Focal Segmental Glomerulosclerosis (FSGS)

FSGS is a rare, serious kidney disorder characterized by progressive scarring (sclerosis) in parts of the glomeruli—the kidney’s filtering units. This scarring leads to proteinuria, progressive loss of kidney function, and often end-stage renal disease. FSGS is increasingly understood to have an inflammatory component, with monocyte and macrophage activation contributing to glomerular injury.

In the United States, more than 40,000 people are estimated to be living with FSGS, including both adults and children. There are no therapies specifically approved for FSGS in the U.S., and management relies on non-specific immunosuppressive and supportive therapies.

In patients with progressive or treatment-resistant FSGS, the average time from diagnosis to end-stage kidney disease can be as short as five years. Even among those who undergo kidney transplantation, disease recurrence occurs in up to 60% of cases, underscoring the urgent need for new, disease-modifying treatments.