere.com/press-releases/news-details/2026/Travere-Therapeutics-Announces-FDA-Extends-Review-of-sNDA-for-FILSPARI-sparsentan-in-FSGS/default.aspx
6. Study of sparsentan in patients with primary focal segmental glomerulosclerosis (FSGS) (DUPLEX). ClinicalTrials.gov. Updated June 12, 2025. Accessed April 13, 2026. https://clinicaltrials.gov/study/NCT03493685