Travere Therapeutics won full approval for Filspari, which treats a rare autoimmune disease that affects the kidneys.
Filspari, also known as sparsentan, received an accelerated approval in 2023 for patients with IgA nephropathy (IgAN) who are at risk of rapid progression, measured by proteinuria or elevated protein levels in the urine. Travere announced the full approval on Thursday. In addition to converting the label to a full approval, regulators also broadened the label to include patients at risk of progression, regardless of a specific proteinuria level.
Travere’s Chief Commercial Officer Peter Heerma said on a Thursday call with investors that the company will aim to treat patients earlier, potentially increasing their eligible patient population from 30,000 to 50,000 following accelerated approval to now more than 70,000 people.
Jula InrigTravere’s stock $TVTX was up 10.4% on Friday.
“The definition of risk for a patient is changing,” Travere Chief Medical Officer Jula Inrig told Endpoints News ahead of the full approval. “Most of the patients with IGA nephropathy will face kidney failure in their lifetime unless we get their proteinuria down to close to normal.”
The full approval comes months after Travere announced that it narrowly missed a key confirmatory endpoint, a measure of kidney function known as estimated glomerular filtration rate (eGFR) total slope. However, a Travere spokesperson said Friday that the FDA preferred a modified analysis that handled missing data “slightly differently,” resulting in a statistically significant treatment effect.
Travere said more patients in the comparator arm discontinued treatment early or required rescue immunosuppression, leading to “a favorable bias” toward the comparator in the prior analysis.
“This is about the FDA learning as they’re going along. You can see for other trials they might have slightly different measures of how they measure kidney function,” Inrig told Endpoints ahead of the FDA decision. “The data show the benefit on preserving kidney function for Filspari. That’s the important thing.”
Filspari competes with Calliditas’ Tarpeyo, which won full approval for IgAN in December, and Novartis’ Fabhalta, which was given an accelerated approval last month.
Eric DubeInrig said Filspari stands out as an option that is not immunosuppressive. CEO Eric Dube said on the company’s second-quarter earnings call that Travere had received 2,484 patient start forms since the drug launched in February 2023. Filspari generated $29.2 million in 2023.
Filspari’s label includes boxed warnings for liver toxicity and potential birth defects if used during pregnancy, though Travere said it has not seen any cases of liver toxicity or drug-induced liver damage. Dube noted that risk mitigation strategies are in place for embryo-fetal effects across the entire class of endothelin receptor agonists. The company said Thursday that it will ask the FDA to modify the label’s liver-monitoring recommendations.