Abstract: FR-OR032
Impact of Histology on Efficacy of Sparsentan Therapy in IgAN: Central Biopsy Review of Patients in the PROTECT Trial
Session Information
- Glomerular Disease Outcomes: Measuring What Matters
November 07, 2025 | Location: Room 310A, Convention Center
Abstract Time: 05:10 PM - 05:20 PM
Category: Glomerular Diseases
- 1402 Glomerular Diseases: Clinical, Outcomes, and Therapeutics
Authors
- Roberts, Ian, Oxford University Hospitals, Oxford, United Kingdom
- Hendry, Bruce M., Travere Therapeutics, Inc., San Diego, California, United States
- Mercer, Alex, JAMCO Pharma Consulting, Stockholm, Sweden
- Moody, Stephanie, Travere Therapeutics, Inc., San Diego, California, United States
- Murphy, Edward, Travere Therapeutics, Inc., San Diego, California, United States
- Komers, Radko, Travere Therapeutics, Inc., San Diego, California, United States
Background
In PROTECT, sparsentan (SPAR), a non-immunosuppressive, dual endothelin angiotensin receptor antagonist, resulted in significant reduction in proteinuria and preservation of kidney function when compared to irbesartan (IRB) in adults with IgA nephropathy. Here we investigate the impact of biopsy histology of PROTECT participants (pts) on the clinical efficacy of SPAR.
Methods
Clinical sites provided biopsy slides or whole slide images from 107 pts for central review. Biopsy scoring was carried out on digital slides by a single pathologist who was blinded to clinical and treatment data. 15 histological data items were included in the analysis (Oxford Classification MEST-C scores, podocytopathic changes, continuous MEST-C data, and vascular lesion scoring).
Results
Of 107 biopsies, 18 contained <8 glomeruli and were inadequate for MEST-C scoring. Of the remaining biopsies, 12% were scored M1, 22% E1, 80% S1, 23% T1, 4% T2, and 21% C1. The median (Q1, Q3) time from adequate biopsy to enrolment was 4 (1, 8) years; 30% of biopsies were performed within 12 months of study entry. Baseline (BL) eGFR was significantly lower in pts with T1/T2 vs T0. The % tubular atrophy/interstitial fibrosis and % of glomeruli showing segmental sclerosis showed a significant negative correlation with BL eGFR whilst % of glomeruli showing endocapillary hypercellularity positively correlated with BL eGFR. The reduction in proteinuria at 36 weeks in pts treated with SPAR (n=47) was consistent across MEST-C scores or continuous histological data; pts showed treatment benefit in all groups (Fig 1)
Conclusion
Whilst histological features are associated with baseline eGFR and proteinuria, the therapeutic efficacy of SPAR is independent of biopsy findings, including the Oxford Classification MEST-C scores.
Funding
- Commercial Support – Travere Therapeutics, Inc.