Filspari (sparsentan) received full FDA approval on April 13, 2026, becoming the first and only FDA-approved medicine for treating focal segmental glomerulosclerosis (FSGS) without nephrotic syndrome13
The approval is indicated for adults and pediatric patients aged 8 years and older with FSGS without nephrotic syndrome12
In the Phase 3 DUPLEX Study, Filspari demonstrated a statistically significant 46% reduction in proteinuria from baseline to Week 108 compared to 30% for irbesartan in the overall population, and 48% versus 27% in patients without nephrotic syndrome34
The U.S. addressable population for FSGS without nephrotic syndrome is estimated at more than 30,000 individuals, expanding Filspari's total addressable population across both indications (FSGS and IgA nephropathy) to more than 100,000 patients13
Filspari requires enrollment in the FILSPARI REMS program due to risks of hepatotoxicity and embryo-fetal toxicity, with prescribers, patients, and pharmacies needing to comply with program requirements3
The drug showed a modest eGFR benefit with a treatment difference of 1.1 mL/min/1.73 m² and was generally well tolerated with a safety profile comparable to irbesartan34
This approval marks Filspari's expansion beyond its existing indication for IgA nephropathy into a second rare kidney disease13
Sources:
1. https://www.investing.com/news/company-news/fda-approves-filspari-for-fsgs-traveres-second-indication-93CH-4611540
2. https://www.pharmaceutical-technology.com/news/travere-therapeutics-fda-approval-sparsentan/
3. https://www.businesswire.com/news/home/20260413839195/en/Travere-Therapeutics-Announces-Full-FDA-Approval-of-FILSPARI-sparsentan-the-First-and-Only-Approved-Medicine-for-FSGS
4. https://www.stocktitan.net/sec-filings/TVTX/8-k-travere-therapeutics-inc-reports-material-event-0273863512ca.html