FDA

FDA relaxes LFT monitoring requirements for Filspari

September 2, 2025

FDA approved updated Risk Evaluation and Mitigation Strategy (REMS) labeling for Filspari (sparsentan), a dual endothelin/angiotensin receptor antagonist indicated for the treatment of IgA nephropathy (IgAN) in adults. The update lowers the frequency of liver function monitoring to every 3 months from the onset of treatment with Filspari. Previously, liver function monitoring was recommended every month during the first year, and every 3 months thereafter.

The reduction of liver function monitoring from monthly to every three months from the onset of treatment was supported by safety data from post-marketing surveillance as well as the phase 3 PROTECT study (NCT03762850) in IgAN, the phase 3 DUPLEX study (NCT03493685), and the Phase 2 DUET Study (NCT01613118) in focal segmental glomerulosclerosis (FSGS).

In addition, FDA determined that the REMS requirement for embyo-fetal toxicity for Filspari was no longer necessary following an analysis of human pregnancy data compiled from the use of endothelin receptor antagonist medicines from the last two decades.

Sources:

Filspari (sparsentan) [package insert]. Food and Drug Administration. https://www.accessdata.fda.gov/drugsatfda_docs/label/2025/216403s005lbl.pdf Revised August 2025. Accessed August 29, 2025.

Travere Therapeutics announces US FDA approves REMS modification for Filspari® (sparsentan) in IgA nephropathy. [News release]. 2025. https://ir.travere.com/press-releases/news-details/2025/Travere-Therapeutics-Announces-U-S--FDA-Approves-REMS-Modification-for-FILSPARI-sparsentan-in-IgA-Nephropathy/default.aspx