FDA approves sparsentan for pediatric FSGS

The FDA has granted full approval to sparsentan (Filspari) for the treatment of focal segmental glomerulosclerosis (FSGS), establishing the first pharmacologic therapy specifically indicated for a disease that has long confronted pediatric nephrologists and the pediatricians who first encounter it without an approved option.

Announced on April 13, 2026, the approval, which was awarded to Travere Therapeutics, indicates sparsentan for pediatric patients 8 years and older with FSGS without nephrotic syndrome.

“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 chief executive officer of Travere Therapeutics. “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 Filspari’s potential reach to more than 100,000 people in the US with FSGS and [immunoglobulin A] nephropathy who need better treatment options. Filspari will be available for nephrologists to immediately prescribe to individuals with FSGS.”

FSGS is a rare kidney disorder affecting children and adults, characterized by proteinuria due to scarring of the glomeruli. The disease can lead to kidney failure, and affected patients often develop edema, low blood albumin, abnormal lipid profiles, and hypertension. According to recent estimates, FSGS accounts for approximately 12% of pediatric cases of kidney failure.

Pediatric Data From DUPLEX

A subgroup analysis of the phase 3 DUPLEX trial presented at ASN Kidney Week 2025 offered specific insight into the effects of the agent for pediatric practitioners. The pediatric subgroup included 35 patients younger than 18 years, with 16 treated with sparsentan (median age, 14.5 years) and 19 treated with irbesartan (median age, 14.0 years).

By week 108, sparsentan produced a mean 39.5% reduction in urine protein-to-creatinine ratio compared with 24.9% with irbesartan. Complete remission of proteinuria was achieved in 12.5% of sparsentan-treated patients vs 5.3% with irbesartan, while partial remission was observed in 56.3% vs 36.8%, respectively.

Fewer pediatric patients receiving sparsentan progressed to the composite kidney end point, comprising 40% or greater eGFR decline, kidney failure, or death, compared with irbesartan, consistent with renal protective trends observed in the overall DUPLEX population. No patients in the sparsentan arm discontinued therapy due to adverse events compared with 2 patients (10.5%) in the irbesartan group.

Clinical Context for Pediatricians

Until now, management of pediatric FSGS has relied on off-label immunosuppressive agents, including corticosteroids and calcineurin inhibitors, which carry significant toxicity profiles and are ineffective in a substantial proportion of steroid-resistant patients.

The approval was supported by DUPLEX, the phase 3 trial, and the phase 2 DUET study, each of which enrolled patients as young as 8 years. The DUET study’s age floor is notable: patients aged 8 to 75 years with biopsy-proven FSGS, eGFR greater than 30 mL/min/1.73 m², and a urinary protein-to-creatinine ratio ≥1.0 g/g were eligible, with sparsentan demonstrating significantly greater proteinuria reduction vs irbesartan at 8 weeks.

References:

1. Travere Therapeutics. Travere Therapeutics Announces Full FDA Approval of FILSPARI® (sparsentan), the First and Only Approved Medicine for FSGS. Travere.com. Published April 13, 2026. Accessed April 13, 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. Campbell P. Understanding Sparsentan in Pediatric FSGS, With Michelle Rheault, MD. Hcplive.com. Published November 8, 2025. Accessed April 13, 2026. https://www.hcplive.com/view/understanding-sparsentan-in-pediatric-fsgs-with-michelle-rheault-md

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

4. Trachtman H, Nelson P, Adler S, et al. DUET: A Phase 2 Study Evaluating the Efficacy and Safety of Sparsentan in Patients with FSGS. J Am Soc Nephrol. 2018;29(11):2745-2754. doi:10.1681/ASN.2018010091