Travere Therapeutics, Inc. (TVTX) is having one of those weeks. The biotech company's stock took a hit Tuesday after announcing that the FDA needs more time to review its application for Filspari (sparsentan) as a treatment for focal segmental glomerulosclerosis, or FSGS if you prefer not getting tongue-tied.
The timing feels particularly rough given that the broader market wasn't exactly providing cover, with the S&P 500 down 0.16% and the Nasdaq barely positive at 0.02%.
The FDA Wants Another Look
Here's what happened: The U.S. Food and Drug Administration extended the review timeline for Travere's supplemental New Drug Application for Filspari in FSGS. The new Prescription Drug User Fee Act target action date is now April 13, giving the agency additional time to evaluate the drug's clinical benefit.
This extension comes after the FDA requested more information to better understand how well Filspari actually works. Travere recently submitted its responses to those questions. The good news, if you can call it that, is the FDA isn't asking for additional safety data or manufacturing information. They just want to be really, really sure about the clinical benefits before giving this one the green light.
The stakes here are significant. If approved, Filspari would become the first medication specifically indicated for FSGS, a rare and serious kidney disorder characterized by proteinuria that progressively destroys kidney function and can lead to complete kidney failure. That's a big deal for patients who currently have limited treatment options.
Filspari isn't exactly unproven territory, though. The drug already has full approval from both the FDA and European Medicines Agency to slow kidney function decline in adults with IgA nephropathy, a different kidney condition. So there's an established track record, just not yet for this particular indication.
Financial Results Provide Some Bright Spots
Amid the regulatory uncertainty, Travere dropped some financial updates on Monday that weren't all bad news. The company expects U.S. net product sales for the fourth quarter of 2025 to land at approximately $127 million. That's actual revenue, not just promises and projections.
Even better, Travere picked up a $40 million milestone payment from its collaborator CSL Vifor, triggered by market access achievements. That's the kind of cash infusion that helps keep the lights on while you wait for regulatory decisions.
The company also shared progress on another front: following manufacturing process optimization throughout 2025, Travere is ready to restart the pivotal Phase 3 HARMONY Study of pegtibatinase in classical homocystinuria during the first quarter of 2026. So there's more than one iron in the fire here.