FDA Approves Sparsentan as First FSGS Treatment

Expanded indication supported by mixed bag of trial data

Apr. 14, 2026 at 9:22pm

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A detailed, translucent X-ray image of a human kidney, with areas of damage and scarring visible, conceptually representing the impact of focal segmental glomerulosclerosis on the organ.The FDA's approval of sparsentan as the first targeted treatment for FSGS offers new hope for patients with this debilitating kidney disease, though its efficacy and safety profile will require close monitoring.Philadelphia Today

The FDA has expanded the indication of sparsentan (Filspari) to make it the first treatment for focal segmental glomerulosclerosis (FSGS), a progressive kidney disease that can lead to kidney failure. Sparsentan is a once-daily oral tablet that features a dual mechanism of action, targeting both endothelin A and angiotensin II receptors.

Why it matters

For decades, treatment options for FSGS have been limited, often relying on off-label therapies that can carry significant burdens for patients. The approval of sparsentan provides a new, targeted therapy option for FSGS patients, particularly those without nephrotic syndrome, where optimizing foundational therapy is critical.

The details

The regulatory path for sparsentan's FSGS indication was not as smooth as its initial approval for IgA nephropathy. While the pivotal DUPLEX study missed its primary endpoint of showing a significant difference in total estimated glomerular filtration rate (eGFR) slope, sparsentan did demonstrate the ability to reduce proteinuria, especially in the subgroup of patients without nephrotic syndrome. The most common adverse events associated with sparsentan include peripheral edema, hypotension, hyperkalemia, dizziness, and anemia. Sparsentan is available only through a risk evaluation and mitigation strategies (REMS) program due to the risk of hepatotoxicity.

  • The FDA expanded the indication of sparsentan (Filspari) on April 14, 2026.
  • Sparsentan was initially approved for the treatment of IgA nephropathy in February 2023.

The players

Travere Therapeutics

The developer of sparsentan (Filspari).

Kirk Campbell, MD

A nephrologist at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, who commented on the significance of the sparsentan approval for FSGS patients.

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What they’re saying

“For decades, treatment options have been limited, often relying on off-label therapies such as long-term steroids that can carry a significant burden for patients.”

— Kirk Campbell, MD, Nephrologist, Perelman School of Medicine at the University of Pennsylvania

What’s next

The judge in the case will decide on Tuesday whether or not to allow Walker Reed Quinn out on bail.

The takeaway

The approval of sparsentan as the first treatment specifically for FSGS represents an important new option for patients, particularly those without nephrotic syndrome, where managing proteinuria is critical to slowing disease progression. However, the mixed results from the pivotal trial and the drug's safety profile, including the need for a REMS program, suggest that sparsentan's real-world effectiveness and tolerability will need to be closely monitored.