FDA Approves Travere’s Filspari for Rare Kidney Disease IgA Nephropathy

The US Food and Drug Administration (FDA) has granted full approval to Travere Therapeutics' Filspari (sparsentan) for the purpose of slowing kidney function decline in adults suffering from primary IgA nephropathy (IgAN).

IgAN affects up to 150,000 individuals in the United States. This condition occurs when Immunoglobulin A (IgA) accumulates in the kidneys, causing damage. This impairment affects the kidneys' filtering capabilities, resulting in the leakage of substances such as blood and protein into the urine.

Initially approved in February 2023 under the FDA’s accelerated approvals pathway, Filspari was indicated for primary IgAN patients at risk of rapid disease progression. This medication is a once-daily, oral non-immunosuppressive treatment that aims at directly targeting glomerular injury in the kidney by blocking two critical pathways involved in the progression of IgAN.

The FDA’s recent decision expands the drug’s indication to include all patients at risk of disease progression. This approval was backed by positive long-term results from the phase 3 PROTECT study. In this study, Filspari demonstrated a significant slowdown in kidney function decline over a two-year period when compared to irbesartan.

The study's findings revealed that the positive effects of Filspari on proteinuria (presence of protein in the urine) observed at week 36 were sustained up to the two-year mark. Additionally, the results indicated that Filspari was well tolerated, with a “clearly defined” safety profile that has remained consistent across all the clinical trials conducted thus far, according to Travere.

Eric Dube, the president and CEO of Travere, stated: “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.”

This announcement closely follows the FDA’s accelerated approval, just a month prior, of Novartis’ Fabhalta (iptacopan) for reducing proteinuria in adults with IgAN at risk of rapid disease progression. Fabhalta is an oral factor B inhibitor targeting the alternative complement pathway and is already approved in the United States for the treatment of the rare blood disorder paroxysmal nocturnal haemoglobinuria.