FDA has fully approved Travere’s Filspari for focal segmental glomerulosclerosis, making it the first approved therapy for the rare kidney disease and expanding its role beyond IgA nephropathy.
FDA fully approved Filspari (sparsentan) for focal segmental glomerulosclerosis, (FSGS), making it the first and only approved treatment for the rare kidney disease.
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The approval extends Travere Therapeutics' reach and moves Filspari into a second proteinuric kidney condition beyond its
"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, Ph.D., president and CEO of Travere Therapeutics. "This approval reflects years of perseverance and our belief that those living with FSGS deserve better."
FSGS is a rare proteinuric kidney disorder characterized by progressive scarring of the kidney's glomeruli that often leads to kidney failure if left untreated.1 Protein leaks into the urine due to a breakdown in normal kidney filtration, and that protein is believed to be toxic to other parts of the kidney, driving further disease progression.1 Until now, patients have largely relied on off-label therapies including long-term steroids, which carry significant side effect burdens.
Filspari is now indicated to reduce proteinuria in adult and pediatric patients aged 8 and older with FSGS without nephrotic syndrome.1 The company estimates the addressable U.S. population at more than 30,000 individuals with FSGS who do not have nephrotic syndrome, and says the combined population of FSGS and IgAN patients who could benefit from Filspari exceeds 100,000 in the U.S.
Josh Tarnoff, CEO of NephCure, called the approval "a life-changing moment for patients and families who have waited far too long," adding: "When science and community unite with purpose, we can redefine what's possible in rare disease care and bring light to those who have long lived in uncertainty."
Filspari works through a dual mechanism targeting endothelin A and angiotensin II receptors, two pathways believed to drive the inflammation and scarring that characterize FSGS without nephrotic syndrome.1
The drug is expected to be immediately available for nephrologists to prescribe.1
The approval is based on results from the Phase III Duplex Study, the largest interventional study ever conducted in FSGS, which enrolled 371 patients aged 8 to 75 with biopsy-proven or genetic FSGS across a global, randomized, double-blind trial.2 Patients were randomized to receive either Filspari or irbesartan at maximum labeled doses.
In the overall study population, patients treated with Filspari experienced a statistically significant 46% reduction in proteinuria from baseline to week 108, compared to 30% for irbesartan.2
In the subgroup without nephrotic syndrome, the approved population, results were even stronger with a 48% reduction using Filspari versus 27% with irbesartan, also statistically significant.2
Filspari -treated patients without nephrotic syndrome also demonstrated a modest benefit in eGFR, a measure of kidney function. The safety profile was generally comparable to irbesartan across both adult and pediatric patients. Two-year results were published in the New England Journal of Medicine.
Kirk Campbell, M.D., president of the National Kidney Foundation, said: "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. In the Duplex Study, Filspari delivered rapid and sustained reductions in proteinuria compared to irbesartan, with particularly meaningful effects in patients without nephrotic syndrome."
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