The FDA expanded Travere Therapeutics’ label for Filspari (sparsentan), approving it as the first and only fully approved therapy for focal segmental glomerulosclerosis (FSGS). The decision adds a second major market for the company after earlier approvals in IgA nephropathy (IgAN), with regulators validating proteinuria reduction as a surrogate endpoint in the FSGS review package. Travere’s approval covers children and adults age 8 and older who do not have nephrotic syndrome, an exclusion that caught some analysts by surprise but still materially broadens the therapy’s addressable population. The company’s shares surged on the news, and analysts are positioning the drug for potential blockbuster-scale revenue across both kidney indications. With surrogate endpoint acceptance central to the label expansion, the FDA action also reinforces the pathway used in other proteinuria-led nephrology programs where direct clinical endpoints may be slower to demonstrate.