Travere to Present New FILSPARI Data in IgA Nephropathy and FSGS at ASN Kidney Week 2026
Travere Therapeutics, Inc. (Nasdaq: TVTX) is set to present nine new data analyses, including five oral presentations, at the American Society of Nephrology (ASN) Kidney Week 2026, taking place October 21–25 in Denver, Colorado. The company’s presentation program will feature new clinical, biomarker, proteomic, transcriptomic and real-world evidence involving FILSPARI® (sparsentan), an oral, non-immunosuppressive therapy being studied and used in patients with IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS).
The data package is expected to provide additional insight into the potential role of sparsentan in reducing proteinuria, preserving kidney function and addressing biological pathways associated with progressive glomerular disease. Several of the presentations will focus on longer-term outcomes and treatment responses, while others will examine the mechanisms through which sparsentan may influence kidney inflammation and disease progression.
According to Travere, the presentations include final results from the Phase 2 SPARTAN study of first-line FILSPARI treatment in IgAN, a post hoc analysis from the Phase 3 DUPLEX trial in patients with FSGS without nephrotic syndrome, and new urinary biomarker findings from the Phase 3 PROTECT study. Together, the analyses are intended to expand the clinical and mechanistic evidence surrounding sparsentan across two rare and progressive kidney diseases.
“The final SPARTAN analysis provides a compelling picture of what’s possible when FILSPARI is used as a first-line therapy in IgAN. Over two years, patients experienced high rates of complete proteinuria remission and near physiologic eGFR decline, highlighting the potential for an oral, non-immunosuppressive therapy to address both key treatment goals early in the disease course,” said Jula Inrig, M.D., chief medical officer of Travere Therapeutics.
She added that the DUPLEX analysis provides further evidence concerning the use of FILSPARI in patients with FSGS who do not have nephrotic syndrome. According to Inrig, the analysis showed higher rates of complete proteinuria remission and lower observed rates of kidney failure compared with irbesartan.
“Together, these data reinforce the clinical value of FILSPARI across two rare, progressive kidney diseases,” Inrig said.
SPARTAN Analysis Shows Proteinuria Remission and Stable Kidney Function
One of the key data sets Travere will present at Kidney Week 2026 comes from the final analysis of the Phase 2 SPARTAN study. The open-label study evaluated once-daily oral FILSPARI as a first-line treatment for patients with IgA nephropathy.
IgAN is a progressive kidney disease characterized by the accumulation of immunoglobulin A in the kidneys, which can trigger inflammation and damage to the glomeruli. Proteinuria, or elevated levels of protein in urine, is an important marker of kidney injury and is commonly monitored as part of disease management. Preservation of estimated glomerular filtration rate (eGFR), meanwhile, is a key measure of kidney function over time.
In the final SPARTAN analysis, 75% of study participants achieved complete proteinuria remission at some point during the study. Complete remission was defined as urinary protein excretion (UPE) below 0.3 grams per day.
The analysis also showed that kidney function remained stable through 110 weeks of treatment. The least-squares mean change in eGFR from baseline at week 110 was −1.75 mL/min/1.73 m².
The chronic eGFR slope between weeks 6 and 110 was −1.11 mL/min/1.73 m² per year, while the total eGFR slope from baseline through week 110 was −1.54 mL/min/1.73 m² per year.
Travere said the findings are significant because they demonstrate reductions in proteinuria alongside relatively limited decline in kidney function over approximately two years. The company noted that the results address two important dimensions of treatment emphasized in Kidney Disease: Improving Global Outcomes (KDIGO) guidelines.
Chee Kay Cheung, M.B.Ch.B., Ph.D., consultant nephrologist at University Hospitals of Leicester NHS Trust, said the results demonstrate consistency of response over an extended treatment period.
“Since FILSPARI was first approved, it has changed how many clinicians approach IgAN, offering an oral, non-immunosuppressive therapy in place of traditional RAS inhibition,” Cheung said.
He added that the SPARTAN results showed continued kidney function stability and complete proteinuria remission in a substantial proportion of participants, providing additional evidence relevant to earlier treatment approaches in IgAN.
The SPARTAN findings will be presented as poster TH-PO0453 on October 22 from 10:00 a.m. to 12:00 p.m. MDT in Exhibit Hall A.
DUPLEX Analysis Examines FSGS Without Nephrotic Syndrome
Travere will also present additional findings from the Phase 3 DUPLEX trial, focusing on patients with FSGS who did not have nephrotic syndrome. The analysis included 254 patients and represents the population covered by FILSPARI’s U.S. FSGS indication.
FSGS is a kidney disorder involving scarring of the glomeruli, the filtering structures of the kidneys. The disease can progress to significant loss of kidney function and kidney failure. Proteinuria is an important clinical feature and treatment target.
In the post hoc DUPLEX analysis, FILSPARI was associated with a 48% mean reduction in urine protein-to-creatinine ratio (UPCR) at week 108, compared with a 27% reduction among patients receiving the maximum labeled dose of irbesartan.
