#Japan #Tokyo #Sparsentan #Renalys Pharma #IgA nephropathy

Promising Phase III Results for Sparsentan in Japanese IgA Nephropathy Patients

Renalys Pharma, Inc. recently announced the topline results from their Phase III clinical study investigating sparsentan, a dual endothelin and angiotensin II receptor antagonist, specifically in Japanese patients suffering from IgA nephropathy (IgAN). The findings highlight a significant efficacy in reducing proteinuria, characterized by a -58.54% change from baseline in the 24-hour urine protein-to-creatinine ratio at Week 36, which stood as the primary objective of the study involving 35 patients.

This clinical trial succeeded in demonstrating that sparsentan, which is administered orally, is not only effective but also well tolerated among participants, exhibiting a safety profile that aligns with data from prior global studies. Notably, no new safety risks emerged specific to the Japanese cohort involved in the trial.

The Study and Its Impact

BT Slingsby, the Chairman and CEO of Renalys, expressed the urgent need for effective treatment options in Japan, given the existing limitations patients currently face. He underscored the company’s commitment to expediting the delivery of this potentially life-changing therapy to ensure that Japanese patients have access to sparsentan as swiftly as possible. Slingsby identified the significant unmet medical needs regarding IgAN treatment and emphasized the importance of bridging the gap in access to effective medications.

In addressing the nuances of local regulatory requirements, Ryutaro Shimazaki, Chief Development Officer of Renalys, pointed out that the Phase III study in Japan was designed as a bridging study, facilitated by productive discussions with the Pharmaceuticals and Medical Devices Agency (PMDA). This improves upon the existing data drawn from large-scale international trials, establishing a robust foundation for the study’s findings across varied patient demographics, including adults and adolescents from the age of 10 and above.

The results reported not only mirror earlier trials conducted globally but also instill hope within the Japanese medical community. Naoki Kashihara, MD, PhD, President of the Japan Kidney Association, celebrated the promising outcomes that sparsentan has shown in terms of proteinuria reductions and favorable safety indicators. He noted that this advancement represents a significant milestone in the development of effective therapies for such rare kidney diseases that had witnessed stagnation for too long.

Future Prospects and Plans

With these compelling results in hand, Renalys Pharma is gearing up to submit a New Drug Application (NDA) for sparsentan in Japan, expected in 2026. This submission is anticipated to streamline the approval process and facilitate timely access to this innovative treatment for the countless patients grappling with IgAN.

Sparsentan, which has already been granted approval in both the United States and Europe, is designed to slow the progression of chronic kidney disease, a common complication for individuals with IgAN. CEO Slingsby articulated the company's regard for patient welfare, highlighting the need for responsible drug development practices that effectively address the burdens faced by renal disease patients in Japan and the broader Asian region.

About Sparsentan and Renalys Pharma

Sparsentan is produced by Travere Therapeutics, which holds the rights for development and commercialization in Japan and several Asian territories. Full FDA approval in the U.S. was achieved in 2024 under the brand name FILSPARI, and the drug's performance in the PROTECT Study against irbesartan confirmed its efficacy in slowing down kidney function decline over a two-year horizon.

As Renalys Pharma, a privately-held clinical biopharmaceutical company based in Tokyo, continues its pathway for bringing sparsentan to market, it stands at the forefront of addressing the pressing healthcare challenges posed by chronic kidney diseases in Japan. The drive to improve patient outcomes and reduce treatment delays remains a priority as Renalys works toward executing its mission effectively.

In conclusion, the favorable results from this Phase III study signify a pivotal advance in the treatment landscape for IgA nephropathy, potentially altering the course of care for many patients navigating this challenging condition. Renalys Pharma’s plans to introduce sparsentan to the Japanese market could mark a new era of effective therapeutic avenues for managing IgAN.