FDA Approves FILSPARI for FSGS After 46% Proteinuria Drop, Ligand to Earn 9%
Travere Therapeutics received FDA approval for FILSPARI in focal segmental glomerulosclerosis patients aged eight and older as the first and only approved therapy for this rare kidney disease. Ligand will earn a 9% royalty on FILSPARI sales after Phase 3 showed a 46% proteinuria reduction versus 30% for irbesartan.
1. FDA Approval of FILSPARI for FSGS
Travere Therapeutics received full FDA approval on April 14, 2026 for FILSPARI (sparsentan) to treat focal segmental glomerulosclerosis in patients aged eight and older, establishing it as the first and only therapy approved for this rare kidney disorder in both adults and children.
2. Phase 3 DUPLEX Study Outcomes
In the global Phase 3 DUPLEX study involving 371 patients, FILSPARI achieved a 46% reduction in proteinuria from baseline to Week 108 compared to a 30% reduction with maximum labeled-dose irbesartan (p=0.0299). Among patients without nephrotic syndrome, FILSPARI delivered a 48% proteinuria reduction versus 27% for irbesartan (p=0.0075) and demonstrated a 1.1 mL/min/1.73 m2 eGFR benefit.
3. Royalty and Market Impact for Ligand
Ligand Pharmaceuticals is entitled to a 9% royalty on worldwide net sales of FILSPARI. With more than 30,000 estimated U.S. FSGS patients without nephrotic syndrome, this approval is poised to drive meaningful royalty growth for Ligand in 2026 and beyond.