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Sparsentan vs. Irbesartan in Pediatric Patients With Focal Segmental Glomerulosclerosis (FSGS) in the Phase 3 DUPLEX Trial

Poster
Published on November 7, 2025

Topics:

Nephrology FSGS
Contributors
Rheault MN, Dell KM, Lieberman K et al.


Presented at:
ASN 2025


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About the research

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Summary

Background

Read about proteinuria reduction across a range of UPCR thresholds in the DUPLEX trial.


Aim

To assess the efficacy and safety of sparsentan in a subgroup of pediatric patients in the DUPLEX trial.1


Approach

DUPLEX was a Phase 3 randomized trial that evaluated the efficacy and safety of sparsentan versus maximum labeled dose irbesartan in 371 patients with FSGS over a period of 108 weeks.1,6

Outcomes included1,6:

  • UPCR change from baseline
  • Complete remission (CR) of proteinuria: UPCR <0.3 g/g at any time
  • FSGS partial remission endpoint: UPCR ≤1.5 g/g and >40% reduction from baseline at any time
  • Composite kidney endpoint: confirmed 40% decline in estimated glomerular filtration rate (eGFR), KF, or death
  • Safety, including incidence and severity of treatment-emergent adverse events (TEAEs)

This subanalysis included data from 35 pediatric patients (median age 14 years), who had been randomized to receive sparsentan (n=16) or maximum labeled dose irbesartan (n=19).1


Key findings

Compared to irbesartan, sparsentan treatment in pediatric patients over 108 weeks led to:

  • Rapid and sustained decline in UPCR (mean UPCR reduction at Week 108: 39.5% with sparsentan vs. 24.9% with irbesartan)1
  • More patients achieving low proteinuria thresholds (including CR of proteinuria)1
    • 12.5% of patients achieved CR of proteinuria at any time with sparsentan vs. 5.3% with irbesartan
    • Higher proportions of patients consistently reached low proteinuria thresholds ranging from <0.3 g/g to <1.0 g/g, including a UPCR of ≤1.5 g/g and >40% reduction in proteinuria from baseline with sparsentan compared to irbesartan
  • Fewer patients reaching the composite kidney endpoint or progressing to KF with sparsentan (12.5%) vs. irbesartan (36.8 %)1

In this pediatric patient cohort, sparsentan was well tolerated at doses up to 800 mg/day (median weight-based dose of 8.8 mg/kg), with a safety profile comparable to that of maximum-labeled dose irbesartan.1

  • Most common TEAEs with sparsentan included COVID-19 (38%),* dizziness (31%), diarrhea (25%), pyrexia (25%), increased blood creatinine (25%), and anemia (25%)1
  • TEAEs of interest with sparsentan included hyperkalemia (13%) and hypotension (19%)1

Conclusions

In pediatric patients with FSGS, sparsentan led to rapid and sustained proteinuria reductions.1 These benefits were consistent with those in the overall DUPLEX population.1,6,7

More pediatric patients achieved low proteinuria thresholds (including CR of proteinuria) and fewer progressed to KF with sparsentan than with irbesartan.1

Sparsentan was well tolerated by pediatric patients at doses up to 800 mg/day (median weight-based dose of 8.8 mg/kg) and with a safety profile that was comparable to maximum-labeled dose irbesartan and consistent across clinical trials.1,6-8

These findings suggest that sparsentan was well tolerated and led to proteinuria reductions in children with FSGS.1





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Footnotes

*Study was conducted during the COVID-19 pandemic.

CR, complete remission; DEARA, Dual Endothelin Angiotensin Receptor Antagonist; eGFR, estimated glomerular filtration rate; FDA, US Food and Drug Administration; FSGS, focal segmental glomerulosclerosis; KF, kidney failure; TEAE, treatment-emergent adverse event; UPCR, urine protein-to-creatinine ratio.

  1. Rheault MN et al. Presented at: ASN Kidney Week; November 5-9, 2025; Houston, TX.
  2. Trachtman H. Expert Opin Emerg Drugs. 2020;25(3):367-375.
  3. Gipson D. Semin Nephrol. 2016;36(6):453-459.
  4. Smith A. Presented at: ASN Kidney Week; October 23-27, 2024; San Diego, CA.
  5. Kohan DE et al. Clin Sci. 2024;5;138(11):645-662.
  6. Rheault MN et al. N Eng J Med. 2023;389(26):2436-2445.
  7. Tesar A et al. Presented at: 62nd ERA Congress; June 4-7, 2025; Vienna, Austria.
  8. Rovin BH et al. Lancet. 2023;402(10417):2077-2090.


MA-SP-25-0210 | November 2025