Renalys Announces Completion of Primary Endpoint Data Collection for Phase III Clinical Trial of Sparsentan for Iga Nephropathy in Japan

TOKYO, Oct. 10, 2025 /PRNewswire/ -- Renalys Pharma, Inc. (Headquarters: Chuo-ku, Tokyo; "Renalys") announced today that it has completed data collection for the primary endpoint in the Phase III clinical trial of sparsentan (development code: RE-021) for IgA nephropathy in Japan.

The primary endpoint evaluated was the urine protein creatinine ratio (24-hour urine collection) at 36 weeks and data have now been collected for all eligible patients. Renalys will proceed with analyses of efficacy and safety through 36 weeks of treatment, as well as comparisons with global Phase III trial results, in preparation for the submission of a New Drug Application (NDA).

Renalys is committed to improving the lives of patients in Japan and across Asia by developing innovative therapies for kidney disease, with a primary focus on delivering sparsentan to patients as quickly as possible.

About sparsentan

Sparsentan is an oral dual endothelin and angiotensin II receptor antagonist developed by Travere Therapeutics, Inc. ("Travere"). Renalys has an exclusive license for development and commercialization of sparsentan in Japan and several Asian territories. In 2024, Travere received full FDA approval for sparsentan (U.S. brand name: FILSPARI®) to slow kidney function decline in adults with primary IgA nephropathy who are at risk of disease progression. *Full approval is based on positive long-term confirmatory results from the PROTECT Study demonstrating that FILSPARI significantly slowed kidney function decline over two years compared to irbesartan. In the PROTECT Study, the only head-to-head study in IgA nephropathy versus an active comparator, FILSPARI® demonstrated a significant reduction in proteinuria, preservation of kidney function and a well-tolerated safety profile compared with active control irbesartan. In 2025, the FDA accepted Travere's supplemental new drug application (sNDA) for FILSPARI® for the treatment of focal segmental glomerulosclerosis (FSGS). In Europe, it also obtained standard EU approval for the IgA nephropathy indication in 2025.

*FILSPARI® (sparsentan) U.S. Indication:

FILSPARI is an endothelin and angiotensin II receptor antagonist indicated to slow kidney function decline in adults with primary IgA nephropathy who are at risk of disease progression.

About IgA Nephropathy

The management of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) has become a social issue that places a heavy burden on the Japanese healthcare system. IgA nephropathy is widely known as one of the main causes of kidney failure and is considered to develop when abnormal IgA proteins are deposited in kidney tissue, inhibiting kidney function and causing inflammation. IgA nephropathy is a rare intractable disease (designated as an intractable disease 66) with many unresolved mechanisms of onset and severity. Currently, there is significant unmet need for approved treatment for IgA nephropathy in Japan.

About Renalys Pharma, Inc.

Renalys, a privately held late-stage clinical biopharmaceutical company based in Japan, is committed to the development of multiple innovative therapeutics targeting unmet needs in the management of renal disease for Japanese and Asian patients. Founded by Catalys Pacific and SR One in 2023, the company aims to address the growing problem of "drug loss" by catalyzing access to new treatments for kidney disease patients in Japan and other Asian regions.

Company Name: Renalys Pharma, Inc.
Address: 3-11, Nihonbashi-honcho 2-chome, Chuo-ku, Tokyo, Japan
Representative: BT Slingsby, MD, PhD, MPH
Established: April 2023
URL: https://renalys.com/

Disclaimer

Information concerning pharmaceutical products (compound under development) contained herein is not intended as advertising or as medical advice, but intended for disclosure of management information.

SOURCE Renalys Pharma, Inc.