Driving change in nephrology: PARASOL project leads to FDA acceptance of proteinuria

In a landmark moment for nephrology research, the FDA has accepted proteinuria as a surrogate endpoint for Focal Segmental Glomerulosclerosis (FSGS) clinical trials—for the first time ever. This milestone is the result of rigorous collaboration, data, and advocacy from the PARASOL project, a global initiative that Fortrea’s Barbara Gillespie, MD, MMS, FASN, VP, Therapeutic Head of Nephrology and Adjunct Professor at the University of North Carolina, proudly serves on as a steering committee member. She was invovled in similar efforts for the KHI (Kidney Health Iitiatieve) work that supported proteinuria reduction as a surrogate EP in IgAN trials, which has led to the approval of several new IgAN drugs. By defining a clear succesful regulatory path, this endpoint work has facilitated getting new treatments into the hands of patients.

"The success of the PARASOL project reflects Fortrea’s commitment to advancing nephrology research—not just as a service provider, but as a scientific collaborator. As illustrated by Dr. Gillespie's contributions to this important advance, many of our experts are leaders in their fields and serve on the adjunct faculty at academic medical centers. This positions us uniquely to support our mission to advance clinical research and speed new treatments to patients in need."
— Oren Cohen, MD, Chief Medical Officer, Fortrea 

What is the PARASOL project?

PARASOL is a collaborative international effort focused on validating proteinuria and eGFR-based endpoints for use in FSGS clinical trials. Its mission: to define the quantitative relationships between short-term biomarker changes and long-term kidney outcomes. The goal? To make clinical trials more efficient, more predictive, and more aligned with regulatory expectations.

This work has now paid off. The FDA’s acceptance of proteinuria as a surrogate endpoint opens the door for faster, more feasible trials - and is already influencing regulatory submissions.

"So happy to see our PARASOL efforts help pave an achievable regulatory path towards new therapies for FSGS. It’s been 101 years since FSGS was first described, and that’s way too long for our patients to not have an approved drug. Data sharing and collaboration matters, and as a PARASOL steering committee member I’m excited to next assess EPs for Membranous Nephropathy."
— Barbara Gillespie, MD, MMS, FASN 

Turning science into solutions

For biotech companies developing therapies for rare kidney diseases, this is a game-changer. Traditional endpoints like kidney failure or dialysis can take years to observe. Meaningful proteinuria reduction, by contrast, can be measured in months—accelerating timelines, reducing costs, and bringing hope to patients faster.

Biotech and pharmaceutical companies now have a clearer, faster path to regulatory accelerated approval in FSGS. We are already aware of a positive impact on the development of 2 different drugs. Travere Therapeutics recently submitted a supplemental New Drug Application (sNDA) for FILSPARI® (sparsentan), supported by data showing significant reductions in proteinuria. Meanwhile, Dimerix is advancing its Phase 3 ACTION3 trial using proteinuria as a primary endpoint—an approach made possible by the groundwork laid by PARASOL.

These examples signal a new era for FSGS drug development—where science, data sharing, and regulatory alignment are accelerating innovation.

Subject Matter Specialist guidance for a new regulatory era

At Fortrea, we’re proud to be part of this progress. Our nephrology collaborators,led by Dr. Barbara Gillespie, MD, MMS, FASN, are at the forefront of shaping the future of kidney disease research. If you’re planning or optimizing your clinical development program for FSGS, or any Glomerular Disease, we’re ready to help you navigate this new regulatory landscape with confidence.

Reach out to us today and let’s talk about how Fortrea can support your next breakthrough – Contact Us. Learn more about our nephrology offering – Nephrology Services.

References

• PARASOL Background & Objectives. Accessed May 23, 2025. https://www.is-gd.org/parasol
• Travere Therapeutics Announces FDA Acceptance of sNDA for FILSPARI® (sparsentan) in FSGS. Travere Therapeutics. Updated May 15, 2025. Accessed May 23, 2025. https://ir.travere.com/press-releases/news-details/2025/Travere-Therapeutics-Announces-FDA-Acceptance-of-sNDA-for-FILSPARI-sparsentan-in-FSGS/default.aspx
• FDA confirms primary goal for Dimerix’s DMX-200 trial to treat FSGS. Clinical Trials Arena. Updated April 29, 2025. Accessed May 23, 2025. https://www.clinicaltrialsarena.com/news/fda-dimerix-trial/