FDA Grants Full Approval to Travere's IgAN Drug Filspari

Travere Therapeutics has received traditional approval from the FDA for its drug Filspari (sparsentan) to treat primary IgA nephropathy (IgAN). This approval broadens Filspari's usage, now allowing it to be prescribed to adult patients at risk of disease progression without the previous limitation of needing a specific urinary protein level. Filspari distinguishes itself as the only oral, once-daily, non-immunosuppressive option aimed at treating glomerular injury in the kidneys.

Travere’s CEO, Eric Dube, emphasized that this full approval enables physicians to prescribe Filspari more broadly, enhancing the preservation of kidney function and potentially replacing the current standard treatments. He highlighted Filspari's potential to become a cornerstone in IgAN care as treatment paradigms evolve.

Jefferies analyst Maury Raycroft noted that the timing of Filspari’s approval aligns well with the new draft guidance from Kidney Disease Improving Global Outcomes (KDIGO), which was issued on August 30. This guidance lowers the urine protein-creatinine ratio (UPCR) threshold for at-risk patients and raises treatment goals. Raycroft pointed out that Filspari is one of the few treatments that can meet these new KDIGO guidelines, addressing both immune and inflammatory drivers of IgAN as well as general drivers of chronic kidney disease.

Filspari operates as a small molecule blocker targeting the endothelin and angiotensin II receptors, both implicated in the pathogenesis of IgAN. Despite its benefits, Filspari carries a boxed warning for potential hepatotoxicity and embryo-fetal toxicity and is available only through a restricted program designed to mitigate these risks.

Initially, the FDA granted Filspari accelerated approval in February 2023 based on proteinuria data from the Phase III PROTECT study. This study demonstrated that Filspari could reduce urine protein levels significantly more than Avapro (irbesartan), which served as the active control. The PROTECT study continued as a confirmatory trial, although it narrowly missed its primary endpoint related to the estimated glomerular filtration rate (eGFR). Still, Travere remains optimistic, citing Filspari’s benefits in reducing proteinuria and slowing eGFR decline.

In the latest announcement, Travere highlighted that Filspari significantly slows kidney function decline. After 110 weeks of treatment, patients on Filspari showed a mean eGFR slope of –3.0 mL/min/1.73m²/year, compared to –4.2 mL/min/1.73m²/year for those on Avapro. This difference was statistically significant, with a p-value of 0.0168. Additionally, long-term data from the PROTECT study indicated that the benefits observed in proteinuria reduction persisted through 110 weeks.

Travere faces competition in the IgAN market from Calliditas Therapeutics and Novartis. Calliditas received full approval for its drug Tarpeyo (budesonide) in December 2023, while Novartis was granted accelerated approval for its treatment Fabhalta (iptacopan) last month.

How to obtain the latest research advancements in the field of biopharmaceuticals?

In the Synapse database, you can keep abreast of the latest research and development advances in drugs, targets, indications, organizations, etc., anywhere and anytime, on a daily or weekly basis. Click on the image below to embark on a brand new journey of drug discovery!