Travere Therapeutics TVTX announced that the FDA granted full approval to its oral non-immunosuppressive drug Filspari (sparsentan) in IgA nephropathy (IgAN) indication, a rare progressive kidney disease.

Following this decision, Filspari is approved for slowing kidney function decline in adults with primary IgAN who are at risk of disease progression. The FDA’s decision also makes Filspari the only non-immunosuppressive medication in the IgAN space.

Filspari was initially granted accelerated approval in February 2023 to reduce proteinuria (protein in the urine) in adults with primary IgAN who are at risk of rapid disease progression.

Travere’s shares were up nearly 11% on Friday after the announcement. Investors were impressed with Filspari’s label expansion as it expanded the drug’s total addressable patient population. Before full approval, the drug was approved only to treat patients at higher risk of disease progression. The drug is approved to treat patients who are at risk of disease progression — including individuals at low risk of disease progression.

Year to date, the stock has increased 22.1% against the industry’s 2.8% fall.

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Did Travere’s Filspari Meet Study Goals?

The approval is based on data from the pivotal phase III PROTECT study, which evaluated Filspari against irbesartan head-to-head in adults with primary IgAN for more than two years. Data from the study showed that treatment with Filspari demonstrated long-term kidney function preservation in IgAN patients compared with irbesartan.

The above data is based on a modified intention to treat (ITT) analysis, which included data from all patients, even those who stopped treatment. This approach was also favored by the FDA.

We remind investors that Travere Therapeutics reported the PROTECT study last year in September, wherein the study results narrowly missed out on failing to meet the key secondary endpoint of the estimated glomerular filtration rate (eGFR) total slope. This endpoint is required to be achieved for a regulatory review in the United States. The study did meet the other confirmatory secondary endpoint of the eGFR chronic slope, which is necessary for regulatory purposes in the European Union.

The modified analysis of data helped the PROTECT study achieve the eGFR total slope endpoint. Patients who received Filspari achieved a mean eGFR slope of -3.0 mL/min/1.73 m²/year from baseline to Week 110 compared with -4.2 mL/min/1.73 m²/year for irbesartan.

Monitoring For Liver Diseases & Child Defects

Despite the full approval, the drug has been added to the FDA’s Risk Evaluation and Mitigation Strategies (REMS) program. Doctors must monitor patients' liver enzymes before starting treatment, every month for the first year and then every three months during treatment. Travere is planning to engage in discussions with the FDA to remove Filspari from the REMS program eventually.

Filspari also comes with a boxed warning for severe birth defects in case the drug is taken during pregnancy.

Other Players in the IgAN Space

Apart from TVTX, the space is dominated by CalliditasTherapeutics CALT, which markets Tarpeyo, the first fully-approved FDA drug for IgAN based on a measure of kidney function. The approval history of CALT’s Tarpeyo is similar to Filspari — the drug was granted full approval by the FDA in December 2023 for an indication similar to Filspari.

In July, Calliditas announced that it had secured full marketing authorization for Tarpeyo in IgAN indication. The drug is being marketed by its commercial partner, STADA Arzneimittel AG, under the trade name Kinpeygo.

Last month, pharma giant Novartis NVS also entered the IgAN market after the FDA granted accelerated approval to Fabhalta for reducing proteinuria in adults with primary IgAN at risk of rapid disease progression. This approval marks the first FDA nod for Novartis’ renal pipeline. Fabhalta was initially approved by the FDA in paroxysmal nocturnal hemoglobinuria (PNH) indication.

Apart from Fabhalta, Novartis is also developing other candidates in IgAN indication. The company’s acquisition of Chinook Therapeutics last year added late-stage candidates atrasentan and zigakibart to its pipeline, both of which are being developed in IgAN indication. An FDA filing is currently under review seeking approval for atrasentan in adults with IgAN.

Travere Therapeutics, Inc. Price

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TVTX’s Zacks Rank

Travere currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank stocks here.

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