The analysis also evaluated the proportion of patients achieving specific proteinuria thresholds. Twenty percent of patients treated with FILSPARI achieved complete proteinuria remission at any point during treatment, compared with 6% of patients receiving irbesartan.
In addition, 79% of FILSPARI-treated patients reached a UPCR level below 1.5 g/g, a threshold associated with partial remission, compared with 50% of patients receiving irbesartan.
Measures of kidney function also differed between the treatment groups. The chronic eGFR slope was −3.7 mL/min/1.73 m² per year with FILSPARI compared with −6.2 mL/min/1.73 m² per year with irbesartan. The total eGFR slope was −4.1 mL/min/1.73 m² per year for FILSPARI and −6.2 mL/min/1.73 m² per year for irbesartan.
The analysis further reported that 2% of patients receiving FILSPARI reached kidney failure, compared with 8% of those receiving irbesartan.
Safety findings were broadly comparable. Treatment-emergent adverse events occurred in 92% of patients receiving FILSPARI and 94% of patients receiving irbesartan.
The DUPLEX analysis will be presented as poster FR-PO0645 on October 23 from 10:00 a.m. to 12:00 p.m. MDT in Exhibit Hall A.
Biomarker Data Explore Anti-Inflammatory Effects
Another major component of Travere’s ASN Kidney Week program will focus on biological markers associated with kidney inflammation.
New urinary biomarker findings from the Phase 3 PROTECT study indicate that FILSPARI treatment was associated with rapid and sustained reductions in markers linked to macrophage activation, B-cell activation, inflammation and complement activation.
At week 110, reductions across all four biomarker categories were significantly greater with FILSPARI than with the maximum labeled dose of irbesartan.
The findings provide additional information beyond conventional clinical measures such as proteinuria and eGFR. By examining inflammatory and immune-related biomarkers, researchers can investigate how treatment may affect biological processes involved in IgAN.
Travere describes the findings as supporting potential renal anti-inflammatory activity for sparsentan.
The PROTECT urinary biomarker data will be presented as oral abstract FR-OR069 on October 23 from 4:30 p.m. to 6:00 p.m. MDT in Room 501.
Proteomic and Transcriptomic Studies Add Mechanistic Insight
Travere’s Kidney Week presentations will also include studies designed to investigate the molecular effects of sparsentan.
One oral presentation will examine the effects of sparsentan on the urine and plasma proteome of patients with IgAN using findings from the SPARTAN study. Proteomics can provide information about changes in proteins and biological pathways associated with disease and treatment.
Another presentation will use spatial transcriptomics to evaluate sparsentan-associated remodeling of complement-active renal niches in IgAN. Spatial transcriptomics allows researchers to examine gene-expression patterns in specific areas of tissue, potentially providing greater insight into how disease-associated biological activity is distributed within the kidney.
The spatial transcriptomics study, titled “Spatial transcriptomics reveals sparsentan-associated remodelling of complement-active renal niches in IgA Nephropathy,” will be presented as oral abstract SA-OR048 on October 24 from 4:30 p.m. to 6:00 p.m. MDT in Mile High Ballroom 4A.
Pediatric and International Data Expand FILSPARI Evidence
Travere’s ASN program will also include an interim analysis of proteinuria reduction in Japanese pediatric and adult patients with IgAN.
The study, titled “Proteinuria-Reducing Effect of Sparsentan in Japanese Pediatric and Adult Patients with IgA Nephropathy: Interim Analysis at Week 36,” will be presented as oral abstract FR-OR066 on October 23 from 4:30 p.m. to 6:00 p.m. MDT in Room 501.
The presentation adds to the broader evidence base examining sparsentan across patient populations and geographic settings.
The company will additionally present research on the natural history of recurrent IgAN following kidney transplantation. The analysis draws on data from the United Kingdom National Registry of Rare Kidney Diseases (RaDaR) and is scheduled as oral abstract FR-OR067 during the same October 23 session.
Additional Research Covers Disease Biology and Patient Outcomes
The remaining presentations will address other aspects of glomerular disease and treatment outcomes.
A preclinical study titled “Sparsentan Reduces Glomerular IgA Deposition in gddY mice and Suppresses Mesangial Autoantigen Exposure; Potential Role of cAMP” will investigate the biological effects of sparsentan in a mouse model of IgAN. The research will examine IgA deposition and mesangial autoantigen exposure, while also exploring a potential role for cyclic adenosine monophosphate (cAMP).
The study will be presented as poster TH-PO0268 on October 22 from 10:00 a.m. to 12:00 p.m. MDT in Exhibit Hall A.
Another poster will examine the association between achieving lower proteinuria levels and health-related quality of life among people with FSGS. The pooled analysis uses data from the DUET and DUPLEX studies and will be presented as poster TH-PO0452 on October 22.
