FDA Grants Accelerated Approval to Travere Filspari to treat Reduce Proteinuria in IgA Nephropathy

Rare Daily Staff

The U.S. Food and Drug Administration granted accelerated approval to Travere Therapeutics for Filspari to reduce proteinuria in adults with primary IgA neuropathy.

It is the first and only non-immunosuppressive therapy approved to treat the condition.

IgA nephropathy (IgAN), also called Berger’s disease, is a rare progressive kidney disease characterized by the buildup of immunoglobulin A (IgA), a protein that helps the body fight infections, in the kidneys. The deposits of IgA cause a breakdown of the normal filtering mechanisms in the kidney, leading to blood in the urine, protein in the urine, and a progressive loss of kidney function. Other symptoms of IgAN may include swelling and high blood pressure.

Filspari is a once-daily, oral medication designed to selectively target two critical pathways in the disease progression of IgAN. It is indicated to reduce proteinuria in adults with primary IgAN at risk of rapid disease progression.

The agency granted accelerated approval to Filspari based on reduction in proteinuria. It has not been established whether Filspari slows kidney function decline in patients with IgAN. The continued approval of Filspari may be contingent upon confirmation of a clinical benefit in the ongoing phase 3 PROTECT study, which is designed to demonstrate whether Filspari slows kidney function decline. Topline results from the two-year confirmatory endpoints in the PROTECT study are expected in the fourth quarter of 2023 and are intended to support traditional approval of Filspari.

“The accelerated approval of Filspari is a significant milestone on our path to advancing a transformative treatment for the IgA nephropathy community,” said Eric Dube, president and CEO of Travere Therapeutics. “As a first-of-its-kind, non-immunosuppressive therapy, we believe Filspari has the potential to ultimately become the new standard of care for IgA nephropathy and offer hope to those living with this condition who until now have had few treatment options.”

In August 2021, the company announced positive topline interim results that were based on the pre-specified, primary analyses set which showed that after 36 weeks of treatment, patients receiving Filspari achieved a mean reduction in proteinuria from baseline of 49.8 percent, compared to a mean reduction in proteinuria from baseline of 15.1 percent for irbesartan-treated patients.

Results from the interim assessment in the PROTECT study showed that Filspari was well tolerated with a clearly defined safety profile that has been consistent across all clinical trials conducted to date. In PROTECT, the most common adverse reactions are peripheral edema, hypotension (including orthostatic hypotension), dizziness, hyperkalemia, and anemia. Because of the risks of liver injury and birth defects, Filspari has a boxed warning and is available only through a Risk Evaluation and Mitigation Strategy approved by the FDA.

In the second half of 2023, the company together with its collaborator CSL Vifor, anticipates a review decision by the European Medicines Agency on the potential approval of the Conditional Marketing Authorization application for Filspari for the treatment of IgAN in Europe.

Photo: Eric Dube, president and CEO of Travere Therapeutics