The U.S. Food and Drug Administration (FDA) has approved sparsentan as the first dedicated treatment for focal segmental glomerulosclerosis (FSGS), a rare and often progressive kidney disease. The decision follows positive results from a Phase 3 clinical trial showing significant reduction in proteinuria compared to standard therapy.
FSGS affects approximately 40,000 Americans and can lead to kidney failure within 5-10 years of diagnosis. Until now, treatment has relied on off-label use of immunosuppressants and blood pressure medications with limited efficacy. “This approval addresses a critical unmet need,” said a nephrology specialist familiar with the application who requested anonymity due to ongoing research involvement.
The drug’s manufacturer reports sparsentan demonstrated a 50% reduction in proteinuria (excess protein in urine) versus 30% with irbesartan after 36 weeks. However, analysts note the $120,000 annual price tag may create access challenges. Medicare is expected to cover the treatment beginning Q3 2024.
Researchers caution that while proteinuria reduction is an important biomarker, longer-term studies are needed to confirm whether sparsentan slows progression to kidney failure. The FDA has required post-marketing studies through 2028 to evaluate this endpoint.