Full FDA approval for Filspari (sparsentan), the only non-immunosuppressive treatment that significantly slows kidney function decline in IgA nephropathy.- Travere Therapeutics

Filspari was granted accelerated approval in February 2023 based on the surrogate marker of proteinuria. Full approval is based on positive long-term confirmatory results from the PROTECT Study demonstrating that Filspari significantly slowed kidney function decline over two years compared to irbesartan.

“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, Ph.D., president and chief executive officer of Travere Therapeutics. “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.

Filspari is the only oral, once-daily, non-immunosuppressive medication that directly targets glomerular injury in the kidney by blocking two critical pathways of IgAN disease progression (endothelin-1 and angiotensin II).

The two-year efficacy data contained in the FDA-approved label is a modified intention to treat (ITT) analysis, and as preferred by the FDA, evaluates data from all patients regardless of treatment discontinuation. In the final analysis of the 404 randomized patients, Filspari significantly reduced the rate of decline in kidney function from baseline to Week 110 compared to irbesartan. In the ITT analysis included in the label, the mean eGFR slope from baseline to Week 110 was -3.0 mL/min/1.73 m2/year for Filspari and -4.2 mL/min/1.73 m2/year for irbesartan, corresponding to a statistically significant treatment effect of 1.2 mL/ min/1.73 m2/year (p=0.0168). The positive treatment effects on proteinuria compared to the active control irbesartan that were observed at Week 36 were durable out to the two-year measurement period.

Additional results from the PROTECT Study demonstrated the benefit of Filspari on absolute eGFR accrued 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.

Results from 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. Following engagement with the FDA, the Company expects to submit an sNDA for a potential modification to the liver-monitoring REMS.