Confirmatory data from the phase III PROTECT study of Filspari demonstrates long-term kidney function preservation in IgA nephropathy; narrowly missing eGFR total slope endpoint versus active control, irbesartan

Filspari demonstrated long-term kidney function preservation and achieved a clinically meaningful difference in estimated glomerular filtration rate (eGFR) total and chronic slope versus irbesartan, narrowly missing statistical significance in eGFR total slope while achieving statistical significance in eGFR chronic slope for purposes of regulatory review in the EU. Filspari is currently available under accelerated approval in the U.S. The Company will engage with regulators and expects to submit a supplemental New Drug Application (sNDA) in 1H 2024 for full approval in the U.S.

PROTECT Study Results: In the PROTECT Study, a total of 404 patients with persistent proteinuria despite active angiotensin-converting enzyme (ACE) inhibitor or angiotensin-receptor blocker (ARB) treatment, were randomized 1:1 to receive once daily oral doses of either Filspari or irbesartan, the active control. eGFR total and chronic slope are the secondary confirmatory endpoints for the U.S. and the EU, respectively. All topline efficacy endpoints favored Filspari as compared to irbesartan.

Preliminary review of the safety results through 110 weeks of treatment indicates Filspari was generally well-tolerated and the overall safety profile in the study has been consistent between treatment groups.

“The confirmatory results of the PROTECT Study demonstrated treatment with Filspari resulted in the largest sustained reduction in proteinuria and one of the slowest rates of eGFR decline in a controlled study of IgAN patients, to date. This outcome is incredibly important for IgAN patients, who face the risk of progression to kidney failure in their lifetime. We’re proud of the high bar we’ve set in delivering the only head-to-head study in IgAN, which compares Filspari against a maximally tolerated dose of irbesartan,” said Eric Dube, Ph.D., president and CEO of Travere Therapeutics. “Since our accelerated approval, we’ve continued to hear inspiring stories of the impact this medicine is having on people living with IgAN. While eGFR total slope narrowly missed statistical significance, the overall evidence from PROTECT suggests potential long-term benefit of Filspari as a foundational treatment for patients with IgAN. Filspari has the potential to transform the treatment paradigm in this rare kidney disease, and we look forward to engaging with FDA to discuss our planned sNDA submission.”

“In clinical practice, nephrologists managing IgA nephropathy patients work to reduce proteinuria as much as possible because this leads to a slower rate of decline in kidney function. Our main goal is to avoid the need for dialysis or kidney transplantation. The results of the PROTECT trial clearly show that when compared to an active control of maximally tolerated irbesartan, Filspari delivered a rapid and sustained antiproteinuric effect over two years along with a clinically meaningful attenuation in the decline of eGFR that should preserve long-term kidney function in patients with IgAN,” said Brad Rovin, M.D., Medical Director at Ohio State University Center for Clinical Research Management, Director of the Division for Nephrology, and steering committee member for the PROTECT clinical trial. “Because Filspari is not an immunosuppressive agent and has a safety profile similar to irbesartan, it has the potential to become long-term foundational therapy for IgAN that could be combined with other therapies as appropriate. This is a promising outcome for patients suffering from IgAN who are at risk for progressive kidney failure.”