Nine Presentations Highlight Broad FILSPARI Development Program
Overall, Travere’s ASN Kidney Week 2026 program reflects the breadth of the company’s ongoing clinical and scientific work surrounding FILSPARI. The presentations cover long-term clinical outcomes, proteinuria reduction, kidney-function preservation, biomarkers, molecular mechanisms, pediatric and adult populations, post-transplant disease, quality-of-life outcomes and preclinical disease biology.
The nine scheduled presentations are:
- Sparsentan Reduces Glomerular IgA Deposition in gddY mice and Suppresses Mesangial Autoantigen Exposure; Potential Role of cAMP — Poster TH-PO0268, October 22.
- The Association between Achievement of Low Proteinuria Thresholds and Health-Related Quality of Life in Focal Segmental Glomerulosclerosis: Pooled DUET & DUPLEX Analysis — Poster TH-PO0452, October 22.
- Incident Patients With IgA Nephropathy Demonstrated Stable eGFR With First-Line Sparsentan Over 2 Years in the SPARTAN Final Analysis — Poster TH-PO0453, October 22.
- Spatial transcriptomics reveals sparsentan-associated remodelling of complement-active renal niches in IgA Nephropathy — Oral abstract SA-OR048, October 24.
- Sparsentan vs. Irbesartan in Patients With FSGS Without Nephrotic Syndrome in the Phase 3 DUPLEX Trial — Poster FR-PO0645, October 23.
- Proteinuria-Reducing Effect of Sparsentan in Japanese Pediatric and Adult Patients with IgA Nephropathy: Interim Analysis at Week 36 — Oral abstract FR-OR066, October 23.
- Natural History of Recurrent IgA Nephropathy after Kidney Transplantation: Findings from the UK National Registry of Rare Kidney Diseases — Oral abstract FR-OR067, October 23.
- Urinary Biomarker Data from the PROTECT Study in IgA Nephropathy Demonstrate Renal Anti-Inflammatory Actions of Sparsentan — Oral abstract FR-OR069, October 23.
- The Effect of Sparsentan on Urine and Plasma Proteome of Patients with IgAN – Findings from the SPARTAN Study — Oral abstract FR-OR072, October 23.
Travere said the complete ASN Kidney Week 2026 program will provide additional evidence concerning FILSPARI’s effects across different dimensions of progressive kidney disease. The company will be presenting data in both IgAN and FSGS, while also examining molecular pathways that may help explain clinical observations.
The company’s participation comes as researchers and nephrologists continue to evaluate treatment strategies aimed not only at reducing proteinuria but also at preserving kidney function over the long term. The SPARTAN and DUPLEX findings, together with biomarker and molecular analyses from PROTECT and SPARTAN, provide multiple perspectives on the potential clinical and biological effects of sparsentan.
Travere Therapeutics is expected to share the new findings with the nephrology community during ASN Kidney Week 2026 in Denver, where the presentations will contribute to ongoing discussion about treatment approaches for IgAN and FSGS.
About the DUPLEX Study
The Phase 3 DUPLEX study is the largest interventional trial to date in FSGS. It was a global, randomized, multicenter, double-blind, parallel-arm, active-controlled Phase 3 clinical trial that assessed the efficacy and safety of FILSPARI in 371 patients ages 8 to 75 years with biopsy-proven or genetic FSGS. After a two-week washout period, patients were randomized 1:1 to receive either FILSPARI or irbesartan, the active control, and subsequently dose titrated to the maximum dose of 800 mg of FILSPARI or 300 mg of irbesartan, as tolerated.
The primary efficacy endpoint at the final analysis was the rate of change in eGFR from baseline to Week 108. The two-year results from the study were published in the New England Journal of Medicine. Patients who completed the DUPLEX double-blind portion of the study on treatment were eligible to participate in the open-label extension of the trial.
About the SPARTAN Study
The Phase 2 SPARTAN study was a multi-center, open-label, single-group trial exploring the safety and response to first-line sparsentan treatment in newly diagnosed, renin angiotensin system (RAS) blockade-naïve adult patients with biopsy-proven IgAN. The study was a collaboration between Travere Therapeutics and the University of Leicester (Study Sponsor) and was conducted in 5 hospitals in the UK.
Participants (n=12) were administered sparsentan (target dose of 400 mg) for 110 weeks, followed by a 4-week safety period. In addition to established safety and efficacy assessments, including incidence of adverse events, change in proteinuria and eGFR, the mechanistic actions of sparsentan were explored through renal MRI assessments and analyses comparing diagnostic biopsies with repeat biopsies performed at week 24.
About Travere Therapeutics
At Travere Therapeutics, we are in rare for life. We are a biopharmaceutical company that comes together every day to help patients, families and caregivers of all backgrounds as they navigate life with a rare disease. On this path, we know the need for treatment options is urgent – that is why our global team works with the rare disease community to identify, develop and deliver life-changing therapies. In pursuit of this mission, we continuously seek to understand the diverse perspectives of rare patients and to courageously forge new paths to make a difference in their lives and provide hope – today and tomorrow. For more information, visit travere.com.