FDA Approves Filspari for Adults with IgA Nephropathy

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The FDA has approved Travere Therapeutics’ Filspari (sparsentan) to treat adults with IgA nephropathy (IgAN). According to the company, Filspari is the first non-immunosuppressive treatment approved by the FDA with the ability to significantly slow kidney function decline in adults with IgAN. The regulatory action was based on positive results from the PROJECT study, which found that Filspari outperformed irbesartan in preserving kidney function over two years.¹

“We know that most people living with IgAN are at risk of disease progression and are seeking a safe, effective and convenient treatment option that can help preserve their kidney function. Full approval now enables physicians to confidently prescribe Filspari more broadly as a once-daily, oral, non-immunosuppressive treatment, that can provide superior preservation of kidney function and replace current standard of care,” said Eric Dube, PhD, president, CEO, Travere Therapeutics, in a press release. “With KDIGO’s recent draft guidelines recommending Filspari as a foundational kidney-targeted therapy and lowering the targeted proteinuria level for all IgAN patients to under 0.5 g/day or 0.3 g/day—Filspari is well positioned to become foundational care for IgAN as the treatment landscape evolves. We are grateful to the patients, caregivers, clinical trial investigators, healthcare providers, and advocates who have worked alongside our team at Travere for so many years to help raise the bar on protecting and preserving kidney health for those living with rare kidney disease.”

The Phase III global, randomized, multicenter, double-blind, parallel-arm, active-controlled PROTECT clinical trial evaluated the safety and efficacy of 400 mg of Filspari compared to 300 mg of irbesartan. The trial included 404 individuals over 18 years of age with IgAN and persistent proteinuria despite receiving at least 50% of max label dose and maximally tolerated angiotensin converting enzyme inhibitor or angiotensin II receptor blocker (ARB) therapy. The primary endpoint of the study was change from baseline in urine protein/creatinine ratio at week 36, with the secondary endpoint of the rate of change in eGFR over a 110-week period following initiation of randomized therapy.

Results demonstrated that after 36 weeks, Filspari achieved a mean reduction in proteinuria from baseline of 49.8%, compared to a mean reduction in proteinuria from baseline of 15.1% in patients treated with irbesartan. Additionally, the benefit of the treatment on absolute eGFR was found to accrue over time and by week 110, resulted in a 3.8 mL/min/1.73 m2 difference in the mean change from baseline between Filspari and irbesartan.

Common adverse events (AEs) of Filspari include hyperkalemia, hypotension, peripheral edema, dizziness, anemia, and acute kidney injury. Travere warns against co-administering Filspari with ARBs, ERAs, or aliskiren due to increased risks of hypotension, syncope, hyperkalemia, and changes in renal function.¹

According to the IGA Nephropathy Foundation, it is estimated that IgA nephropathy affects roughly 1 in 100,000 people in the United States and Europe, while in Japan and China, estimates suggest that it could be as common as one in 10,000 people.²

“As a physician who has dedicated my career to treating patients with glomerular diseases, I believe the full approval of Filspari for IgAN provides us with a critically important tool for patient management,” said Brad Rovin, MD, medical director, The Ohio State University Center for Clinical Research Management, director, division of nephrology, steering committee member for the PROTECT Study, in the press release. “This approval should facilitate patient access to a medication that targets injury directly in the kidney, reduces proteinuria, even to the point of complete remission in some patients, and is more effective than current standard-of-care treatment in preserving kidney function over time. This is a very exciting milestone in the evolution of treating IgAN.”

References

1. Travere Therapeutics Announces Full FDA Approval of FILSPARI® (sparsentan), the Only Non-Immunosuppressive Treatment that Significantly Slows Kidney Function Decline in IgA Nephropathy. Travere. September 5, 2024. Accessed September 9, 2024. https://ir.travere.com/news-releases/news-release-details/travere-therapeutics-announces-full-fda-approval-filsparir

2. IgA Nephropathy. IGA Nephropathy Foundation. Accessed September 9, 2024. https://igan.org/faq/#:~:text=While%20exact%20numbers%20can%20be,the%20United%20States%20and%20Europe.