Travere Therapeutics announces data from Phase 3 DUPLEX study of FILSPARI

Travere Therapeutics (TVTX) announced new data from the Phase 3 DUPLEX Study demonstrating that patients with focal segmental glomerulosclerosis treated with FILSPARI were significantly more likely to reach proteinuria levels below 0.7 g/g compared to those receiving the maximum labeled dose of irbesartan, and achievement of this threshold correlated with reduced risk of kidney failure. The data were presented as a late-breaking poster at the American Society of Nephrology Kidney Week 2025 in Houston, TX, November 6-9. The PARASOL Project previously identified urine protein-to-creatinine ratio below 0.7 g/g as a clinically meaningful proteinuria target in FSGS. This late-breaking poster reported the proportion of FILSPARI-treated patients reaching this threshold compared to the maximum labeled dose of irbesartan in the DUPLEX Study, and the effect of reaching this target on progression to kidney failure. A DUPLEX-aligned cohort of patients with FSGS from the UK National Registry of Rare Kidney Disease was then utilized to model the impact of achieving UPCR below 0.7 g/g on five-year kidney failure risk, during a 24-month period. Key findings from the late-breaking analyses include: In DUPLEX, significantly more patients treated with FILSPARI achieved UPCR below 0.7 g/g earlier and more often than those treated with irbesartan at any time and at week 108. Irrespective of treatment with FILSPARI or irbesartan, patients who achieved UPCR below 0.7 g/g at any time were less likely to reach kidney failure than those who did not. In the DUPLEX-aligned RaDaR cohort, achieving UPCR below 0.7 g/g at 24-months was associated with lower risk of kidney failure over an additional 60-months of follow up. A similar lower risk was observed for those who achieved UPCR below 0.7 g/g at any time over 24-months. In a separate oral presentation, the Company shared an analysis predicting the reduction in risk of kidney failure events at five-years for patients treated with FILSPARI based on the relative reduction in proteinuria from the DUPLEX Study. As previously published in the New England Journal of Medicine, the DUPLEX Study demonstrated that treatment with FILSPARI resulted in a clinically meaningful and durable reduction in proteinuria, with FSGS patients achieving a 50% reduction from baseline UPCR, compared to a 32% reduction with the maximum labeled dose of irbesartan. This translates to a 26% relative reduction in UPCR for FILSPARI-treated patients compared to the maximum labeled dose of irbesartan at 24 months. The analysis uses a DUPLEX-aligned cohort of patients from RaDaR to examine the correlation between reduction in proteinuria and the long-term risk of kidney failure. Key findings from the RaDaR analysis include: Within the RaDaR cohort, robust reductions in the risk of kidney failure were observed for patients achieving complete remission and proteinuria below 0.7 g/g at 24-months. These findings support the overall conclusions of the PARASOL Project. Any reduction in UPCR correlated to a reduction in risk of kidney failure events at 5-years.When applied to the DUPLEX Study, the 26% relative reduction in UPCR for patients treated with FILSPARI compared to irbesartan, correlates to a significant and clinically meaningful reduction in 5-year risk of kidney failure of 24%.