FILSPARI secures full European approval: A major breakthrough for IgA nephropathy patients

The European Commission has granted standard marketing authorization for FILSPARI® (sparsentan) for the treatment of adults with primary Immunoglobulin A nephropathy (IgAN), following a positive recommendation from the Committee for Medicinal Products for Human Use (CHMP) in February 2025. This decision, announced by CSL Vifor and Travere Therapeutics, Inc. (NASDAQ: TVTX), converts the previous conditional approval into full authorization across the European Union, including Iceland, Liechtenstein, and Norway.

FILSPARI, a dual endothelin angiotensin receptor antagonist (DEARA), is now fully approved for adult patients exhibiting significant proteinuria, defined as urine protein excretion of ≥1.0 g/day or a urine protein-to-creatinine ratio ≥0.75 g/g. The European Commission’s ruling follows a comprehensive review of the pivotal phase-III PROTECT study, which demonstrated significant kidney function preservation compared to standard therapies.

What Led to the European Commission’s Standard Approval of FILSPARI?

The transition from conditional to standard approval is based on the complete dataset from the PROTECT trial, a large global phase-III study involving 404 patients with IgAN. Interim analysis results had earlier shown that patients treated with FILSPARI achieved a mean reduction in proteinuria of nearly 50 percent, compared to a 15 percent reduction observed with irbesartan, an angiotensin II receptor blocker.

Two-year confirmatory outcomes reinforced the drug’s efficacy, showing statistically significant benefits on the eGFR chronic slope, a key indicator of kidney function decline. Safety profiles were comparable between the treatment arms, with dizziness and hypotension being slightly more prevalent in the FILSPARI group.

What Experts Are Saying About FILSPARI’s Full Approval

Dr. Vinicius Gomes De Lima, Head of Global Medical Affairs at CSL Vifor, remarked that the European Commission’s decision represents a major step for patients living with IgAN across Europe. He indicated that the full approval, achieved without changes to the original indication, highlights the strength of the clinical data and the company’s commitment to expanding access.

Dr. Jula Inrig, Chief Medical Officer at Travere Therapeutics, echoed this sentiment, suggesting that the decision validates the outcomes of the PROTECT study and strengthens the company’s resolve to improve treatment availability for rare kidney disease patients in Europe.

How FILSPARI is Positioned in the Treatment of IgA Nephropathy

FILSPARI remains the only approved non-immunosuppressive therapy of its kind in Europe for IgA nephropathy. Its dual mechanism, selectively targeting both the endothelin A receptor (ETAR) and the angiotensin II type 1 receptor (AT1R), differentiates it from traditional therapies like ACE inhibitors and ARBs, which have limited effectiveness in slowing disease progression.

Following the initial conditional approval in April 2024, FILSPARI had been launched in Germany, Austria, and Switzerland. The latest authorization paves the way for broader market access throughout the European Economic Area.

Understanding IgA Nephropathy and the Unmet Medical Need

IgA nephropathy, also known as Berger’s disease, is a rare but serious progressive kidney disorder caused by deposits of immunoglobulin A in the glomeruli. These deposits trigger inflammation that can lead to hematuria, proteinuria, and ultimately chronic kidney disease or kidney failure.

Despite being classified as a rare disease, IgAN is the most common form of primary glomerular disease globally and remains a leading cause of end-stage renal disease. In Europe, Australia, and New Zealand, it is estimated that up to 250,000 people are affected by this condition, underscoring a significant unmet clinical need.

Inside the Phase-III PROTECT Study: Critical Data That Drove Approval

The PROTECT study is recognized as one of the most robust clinical evaluations in IgAN research. It was a randomized, multicenter, double-blind, active-controlled trial comparing 400 mg of sparsentan to 300 mg of irbesartan in patients with persistent proteinuria despite optimized background therapy.

Results demonstrated that FILSPARI significantly slowed the decline in kidney function over two years compared to irbesartan. Notably, the study achieved its primary endpoint early, enabling regulatory authorities to move forward with confidence in the drug’s clinical benefits.

Treatment-emergent adverse events were balanced across treatment arms, suggesting a favorable risk-benefit profile for FILSPARI over standard care.

Expanding FILSPARI’s Reach and Impact

Following the European Commission’s full approval, CSL Vifor and Travere Therapeutics plan to accelerate efforts to ensure widespread access across Europe. Discussions with national reimbursement agencies are anticipated to facilitate broader patient reach.

Analysts anticipate that the standard marketing authorization will enhance FILSPARI’s commercial trajectory in Europe, offering a new therapeutic option for nephrologists and patients managing IgAN. CSL Vifor’s exclusive commercialization rights for FILSPARI in Europe, Australia, and New Zealand position the company strategically for continued growth in the nephrology market.

About CSL Vifor and Travere Therapeutics

CSL Vifor, a part of CSL Limited (ASX: CSL; USOTC: CSLLY), specializes in therapies for iron deficiency and nephrology and operates through strategic partnerships and in-house development. Headquartered in St. Gallen, Switzerland, CSL Vifor operates globally with an emphasis on precision healthcare solutions.

Travere Therapeutics focuses exclusively on rare diseases, aiming to develop and deliver life-changing therapies for underserved patient communities. The San Diego-based company continues to strengthen its position in nephrology through collaborations and innovative pipeline programs.

Travere Therapeutics, listed on NASDAQ under TVTX, experienced a slight uptick in investor sentiment following the announcement. Market analysts noted that securing full approval in a major regulatory jurisdiction strengthens Travere’s value proposition in the rare disease segment. CSL Limited shares on the ASX remained stable, reflecting a broader positive outlook tied to its diversified biopharmaceutical portfolio.

Investors are expected to closely monitor upcoming reimbursement discussions and launch timelines across key European markets as potential catalysts for further upside.